The Role of Adjuvant Chemotherapy in Metaplastic Breast Carcinoma: A Competing Risk Analysis of the SEER Database

Abstract

Purpose: Chemotherapy is the clinically recommended treatment for patients with operable metaplastic breast carcinoma (MBC); however, its impact remains controversial. This study investigated the possible role of chemotherapy in the treatment of MBC.Methods: The Surveillance, Epidemiology, and End Results (SEER) database was used to identify the operable MBC patients. The competing risk analysis along with the propensity score matching (PSM) method was performed to evaluate the effect of chemotherapy. Moreover, a competing risk nomogram was built to identify prognosis in patients with MBC.Results: Of the 1137 patients with MBC, 775 received chemotherapy and 362 did not receive chemotherapy. The 5-year cumulative incidence of breast cancer-specific death (BCSD) showed similar outcomes in both the Chemo and No-Chemo groups (21.1 vs. 24.3%, p = 0.57). Chemotherapy showed no apparent association with BCSD (HR, 1.07; 95% CI, 0.72–1.60; p = 0.72), even after subgroup analysis or PSM. Race, tumor size, lymph node status, and radiation were identified as the significant factors for MBC after a penalized variable selection process. In addition, a competing risk nomogram showed relatively good accuracy of prediction with a C-index of 0.766 (95% CI, 0.700–0.824).Conclusion: Our findings demonstrated that chemotherapy did not improve BCSD for operable MBC patients. Thus, it may indicate the need to reduce exposure to the current chemotherapy strategies for patients with resectable MBC. Additionally, some novel treatment strategies are required urgently to identify and target the potential biomarkers.

Chemotherapy significantly improves long-term survival of small lesion node negative metaplastic breast carcinoma in T1c population rather than T1a and T1b

“…Most of the literature reports that chemotherapy is less effective in MpBC 19 , and it is more likely to develop drug resistance than nonspecial types of invasive breast cancer 20 . Several studies have reported that chemotherapy was associated with a better outcome, although the effect was limited in early-stage cases 18 , 21 .…”

“…Considering poor response rate of chemotherapy and low HER2 receptor positive rate of MpBC 19 , 22 , seeking novel therapeutic targets warrants attention. In our study, we found that 66.3% of MpBC were triple-negative subtype.…”

Mixed Metaplastic Carcinoma of the Breast: A Case Report

“…Despite poor chemotherapy response, the addition of adjuvant radiation to surgical resection has been shown to signi cantly improve survival in patients with MPBC 1,13 . The addition of chemotherapy has also been shown to have a survival bene t in many of these patients as well, though this bene t is debated in patients with operable disease 1,13,14 . Although there has been some bene t shown to chemotherapy in these patients, little evidence compares adjuvant to neoadjuvant chemotherapy.…”

Construction and validation of prognostic nomogram for metaplastic breast cancer

“…Variables of interest for each case included age at diagnosis, race, grade, histology, status of ER, PR and HER2, American Joint Committee on Cancer (AJCC) tumor stage (7 th Edition), T stage, N stage, exact tumor size, and treatment information (including chemotherapy and adjuvant radiotherapy) were obtained from the database. The following SEER ICD-0-3 codes, including 8052, 8070-8072, 8074, 8560, 8571, 8572, 8575, and 8980, were adopted to identify cases of MBC [ 12 ]. Patients with missing demographic, pathological, or survival data were excluded from the study.…”

“…At present, to the best of our knowledge, there are no available nomograms for predicting survival of the MBC patients. Two nomograms were developed for MBC, one for analyzing the role of chemotherapy in MBC [ 12 ] and second for the preoperative prediction of lymph node metastasis (LNM) in MBC patients [ 13 ]. Both studies show the utility of using nomograms for the analysis of MBC in the SEER database.…”