(Reuters Health) - Some women with breast or ovarian cancer might benefit from genetic testing to guide their treatment and follow-up care, but less than one in five of those women actually get tested, a recent U.S. study suggests.
Of an estimated 3.8 million women in the U.S. with a history of breast or ovarian malignancies, up to 15 percent might have inherited genetic mutations that could help determine the best approach to their care, researchers note in the Journal of Clinical Oncology.
For the study, researchers focused on women who were considered eligible for genetic testing by current guidelines. All women with ovarian cancer are eligible. With breast cancer, eligibility depends on women’s age at diagnosis as well as the age at diagnosis for any close relatives with breast tumors.
Among women diagnosed with breast cancer, about 36 percent were eligible for genetic testing but just 15 percent got tested, the study found. Only 11 percent of women with ovarian cancer got tested.
“Over a million women with breast or ovarian cancer who should get getting genetic testing have not,” said lead study author Dr. Christopher Childers of the University of California, Los Angeles.
“Perhaps more shocking was that over 75 percent of these women have never even discussed the possibility of genetic testing with a healthcare provider,” Childers told Reuters Health by email.
Women with certain gene mutations may have especially aggressive tumors that grow rapidly and spread quickly. Genetic tests can identify which women may benefit from a newer generation of targeted cancer therapies that attack tumors caused by specific gene mutations, most of which are inherited.
Results may also help a woman decide what type of surgery to have based on her risk for recurrent cancer or new cancers, and can also guide testing for daughters or other close female family members.
For the study, researchers examined survey responses from a nationally representative sample of U.S. adults, including 47,218 women with complete information on whether they had discussed genetic testing with their doctors, were told to get tests and actually received tests.
Among these women, about 2.7 percent had been diagnosed with breast cancer and 0.4 percent had been diagnosed with ovarian tumors.
About 29 percent of the women with breast cancer who were eligible for testing discussed it with healthcare providers, and 20 percent were told to get tests.
Women with breast cancer were a little more likely to get needed tests when they were 45 or younger at the time of their diagnosis than those who were older.
Only about 15 percent of women with ovarian cancer who were eligible for genetic testing discussed it with providers, and just 13 percent were advised to get tests.
One limitation of the study is that it relied on survey data, requiring women to accurately recall and report on conversations about genetic testing that might have happened many years ago, the authors note.
But the results still highlight a need to get more patients tested, said Dr. Kevin Hughes of Massachusetts General Hospital and Harvard Medical School in Boston.
“If the woman or any member of her family had ovarian cancer, if there are more than 3 breast cancers in her family, if a male has had breast cancer, testing is always needed,” Hughes, author of an accompanying editorial, said by email.
“But even lesser family histories can prompt testing,” Hughes added. “We have entered an era where testing is inexpensive and its benefits are obvious, and therefore we have lowered the threshold as to who can be tested.”