Pathologic complete response and survival after neoadjuvant chemotherapy in cT1-T2/N0 HER2+ breast cancer

Nodal involvement in patients with small, clinically node-negative HER2-positive breast cancer after staging with FDG-PET/CT and neoadjuvant systemic therapy

BACKGROUND

Guidelines recommend systemic therapy for stage I HER2+ breast cancer (BC). Neoadjuvant systemic treatment (NAST) allows response-guided adjuvant treatment. However, prior to NAST only clinical nodal staging is available, risking undertreatment if ypN+ is observed. Here, we aim to evaluate the impact of FDG-PET/CT and NAST on nodal disease status in patients with small, node-negative HER2+ BC.

METHODS

This retrospective study included patients with small (≤3 cm), clinically node-negative HER2+ BC diagnosed between 2011 and 2023. Primary outcome was the proportion of patients with nodal disease on final pathology after upfront surgery or NAST followed by surgery with or without FDG-PET/CT. Patients received either paclitaxel + trastuzumab (PT) or a more extensive regimen.

RESULTS

Of the 370 included patients, 183 underwent FDG-PET/CT, detecting regional or distant metastases in 14 patients (7.7 %). Among 356 patients with cN0 disease, 44.1 % (n = 157/356) had upfront surgery, with only 3 % (5/157) having an FDG-PET/CT. The remaining 55.9 % (199/356) started with NAST, with 82 % (n = 164/199) having an FDG-PET/CT. Among patients treated with NAST, 36 % received PT. Nodal involvement on pathology was seen in 19.1 % (n = 29/152) after upfront surgery without FDG-PET/CT and 6.1 % (10/164) after NAST combined with FDG-PET/CT. After NAST, 58 % had a pCR (PT: 49 %, other: 63 %). Nodal involvement on final pathology was seen in 6.9 % after PT and in 5.5 % after more extensive regimen.

CONCLUSIONS

The proportion of patients with ypN + after NAST combined with FDG-PET/CT was only 6.1 %. Neoadjuvant treatment can be a safe treatment strategy for patients with stage I HER2+ BC.

In-Breast Tumor Progression During Neoadjuvant Chemotherapy: Impact on and Factors Influencing Distant Recurrence-Free Survival

BACKGROUND

Most patients with breast cancer treated with neoadjuvant chemotherapy (NAC) experience clinical benefit, however, a small proportion progress. We aimed to characterize factors predicting in-breast tumor progression and impact on distant recurrence.

PATIENTS AND METHODS

We reviewed all patients with clinical stage I-III breast cancer treated with NAC in 2006-2021 at our institution. We compared in-breast progressive disease (PD), defined as ≥ 20% increase in tumor size, with stable disease (SD) or response. Distant recurrence-free survival (DRFS) was analyzed using the Kaplan-Meier method and Cox proportional hazards regression.

RESULTS

Of 1403 patients, 70 (5%) experienced in-breast PD, 243 (17%) SD, 560 (40%) partial response (PR), and 530 (38%) breast pathologic complete response (breast pCR, ypT0/Tis). The rate of PD varied by tumor subtype (8% in HR+/HER2-, 5% TNBC, 2% HER2+, p < 0.001). With median 48 months follow-up, the rates of DRFS were significantly different according to clinical breast response as follows: PD 56%, SD 68%, PR 82%, or breast pCR 93%, p < 0.001. In patients with PD on multivariable analysis, post-NAC grade (adjusted HR 2.9, p = 0.002) and ypT3-4 category (adjusted HR 2.4, p = 0.03) were the strongest predictors of DRFS. Combining these factors, 23% had neither, 44% had one, and 33% had both, which stratified outcome in PD with 3-year DRFS of 100%, 77%, and 30%, respectively (p < 0.001).

CONCLUSIONS

While in-breast PD during NAC is uncommon (5%), it predicts poor survival. Among patients with in-breast PD, post-NAC tumor grade and T category predict outcomes and may be useful to guide treatment escalation.

Drug-resistant profiles of extracellular vesicles predict therapeutic response in TNBC patients receiving neoadjuvant chemotherapy

BACKGROUND

Predicting tumor responses to neoadjuvant chemotherapy (NAC) is critical for evaluating prognosis and designing treatment strategies for patients with breast cancer; however, there are no reliable biomarkers that can effectively assess tumor responses. Therefore, we aimed to evaluate the clinical feasibility of using extracellular vesicles (EVs) to predict tumor response after NAC.

METHODS

Drug-resistant triple-negative breast cancer (TNBC) cell lines were successfully established, which developed specific morphologies and rapidly growing features. To detect resistance to chemotherapeutic drugs, EVs were isolated from cultured cells and plasma samples collected post-NAC from 36 patients with breast cancer.

RESULTS

Among the differentially expressed gene profiles between parental and drug-resistant cell lines, drug efflux transporters such as MDR1, MRP1, and BCRP were highly expressed in resistant cell lines. Drug efflux transporters have been identified not only in cell lines but also in EVs released from parental cells using immunoaffinity-based EV isolation. The expression of drug resistance markers in EVs was relatively high in patients with residual disease compared to those with a pathological complete response.

CONCLUSIONS

The optimal combination of drug-resistant EV markers was significantly efficient in predicting resistance to NAC with 81.82% sensitivity and 92.86% specificity.

Oncologic Outcomes of Immediate Breast Reconstruction in the Setting of Neoadjuvant Chemotherapy: A Long-term Follow-up Study of a Matched Cohort

PURPOSE

Despite the increasing use of immediate breast reconstruction (IBR), its oncologic safety in the setting of neoadjuvant chemotherapy (NACT) needs to be comprehensively clarified in breast cancer management. The objective of the present study was to analyze the oncologic safety of IBR following NACT.

METHODS

In total, 587 patients with breast cancer who underwent a total mastectomy (TM) with IBR after NACT between 2008 and 2017 at a single institution were retrospectively reviewed. The reviewed patients with IBR following skin-sparing mastectomy (SSM) or nipple-sparing mastectomy (NSM) were matched 1:3 to patients who underwent TM alone after NACT. Matching variables included age, clinical T and N stages before NACT, response to NACT, pathologic T and N stages, and molecular subtypes.

RESULTS

After propensity score matching, 95 patients who underwent IBR following SSM/NSM after NACT (IBR group) and 228 patients who underwent TM alone after NACT (TM group) were selected. The median follow-up period was 73 (range, 5-181) months after matching. After matching, there were no significant differences between the two groups in 5-year locoregional recurrence-free survival (88.8% vs. 91.2%, p = 0.516), disease-free survival (67.3% vs. 76.6%, p = 0.099), distant metastasis-free survival (71.9% vs. 81.9%, p = 0.057), or overall survival (84.1% vs. 91.5, p = 0.061) rates. In multivariate analyses, conducting IBR was not associated with increased risks for locoregional recurrence, any recurrence, distant metastasis, or overall death.

CONCLUSION

Our findings suggest that IBR following SSM/NSM elicits comparable long-term oncologic outcomes to those of TM alone in the setting of NACT.

Localised breast cancer: neoadjuvant chemotherapy impact evaluation on the pathological complete response (PCR) in a lower middle-income country

Introduction

Neoadjuvant chemotherapy followed by surgery remains the current recommended therapeutic strategy for the management of locally advanced breast cancer. The standard chemotherapy protocol is sequential with anthracycline followed by taxanes. However public hospitals in Morocco are confronted with a shortage in healthcare products. We, therefore, evaluated the efficacy of the different protocols proposed to patients, by evaluating the clinical response after chemotherapy especially through the pathological complete response (PCR) after surgery.

Methods

We focused on the database of the medical oncology department of the only public hospital covering middle and southern Morocco. We included patients diagnosed between 2018 and 2020. Two groups of patients distinguished in group A (GA) received the standard therapy, and group B (GB) received a non-standard protocol. The therapeutic response was assessed clinically before surgery and then by pathological examination of the surgical specimens. The Sataloff classification defined the histological response for both tumour and lymph nodes. We included both groups in one variable to determine their impact on outcomes. A logistic regression-based analysis was adopted to define variables related to the PCR.

Results

Over the study period, 120 patients met our inclusion criteria. They were distinguished at 72% in GA and 28% in GB. 60.8% over 120 got a partial response, whereas, only 33.3% achieved a complete response. The general PCR rate was 28% with 14.3% in GB and 85.7% in GA. The tumour PCR was obtained in 40 (33.3%) over 120 patients and 51.7% of lymph node PCR. The multivariate logistic regression analysis results show no relative factors associated with general PCR achievement.

Conclusion

These first interesting results from an institutional database inform us about our clinical practice and require additional research using prospective randomised controlled studies.