Impact of preoperative BRCA1/2 testing on surgical decision making in patients with newly diagnosed breast cancer.

The utility and benefit of integrating germ-line genetic testing into the management of newly diagnosed breast cancer is not fully understood. This study evaluates the impact of preoperative genetic testing on surgical decision making in patients with newly diagnosed breast cancer. Women with newly diagnosed breast cancer were classified into preoperative or postoperative genetic testing group, depending on whether they received their genetic testing results prior to or after their first surgery. Demographics, tumor characteristics, surgical treatment, and results of genetic testing were retrospectively collected. A total of 997 patients were evaluated, 531 (53.3%) in the preoperative genetic testing group and 466 (46.7%) in the postoperative group. Majority (87.2%) of BRCA-positive women in the preoperative group underwent bilateral mastectomy as first surgery. Majority (70.6%) of BRCA-positive women in postoperative group underwent partial mastectomy as first surgery prior to receiving their genetic testing result. Nearly half (41.2%) of these women in the postoperative group with partial mastectomy underwent bilateral mastectomy after receiving their BRCA-positive result. Time from diagnosis to first surgery was longer in the preoperative genetic testing group. Younger age, bilateral cancer, BRCA1/2-positive results, and preoperative genetic testing were significant predictors of bilateral mastectomy at first surgery. Preoperative genetic testing impacts initial surgical treatment in BRCA1/2-positive patients and reduces the need for additional surgeries.

Preoperative genetic testing impacts surgical decision making in BRCA mutation carriers with breast cancer: a retrospective cohort analysis.

BACKGROUND: The impact of timing of genetic testing on surgical decision making in women with breast cancer and BRCA mutation is not well known. METHODS: Women who were found to carry a deleterious BRCA mutation and had been diagnosed with breast cancer were identified from a database at Beaumont Health. Women who had received BRCA positive results at least a day prior to their index surgery were considered to be aware of their mutation status prior to surgery. Baseline characteristics and surgical choices were compared between women who were aware of their mutation status prior to surgery and those who were not. Fischer's exact test was used for categorical variables and Mann-Whitney U-Test was used for continuous variables. RESULTS: A total of 220 patients were included in the final analysis, 208 (94.5%) with unilateral breast cancer and 12 (5.5%) with bilateral breast cancer. Out of the 208 patients with unilateral breast cancer, 106 (51.0%) patients were aware of their mutation status prior to index surgery while 102 (49%) were not. A significantly (p < 0.05) higher proportion of women underwent contralateral prophylactic mastectomy in the group that was aware of their mutation status prior to index surgery compared to the group that was not (76.4% vs 14.7%). CONCLUSIONS: Our study demonstrates that knowledge of BRCA mutation status impacts surgical decision making in favor of bilateral mastectomy in patients who are aware of their results prior to index surgery. This finding supports the practice of preoperative genetic testing in patients with newly diagnosed breast cancer.