African-American men with prostate cancer were more likely to report a family history of prostate cancer and breast cancer among siblings than men who did not have prostate cancer, according to researchers at the University of Michigan Comprehensive Cancer Center.
The data were part of the Flint Men's Health Study, a population-based study of African-American men ages 40-79 who live in Flint, Mich. The Flint Men's Health Study focuses specifically on African-American men as part of an effort to determine why they face a higher risk of prostate cancer than white men.
The findings from this study support previous studies that have found increased risk of prostate cancer among men reporting a brother diagnosed with the disease. Furthermore, breast cancer diagnosed among both sisters and mothers of men with prostate cancer was more often diagnosed at a younger age, suggesting premenopausal breast cancer. Both breast and prostate cancer typically occur in older populations. Results of the study appear in the November issue of Urology.
Some 121 men with prostate cancer completed surveys about their family history of cancer, including prostate cancer among the men in their family and breast cancer among the women. Another 179 control men without prostate cancer were also surveyed.
Men with prostate cancer were 4.8 times more likely to report having a brother diagnosed with prostate cancer and about four times more likely to report a sister diagnosed with breast cancer, the researchers found.
"Previous studies have suggested having a brother with prostate cancer confers higher risk than another relative, such as a father or son. But this is the first time a link has been shown between sisters with breast cancer and prostate cancer risk among African-American men," says lead study author Jennifer Beebe-Dimmer, MPH, Ph.D., assistant research scientist and lecturer in the Department of Epidemiology at the U-M School of Public Health.
"This is an important finding because the Flint Men's Health Study is one of a few studies conducted exclusively in a minority population that is known to be at high risk for developing prostate cancer," Beebe-Dimmer says. Black men are 60 percent more likely to be diagnosed with prostate cancer, regardless of family history.
Older age and a family history of prostate cancer are the primary risk factors for the disease, in both blacks and whites. A first-degree relative with prostate cancer increases a man's risk by two to four times, and the more relatives who are affected, the more the risk increases.
"Collecting a family history of prostate and breast cancer, especially among siblings, could be a key component of assessing prostate cancer risk among African-American men. A well-documented family history may signal a need for more intense prostate cancer screening," says senior study author Kathleen Cooney, M.D., professor of internal medicine and urology at the U-M Medical School.
"In addition, these findings give potential to identifying new genes associated with prostate cancer or breast cancer," adds Cooney, co-director of Urologic Oncology at the U-M Comprehensive Cancer Center.
Some 234,460 men will be diagnosed with prostate cancer this year, and 27,350 will die from the disease, according to the American Cancer Society.