Postmastectomy Radiation Therapy Based on Pathologic Nodal Status in Clinical Node-Positive Stage II to III Breast Cancer Treated with Neoadjuvant Chemotherapy

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.

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.

Post-mastectomy Radiation Therapy in HER-2 Positive Breast Cancer after Primary Systemic Therapy: Pooled Analysis of TRYPHAENA and NeoSphere Trials

PURPOSE

The role of post-mastectomy radiation therapy (PMRT) following primary systemic therapy (PST) in HER-2 positive breast cancer (Her2+BC) remains poorly understood. The current study evaluates PMRT based on the pathological response to PST in Her2+BC.

METHODS AND MATERIALS

TRYPHAENA and NeoSphere are randomized phase II trials that investigated PST for Her2+BC. Our study is a pooled analysis of both trials, including 312 node-positive patients treated with HER-2 targeted PST followed by mastectomy with or without PMRT. The primary endpoint is loco-regional recurrence-free survival (LRRFS).

RESULTS

Our analysis included 172 (55%) patients who achieved complete nodal pathological response (ypN0) and 140 (45%) patients who did not. Patients with ypN0 had a 5-year LRRFS of 97% in both, the PMRT and no PMRT, groups (p=0.94). Patients with ypN+ had 5-year LRRFS of 89% in the PMRT group and 82% in the no PMRT group (p=0.17). Patients with ypN1 (n=62) disease who received PMRT (n=40) had a 5-year LRRFS of 85% as compared to 89% in those who did not (n=22); (p=0.60). A significant LRRFS difference was noted in patients with ypN2-3 (n=78) disease who received PMRT (n=53) compared to those who did not (n=25) (5-year LRRFS 92% vs. 75%; p=0.019). On multivariate analysis, clinical nodal disease at diagnosis and ypN0 were significantly associated with loco-regional recurrence (LRR).

CONCLUSIONS

Her2+BC patients who achieve ypN0 after PST have excellent locoregional-control which supports de-escalation of PMRT. In contrast, patients with ypN2-3 disease derive significant benefit from PMRT. Clinical nodal stage at presentation and ypN0 status are significantly associated with LRR risk in Her2+BC.

Level I axillary dissection in patients with breast cancer and tumor-involved sentinel lymph node after NAC is not sufficient for adequate nodal staging

Objectives

The purpose of the study was to investigate the oncological sufficiency of level I axillary dissection for adequate histological nodal staging (ypN) in patients with breast cancer and tumor-involved sentinel lymph node (SLN) after neoadjuvant chemotherapy (NAC).

Material and Methods

A prospective multicentre pilot study took place from 01.01.2018 to 30.11.2020 in three mammary centres in the Czech Republic in patients with breast cancer after NAC (NCT03556397). Patients in the cohort with positive histological frozen section of SLN were indicated to separate axillary dissection of levels I and II.

Results

Sixty-one patients with breast cancer after NAC were included in the study according to inclusion and exclusion criteria. Twelve patients with breast cancer and tumour involved SLN after NAC were further included in the analysis. Two (16.7%) patients had positive non-sentinel lymph nodes in level I only, one (8.3%) patient had positive lymph nodes in level II only, and seven (58.3%) patients had positive lymph nodes in both levels. Level I axillary dissection in a patient with tumour involved SLN after NAC would have resulted in understaging in five (41.7%) patients, mostly ypN1 instead of ypN2.

Conclusion

According to our pilot result, level I axillary dissection is not sufficient in terms of adequate histological nodal staging in breast cancer patients after NAC, and level II axillary dissection should not be omitted.

The prognostic differences and the effect of postmastectomy radiotherapy between post-chemotherapy ypT1-2ypN1 and de novo pT1-2N1 breast cancer

BACKGROUND

The prognosis and the value of postmastectomy radiotherapy (PMRT) between post-chemotherapy ypT1-2ypN1 and de novo pT1-2N1 breast cancer (BC) remain controversial. We aimed to evaluate the prognostic differences and the effect of PMRT between the two patient subsets.

METHODS

Patients diagnosed with pT1-2N1M0 BC were identified between 2010 and 2018. The study endpoints were overall survival (OS), breast cancer-specific survival (BCSS), locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS) and disease-free survival (DFS). The chi-square test, Kaplan-Meier method and Cox regression analysis were used for data analysis.

RESULTS

Total number of 2103 pT1-2N1M0 BC patients were included in the study, including 270 post-chemotherapy (97 without PMRT, 173 with PMRT) and 1833 de novo cases (993 without PMRT, 840 with PMRT). No significant differences were found between post-chemotherapy ypT1-2ypN1 and de novo pT1-2N1 BC patients in 5-year OS (p = 0.068), BCSS (p = 0.054), LRFS (p = 0.241), DMFS (p = 0.104) or DFS (p = 0.08). PMRT did not improve any survival outcome in patients receiving neoadjuvant chemotherapy; however, the PMRT group had a better 5-year BCSS (97.0% vs. 95.8%, p = 0.033) in de novo pT1-2N1 BC. Cox multivariate analysis demonstrated that PMRT was a significant independent predictor of BCSS (HR 0.628; 95% CI, 0.403-0.978; p = 0.04) in de novo pT1-2N1 patients.

CONCLUSIONS

There seemed no survival difference in post-chemotherapy ypT1-2ypN1 and de novo pT1-2N1 BC patients with contemporary systemic therapy. In addition, PMRT might be exempted in patients with post-chemotherapy ypT1-2ypN1 BC, while not in patients with de novo pT1-2N1 BC.

Radiation therapy on the axilla after neoadjuvant chemotherapy

PURPOSE OF REVIEW

The introduction of primary systemic therapy has established a new treatment paradigm for breast cancer patients. However, recommendations for regional node irradiation after neoadjuvant chemotherapy are not supported by level I evidence, yet.

RECENT FINDINGS

In addition to strategies optimising systemic treatments and surgery, current discussions focus on tailoring radiation therapy for breast cancer. Especially in view of the increasingly pivotal role of neoadjuvant chemotherapy, gauging the extent of radiation therapy in the breast and nodal volumes.

SUMMARY

The current review focuses on recent evidence regarding radiation therapy of the breast and axilla in patients receiving neoadjuvant chemotherapy for primary breast cancer based on a PubMed and EMBASE literature search for publication years 2020-2022.

Adjuvant locoregional radiation therapy in breast cancer patients with pathologic complete response after neoadjuvant chemotherapy: A systematic review and meta-analysis

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Adjuvant locoregional radiation therapy (LRRT) is standard of care in pN+ breast cancer.

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Adjuvant LRRT in pN0 after neoadjuvant chemotherapy (NACT) is controversial.

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Thirteen studies were found to be eligible to a meta-analysis.

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Adjuvant LRRT seems to almost halve the risk for locoregional recurrence.

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No improvement in disease-free or overall survival was observed.

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The current level of evidence is low.

Purpose

The aim of the present meta-analysis was to investigate the impact of adjuvant locoregional radiation therapy (LRRT) in breast cancer patients with clinical lymph node metastatic disease achieving ypN0 after neoadjuvant chemotherapy (NACT).

Materials and methods

A systematic review of studies on PubMed was performed. A meta-analysis was conducted by computing extracted hazard ratios (HRs) and 95% confidence intervals (CIs) into a fixed-effects model.

Results

Thirteen studies were included in the meta-analysis. Adjuvant LRRT significantly reduced the risk of locoregional recurrence (LRR) in patients with N+ at diagnosis and ypN0 (HR 0.59; 95% CI 0.42–0.81). However, no statistically significant difference on disease-free survival (DFS) or overall survival (OS) was found.

Conclusions

LRRT significantly reduced the risk of LRR in patients with ypN0 after NACT whereas no impact on DFS or OS was observed. The low level of evidence should be considered when interpreting the results in clinical practice.

Mitochondrial dysfunction is involved in the cellular activity inhibition by eleutheroside B in SMMC-7721 and HeLa cells

Eleutheroside B, also known as syringin, has been shown to have various pharmacological activities such as anti-inflammatory, anti-irradiation and antidepressant, but there are few studies on its anti-cancer activity. Its anti-tumor effect on SMMC-7721 cells has not been revealed. Moreover, whether it induces autophagy is still unclear. Thus, the present study investigated whether Eleutheroside B induces apoptosis, autophagy and cellular motility in SMMC-7721 cells and HeLa cells, and explored the underlying molecular mechanisms. SMMC-7721 cells and HeLa cells treated with Eleutheroside B and cell viability measured by MTT assay and trypan blue dye exclusion assay. Apoptosis checked by flow cytometry combined, fluorescent staining. Apoptotic signal proteins and autophagy proteins were checked by Western blot. This study showed that Eleutheroside B inhibited the cell proliferation and blocked cell cycle, migration and invasion as well. Moreover, Eleutheroside B induced apoptosis in SMMC-7721 cells and HeLa cells. It upregulated Bax expression, while simultaneously decreasing Bcl-2 expression. Further elucidation of the mechanism revealed that Eleutheroside B induced mitochondrial dysfunction, with mitochondrial membrane potential collapse and cytochrome c release, suggesting that Eleutheroside B induced apoptosis by triggering mitochondrial pathway. Most importantly, Eleutheroside B could induce autophagy in SMMC-7721 cells and HeLa cells. Taken together, these results suggested Eleutheroside B is a potential therapeutic candidate for HCC and Human cervical cancer.

The Impact of Post-Mastectomy Radiotherapy on Survival Outcomes in Breast Cancer Patients Who Underwent Neoadjuvant Chemotherapy

Simple Summary

The benefits of post-mastectomy radiotherapy (PMRT) may vary depending on patients’ responses to neoadjuvant chemotherapy (NAC), although PMRT is useful for patients who underwent NAC. One can consider omitting PMRT in patients who have achieved pathologic complete response or who have minimal residual disease, with a neoadjuvant response index value of 0.7–1.0.

Abstract

This study aimed to determine whether post-mastectomy radiotherapy (PMRT) is beneficial for the prognosis of patients who achieved pathologic complete response (pCR), or who had minimal residual disease, after undergoing neoadjuvant chemotherapy (NAC). Patients who underwent a total mastectomy between 2006 and 2018, after NAC, were included. Patients who did not receive PMRT were matched using 1:3 propensity score matching (PSM). Kaplan–Meier survival curves were used to compare locoregional recurrence-free survival (LRRFS) and overall survival (OS). A total of 368 patients were included after 1:3 PSM. PMRT improved the LRRFS (p = 0.016) and OS (p = 0.017) rates of patients who underwent NAC. However, PMRT did not affect the prognosis of patients with pCR (LRRFS: p = 0.999; OS: p = 0.453). In addition, PMRT had a limited effect on LRRFS and OS in patients who responded well to NAC, with a neoadjuvant response index (NRI) value of 0.7–1.0 (LRRFS: p = 0.568; OS: p = 0.875). PMRT improved the OS of patients with a large residual tumor burden, such as nodal metastases or pathologic stage II/III. The benefits of PMRT vary depending on the patients’ response to NAC, although PMRT is useful for treating patients who underwent NAC. PMRT can be omitted, not only in patients with pCR, but also in good responders with an NRI value of 0.7–1.0.