Genetic Testing Not Offered Enough to Breast Cancer Patients

Pam Harrison

February 07, 2017

Only a relatively small proportion of women with early-stage breast cancer receive genetic testing prior to surgery, despite the fact that the majority of such women would like to be tested, and many women would stand to benefit from knowing their mutation carrier status, a large, population-based study concludes.

Among the women who are tested, many are not counseled as to what having a cancer-specific mutation might mean for their prognosis, it also found.

The study was published online February 7 in JAMA.

"Genetic testing results can affect what sort of surgery a woman may choose to treat her existing breast cancer, as well as what treatments she should pursue to reduce the risk of forming new cancers in the future," one of the senior authors of the study, Reshma Jagsi, MD, DPhil, University of Michigan, in Ann Arbor, said in a statement.

"We don't have a crystal ball, but genetic testing can be a powerful tool for certain women, [and] it is worrisome to see so many of those women at highest risk for mutations failing even to have a visit focused on genetic counseling," he added.

Fellow senior author Allison Kurian, MD, associate professor of medicine and of health research and policy, Stanford University School of Medicine, in California, agrees, saying in an email to Medscape Medical News that knowing that a patient has a mutation ― and not just that she is at high risk of carrying a mutation because of her personal or family cancer history — enables clinicians to give patients precise estimates of the patient's future cancer risks and those of her family.

"For example, if we learn that a breast cancer patient has a BRCA1 mutation, we have learned that she has a very high risk for ovarian cancer, a disease that often kills patients and which can be prevented by surgery," she noted.

Furthermore, the patient's relatives can also be tested to determine whether they carry the same mutation.

"If they do, then they also have a high breast and ovarian cancer risk and can be offered intensive screening or prevention interventions that can save lives," Dr Kurian added. "So knowing about a genetic mutation can change care and save lives of many people, namely, the patient and many of her relatives."

Study Details

The study was based on a survey that was mailed to patients with early-breast cancer about 2 months after they had undergone surgery. The survey asked patients how much they wanted to receive genetic testing; whether they had discussed genetic testing with a physician or any other healthcare professional during the course of their treatment; whether an expert in genetic testing had counseled them about the consequences of having a genetic test when a mutation is found; and whether they had undergone genetic testing.

"Cancer family history, ancestry, and clinical information were used to construct a guideline-concordant measure of high pretest risk for mutation carriage," Dr Kurian and colleagues note.

Some 2529 women responded to the survey. The mean age of respondents was 62 years, and all had been diagnosed with stages 0-II breast cancer between July 2013 and September 2014.

"Sixty-six percent...reported wanting testing and 29.0%...reported having a test," the investigators report.

Of the total number of respondents, 31% were judged to be at high risk of carrying a mutation that increased breast cancer risk. Among these women who were at high risk for carrying a mutation, 61.7% received genetic counseling with an expert, the study authors note.

Table. Wanting vs Receiving Genetic Testing/Counseling Among Women With Breast Cancer

  Wanted to Be Tested Discussed Testing With an MD/Other HCP Was Tested Had a Session With a Genetic Counseling Expert
Average-risk women 59.3% 35.9% 17.8% 14.4%
High-risk women 80.9% 70.9% 52.9% 39.6%

HCP, healthcare provider

 

By far and away, the most common reason cited by women for not undergoing genetic testing was that their physician did not recommend it (56%), the investigators observe.

Expense was cited by fewer than 14% of survey respondents as the main reason why they did not undergo genetic testing, and fewer than 11% of women indicated they did not undergo testing because they did not want it.

Women of Asian descent and older women were especially unlikely to have undergone genetic testing, despite the fact that both groups are at risk of carrying mutations that confer a high risk for breast cancer, the investigators note.

 
Genetic counseling and testing are not well-matched to medical need. Dr Allison Kurian
 

"Genetic counseling and testing are not well-matched to medical need, and this is particularly worrisome, because it means that doctors are missing the opportunity to prevent cancer deaths among mutation carriers and their families," Dr Kurian concluded.

"[And because] patients are very interested in genetic testing, this suggests that clinicians may be part of the problem [either] due to a lack of genetic knowledge or a lack of access to genetic counseling and testing services," she added.

Dr Kurian has received grants from Myriad Genetics, Invitae, and Ambry Genetics.

JAMA. Published online February 7, 2017. Abstract

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