Leveraging real-world data from multiple institutions to assess the rate of bilateral mastectomy after cancer genetics evaluations with genetic counselors.

Abstract

e22551 Background: Genetic counselors (GCs) assess patients’ risk of cancer and counsel them on cancer screening and preventative measures, based on national guidelines. Prior studies have found that adherence to guideline-based care is higher after genetic counseling. Thus care provided by GCs leads to a variety of imaging and surgical services that can both improve patient outcomes and generate revenue for health systems, which can in turn help financially support cancer genetics programs. Research that quantifies such downstream services and revenue is lacking. We aimed to address this gap by using real-world data from multiple institutions to quantify the rate of bilateral mastectomies occurring after cancer genetics evaluations performed by GCs. Methods: We studied consecutive patients from a nationwide telehealth practice who underwent genetic counseling and cancer risk assessment with a GC after having germline genetic testing. Structured data obtained from multiple care sites via health information networks and manual chart review of electronic medical records was utilized to determine whether patients had bilateral mastectomies after the GC appointment. Results: Of the 460 consecutive patients seen by a GC, 30 were advised to consider bilateral mastectomy, based on their genetic test results and national guidelines. Data was available from the health information networks for all (29/29 (100%)) of these patients who live in the United States, with a mean follow-up of 2.7 years (SD 0.23). These 29 patients had a mean age of 43.3 years (SD 15.3), were all female, and carried mutations in BRCA2 (18/29 (62%)), BRCA1 (6/29 (21%)), or PALB2 (5/30 (17%)). Clinical data was collected from 468 locations, a median of 23 unique locations per patient. At the time of the GC appointment, 7/29 (24%) had active breast cancer, 19/29 (66%) were unaffected, and 3/29 (10%) had a history of previously treated breast cancer. Two patients were diagnosed with breast cancer after the GC appointment. 15/29 (52%) patients underwent bilateral mastectomy after the GC appointment, including most patients with active breast cancer (7/9 (78%)), 8/17 (47%) unaffected patients, and none (0/3 (0%)) with a previously treated breast cancer. Among those without breast cancer, the mean time from the GC appointment to the bilateral risk-reducing mastectomy was 8.6 months (SD 4.4). Conclusions: Half of patients who had bilateral mastectomy indicated because of their genetic test results elected to have mastectomy done after discussion of this guideline-based care option with a GC. As evidenced in prior research, bilateral mastectomy markedly reduces risk of breast cancer. In addition to improved patient outcomes, the revenue a health system receives from these surgeries can also help to support cancer genetics services.