LAPAROSCOPY
Posted by on Saturday, 16th May 2009
Anatomy and Physiology
Laparoscopic surgery is performed to diagnose and treat conditions affecting the organs and tissues of the abdomen and pelvis.
Traditional open surgery requires a relatively large incision. Laparoscopic surgery involves the creation of one or more tiny “keyhole” incisions, through which pencil–thin instruments are inserted to view the inside of the abdomen or pelvis, and to perform various procedures. This technique considerably reduces recovery time.
Reasons for Procedure
Laparoscopy is done to examine, diagnose, and treat problems inside the abdomen and/or pelvis. The procedure can: diagnose, and sometimes treat, causes of pain, retrieve a tissue sample, evaluate the presence of abnormal fluid, evaluate infertility, help determine if a cancer has spread, monitor previously treated cancer.
Treatments
Many surgeries that were traditionally performed through an open incision can now be performed laparoscopically. These include: appendectomy, ectopic pregnancy removal, egg retrieval for assisted reproductive technology, hernia repair, hysterectomy, certain surgeries of the gallbladder, stomach, colon, liver, spleen, adrenal gland, or kidney, biopsies, which entail retrieving a tissue sample, tubal ligation, and/or tumor removal In some of these cases, an open surgical procedure may still be required.
Procedure
In the days leading up to your procedure: Arrange for a ride to and from the hospital, and for help at home as you recover. The night before, eat a light meal and do not eat or drink anything after midnight. If you regularly take medications, ask your doctor if you need to temporarily discontinue them. Do not start taking any new medications before consulting your doctor.
Depending on the type of operation, laparoscopic surgery may be done under general, spinal, or local anesthesia. In general anesthesia, you will be asleep during the entire procedure. In spinal anesthesia, you will be rendered numb from the chest down. In local anesthesia, you will be numb at the site of the incision only.
To begin the procedure, your surgeon will insert a sharp instrument called a trocar through a small half–inch opening, usually just above or below your navel. The exact location of this opening will depend on the type of operation being performed.
In most cases, your surgeon will then pump carbon dioxide gas though this port in order to puff up your abdomen so its contents can be viewed more easily.
Next, your surgeon will insert the laparoscope. Images from its camera are magnified and projected onto a video monitor in the operating room. The surgeon will carefully examine your abdominal or pelvic organs and tissues, looking for signs of disease that might explain your symptoms.
Your surgeon may place other trocars through which surgical instruments can be inserted. These instruments may be used to: Move organs out of the way for better viewing Remove diseased or scarred organs or tissue Take tissue biopsies Sample and drain abnormal fluid Perform other surgical techniques
When the laparoscope is removed, all of the gas will be allowed to escape.
Each keyhole incision will be closed with just a few sutures or staples, and then covered with bandages.
Risks and Benefits
Possible complications of laparoscopy include: damage to blood vessels or organs in the surgical area, excessive bleeding Infection, anesthesia–related problems, during the laparoscopic procedure, your surgeon may need to switch to a traditional open procedure. This may occur if the area is damaged or it appears that the laparoscopic approach is not going to be successful.
Compared to traditional open surgeries, the benefits of laparoscopy include: smaller scars, shorter hospital stay or same–day discharge, fewer complications, less pain after the operation, and/or shorter recovery time.
However, these benefits are a tradeoff with the limited access available through the laparoscopic approach.
In a laparoscopy, or any procedure, you and your doctor must carefully weigh the risks and benefits to determine whether it’s the most appropriate treatment choice for you.
After the Procedure
In most cases, patients are discharged within one to two days of their procedure. Depending on the reason for your laparoscopy, you may be able to leave the hospital the same day it was performed.
Proper care after your laparoscopy largely depends on the particular operation performed. In most cases, however, you will be advised to: remove the bandages the morning after surgery, return to your usual activities within a few days, avoid heavy lifting for several weeks.
Be sure to call your doctor immediately if you experience: severe nausea or vomiting. faintness or dizziness, coughing, shortness of breath, or chest pain, fever or chills, redness, swelling, increasing pain, excessive bleeding, or discharge from any of the incisions, difficulty urinating.
Rate It
COLONOSCOPY
Posted by on Saturday, 16th May 2009
Anatomy and Physiology
Your colon, or large intestine, is a long muscular tube located in the last section of your intestines. After the stomach and small intestine digest food, the remaining material is passed through the colon, where water and electrolytes are absorbed. Formed stools are the end product of this process.
The colon is made up of: the cecum, the ascending colon, the transverse colon, the descending colon, the sigmoid colon, and the rectum.
Most of the conditions that are diagnosed or treated via colonoscopy affect the layer of cells that line the inside of the colon. A doctor can use the colonoscope to directly view this mucosal lining.
Reasons for Procedure
Conditions commonly diagnosed and/or treated with colonoscopy include: Colon cancer, colorectal polyps, colonic ulcers, colitis, or inflammation of the colon, diverticulosis.
Colorectal cancer, which initially occurs in the colon or rectum, is one of the most common types of cancer.
Essentially all colorectal cancers are believed to begin as polyps, which are abnormal growths of the mucosal lining. Detecting these polyps early is the key to preventing colorectal cancer.
In most cases, polyps cause no symptoms. colorectal cancer, however, can cause symptoms including: changes in bowel habits, blood in the stool, stools that are narrower than usual, abdominal discomfort, unexplained weight loss or fatigue.
Treatments
A colonoscopy is commonly used to screen for colorectal polyps. The purpose of a screening test is to detect a problem before it causes symptoms or serious harm. If left untreated, polyps may eventually develop into colorectal cancer. Colonoscopy is also used to treat polyps by completely removing them.
In a full colonoscopy, your doctor is able to see the entire colon, from the anus to the cecum, where it connects with the small intestine. In a sigmoidoscopy, your doctor is only able to see about half that distance, to the top of the descending colon. Either technique can be used to take a sample of tissue or remove a polyp.
Other screening tests for colorectal polyps or cancer include: fecal occult blood test, which is used to identify hidden blood in the stool; barium enema, which is a series of x–rays of the colon and rectum; digital rectal exam, which is a manual examination of the rectum; virtual colonoscopy, which uses a CT scan and computer to recreate a three–dimensional image of the colon lining.
The primary disadvantage of these tests is that they cannot be used to obtain a tissue sample or remove a polyp.
If you are diagnosed with colorectal cancer, your doctor will likely advise you to have other tests, such a CT scan of your abdomen.
Procedure
In the days leading up to your procedure: do not eat any solid food for 24 hours, or drink anything for 8–10 hours, before the procedure. Your doctor will recommend a preparation to clean the colon in order to make sure it is completely empty for the procedure. In addition to following a clear liquid diet, this may include taking laxatives, or performing an enema.
Also in the days leading up to your procedure: If you take medications, particularly nonsteroidal anti–inflammatory drugs such as aspirin, or blood thinners such as coumadin, ask your doctor if you need to temporarily discontinue them or change the doses. Do not start taking any new medications before consulting with your doctor. Be sure to arrange for a ride to and from the procedure.
A colonoscopy generally takes 15–60 minutes. Before the procedure, an intravenous line will be started, and you will be offered pain medication and a mild sedative to help you relax.
During the exam, you will lie on your left side with your knees bent. A colonoscopy is performed using an endoscope, which is a long, thin, flexible tube with a light and a tiny video camera attached to the end.
Your doctor will insert the endoscope into your rectum and slowly guide it to the point where your colon meets your small intestine. Your doctor will blow air through the endoscope into your colon to inflate it for better viewing.
The camera transmits an image to a TV monitor so your doctor can view the lining of your intestine.
If your doctor locates a polyp during the procedure, he or she may remove it using special instruments passed through the endoscope. The tissue obtained during this polypectomy is then sent to a laboratory for examination.
Risks and Benefits
Colonoscopy, with or without a polypectomy, is generally a very safe procedure. However, there is a chance you will experience some abdominal discomfort and/or distension. Other less common complications include: adverse reaction to medications, bleeding in the colon or rectum after a biopsy or polypectomy, a perforation, or tear, through the bowel wall, infection in the blood, heart and lung problems.
Benefits of a colonoscopy include: effective screening for colorectal cancer; both the diagnosis and treatment of colorectal polyps; diagnosis of other conditions such as colitis, or inflammation of the colorectal lining; diagnosis, and even treatment, of other causes of bleeding from the colon or rectum.
In a colonoscopy, or any procedure, you and your doctor must carefully weigh the risks and benefits to determine whether it's the most appropriate intervention for you.
After the Procedure
Colonoscopy is an outpatient procedure, so you will be able to go home after your sedative wears off, which generally takes 1–2 hours. You should receive your results over the phone, by mail, or at a follow–up appointment.
Air that is left in your intestines after the procedure may cause some persistent abdominal discomfort and bloating, which usually is resolved when the trapped air passes. If you had a polypectomy, you may feel some additional abdominal discomfort for up to five days after the procedure, but symptoms usually clear within 48 hours.
Be sure to contact your doctor if you experience: signs of infection, such as fever and chills, severe or worsening abdominal pain, rectal bleeding.
Rate It
Bariatric (Antiobesity) Surgery
Posted by on Saturday, 16th May 2009
Anatomy and Physiology
Obesity is an excess of body fat. Many factors influence body fat, including lifestyle habits and genetics. There are many ways to treat obesity. Bariatric surgery treats obesity by altering the digestion and absorption of food.
In normal digestion, food moves through the mouth, down the esophagus, and into the stomach. Here, food is mixed with digestive juices. The partially digested material is slowly released into the small intestine.
In the small intestine, digestion is completed. Nutrients and calories are absorbed into the blood stream. There are three parts to the small intestine—duodenum, jejunum, and ileum. Wastes are eventually passed to the colon and released as stool.
There are two types of bariatric surgery. “Restrictive” procedures decrease the size of the stomach so a person feels full quickly. After surgery, the stomach holds about one cup of food; a normal stomach holds 4–6 cups. “Malabsorptive” procedures decrease the absorption of calories in the small intestine. The most common procedure, the Roux–en–Y gastric bypass, is both restrictive and malabsorptive.
Reasons for Procedure
Obesity is a serious health concern. It increases the risk of numerous diseases, some of which include: diabetes, cardiovascular disease, including coronary heart disease, high blood pressure, and stroke, certain types of cancer, gallstones, osteoarthritis, gout, and breathing problems such as sleep apnea.
Obesity is often diagnosed by using the body mass index, or BMI. This is a measure of body fat based on the relationship between a person’s height and weight: 18.5–24.9 is normal weight, 25–29.9 is overweight, 30–39.9 is obesity, 40 or greater is morbid obesity.
Morbid obesity is also defined as 100 pounds over what is considered a healthy weight for a person’s height.
People who carry fat in their abdomen, as opposed to on their hips, are at greater risk for some of the health problems associated with obesity. Therefore, waist circumference is also used to assess weight. A waist circumference greater than 35 inches for women or 40 inches for men is considered high risk.
Treatments
Weight loss efforts should begin with lifestyle changes, such as eating a low calorie, well–balanced diet and exercising regularly. If obesity persists despite an aggressive diet and exercise program, your doctor may advise adding weight loss medications.
If lifestyle changes and medications are unsuccessful or not possible, bariatric surgery may be considered in the following cases: BMI greater than 40, BMI 35–39.9, and a life–threatening condition, such as heart disease or diabetes, severe physical limitations that affect employment, mobility, and family life.
All candidates for bariatric surgery must commit to major lifestyle changes indefinitely after the procedure.
Procedure
In the days leading up to your procedure: arrange for a ride to and from the hospital, and for help at home as you recover; the night before, eat a light meal and do not eat or drink anything after midnight; if you regularly take medications, herbs, or dietary supplements, your doctor may recommend temporarily discontinuing them; do not start taking any new medications, herbs, or dietary supplements without consulting your doctor; you may be given antibiotics to take before coming to the hospital; you may be given laxatives and/or an enema to clear your intestines.
Before the procedure, an intravenous line will be started. Bariatric surgery requires general anesthesia, which puts you to sleep for the duration of the procedure. A breathing tube will be inserted through your mouth and into your windpipe to help you breathe during the operation.
Gastric bypass, technically referred to as Roux–en–Y gastric bypass, is both a restrictive and malabsorptive procedure. There are two surgical methods used for gastric bypass. The open method requires an 8–10 inch incision in the abdomen. The laparoscopic method only requires several small “keyhole” incisions through which your surgeon will pass a laparoscope and surgical tools. A laparoscope is a thin, lighted instrument that projects images of the surgery on a monitor in the operating room.
In the Roux–en–Y gastric bypass procedure, your surgeon will use surgical staples to create a small compartment, which will serve as your new stomach. This pouch will hold about one cup of food. The lower portion of the stomach continues to secrete digestive juices, but does not receive food.
Next, your surgeon will cut the small intestine well beyond the stomach and bring one free end up and attach it to the pouch. He or she will then attach the other free end lower down on the small intestine, creating a Y–shape. By bypassing the lower stomach and the first part of the small intestine, fewer calories will be absorbed as food passes though this new pathway.
Banding techniques are restrictive procedures. They help decrease food intake in two ways: by shrinking the stomach to a small pouch and making a tiny opening from the pouch to the rest of the stomach. Food moves slowly through this opening. These factors make you feel full quicker and for a longer time.
In vertical banded gastroplasty, your surgeon will place staples across your stomach to create a small pouch on top. Food will move from this pouch through a tiny opening into the lower stomach and the rest of the digestive tract. To prevent stretching, your surgeon will wrap a rigid, plastic band around the opening.
For adjustable gastric banding, your surgeon will wrap an inflatable band around the top of the stomach. As the band is inflated, it will squeeze the stomach to create a small pouch and a narrow opening into the larger, lower portion. This may be done though tiny incisions using a laparoscope. The band may be adjusted at any time.
In biliopancreatic diversion, which is a malabsorptive procedure, your surgeon will begin by removing part of the stomach, leaving only a small pouch behind. Next, he or she will sew the small intestine to the pouch. This creates a direct route from the pouch to the end of the small intestine. The duodenum and jejunum are bypassed, so few calories and nutrients are absorbed.
For all methods of bariatric surgery, your surgeon will close your incisions with staples or stitches. You will then be brought to the recovery room.
Risks and Benefits
Obesity itself is a risk factor for complications in any surgery. Risks associated with bariatric surgery include: nutritional deficiencies, abdominal hernia, gallstones, infection, heart and lung problems, blood clots in the legs, which can travel to the lungs, complication of the general anesthesia, and/or death.
Additional risks associated with restrictive procedures include: vomiting from eating too much or not chewing enough, band slippage, breakdown of the staple line leading to leakage of stomach juices into the abdomen, ulcers that may bleed.
Patients who have a malabsorptive procedure may also experience dumping syndrome, which occurs when stomach contents move too quickly through the small intestine. Symptoms, which occur after eating, include: nausea, weakness, sweating, faintness, and diarrhea.
If post–surgical lifestyle changes are made and maintained, the benefits of bariatric surgery include: long–term, consistent weight reduction, for some people, 100 pounds or more may be lost, improvement in many obesity–related conditions, such as decreased blood sugar and blood pressure, and enhanced self–esteem.
In gastric bypass surgery, or any procedure, you and your doctor must carefully weigh the risks and benefits to determine whether it’s the most appropriate treatment choice for you.
After the Procedure
After your procedure, the breathing tube will be removed and you will be taken to the recovery area for monitoring. You will be given pain medication and your diet will be gradually advanced over several days. If you had a laparoscopic procedure, you can expect to be discharged home in 2–5 days. After an open procedure, your hospital stay may be longer.
Once you are home, be sure to contact your doctor if you experience: signs of infection such as fever and chills, redness, swelling, increasing pain, bleeding, or discharge at the site of your incisions, cough, shortness of breath, or chest pain, worsening abdominal pain, blood in the urine or stool, pain, burning, urgency, or frequency of urination, persistent nausea and/or vomiting, pain or swelling in your feet, calves, or legs, any other worrisome symptoms.
You may be out of work for 4–5 weeks. For best results after bariatric surgery, you’ll need to practice lifelong healthful habits. These include exercise and specific nutrition guidelines. It will be essential to meet regularly with your healthcare team to help you stay on track.
Rate It
Colon & Rectal Cancer
Posted by on Saturday, 16th May 2009
Colon and Rectal Cancer
Cancer affects our cells, the body's basic unit of life. To understand cancer, it is helpful to know what happens when normal cells become cancerous.
The body is made up of many types of cells. Normally, cells grow, divide, and produce more cells as they are needed to keep the body healthy and functioning properly. Sometimes, however, the process goes astray -- cells keep dividing when new cells are not needed. The mass of extra cells forms a growth or tumor. Tumors can be either benign or malignant.
� Benign tumors are not cancer. They often can be removed and, in most cases, they do not come back. Cells in benign tumors do not spread to other parts of the body. Most important, benign tumors are rarely a threat to life.
� Malignant tumors are cancer. Cells in malignant tumors are abnormal and divide without control or order. These cancer cells can invade and destroy the tissue around them. Cancer cells can also break away from a malignant tumor. They may enter the bloodstream or lymphatic system (the tissues and organs that produce and store cells that fight infection and disease). This process, called metastasis, is how cancer spreads from the original (primary) tumor to form new (secondary) tumors in other parts of the body.
The Colon and Rectum
The colon and rectum are parts of the body's digestive system, which removes nutrients from food and stores waste until it passes out of the body. Together, the colon and rectum form a long, muscular tube called the large intestine (also called the large bowel). The colon is the first 6 feet of the large intestine, and the rectum is the last 8 to 10 inches.
Understanding Colorectal Cancer
Cancer that begins in the colon is called colon cancer, and cancer that begins in the rectum is called rectal cancer. Cancers affecting either of these organs may also be called colorectal cancer.
Colorectal Cancer: Who's at Risk?
The exact causes of colorectal cancer are not known. However, studies show that the following risk factors increase a person's chances of developing colorectal cancer:
� Age. Colorectal cancer is more likely to occur as people get older. This disease is more common in people over the age of 50. However, colorectal cancer can occur at younger ages, even, in rare cases, in the teens.
� Diet. Colorectal cancer seems to be associated with diets that are high in fat and calories and low in fiber. Researchers are exploring how these and other dietary factors play a role in the development of colorectal cancer.
� Polyps. Polyps are benign growths on the inner wall of the colon and rectum. They are fairly common in people over age 50. Some types of polyps increase a person's risk of developing colorectal cancer.
A rare, inherited condition, called familial polyposis, causes hundreds of polyps to form in the colon and rectum. Unless this condition is treated, familial polyposis is almost certain to lead to colorectal cancer.
� Personal medical history. Research shows that women with a history of cancer of the ovary, uterus, or breast have a somewhat increased chance of developing colorectal cancer. Also, a person who has already had colorectal cancer may develop this disease a second time.
� Family medical history. First-degree relatives (parents, siblings, children) of a person who has had colorectal cancer are somewhat more likely to develop this type of cancer themselves, especially if the relative had the cancer at a young age. If many family members have had colorectal cancer, the chances increase even more.
� Ulcerative colitis. Ulcerative colitis is a condition in which the lining of the colon becomes inflamed. Having this condition increases a person's chance of developing colorectal cancer.
Risk Factors Associated with Colorectal Cancer
� Age
� Diet
� Polyps
� Personal History
� Family History
� Ulcerative Colitis
Having one or more of these risk factors does not guarantee that a person will develop colorectal cancer. It just increases the chances. People may want to talk with a doctor about these risk factors. The doctor may be able to suggest ways to reduce the chance of developing colorectal cancer and can plan an appropriate schedule for checkups.
Colorectal Cancer: Reducing the Risk
The National Cancer Institute supports and conducts research on the causes and prevention of colorectal cancer. Research shows that colorectal cancer develops gradually from benign polyps. Early detection and removal of polyps may help to prevent colorectal cancer. Studies are looking at smoking cessation, use of dietary supplements, use of aspirin or similar medicines, decreased alcohol consumption, and increased physical activity to see if these approaches can prevent colorectal cancer. Some studies suggest that a diet low in fat and calories and high in fiber can help prevent colorectal cancer.
Researchers have discovered that changes in certain genes (basic units of heredity) raise the risk of colorectal cancer. Individuals in families with several cases of colorectal cancer may find it helpful to talk with a genetic counselor. The genetic counselor can discuss the availability of a special blood test to check for a genetic change that may increase the chance of developing colorectal cancer. Although having such a genetic change does not mean that a person is sure to develop colorectal cancer, those who have the change may want to talk with their doctor about what can be done to prevent the disease or detect it early.
Detecting Cancer Early
People who have any of the risk factors described under "Colorectal Cancer: Who's at Risk?" should ask a doctor when to begin checking for colorectal cancer, what tests to have, and how often to have them. The doctor may suggest one or more of the tests listed below. These tests are used to detect polyps, cancer, or other abnormalities, even when a person does not have symptoms. Your health care provider can explain more about each test.
� A fecal occult blood test (FOBT) is a test used to check for hidden blood in the stool. Sometimes cancers or polyps can bleed, and FOBT is used to detect small amounts of bleeding.
� A sigmoidoscopy is an examination of the rectum and lower colon (sigmoid colon) using a lighted instrument called a sigmoidoscope.
� A colonoscopy is an examination of the rectum and entire colon using a lighted instrument called a colonoscope.
� A double contrast barium enema (DCBE) is a series of x-rays of the colon and rectum. The patient is given an enema with a solution that contains barium, which outlines the colon and rectum on the x-rays.
� A digital rectal exam (DRE) is an exam in which the doctor inserts a lubricated, gloved finger into the rectum to feel for abnormal areas.
Recognizing Symptoms
� A change in bowel habits
� Diarrhea, constipation, or feeling that the bowel does not empty completely
� Blood (either bright red or very dark) in the stool
� Stools that are narrower than usual
� General abdominal discomfort (frequent gas pains, bloating, fullness, and/or cramps)
� Weight loss with no known reason
� Constant tiredness
� Vomiting
These symptoms may be caused by colorectal cancer or by other conditions. It is important to check with a doctor.
Diagnosing Colorectal Cancer
To help find the cause of symptoms, the doctor evaluates a person's medical history. The doctor also performs a physical exam and may order one or more diagnostic tests.
� X-rays of the large intestine, such as the DCBE, can reveal polyps or other changes.
� A sigmoidoscopy lets the doctor see inside the rectum and the lower colon and remove polyps or other abnormal tissue for examination under a microscope.
� A colonoscopy lets the doctor see inside the rectum and the entire colon and remove polyps or other abnormal tissue for examination under a microscope.
� A polypectomy is the removal of a polyp during a sigmoidoscopy or colonoscopy.
� A biopsy is the removal of a tissue sample for examination under a microscope by a pathologist to make a diagnosis.
Stages of Colorectal Cancer
If the diagnosis is cancer, the doctor needs to learn the stage (or extent) of disease. Staging is a careful attempt to find out whether the cancer has spread and, if so, to what parts of the body. More tests may be performed to help determine the stage. Knowing the stage of the disease helps the doctor plan treatment. Listed below are descriptions of the various stages of colorectal cancer.
� Stage 0. The cancer is very early. It is found only in the innermost lining of the colon or rectum.
� Stage I. The cancer involves more of the inner wall of the colon or rectum.
� Stage II. The cancer has spread outside the colon or rectum to nearby tissue, but not to the lymph nodes. (Lymph nodes are small, bean-shaped structures that are part of the body's immune system.)
� Stage III. The cancer has spread to nearby lymph nodes, but not to other parts of the body.
� Stage IV. The cancer has spread to other parts of the body. Colorectal cancer tends to spread to the liver and/or lungs.
� Recurrent. Recurrent cancer means the cancer has come back after treatment. The disease may recur in the colon or rectum or in another part of the body.
Treatment for Colorectal Cancer
Treatment depends mainly on the size, location, and extent of the tumor, and on the patient's general health. Patients are often treated by a team of specialists, which may include a gastroenterologist, surgeon, medical oncologist, and radiation oncologist. Several different types of treatment are used to treat colorectal cancer. Sometimes different treatments are combined.
� Surgery to remove the tumor is the most common treatment for colorectal cancer. Generally, the surgeon removes the tumor along with part of the healthy colon or rectum and nearby lymph nodes. In most cases, the doctor is able to reconnect the healthy portions of the colon or rectum. When the surgeon cannot reconnect the healthy portions, a temporary or permanent colostomy is necessary. Colostomy, a surgical opening (stoma) through the wall of the abdomen into the colon, provides a new path for waste material to leave the body. After a colostomy, the patient wears a special bag to collect body waste. Some patients need a temporary colostomy to allow the lower colon or rectum to heal after surgery. About 15 percent of colorectal cancer patients require a permanent colostomy.
� Chemotherapy is the use of anticancer drugs to kill cancer cells. Chemotherapy may be given to destroy any cancerous cells that may remain in the body after surgery, to control tumor growth, or to relieve symptoms of the disease. Chemotherapy is a systemic therapy, meaning that the drugs enter the bloodstream and travel through the body. Most anticancer drugs are given by injection directly into a vein (IV) or by means of a catheter, a thin tube that is placed into a large vein and remains there as long as it is needed. Some anticancer drugs are given in the form of a pill.
� Radiation therapy, also called radiotherapy, involves the use of high-energy x-rays to kill cancer cells. Radiation therapy is a local therapy, meaning that it affects the cancer cells only in the treated area. Most often it is used in patients whose cancer is in the rectum. Doctors may use radiation therapy before surgery (to shrink a tumor so that it is easier to remove) or after surgery (to destroy any cancer cells that remain in the treated area). Radiation therapy is also used to relieve symptoms. The radiation may come from a machine (external radiation) or from an implant (a small container of radioactive material) placed directly into or near the tumor (internal radiation). Some patients have both kinds of radiation therapy.
� Biological therapy, also called immunotherapy, uses the body's immune system to fight cancer. The immune system finds cancer cells in the body and works to destroy them. Biological therapies are used to repair, stimulate, or enhance the immune system's natural anticancer function. Biological therapy may be given after surgery, either alone or in combination with chemotherapy or radiation treatment. Most biological treatments are given by injection into a vein (IV).
� Clinical trials (research studies) to evaluate new ways to treat cancer are an appropriate option for many patients with colorectal cancer. In some studies, all patients receive the new treatment. In others, doctors compare different therapies by giving the promising new treatment to one group of patients and the usual (standard) therapy to another group.
Research has led to many advances in the treatment of colorectal cancer. Through research, doctors explore new ways to treat cancer that may be more effective than the standard therapy. The NCI publication Taking Part in Clinical Trials: What Cancer Patients Need To Know provides information about how these studies work. PDQ(r), NCI's cancer information database, contains detailed information about ongoing studies for colorectal cancer. NCI's Web site includes a section on clinical trials at http://cancer.gov/clinical_trials. This section provides both general information about clinical trials and detailed information about specific ongoing studies for colorectal cancer.
The NCI's Cancer.gov(tm) Web site provides information from numerous NCI sources, including PDQ(r), NCI's cancer information database. PDQ contains current information on cancer prevention, screening, diagnosis, treatment, genetics, supportive care, and ongoing clinical trials. Cancer.gov can be accessed at http://www.cancer.gov on the Internet.
Side Effects of Treatment
The side effects of cancer treatment depend on the type of treatment and may be different for each person. Most often the side effects are temporary. Doctors and nurses can explain the possible side effects of treatment. Patients should report severe side effects to their doctor. Doctors can suggest ways to help relieve symptoms that may occur during and after treatment.
� Surgery causes short-term pain and tenderness in the area of the operation. Surgery for colorectal cancer may also cause temporary constipation or diarrhea. Patients who have a colostomy may have irritation of the skin around the stoma. The doctor, nurse, or enterostomal therapist can teach the patient how to clean the area and prevent irritation and infection.
� Chemotherapy affects normal as well as cancer cells. Side effects depend largely on the specific drugs and the dose (amount of drug given). Common side effects of chemotherapy include nausea and vomiting, hair loss, mouth sores, diarrhea, and fatigue. Less often, serious side effects may occur, such as infection or bleeding.
� Radiation therapy, like chemotherapy, affects normal as well as cancer cells. Side effects of radiation therapy depend mainly on the treatment dose and the part of the body that is treated. Common side effects of radiation therapy are fatigue, skin changes at the site where the treatment is given, loss of appetite, nausea, and diarrhea. Sometimes, radiation therapy can cause bleeding through the rectum (bloody stools).
� Biological therapy may cause side effects that vary with the specific type of treatment. Often, treatments cause flu-like symptoms, such as chills, fever, weakness, and nausea.
Several useful NCI booklets, including Chemotherapy and You, Radiation Therapy and You, and Eating Hints for Cancer Patients, suggest ways for patients to cope with their side effects during cancer treatment.
The health care team can explain the possible side effects of treatment. Patients should report severe side effects. Doctors and nurses can suggest ways to help relieve symptoms that may occur during and after treatment.
The Importance of Followup Care
Followup care after treatment for colorectal cancer is important. Regular checkups ensure that changes in health are noticed. If the cancer returns or a new cancer develops, it can be treated as soon as possible. Checkups may include a physical exam, a fecal occult blood test, a colonoscopy, chest x-rays, and lab tests. Between scheduled checkups, a person who has had colorectal cancer should report any health problems to the doctor as soon as they appear.
Providing Emotional Support
Living with a serious disease, such as cancer, is challenging. Apart from having to cope with the physical and medical challenges, people with cancer face many worries, feelings, and concerns that can make life difficult. Some people find they need help coping with the emotional as well as the practical aspects of their disease. In fact, attention to the emotional burden of having cancer is often a part of a patient's treatment plan. The support of the health care team (doctors, nurses, social workers, and others), support groups, and patient-to-patient networks can help people feel less alone and upset, and improve the quality of their lives. Cancer support groups provide a setting where cancer patients can talk about living with cancer with others who may be having similar experiences. Patients may want to speak to a member of their health care team about finding a support group. Many also find useful information in NCI fact sheets and booklets, including Taking Time and Facing Forward.
Questions for Your Doctor
This booklet is designed to help you get information you need from your doctor, so that you can make informed decisions about your health care. In addition, asking your doctor the following questions will help you understand your condition better. To help you remember what the doctor says, you may take notes or ask whether you may use a tape recorder. Some people also want to have a family member or friend with them when they talk to the doctor -- to take part in the discussion, to take notes, or just to listen.
Diagnosis
� What tests can diagnose colorectal cancer? Are they painful?
� How soon after the tests will I learn the results?
� Are my children or other relatives at higher risk for colorectal cancer?
Treatment
� What is the stage of my cancer?
� What treatments are recommended for me?
� Should I see a surgeon? Medical oncologist? Radiation oncologist?
� What clinical trials might be appropriate?
� Will I need a colostomy? Will it be permanent?
� What will happen if I don't have the suggested treatment?
� Will I need to be in the hospital to receive my treatment? For how long?
� How might my normal activities change during my treatment?
� After treatment, how often do I need to be checked? What type of followup care should I have?
Side Effects
� What side effects should I expect? How long will they last?
� What side effects should I report? Whom should I call?
The Health Care Team
� Who will be involved with my treatment and rehabilitation? What role will each member of the health care team play in my care?
� What has been your experience in caring for patients with colorectal cancer?
Resources
� Are there support groups in the area with people I can talk to?
� Where can I get more information about colorectal cancer?
SOURCE: National Cancer Institute
Rate It
GIST(GASTROINTESTINAL STROMAL TUMOURS)
Posted by on Tuesday, 17th February 2009
Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. GISTs can also originate in the mesentery and omentum. Overall, GISTs are rare and rank a distant third in prevalence behind adenocarcinomas and lymphomas among the histologic types of gastrointestinal tract tumors. Historically, these lesions were classified as leiomyomas or leiomyosarcomas because they possessed smooth muscle features when examined under light microscopy.
Since the term GIST was introduced by Mazur and Clark in 1983, laboratory investigations aimed at the subcellular and molecular levels have demonstrated that GISTs do not possess the ultrastructural and immunohistochemical features characteristic of smooth muscle differentiation, as are seen in leiomyomas and leiomyosarcomas.1 Therefore, the determination was made that GISTs do not arise from smooth muscle cells, but from another mesenchymal derivative such as the progenitors of spindle and epithelioid cells.
According to the work of Kindblom and associates reported in 1998, the actual cell of origin of GISTs is a pluripotential mesenchymal stem cell programmed to differentiate into the interstitial cell of Cajal.2 These are GI pacemaker cells and are largely responsible for initiating and coordinating GI motility. This finding led Kindblom and coworkers to suggest the term GI pacemaker cell tumors.2 Perhaps the most critical development that distinguished GISTs as a unique clinical entity was the discovery of c-kit proto-oncogene mutations in these tumors by Hirota and colleagues in 1998.3
These advances have led to the classification of GISTs as an entity separate from smooth muscle tumors, helped elucidate their etiology and pathogenesis at a molecular level, and led to the development of molecular-targeted therapy for this disease.
Clinical
History
•Up to 75% of GISTs are discovered when they are less than 4 cm in diameter and are either asymptomatic or associated with nonspecific symptoms. They are frequently diagnosed incidentally during endoscopic or surgical procedures or during radiologic studies performed to investigate protean manifestations of gastrointestinal tract disease or to treat an emergent condition such as hemorrhage or obstruction. Lesions greater than 4 cm in diameter are more likely to be symptomatic.
•The most common symptoms associated with GISTs are vague, nonspecific abdominal pain or discomfort.
•Patients also describe early satiety or a sensation of abdominal fullness. Rarely, an abdominal mass is palpable.
•GISTs may also produce symptoms secondary to obstruction or hemorrhage. GI bleeding is produced by pressure necrosis and ulceration of the overlying mucosa with resultant hemorrhage from disrupted vessels. Patients who have experienced significant blood loss may report malaise, fatigue, or exertional dyspnea. Obstruction can result from intraluminal growth of an endophytic tumor or from luminal compression from an exophytic lesion. The obstructive symptoms can be site-specific (eg, dysphagia with an esophageal GIST, constipation with a colorectal GIST, obstructive jaundice with a duodenal tumor).
•In some cases, the GIST is an unexpected finding during emergency surgery for a perforated viscus.
Physical
•No physical findings specifically suggest the presence of a GIST. Some patients present with a palpable abdominal mass. Others may present with nonspecific physical findings associated with GI blood loss, bowel obstruction, or bowel perforation and abscess formation.
•Patients presenting with significant GI bleeding can manifest vital sign abnormalities or overt shock. In others, fecal occult blood testing may be positive.
•Physical findings associated with bowel obstruction can include a distended, tender abdomen. Duodenal obstruction involving the ampulla may be associated with jaundice and, rarely, even a distended palpable gallbladder.
•If perforation has occurred, focal or widespread signs of peritonitis are present.
Causes
•Gain-of-function mutations in exon 11 of the c-kit proto-oncogene are associated with most GISTs. These mutations lead to constitutive overexpression and autophosphorylation of c-Kit, provoking a cascade of intracellular signaling that propels cells toward proliferation or away from apoptotic pathways.
•This discovery by Hirota and colleagues in 1998 was a landmark elucidation of the etiology of a disease on a molecular level.3 Most of these mutations are of the in-frame type, which allows preservation of c-kit expression and activation. The c-kit proto-oncogene is located on chromosome arm 4q11-12. It encodes KIT, which is a transmembrane tyrosine kinase. Stem cell factor, also called Steel factor or mast cell growth factor, is the ligand for KIT and exists primarily in dimeric form.
•Under normal circumstances, KIT activation is initiated when stem cell factor binds to the extracellular domain of c-Kit. The result is homodimerization of the normally inactive c-Kit monomers. Autophosphorylation of intracellular tyrosine residues then transpires. This exposes binding sites for intracellular signal transduction molecules. What follows is activation of a signaling cascade that involves phosphorylation of several downstream target proteins, including MAP kinase, RAS, and others. Ultimately, the signal is transduced into the nucleus, resulting in mitogenic activity and protein transcription.
•KIT is constitutively phosphorylated in the majority of GISTs. In these instances, stem cell factor is not required to initiate the sequence of c-Kit homodimerization and autophosphorylation. This is termed ligand-independent activation. The increased transduction of proliferative signals to the nucleus favors cell survival and replication over dormancy and apoptosis, leading to tumorigenesis.
•Studies have reported a small subset of KIT-negative GISTs in which mutations of platelet-derived growth factor receptor-alpha (PDGFA), protein kinase C, and FLJ10261 were detected. These mutations and c-kit mutations appear to be mutually exclusive according to the 2003 work of Heinrich and associates. These investigators discovered PDGFA mutations in 14 of 14 subjects with GISTs who lacked c-kit mutations.
•A small minority of GISTs are associated with hereditary syndromes.
•One is characterized by multiple GISTs with or without the presence of dermal and mucous membrane hyperpigmentation, numerous nevi, and urticaria pigmentosa. Mast cell dysfunction and diffuse hyperplasia of GI spindle cells are other features of this syndrome.
•GISTs occur with a higher than expected frequency in patients with type 1 neurofibromatosis.
•GISTs are also a feature of the rare Carney triad, which is observed predominantly in young women. This triad consists of epithelioid gastric stromal tumors, pulmonary chondromas, and extra-adrenal paragangliomas.
Rate It
Why we are No. 1 › 
Category (
Views ( 14728 ) | User Rating
