ASO Author Reflections: Neoadjuvant Chemotherapy for Breast Cancer May Not Alter Increasing Trends for CPM Utilization

Past:

Currently, the use of neoadjuvant chemotherapy (NAC) for breast cancer increases eligibility for breast-conserving surgery (BCS) and decreases need for axillary node dissection. The survival of women undergoing BCS after NAC is equivalent to those undergoing mastectomy.^1,2 Clinical trials have reported improved pathologic complete response rates with modern chemotherapy regimens without a corresponding increase in BCS rates.^2,3

Although about 40% of women are eligible for BCS after NAC, about 20–30% still choose mastectomy.^4,5 Additionally, rates of contralateral mastectomy (CPM) in women receiving NAC are increasing, and mirror what is observed in the primary surgical setting. While factors associated with CPM in the upfront surgical setting have been well described, factors in women choosing CPM after NAC have not been as well studied.

Present:

We performed a retrospective review of a prospectively maintained NAC database to identify all women with clinical stage I-III, unilateral invasive cancer receiving NAC and undergoing unilateral or bilateral (CPM) mastectomy from 9/2013–12/2017.⁶ In our study, 48% of women chose CPM. As expected, women with BRCA mutations or strong family history were very likely to choose CPM. Overall, we identified younger age and earlier-stage disease as highly associated with CPM on multivariable analysis. Additionally, women who were candidates for BCS after NAC were also more likely to select CPM, as well as those who had imaging response after NAC. In our database, the reasons for mastectomy and contraindications to BCS post-NAC were prospectively recorded, and for women undergoing CPM, surgeons cited BRCA mutation or family history as the most common reason. In the subset of women who were eligible for BCS, patient preference was the most commonly cited reason.

Future:

Women who are recommended to receive NAC have historically been higher stage, but current use of NAC in early-stage breast cancer is increasing. The benefits of NAC include both prognostic and predictive information for some molecular subtypes, and NAC does have potential to minimize surgical intervention, particularly for women with nodal involvement. As CPM has not been shown to improve overall or disease-free survival, considerable efforts to understand and potentially reverse this trend are ongoing.

Shared decision making and strategies to communicate risk and treatment options to women need to be further investigated and promoted. Our findings in this study highlight the need to understand patient desire for bilateral mastectomy with CPM prior to NAC, and opportunities for education and intervention. Future study evaluating the impact of both patient education programs and clinician counseling on choice of BCS compared to unilateral or bilateral mastectomy (with CPM) are necessary in the NAC setting.