Surgical decision-making after neoadjuvant chemotherapy for breast cancer.

Abstract

e23282 Background: Following neoadjuvant chemotherapy (NAC), a significant subset of breast cancer patients become candidates for breast conserving surgery (BCS) after tumor downstaging. Studies have shown there is no survival advantage between BCS and mastectomy after NAC and that patient prognosis is largely predicted by the pathologic response to treatment. While the literature highlights many aspects of surgical decision-making in breast cancer, there is little analysis of patient choice after NAC. The goal of this study is to investigate clinical and demographic factors that may associate with patients’ surgical decision-making after receiving NAC as well as related outcomes. Methods: A retrospective chart review was conducted on breast cancer patients at our institution who became BCS candidates after receiving NAC from 1/1/2010 to 9/30/2020. Patient demographics, clinical characteristics, choice of mastectomy versus BCS, and outcomes were compared. Exclusion criteria included inflammatory, recurrent, and bilateral breast cancers, and patients with genetic predisposition. T-tests and chi-squared tests of association were used for continuous and categorical variables respectively. Survival outcomes were reported using the log-rank test. The p-value threshold for significance was p < 0.05. Statistical analysis was performed using R software version 4.2.3. Results: In this analysis, 244 patients met study criteria, of which 181 (74.2%) patients chose BCS and 63 (25.8%) patients elected mastectomy. Patients who chose mastectomy were younger at time of diagnosis than those who chose BCS: median age 48 years in mastectomy group versus 53 years in BCS group (p = 0.003). Regarding physical exam findings, while palpability of the primary breast tumor was not associated with choice of surgery (p = 0.271), presence of axillary lymphadenopathy was associated with a higher likelihood of choosing mastectomy (44.4% in mastectomy subgroup versus 29.3% in BCS subgroup, p = 0.041). Patient race, pre-treatment clinical stage, and doxorubicin-based chemotherapy were not associated with patients’ decisions for type of surgery. With respect to outcomes, follow-up time was similar between both groups with overall median of 5 years, and there was no significant difference in local or distant recurrence, and overall mortality (log-rank p = 0.3). Conclusions: The majority of breast cancer patients elect BCS after downstaging from NAC. Factors that are associated with choosing mastectomy include younger age at diagnosis and pre-treatment palpable axillary lymphadenopathy, which may be perceived as more advanced stage, despite no difference in stage between both groups. Regardless of surgical choice, both recurrence and mortality rates did not significantly differ between patients who chose BCS versus mastectomy, which is consistent with the literature.