Breast Ca surgeon attitudes influence genetic testing
Results of a survey-based study of attending surgeons shows that they play a major role in whether women with breast cancer receive genetic testing. Published in JAMA Surgery, the findings indicate that many women who would benefit from the tests are not getting them, despite recommendations in guidelines.
The data are from the iCanCare study of women aged 20 to 79 (mean 61.4 years) who were diagnosed with ductal carcinoma in situ or invasive breast cancer and whose cases were reported to the Georgia or Los Angeles (California) Surveillance, Epidemiology and End Results registry. The researchers sent surveys to 5080 women with stages 0 to II breast cancer who were treated between July 1, 2013 and August 31, 2015, 98.0% and who identified their attending surgeon. Just over 77% of those surgeons responded to a seven-question survey.
The surveys were sent approximately 2 months after surgery. Four of the questions for the surgeons referred to a scenario in which a patient is deemed by the responding surgeon to be a candidate for genetic testing; in two, the scenario was one in which the surgeon deemed the patient not to be a candidate for testing; and in the last scenario, the surgeon’s confidence in discussing genetic testing was assessed. The researchers then developed a Tendency to Test Scale to assess the responses and determine the likelihood that a surgeon would order genetic testing and counseling in the different scenarios.
Approximately one-third (34.5%) of the women included in the study had an elevated risk of being mutation carriers but overall, 27.0% of the patients had genetic testing. Of those tested, 13.8% were at average pretest risk and 52.1% were at higher pretest risk.
Surgeons scored higher on the scale and were more likely to do genetic testing if they said they often or always delayed surgery to get genetic testing for their patients (35.2%) or were quite or extremely comfortable discussing testing with their patients (50.2%). The odds of testing increased by 1.88 (95% CI, 1.49-2.38) for each 1-SD increase in the scale score. If a patient with the highest pretest risk saw a surgeon in the 5thpercentile of test ordering, she had about a 26.3% (95% CI, 21.9%-31.2%) probability of undergoing testing. However, if she saw a surgeon who ordered genetic tests more often than 95% of the other surgeons included in the study, she had a 72.3% (95% CI, 66.7%-77.2%) of having a genetic test done. For average-risk women, the probabilities of testing were 4.1% (95% CI, 2.9%-5.6%) and 23.8% (95% CI, 20.0%-27.9%), respectively, for the 5thand 95thpercentiles.
The researchers found that about 17.3% of the variation in genetic testing rates could be accounted for based on the surgeons’ practice patterns. In regard to the highest-volume surgeons, patients seen by medium- and lower-volume surgeons were less likely to be tested.
The authors mentioned a few strengths and limitations to their study. Among the noted strengths were the large population-based sample of patients, genetic test information gathered directly from the testing laboratories, a valid measure of clinical indication for testing, and high response rates. Among the noted limitations were possible missed details of pretest risk of mutation carriage based on family history, inability to directly measure whether surgeons appropriately recommended testing or counseling to a given patient, and the fact that data were collected solely from two states and may not be applicable to the general US population. The authors believe the results from this study illustrate the need to build consensus about approaches to genetic testing and counseling as well as risk evaluation for breast cancer patients.