October 23, 1998

Study of siblings may help predict cancer susceptibility

Study of siblings may help predict cancer susceptibility

Many scientists believe the secret to cancer lies amid the thousands of human genes that carry the body's instructions from conception till death.

But looking for the dozens that may contribute to the development of cancer is like looking for a needle in a haystack.

A new study at the Vanderbilt Cancer Center and 11 other institutions is narrowing the search by focusing on pairs of siblings who have had the same kind of cancer ‹ of the breast, colon, prostate or lung. Scientists are looking for genetic similarities that may help predict who is susceptible to cancer.

"This study is of major importance to our understanding of the genetic susceptibility of cancer and its findings could help identify patients for more intensive screening and preventive measures in the future," said Dr. Russell F. DeVore III, assistant professor of Medicine and principal investigator in the study at Vanderbilt.

A person is eligible for the study if he or she has had breast, colon, prostate or lung cancer and has a living, full-blood brother or sister who has had the same malignancy. The cancer does not have to be active, but the siblings must have a pathology report confirming their cancer diagnosis.

The study requires little of participants other than answering a questionnaire about family history of cancer and donating a couple of teaspoons of blood. The blood is then shipped to the City of Hope Medical Center in Duarte, Calif., where scientists examine about 100 specific gene locations in hopes of discovering similarities that may one day help predict cancer susceptibility.

Confidentiality of the participants is closely maintained.

Each of the 10 participating centers registers participants and manages study data, but the blood can be drawn anywhere. For example, a breast cancer survivor who lives in Nashville might come to the VCC to have her blood drawn, but her sister in Seattle could have her blood drawn at her own primary care physician's office.

"We're trying to make it very convenient for the patients," said Shelley Moore, R.N., M.S.N., the research nurse coordinating this study at the VCC. "There's no charge to the patient, and while we want to get the blood drawn in a timely fashion, if they already have an appointment scheduled with their doctor, we'll work with them to get a specimen for this study at the same time."

The study, supported by the National Institutes of Health, is being conducted over a five-year period through the Eastern Cooperative Oncology Group. Formed in 1955, ECOG is a multi-national network of more than 5,000 physicians, nurses, pharmacists, statisticians and clinical research associates established to work together on studies of potential new cancer treatments.

Identifying and studying a large number of sibling pairs is an important goal of the study. A minority of cancer survivors would have living relatives with the same kind of cancer, DeVore said, but if enough pairs can be studied, the genetic link may be made. During the length of the study, ECOG hopes to conduct genetic studies of about 5,000 pairs of siblings.

The VCC has already enrolled more than two dozen pairs of siblings, all of whom have been motivated by a desire to help future generations.

"This study doesn't affect the participants' current therapy," Moore said. "This really is all about making a contribution to generations of people in the future. The ultimate goal is to prevent cancer."

For more information, please call Moore in the Vanderbilt Cancer Center's Clinical Trials Office at 615-936-5795. She also can be reached by e-mail at shelley.moore@mcmail.vanderbilt.edu.