Parents, siblings, and children of men with prostate cancer face a 20–30 percent greater risk of getting nine other types of cancer, University of Utah School of Medicine researchers report in the first large-scale study of the issue.
In close relatives of men who have familial prostate cancer, the risk for other cancers is even greater, according to a study published online in The Prostate.
U of U researchers led by Lisa A. Cannon-Albright, Ph.D., professor of medical informatics, found that "first-degree" relatives of 16,744 men with prostate cancer, in addition to the well-known increased for prostate cancer in the male relatives, had a significantly increased risk of cancer of the kidney, thyroid, gallbladder, brain, lip, stomach, and rectum, as well as non-Hodgkins lymphoma and leukemia.
"The increased risk for prostate cancer among relatives of men with prostate cancer is well-recognized," Cannon-Albright said. "But, until now, there havent been any large-scale studies to identify the risks for other types of cancer."
Cannon-Albright initially intended to investigate the risk of other cancers in the relatives of men with heritable, or familial, prostate cancer only. She estimated the risk for 36 types of cancer among first-degree relatives of 1,238 men with heritable prostate cancer listed in the Utah Cancer Registry and the Utah Population Data Base--a unique compilation that ties genealogical records with verified cases of disease going back several generations.
To determine risk, Cannon-Albright looked at age- and sex-specific cancer rates in a larger group taken from the Utah Population Data Base. She compared cancer rates of the larger group with those of 10,862 first-degree relatives of men with the heritable form of the disease.
The relatives of men with the heritable form of the disease experienced an 89 percent higher incidence of multiple myeloma than expected. Cancer of the rectum and kidney occurred about 66 percent more often, while colon cancer was 53 percent higher. Non-Hodgkins lymphoma and melanoma occurred nearly 50 percent more often than expected.
Each of these different cancer associations with prostate cancer might represent distinct heritable syndromes involving prostate and other cancers, and Cannon-Albrights group will study such high-risk pedigrees in the search for responsible predisposition genes.
Cannon-Albright also estimated the risk for other cancers in all 16,000-plus men with both heritable and non-heritable prostate cancer. The risks for nine types of other cancer ranged from 20-30 percent higher than expected among the 140,275 first-degree relatives in this group.
The results confirmed the findings of a smaller, previous Utah study, according to Cannon-Albright. Only the increased risk for kidney cancer previously had been reported, in a study in Iceland.
The clustering of different cancers in some families may be an indirect indicator of longevity genes. "Families that live to advanced age may have more cancer than expected," Cannon-Albright said.
Other authors of the study are Nicola J. Camp, Ph.D., assistant professor of medical informatics, James S. Farnham, and Alun Thomas, Ph.D., professor of medical informatics, all U of U School of Medicine, and Angela Schwab, Huntsman Cancer Institute.