Joining FORCES is the FORCE newsletter with news, views and supportive information for individuals concerned about hereditary breast and ovarian cancer.
by Melissa Cranmer
While much is known about managing cancer risk in women with mutations in BRCA and other genes associated with hereditary breast and ovarian cancer, less research focuses on men with mutations. At the 2015 Joining FORCEs conference, Dr. Mary Daly of Fox Chase Cancer Center presented what is known and what research is needed.
In the average-risk population, cancer incidence and mortality is actually greater for males than for females. Several cancers disproportionately affect males. Globally, colorectal cancer rates are higher in men than women, as are lung cancer and bladder cancer. While some of this seems to correlate with increased exposures to certain pathogens, such as smoking and other factors that cause lung and bladder cancer, it is unclear to what extent exposure influences risk. Multiple factors are believed to play a role in cancer risk, including:
How these factors interact and affect one another is poorly understood.
Men who test positive for a genetic mutation exhibit better cancer screening, surveillance, and health habits, which generally have a positive effect on health. Men with children are more likely to be tested for a genetic mutation than those without children, due to their inclination to protect their children (as opposed to protecting themselves). Overall, fewer screening, treatment, and prevention options are available for men with genetic mutations.
BRCA mutations increase the risk of two forms of male cancers: male breast cancer and prostate cancer. Male breast cancer accounts for less than 1% of all breast cancers, however men with a BRCA2 mutation carry a 7% lifetime risk of this type of cancer. Screening for male breast cancer is challenging, as many men lack enough breast tissue to adequately perform a mammogram. Male breast cancers with a palpable mass tend to present at later stages, and no current research exists on effectiveness of ultrasound in men. Treatment of male breast cancers also has unique challenges: no clear guidelines have been developed as to whether or not lumpectomy or mastectomy is best, nor whether lateral or bilateral mastectomy should be performed. In addition, some treatments (such as tamoxifen in ER-positive breast cancer) have undesirable side effects (such as impotence) and may compromise compliance with treatment regimes.
Prostate cancer risk is also increased in men with BRCA mutations, with BRCA1 mutations carrying a 3-fold risk and BRCA2 mutations carrying a 7-fold risk. BRCA mutations are also associated with younger age at initial diagnosis, more aggressive cancers, and higher rates of nodal and distal metastases. Men with BRCA mutations also have a higher rate of recurrence and mortality. Questions on how to best treat and screen BRCA-related prostate cancer (radical vs. local therapy, active surveillance, targeted chemotherapy, PARP inhibitors) remain; however, prostate screening at a younger age (40 years) should be considered.
Colorectal cancer also carries a strong hereditary factor based on multiple mutations and syndromes, including familial adenomatous polyposis, MYH-associated polyposis, Lynch syndrome, familial colorectal and pancreatic cancers, inflammatory bowel disease, Peutz-Jeghers syndrome, and juvenile polyposis. Lynch syndrome not only causes a marked increase in colorectal cancer, but also increases the risk of other cancers as well, including cancers of the brain, urinary tract, pancreas, and small bowel.
Lack of research, public misconceptions about how inheritance affects risk, and a lack of involvement with a family health/ health care delivery system presents additional challenges to effectively screen, prevent, and treat cancer in high-risk men. The future of high-risk cancer screening and prevention may take several forms, including multiple-gene panel testing, whole genome sequencing, and universal genetic testing.
Melissa found FORCE while searching for an internship project as part of her public health degree. Having lost both her mom and maternal grandmother to breast cancer, she strongly connects with FORCE's mission. She also has a master of business administration, and hopes to use her educational background to further public health initiatives, especially in the field of women's health.