Breast Conserving Surgery Does Not Harm Long-term Survival or Time to Progression
Among women who are candidates for lumpectomy after neoadjuvant chemotherapy, breast conserving treatment does not compromise survival.
SAN ANTONIO—Among women who are candidates for lumpectomy after neoadjuvant chemotherapy, breast conserving treatment does not compromise long-term disease-free survival (DFS), overall survival (OS), or time to progression (TTP), reported Jennifer De Los Santos, MD, of the University of Alabama at Birmingham at the 2015 San Antonio Breast Cancer Symposium.1
“In this cohort, type of locoregional treatment was not independently predictive of recurrence or mortality,” Dr De Los Santos reported. Women undergoing breast-conserving therapy had earlier-stage disease than those undergoing mastectomy and a higher prevalence of pathological and radiographic complete response (pCR, rCR).
Their new analysis assessed treatment outcomes across 9 NCI comprehensive cancer centers for women receiving both neoadjuvant chemotherapy and breast MRI, to determine whether or not treatment outcomes differ according to choice of locoregional treatment. A total of 1077 women treated for stage 1-3 invasive breast cancer between 2002 and 2014, were retrospectively identified and included in the analysis.
In multivariate analyses, disease-free survival (DFS) correlated with clinical disease stage, failure to achieve pCR, and tumor subtype (all Ps ≤ .0001), but not treatment type, De Los Santos reported.
Multivariate analyses also revealed that overall survival (OS) was significantly associated with clinical disease stage (P = .02); failure to achieve pCR (hazard ratio [HR] 3.16, 95%CI: 1.49-6.69; P = .003); and tumor subtype (P = .008)—but not type of treatment.
Radiographic complete response (rCR) as determined by breast MRI accurately predicted presence or absence of pCR most cases, but was not independently associated with disease-free or overall survival, nor time to progression.
The retrospective study is “one of the largest reported to date on a heterogeneous group of tumors in the neoadjuvant chemotherapy setting,” she noted.
DFS rates were significantly worse among women with triple-negative disease who were treated with mastectomy and radiation (P = .018). However, “the retrospective design of this study requires that analyses be interpreted with caution as strong selection bias exists,” said Dr De Los Santos.
RELATED: Letrozole Does Not Offer Better Survival, Safety Than Anastrozole in Breast Cancer
“Relatively short follow-up of 4.2 years favors comparatively higher event rates for tumors with short time to progression,” she added, regarding study limitations. “Sixty-four patients with HER2-positive tumors treated before June 2005 did not receive trastuzumab, which may have overestimated the event rate and underestimated the pCR rate that is achieved with HER2 targeted agents.”
- De Los Santos J, Hyslop T, Alvarado M, et al. Treatment outcomes in patients with invasive breast cancer treated with neoadjuvant systemic therapy and breast MR imaging: Results of a secondary analysis of TBCRC 017. Oral presentation at: San Antonio Breast Cancer Symposium 2015; December 10, 2015; San Antonio, TX.