In the most extensive review of cancer patterns among an American Indian tribal group, Roswell Park Cancer Institute (RPCI) researchers analyzed cancer patterns within the Seneca Nation of Indians for the period from 1955 through 2004. The study, led by Arthur Michalek, PhD, FACE, Senior Vice President for Educational Affairs, and Martin C. Mahoney, MD, PhD, Associate Professor of Oncology, Departments of Medicine and Health Behavior, RPCI, was published in a recent issue of the journal Cancer.

The retrospective study examined patterns of cancer incidence in 3,935 males and 4,193 females who were registered tribal members of the Seneca Nation of Indians. Cancer incidence rates were based on data collected through a computer match with the New York State Cancer Registry.

"Among the unique strengths of this study was the reliance on tribal roll books to identify enrolled tribal members and the ability to conduct a comprehensive study over 50 years, leading to the accrual of more than 120,000 person-years of observation. These parameters helped to overcome the issue of limited-sized populations, which has challenged studies among American Indian tribal groups in the past," said Dr. Michalek. "Additionally, the leaders of the Seneca Nation demonstrated their trust in Roswell Park researchers and a commitment to the health of their members by allowing researchers access to information required for this comprehensive analysis."

The study that found overall, no specific type of cancer was significantly elevated - and, in fact, both male and female tribal members demonstrated significantly reduced incidences for all cancers combined. Additionally, no specific age group showed significantly elevated incidence. A total of 233 primary cancers were diagnosed among Seneca males, with colorectal (20%) and prostate cancers (17%) the most common. Among female members, 256 cancers were diagnosed, with lung (20%) and breast cancer (16%) reported as the most common malignancies.

Dr. Mahoney continued, "Cancer remains a relatively rare diagnosis among tribal members, which places some limitation on the interpretation of these results. However, these unique cancer patterns are of extraordinary value to the Seneca Nation leaders as they determine health policy and cancer prevention strategies."