A retrospective cohort study comparing reconstructive techniques and outcomes in post-mastectomy triple negative breast cancer patients.

Background: Up to 42% of all breast cancer patients undergo post-mastectomy reconstruction, however reconstructive techniques have not been widely studied in patients with triple negative breast cancer (TNBC). Reconstructive complications may delay adjuvant treatments; in TNBC, which inherently carries an increased risk of locoregional recurrence, this can greatly affect oncological outcomes. Therefore, we evaluate factors influencing choice of reconstructive techniques following mastectomy in TNBC patients and assess operative and oncologic safety outcomes.

Methods: A single institution retrospective chart review identified TNBC patients who underwent post-mastectomy reconstruction between 2010 to 2020. Clinical characteristics collected included demographics, cancer history, reconstructive techniques [autologous-based reconstruction (ABR) . implant-based reconstruction (IBR)] and surgical and oncologic outcomes such as complications, recurrence, and mortality. Factors impacting whether patients underwent ABR versus IBR were assessed, as well as differences in outcomes between the two procedures. Statistical significance was defined as P<0.05.

Results: During the 10-year period, 52.9% (n=127) of all post-mastectomy TNBC patients (n=240) underwent breast reconstruction, most frequently immediately after mastectomy (97.0%). Most patients underwent IBR compared to ABR (82.4% . 14.5%). Patients undergoing ABR were older than IBR patients (54.3 . 46.4 years; P=0.040) and had a higher body mass index (BMI; 30.0 . 26.1 kg/m; P=0.007). Patients more often pursued ABR if they had a prior breast cancer history (36.8% 16.7%; P=0.041) or experienced TNBC recurrence (26.3% 9.3%; P=0.034), while primary TNBC patients more often opted for IBR. Reconstructive type did not impact complications (ABR 31.6% IBR 16.8%, P=0.131), recurrence (ABR 15.8% IBR 13.0%, P=0.719), or mortality (ABR 0.0% IBR 6.5%, P=0.593) rates.

Conclusions: Factors such as age, BMI, and breast cancer history impacted choice of reconstructive technique among TNBC women. No differences in complications, recurrence, or mortality occur in these high-risk patients regardless of reconstructive technique, highlighting that neither ABR nor IBR is superior in regard to surgical and oncologic safety in post-mastectomy TNBC patients.