The Effect of HER2-Low Status on Pathological Complete Response and Survival in Triple-Negative Breast Cancer: A Systemic Review and Meta-Analysis

The impact of carboplatin on pathologic complete response and survival based on HER2 low and HER2 zero status in triple negative breast cancer patients receiving neoadjuvant chemotherapy: a multicenter real-world analysis

BACKGROUND AND OBJECTIVES

Triple-negative breast cancer (TNBC) has a poor prognosis, and neoadjuvant chemotherapy (NACT) is the standard treatment for locally advanced TNBC. In this study, we aimed to evaluate the efficacy of adding carboplatin to NACT regarding pathological complete response (pCR) and survival in the HER2-low and HER2-zero subgroups of TNBC patients.

MATERIALS AND METHODS

The study included 269 patients from five medical oncology clinics. Patients were divided into two groups: HER2-low (n = 152, 56.5%) and HER2-zero (n = 117, 43.5%). Among HER2-zero patients, 30 (25.6%) received carboplatin, while 38 (25.0%) HER2-low patients received carboplatin. The benefit of adding carboplatin to NACT regarding pCR and survival was assessed in both HER2-zero and HER2-low groups.

RESULTS

When patients were evaluated according to HER2 status, the pCR rates were significantly higher in the HER2-zero group compared to the HER2-low group (45.2% versus 23.7%, p < 0.001). In the HER2-zero group, patients who received carboplatin had significantly higher pCR rates (63.3% versus 39.0%, p = 0.021). Similarly, in the HER2-low group, adding carboplatin significantly increased the pCR rates (36.8% versus 19.3%, p = 0.028). While carboplatin improved pCR rates in both HER2 subgroups, this benefit was not observed in patients with Grade 1 tumors, HER2 score 2-FISH negative tumors, or based on BRCA mutation status. Patients with pCR exhibited significantly prolonged DFS and OS (p = 0.002, p < 0.001, respectively).

CONCLUSIONS

Our research demonstrates that the addition of carboplatin increases pCR rates in both HER2-zero and HER2-low patient cohorts. We suggest that carboplatin should be considered as an addition to standard neoadjuvant chemotherapy for eligible TNBC patients, regardless of HER2-zero or HER2-low status, when appropriate based on individual patient factors and toxicity considerations.

Possibility of Human Epidermal Growth Factor Receptor 2 Expression as a Treatment Selection Indicator in Early Triple-Negative Breast Cancer

Background This study aimed to evaluate the relationship among human epidermal growth factor receptor 2 (HER2) expression level, pathological complete response (pCR) rate of neoadjuvant chemotherapy, and prognosis in early-stage triple-negative breast cancer (TNBC). Methodology This retrospective study analyzed the relationship among HER2 expression level, pCR rate, clinicopathological factors, and prognosis in 39 patients who were diagnosed with TNBC between 2012 and 2020 at Osaka Rosai Hospital and underwent surgery after neoadjuvant chemotherapy (NAC). Results Patients' age ranged 33-86 (median = 57) years, and the observation period ranged 5-130 (median = 60) months. The HER2 expression levels were HER2 (0), HER2 (1+), and HER2 (2+, fluorescence in situ hybridization test (FISH); negative) for 18, 12, and 9 cases, respectively. The pCR rates were 38.9%, 8.3%, and 44.4% for HER2 (0), HER2 (1+), and HER2 (2+, FISH; negative), respectively, and no correlation was observed with the degree of HER2 expression. The prognosis of distant disease-free survival (DDFS) differed depending on the HER2 status (p = 0.032), and this trend was also observed in overall survival (OS) (p = 0.012). This tendency became even stronger when comparing HER2-low and HER2 (0) (p = 0.028 and p = 0.01, respectively). HER2 expression was significantly decreased from before to after NAC (p = 0.001). Conclusions HER2 expression did not correlate with the pCR rate of NAC but did correlate with DDFS and OS. Thus, patients with an HER2 (0) status are considered to have a poor prognosis and should be more aggressively considered for perioperative chemotherapy, e.g., immune checkpoint inhibitors.

The prognostic impact of Her2 status in early triple negative breast cancer: a Turkish Oncology Group (TOG) study

The studies evaluating the impact of Her2 levels in neoadjuvant setting have conflicting data. The aim of the study was to evaluate the prognostic impact of Her2 status in early triple negative breast cancer(TNBC). In the study TNBC patients who were treated with neoadjuvant chemotherapy (NAC) and surgery were analyzed retrospectively. The primary aim of the study was to analyze the impact of Her2 status(Her2-0 and Her2-low) on pathological complete response (pCR). The secondary objectives were disease free survival (DFS) and overall survival (OS). 620 female triple negative breast cancer patients were evaluated. 427 patients (68.9%) had Her2-0 and 193(31.1%) had her2-low pathology. The pCR rates were similar between Her2-0 and Her2-low patients (33.0% vs. 27.5%, p = 0.098). Although Her2-0 group has better DFS (106 vs. 50 months, p = 0.002), in multivariate analysis it had a HR of 0.74 (p = 0.06). In addition, OS was similar (131 vs. 105 months, p = 0.13) with a HR of 0.88 (p = 0.61). In multivariate analysis; presence of LVI (HR:2.2 (95% CI 1.1-3.5) p = 0.001), Clinical stage T1/T2 (HR:0.39 (95% CI 0.2-0.6) p < 0.001) and lymph node negativity (HR:0.35 (95% CI 0.1-0.9) p = 0.03) were independent factors for OS. Although there were pathological and clinical differences, the pCR, DFS and OS were similar between Her2-0 and Her2-low TNBC patients. The importance of Her2 status of TNBC in neoadjuvant setting should be further studied.

Efficacy and prognosis of HER2-Low and HER2-Zero in triple-negative breast cancer after neoadjuvant chemotherapy

Mounting evidence showed that HER2-Low breast cancer patients could benefit from the novel anti-HER2 antibody-drug conjugates (ADCs) treatment, which pointed the way towards better therapy for HER2-Low patients. The purpose of this study was to describe the clinicopathological features, along with chemotherapeutic effects and survival outcomes of HER2-Low and HER2-Zero in TNBC who received neoadjuvant chemotherapy (NACT). We retrospectively evaluated 638 triple-negative breast cancer patients who were treated with neoadjuvant chemotherapy between August 2014 and August 2022. Pathologic complete response (pCR) and survival outcomes were analyzed in HER2-Low cohort, HER2-Zero cohort and the overall patients, respectively. In the entire cohort, 342 (53.6%) patients were HER2-Low and 296 (46.4%) patients were HER2-Zero. No significant difference was found between HER2-Low and HER2-Zero patients based on all the clinical-pathological characteristics. 143 cases (22.4%) achieved pCR after NACT in the overall TNBC patients. The pCR rate of the HER2-Low patients and the HER2-Zero patients was 21.3% and 23.6%, respectively, exhibiting no statistical difference (p = 0.487). The survival of pCR group after NACT significantly improved compared to non-pCR group either in HER2-Low patients or in HER2-Zero patients. Although we found that patients with HER2-Low had longer DFS than patients with HER2-Zero, there was no considerable difference (p = 0.068). However, HER2-Low patients had a dramatically longer OS than HER2-Zero patients (p = 0.012). The data from present study confirmed the clinical importance of HER2-Low expression in TNBC. Further effort is needed to determine whether HER2-Low could be a more favorable prognostic marker for individual treatment.

Impact of HER2 status on clinicopathological characteristics and pathological complete response to neoadjuvant chemotherapy in triple-negative breast cancer

PURPOSE

HER2-low triple-negative breast cancer (TNBC) accounted for up to 34%-39% of primary TNBC and 22.2%-32% of metastatic TNBC. Our study aims to explore the relationship between HER2 expression and clinicopathological characteristics, analyze the impact of HER2 expression on the pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) in TNBC.

METHODS

This study involved 191 patients with TNBC who underwent operation after NAC from October 2021 to August 2022. Clinicopathological characteristics and the frequency of pCR were compared between HER2-low and HER2-0 TNBC.

RESULTS

42.2% (81/191) patients in our cohort were HER2-low. They exhibited differences in menopausal status, body mass index (BMI), androgen receptor (AR) expression, and histological grade (P < 0.05). Particularly, in HER2-low TNBC, AR was associated with tumor size, lymph node metastase, histological grade, and the incidence of multifocal disease (P < 0.05). The total pCR rate of entire cohor was 39.8%. Tumor size (P = 0.025), AR status (P = 0.033) and histological grade (P = 0.007) were significantly associated with the pCR rate of them, while the HER2 status did not exert a similar association. The multivariate analysis revealed that BMI (P = 0.004) and histological grade (P < 0.001) were associated with pCR of HER2-low TNBC, while tumor size (P = 0.034) and AR (P = 0.034) were associated with pCR of HER2-0 TNBC, respectively.

CONCLUSIONS

In our cohort, HER2-low TNBC patients exhibits specific clinical characteristics and response features to NAC.