The role of postmastectomy radiation in patients with ypN0 breast cancer after neoadjuvant chemotherapy: a meta-analysis

Influence of Postmastectomy Radiotherapy on Overall Survival in Patients With Clinical Prognostic Stage I-III Breast Cancer With Positive Responses and Achieving YPN0 Following Neoadjuvant Therapy: A Propensity Score Matching Based on the SEER Database

INTRODUCTION

The role of postmastectomy radiotherapy (PMRT) in clinical prognostic stage I-III breast cancer patients with positive responses and achieving ypN0 after Neoadjuvant therapy (NAT) is controversial.

METHODS

3557 patients with TNM clinical prognostic stage (AJCC 8th Edition) I-III breast cancer with positive responses and achieving ypN0 following neoadjuvant therapy were selected from the Surveillance, Epidemiology, and End Results (SEER) database and followed through the end of 2020. COX proportional hazards models were employed to examine the associations between clinical or pathological parameters and OS. Propensity score matching (PSM) was employed to control for confounding variables and multiple association inference models were used for progressive sensitivity analysis.

RESULTS

In the multivariate analysis, PMRT did not demonstrate a significant improvement in OS (P = .127), while in univariate analysis, it was linked to worse OS (P < .001). PSM and multiple association inference models indicated that PMRT did not confer any significant improvement in patients' OS (all P > .05). Further stratified analysis of the prematch subgroup revealed that PMRT was linked to the 68% lower risk of mortality in patients with the cN3 subgroup (HR: 0.32; 95%CI, 0.11-0.97), and expressly enhanced the OS in cN3 subgroup patients with ER-, PR-, HER-2- status, and PR to NAT.

CONCLUSIONS

Our research indicated that PMRT did not show any survival benefits for clinical prognostic stage I-III breast cancer patients who had positive responses and achieved ypN0 after NAT. PMRT was linked to the reduction in mortality among patients in the cN3 subgroup.

Pre-operative chemoradiotherapy followed by mastectomy and breast reconstruction-A systematic review of clinical, oncological, reconstructive and aesthetic outcomes

BACKGROUND

Pre-operative radiotherapy (PRT) and pre-operative chemoradiotherapy (PCRT) prior to mastectomy and immediate breast reconstruction for locally advanced breast cancer have the potential to reduce radiation late-effects and expedite oncologic treatment. Recent feasibility work indicates that PCRT is safe and technically possible. Here, we present a systematic review of currently available data on clinical, oncological, reconstructive and aesthetic outcomes.

METHODS

A prospectively registered search of Medline (Ovid), EMBASE (Ovid), EMCARE (Ovid) and CINAHL (EBSCO) databases was performed in August 2023. Clinical, oncological, reconstructive and aesthetic outcomes were appraised with risk of bias (ROBINS-I) and methodological quality determined (STROBE checklist) for each study.

RESULTS

Twenty-two published articles (19 journal articles and 3 abstracts) were identified reporting the outcomes of 1258 patients with median follow-up between 19.0-212.4 months. Patients received neoadjuvant chemotherapy in 20 studies. Rates of locoregional recurrence and overall survival ranged between 0-21.7% and 82.0%-98.3% respectively. Rates of flap loss or necrosis ranged from 0-7.6%. Rates of revisional procedures ranged between 1.9-35.3%. Patient-reported outcomes were reported in 7 studies and were mostly 'good' or 'excellent'.

CONCLUSION

PRT and PCRT preceding mastectomy and breast reconstruction produce acceptable oncological outcomes with rates of surgical complication and reconstructive outcomes within normal limits, however, the majority of available studies are of low methodological quality and at high risk of bias. A pragmatic randomised trial comparing PRT versus PMRT in the setting of breast reconstruction is now urgently required to guide surgical practice.

Is postmastectomy radiotherapy necessary for breast cancer patients with clinically node-positive downstaging to ypN0 after neoadjuvant chemotherapy?

PURPOSE

The significance of postmastectomy radiotherapy (PMRT) in breast cancer patients who initially have clinically node-positive (cN +) status but achieve downstaging to ypN0 following neoadjuvant chemotherapy (NAC) remains uncertain. This study aims to assess the impact of PMRT in this patient subset.

METHODS

Patients were enrolled from West China Hospital, Sichuan University from 2008 to 2019. Overall survival (OS), Locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), and breast cancer-specific survival (BCSS) were estimated using the Kaplan-Meier method and assessed with the log-rank test. The impact of PMRT was further analyzed by the Cox proportional hazards model. Propensity score matching (PSM) was performed to reduce the selection bias.

RESULTS

Of the 333 eligible patients, 189 (56.8%) received PMRT, and 144 (43.2%) did not. At a median follow-up period of 71 months, the five-year LRFS, DMFS, BCSS, and OS rates were 99.1%, 93.4%, 96.4%, and 94.3% for the entire cohort, respectively. Additionally, the 5-year LRFS, DMFS, BCSS, and OS rates were 98.9%, 93.8%, 96.7%, and 94.5% with PMRT and 99.2%, 91.3%, 94.9%, and 92.0% without PMRT, respectively (all p-values not statistically significant). After multivariate analysis, PMRT was not a significant risk factor for any of the endpoints. When further stratified by stage, PMRT did not show any survival benefit for patients with stage II-III diseases.

CONCLUSION

In the context of comprehensive treatments, PMRT might be exempted in ypN0 breast cancer patients. Further large-scale, randomized controlled studies are required to investigate the significance of PMRT in this patient subset.

Survival benefits of postoperative radiotherapy in patients with cT1 - 2N1M0 breast cancer after neoadjuvant chemotherapy: a SEER-based population study

BACKGROUND

Whether patients with cT1 - 2N1M0 breast cancer can benefit from postoperative radiotherapy (RT) after receiving neoadjuvant chemotherapy (NAC) has been controversial. Therefore, the purpose of this study was to explore whether postoperative RT can benefit this group of patients in terms of survival.

METHODS

We used Surveillance, Epidemiology, and End Results (SEER) data to conduct a retrospective review of women with cT1 - 2N1M0 breast cancer diagnosed between 20 and 80 years of age who received NAC between 2010 and 2015. Our study compared the impact of postoperative RT on overall survival (OS) and cancer-specific survival (CSS) in breast cancer patients using propensity score matching (PSM) and performed subgroup analysis.

RESULTS

This study finally included 1092 cT1 - 2N1M0 breast cancer patients. Regardless of the patient's PSM status, postoperative RT was significantly associated with OS of cT1-2N1M0 breast cancer patients who received NAC. Specifically, the 10-year OS rate was 78.7% before PSM matching, compared with 71.1% in patients who did not receive postoperative RT, and the difference was more significant after PSM matching, which was 83.1% and 71.1% respectively. However, postoperative RT did not significantly benefit CSS in patients with cT1 - 2N1M0 breast cancer who received NAC. The 10-year CSS rate was 81.4% VS 76.2% (P = 0.085) before PSM matching and 85.8% VS 76.2%(P = 0.076) after matching. Due to the intersection of OS and CSS curves, this restricted mean survival time (RMST) method was chosen as a supplement. After 60 months, the OS difference in RMST between the postoperative RT group and the non-radiotherapy (noRT) group was 7.37 months (95%CI: 0.54-14.21; P = 0.034), and the CSS difference was 5.18 months (95%CI: -1.31-11.68; P = 0.118). Subgroup analysis found that in patients with right-sided breast cancer, postoperative RT improved the patient's OS (HR = 0.45, 95%CI: 0.21-0.95, P = 0.037) and CSS (HR = 0.42, 95%CI: 0.18-0.98, P = 0.045).

CONCLUSIONS

Our results showed that additional postoperative RT improved the OS of cT1 - 2N1M0 breast cancer patients who received NAC, but failed to improve their CSS. It is worth noting that in the subgroup analysis of patients with right-sided breast cancer, we observed significant improvements in OS and CSS. And further prospective studies are still needed to verify the effect of postoperative RT in different subgroups.

Recommandations francophones pour la pratique clinique concernant la prise en charge des cancers du sein de Saint-Paul-de-Vence 2022-2023

With more than 60,000 new cases of breast cancer in mainland France in 2023 and 8% of all cancer deaths, breast cancer is the leading cancer in women in terms of incidence and mortality. While the number of new cases has almost doubled in 30 years, the percentage of patients at all stages alive at 5 years (87%) and 10 years (76%) testifies to the major progress made in terms of screening, characterisation and treatment. However, this progress, rapid as it is, needs to be evaluated and integrated into an overall strategy, taking into account the characteristics of the disease (stage and biology), as well as those of the patients being treated. These are the objectives of the St Paul-de-Vence recommendations for clinical practice. We report here the summary of the votes, discussions and conclusions of the Saint-Paul-de-Vence 2022-2023 RPCs.

Axillary response and outcome in breast cancer patients after neoadjuvant treatment: The role of radiotherapy in reducing recurrence in ypN0 patients with initially cN+ stage

Objective

We aim to explore the clinicopathological features associated with axillary node response and recurrence in breast cancer patients undergoing neoadjuvant treatment (NAT).

Methods

We retrospectively reviewed the medical records of 486 stage I to III breast cancer patients who received NAT and surgery between 2016 and 2021.

Results

A total of 486 cases were reviewed and 154 (31.7%) patients achieved breast pathological complete response (pCR) (ypT0/Tis). Of the 366 cases with initially cN+, 177 (48.4%) cases reach ypN0. Breast pCR is in high accordance to axillary pCR (81.5%). Hormone receptor (HR)-/HER2+ breast cancer patients have the highest axillary pCR rate (78.3%). Patients achieve axillary pCR have a significantly better disease-free survival (DFS) (P=0.0004). Further analysis reveals that the DFS of ypN0 and ypN1 cases are similar (P=0.9049). Moreover, DFS in patients with ypN0 (P&lt;0.0001) and ypN1 (P&lt;0.0001) is significantly better than that in patients with ypN2-3. For post-mastectomy ypN0 cases, radiation could only improve DFS in patients with initially cN+ stage (P=0.0499). Multivariate Cox regression analysis shows that radiation is an independent factor to improve DFS (Hazard ratio (HR): 0.288(0.098-0.841), P=0.0230). Radiation does not improve DFS in pre-cN0/ypN0 patients (P=0.1696).

Conclusion

Axillary pCR rate is higher than breast pCR rate. HR-/HER2+ patients have the highest axillary pCR rate. Axillary pCR is associated with better DFS. Radiation could further improve DFS in ypN0 patients with initially positive nodal disease.

Regional radiotherapy after primary systemic treatment for cN+ breast cancer patients

Pathologic complete response (pCR) after Primary Systemic Treatment (PST) for breast cancer is associated with excellent long-term outcomes. With increasing use of PST, the indication for regional nodal irradiation (RNI) has been challenged. The aim of this paper is to review the literature on de-escalation of RNI in patients treated with PST. We found no level 1 evidence on de-escalation of RNI after PST, but several randomized trials are ongoing. Consequently, current de-escalation strategies are based on cohort studies. These studies showed that in patients with low nodal tumour burden (LNTB) (≤3 suspicious nodes at imaging) prior to PST, and ypN0 based on Axillary Lymph Node Dissection (ALND), omission of RNI resulted in very low regional recurrences (RR) without compromising survival. In patients with LNTB and ypN0 based on Sentinel Lymph Node Biopsy (SLNB), omission of axillary treatment also resulted in low RR; the majority of these patients received local radiotherapy. Similarly, in patients with ypN1 (ALND) disease, omission of RNI resulted in low 5-year RR rates. Low RR-rates were also found in the few studies replacing ALND by RNI, in patients with ypN1 (SLNB) disease. In patients with high nodal tumour burden prior to PST and ypN0 (SLNB), replacing ALND by RNI also resulted in low RR. Due to the limited number of patients, these data should be interpreted with caution. We conclude that although level 1 evidence is lacking, de-escalation of RNI after PST can be considered in selected cases.

The impact of postmastectomy radiotherapy on cT1-2N1 breast cancer patients with ypN0 after neoadjuvant chemotherapy: a retrospective study based on real-world data

BACKGROUND

The role of postmastectomy radiation therapy (PMRT) in clinical T1-2N1 breast cancer patients who achieve axillary pathological complete response (ypN0) after neoadjuvant chemotherapy (NAC) is controversial.

METHODS

Data from cT1-2N1 breast cancer patients who converted to ypN0 after NAC and subsequent surgery were retrospectively analyzed. Disease-free survival (DFS) and overall survival (OS) were estimated using the Kaplan‒Meier method. Univariate and multivariate Cox regression models were applied to investigate the correlations between clinical or pathological parameters and survival.

RESULTS

From 2012-2019, we identified 116 cases for analysis, including 31 (26.7%) who received PMRT and 85 (73.3%) who did not. At a median follow-up time of 56.4 months, the 5-year DFS and OS rates were 90.2% and 96.7% with PMRT and 93.7% and 97.3% without PMRT, respectively. PMRT did not affect either DFS (p = 0.234) or OS (p = 0.878). On multivariate analyses, no differences in DFS or OS between the two groups were detected, taking into consideration the following factors: age, molecular subtype, Ki67 index, cT stage, and in-breast pathologic complete response (DFS: HR 2.260; 95% CI 0.465-10.982; p = 0.312. OS: HR 1.400; 95% CI 0.138-14.202; p = 0.776). This nonsignificant difference was also consistent in subgroup analyses (all p > 0.05).

CONCLUSIONS

PMRT has limited ability to confer DFS or OS benefits for cT1-2N1 breast cancer patients who achieved axillary pathological complete response after NAC and total mastectomy. It is imperative to conduct prospective studies to investigate the safety and feasibility of omitting PMRT.

TRIAL REGISTRATION

This research was approved by the Ethics Committee of The First Affiliated Hospital of Chongqing Medical University (ID: No. 2021-442).

Impact of adjuvant chemotherapy on T1N0M0 breast cancer patients: a propensity score matching study based on SEER database and external cohort

BACKGROUND

There is no clear consensus on the benefits of adjuvant chemotherapy for tumor-node-metastasis (TNM) stage T1 (T1N0M0) breast cancer (BC). Our study investigated the effects of adjuvant chemotherapy on T1N0M0 BC patients.

METHODS

Seventy-five thousand one hundred thirty-nine patients diagnosed with T1N0M0 BC were selected from the Surveillance, Epidemiology, and End Results (SEER) database. Multivariate Cox analyses were performed to investigate the effects of adjuvant chemotherapy on T1a, T1b, and T1cN0M0 BC, including various tumor grades, and four molecular subtypes. Propensity score matching (PSM) was used to eliminate confounding factors and further compare the results between adjuvant chemotherapy and no adjuvant chemotherapy. Additionally, 545 T1N0M0 BC patients treated at the Northern Jiangsu People's Hospital were included as an independent external validation cohort. Univariate and multivariate Cox analyses were used to confirm the effects of adjuvant chemotherapy in T1a, T1b, and T1cN0M0 BC. Survival curves for the different tumor grades and molecular subtypes were plotted using the Kaplan-Meier method.

RESULTS

Adjuvant chemotherapy demonstrated a statistically significant improvement in overall survival (OS) in T1b and T1c BC, but not in T1a BC. Within T1b BC, adjuvant chemotherapy was found to have effects on grade III, and hormone receptor + (HoR +)/human epidermal growth factor receptor 2 + (HER2 +), HoR-/HER2 + , and HoR-/HER2- molecular subtypes, respectively. Adjuvant chemotherapy was beneficial to OS for grade II/III and T1c BC. Identical results were obtained after PSM. We also obtained similar results with external validation cohort, except that adjuvant chemotherapy made a difference in grade II and T1b BC of the external validation dataset.

CONCLUSIONS

Partial T1N0M0 BC patients with grade III T1bN0M0, patients with tumor grade II and III T1cN0M0, and excluding those with HoR + /HER2- subtype tumors, could obtain OS benefits from adjuvant chemotherapy.

Impact of time to initiation of postoperative radiotherapy after neoadjuvant chemotherapy on the prognosis of breast cancer: a retrospective cohort study in China

The optimal time to the initiation of postoperative radiotherapy (TTR) in breast cancer patients after neoadjuvant chemotherapy (NAC) and surgery is unclear. We explored the association between TTR and outcomes among breast cancer females to determine the optimal timing for radiotherapy. We included 1022 women with breast cancer who underwent NAC and surgery between 1997 and 2019. Patients were categorized into three groups based on the TTR: <8 weeks, 8-16 weeks, and > 16 weeks. We used Cox proportional hazards models and analyzed the hazard ratios (HRs) for breast cancer-specific mortality (BCSM) and all-cause mortality (ACM). The median TTR for the cohort was 97 days. Compared to patients with TTRs of 8-16 weeks, those with TTRs <8 weeks or > 16 weeks had an increased risk of BCSM (HR, 2.59; 95% confidence interval [CI], 1.26-5.36 and HR, 2.01; 95% CI, 1.24-3.28, respectively) and ACM (HR, 2.32; 95% CI, 1.17-4.56 and HR, 1.92; 95% CI, 1.24-2.98, respectively) after adjusting for the confounders. Furthermore, at TTR of >16 weeks, each additional week of TTR was associated with a 3% increase in BCSM risk and 2% increase in ACM risk. Our findings suggest that patients who have undergone NAC and surgery show lower BCSM and ACM risks at TTR of 8-16 weeks compared with <8 weeks or > 16 weeks. This article is protected by copyright. All rights reserved.