Investigators may have identified new strategies for use in the primary care setting to improve the detection of cancer-susceptibility genes, according to a recent study published by Swisher et al in JAMA Network Open.
Background
Up to 10% of cancers—including breast cancer, ovarian cancer, colorectal cancer, gastric cancer, endometrial cancer, and pancreatic cancer—are caused by genes that can be detected by commercially available tests. Individuals with a family history of cancer are at the highest risk of carrying these oncogenes. Although they are an ideal group for testing, screening among these patients is rarely performed as part of routine primary care, when it’s most likely to detect the risk prior to cancer development.
“We don’t routinely screen for cancer-susceptibility genes in primary care settings because genetic testing is often considered too complicated and primary care [physicians] already have so many things they need to address,” detailed lead study author Elizabeth Swisher, MD, a gynecological oncologist at the University of Washington School of Medicine, Seattle. “[However], it is an opportunity lost,” she added.
Study Methods and Results
In the study, the investigators analyzed the efficacy of two methods that primary care physicians could use to assess patients’ hereditary cancer risks and deliver testing to those identified as having a higher risk: the point-of-care approach, which involved asking patients either during their clinic visit or prior to their virtual visit to complete a questionnaire, or the direct patient engagement approach, in which patients were sent a series of letters or emails inviting them to complete the questionnaire online from home. The 12 clinics that participated in the study were randomly assigned to use one or the other approach. During the study period, 95,623 patients were seen in the clinics. Among them, 18,030 were approached during their in-clinic visit and 41,558 were sent email or letters.
The questionnaires asked about the patients' cancer history and that of their first- and second-degree relatives. It also asked about relevant ethnicity information such as Ashkenazi Jewish ancestry, which is associated with a genetic risk of several cancer types—including breast cancer, prostate cancer, colorectal cancer, and pancreatic cancer.
The patients whose completed assessment suggested they might carry a cancer-susceptibility gene were offered a test that screened for 29 such genes. The saliva-sample test was offered for free and could be administered at home. All of the patients who were found to have these gene variants were provided genetic counseling.
“The goal was to bypass the primary care physician up until there was a positive test and then provide the physician with a care plan for each patient,” Dr. Swisher noted.
The investigators found that the point-of-care approach resulted in a higher proportion of patients completing the risk assessment compared with the direct patient engagement approach (19.1% vs 8%/7%) relative to the total clinic population. Nonetheless, among those whose assessment indicated they were eligible for testing, a larger proportion of those in the direct patient engagement group received testing compared with those in the point-of-care group (44.7% vs 24.7%). The investigators speculated that the respondents in the direct patient engagement group may have already had concerns regarding their family genetic history. Although fewer patients from this group responded, those who did were more likely to test positive compared with the patients in in the point-of-care group (6.6% vs 3.8%).
Conclusions
“Both strategies had some utility,” Dr. Swisher underscored, “but we need to develop ways to improve uptake of testing and further reduce barriers to the testing process,” she concluded.
Disclosure: For full disclosures of the study authors, visit jamanetwork.com.
