Real-World Assessment of the Effect of Impact of Tumor Size on Pathological Complete Response Rates in Triple Negative Breast Cancer After Neoadjuvant Chemotherapy

Bruno Henrique Rala de Paula; Sanjeev Kumar; Fabiola Marques Morosini; Debora Evelyn Martins Calábria Cardoso; Carlos Augusto Moreira de Sousa; Susanne Crocamo

Disclosures

Chin Clin Oncol. 2020;9(6):78 

In This Article

Abstract and Introduction

Abstract

Background: Triple negative breast cancer (TNBC) is characterized rapid tumor growth, and increased metastatic potential compared to other breast cancer subtypes. However, pathological complete response (pCR) to neoadjuvant chemotherapy (NACT) can predict patients with a better prognosis. Clinical predictors of pCR such as tumor size (TS) are controversial. This study aims to evaluate the influence of TS on achieving pCR, and the associated survival outcomes.

Methods: Medical records from 310 TNBC patients treated with NACT between 2010 and 2013 in National Cancer Institute Brazil were screened. The aim study was to examine the impact of TS on pCR. We used descriptive statistics to organize and summarize TS data and all the other variables of interest. Logistic regression has done to assess if any of these variables were associated with pCR. Survival data were extrapolated using Kaplan-Meier analysis and log-rank tests.

Results: Thirty-nine (21%) of 187 enrolled patients achieved pCR. Median age was 48 years, 50.27% were postmenopausal, 93.03% T3/T4 and 75.39% axillar clinical node-positive; 92.51% received an anthracycline regimen followed by a taxane. Age >40 years (P=0.04, OR 0.45, 95% CI, 0.20–0.95) and tumor infiltrating lymphocytes (TILs) presence (P<0.01, OR 3.71, 95% CI, 1.60–8.60) were factors significantly associated with increased rates of pCR. Neither the TS (IQR: 4; P=0.22, OR 0.93, 95% CI, 0.83–1.03) nor the other subgroups analysed demonstrated any association with achieving pCR. Median follow-up was 36 months. The 5-year OS and RFS of the study population was 71.20% and 61.10% respectively.

Conclusions: Preoperative TS did not significantly impact pCR rate in our cohort of patients receiving NACT for TNBC. Characteristics associated with higher pCR rate included TILs and age >40 years. In addition, pCR, was indicative of better survival outcomes.

Introduction

Triple negative breast cancer (TBNC) represents a heterogeneous disease with poor prognosis and frequently larger primary tumours at diagnosis.[1] Generally, neoadjuvant chemotherapy (NACT) is the standard upfront treatment option in non-metastatic tumours greater than 2 centimetres and/or node positive, with an ultimate goal of pathological complete response (pCR) to improve local outcomes as well as event-free and overall survival (OS).[2]

Standard NACT regimens continue to incorporate an anthracycline and taxane-based backbone.[3] Recent evidences suggest that a dose-dense chemotherapy regimen, +/− the addition of platinum agents and immunotherapy may positively impact pCR rates in TNBC potentially longer-term outcomes.[4,5]

Efforts were undertaken in recent years to establish newer targeted therapies in TNBC. Clinical studies using poly-ADP-ribosyl polymerase (PARP) Inhibitors, novel immune checkpoint inhibitors, PI3K pathway inhibitors, cyclin-dependent kinase (CDK) 4/6 inhibitors and an antibody-drug conjugate that targets Trop-2 are being evaluated in the neoadjuvant setting to define the potential role of these drugs in early-stage disease.[6]

The benefit data for these new target drugs is still getting robust, further studies to understand more accurate molecular characterization of these tumors are needed. Clinical variables may still play a significant role in treatment deciding, which may have paradoxical meaning in comparison to other breast tumor subtypes.[7] An inverse association between tumor size (TS) and pCR rate is known to be mainly evident in hormone-positive and HER2-positive tumors treated with NACT.[8,9] However, the literature is not consistent regarding TNBC.[10–12] In real-world studies, pCR has been reported even in high tumor burden populations, frequently observed in developing countries.[13]

In this study, we retrospectively explore the influence of TS on the rate of pCR and the associated survival outcomes in a real-word cohort of patients with TNBC treated with NACT. We present the following article in accordance with the STROBE reporting checklist (available at https://dx.doi.org/10.21037/cco-20-111).

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