Outcomes of Stage I and II Breast Cancer with Nodal Micrometastases Treated with Mastectomy without Axillary Therapy

Effect of post-mastectomy radiation therapy on survival in breast cancer with lymph nodes micrometastases: a meta-analysis and systematic review

Background

Axillary management of patients with early-stage breast cancer (ESBC) has evolved, especially with the implementation of precision radiotherapy techniques that have resulted in a significant reduction in treatment-related toxicities, but it is unclear whether post-mastectomy radiotherapy (PMRT) improves survival outcomes in breast cancer with lymph nodes micrometastases (BCLNMM, that is T0, T1 ~2NmiM0). Our study is to systematically evaluate the effect of PMRT on survival in breast cancer with lymph nodes micrometastases.

Methods

A literature search was performed for randomized controlled trials (RCTs) or retrospective studies related to PMRT versus non-post-mastectomy radiotherapy (non-PMRT) in the adjuvant treatment of ESBC in PubMed, Cochrane Library, Embase, CNKI and other databases. R package meta software was used to perform meta-analyses with hazard ratio (HR). Newcastle Ottawa scale was selected for quality assessment. The review was prospectively registered on PROSPERO (CRD42024562444).

Results

10 relevant studies were screened, all of which were retrospective studies. The difference in overall survival (OS) was not statistically significant (HR = 0.92, 95%CI: 0.81 ~ 1.04; Z = 1.35, P = 0.177). The difference in breast cancer-specific survival (BCSS) between the PMRT group and the non-PMRT group was not statistically significant HR = 1.18, 95%CI: 0.94 ~ 1.48; Z = 1.41, P =0.160). The difference in disease-free survival (DFS) was statistically significant (HR = 0.47, 95%CI: 0.23 ~ 1.00; Z = 1.96, P =0.049). The difference in local recurrence free survival (LRRFS) was also not statistically significant (HR = 0.50, 95%CI: 0.11 ~ 2.26, P = 0.190). The difference in distant-metastasis free survival (DMFS) was not statistically significant (HR = 0.54, 95%CI: 0.22 ~ 1.35, P = 0.356).

Conclusions

Despite the tendency of PMRT in BCLNMM to improve DFS, OS, BCSS, LRRFS, and DMFS showed no benefit, therefore, PMRT should be used with caution in BCLNMM.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42024562444.

A nomogram to predict the benefit of postmastectomy radiotherapy in breast cancer with nodal micrometastases

BACKGROUND

The role of postmastectomy radiotherapy (PMRT) in breast cancer (BC) with nodal micrometastases (N1mic) remains unclear. This study aimed to evaluate the efficacy of PMRT in T1-2N1mic BC patients who have undergone mastectomy.

METHODS

Female patients with T1-2N1mic BC who underwent mastectomy and were registered in the Surveillance, Epidemiology, and End Results database between 2010 and 2017. The chi-square test, logistic regression analysis, Kaplan-Meier methods, and multivariate Cox proportional hazards analysis were used for statistical analyses. Nomograms for predicting breast cancer-specific survival (BCSS) and overall survival (OS) were created by integrating the independent prognostic factors.

RESULTS

A total of 5948 eligible patients were included in this study. A total of 1207 patients (20.3%) received PMRT, while 4741 patients (79.7%) did not. The use of PMRT increased over the study period, from 15.7% in 2010 to 23.8% in 2017 (P < 0.001). The multivariate Cox proportional hazards analysis showed that PMRT did not improve BCSS and OS. Nomograms were established based on the independent prognostic factors to predict the BCSS and CSS of patients. Regarding BCSS, there were 3627 patients (61.0%) classified as low-risk and 2321 patients (39.0%) classified as high-risk using a cutoff point of 125, PMRT did not improve BCSS in patients with low-risk (P = 0.697) and high-risk (P = 0.149) groups. Regarding OS, there were 4791 patients (80.5%) classified as low-risk and 1157 patients (19.5%) classified as high-risk using a cutoff point of 130, patients who received PMRT had significantly better 5-year OS than those who did not receive PMRT (P = 0.047), while similar outcomes were found between the treatment arms in the low-risk group (P = 0.575).

CONCLUSIONS

While our findings suggest that PMRT does not enhance survival outcomes in T1-T2N1mic BC patients, it may offer a survival advantage in high-risk subgroups.

Axillary management in patients with clinical node-negative early breast cancer and positive sentinel lymph node: a systematic review and meta-analysis

Background

The omission of axillary lymph node dissection (ALND) or axillary radiation (AxRT) remains controversial in patients with clinical node-negative early breast cancer and a positive sentinel lymph node.

Methods

We conducted a comprehensive review by searching PubMed, Embase, Web of Science, and Cochrane databases (up to November 2023). Our primary outcomes were overall survival (OS), disease-free survival (DFS), locoregional recurrence (LRR), and axillary recurrence (AR).

Results

We included 26 studies encompassing 145,548 women with clinical node-negative early breast cancer and positive sentinel lymph node. Pooled data revealed no significant differences between ALND and sentinel lymph node biopsy (SLNB) alone in terms of OS (hazard ratio [HR]0.99, 95% confidence interval [CI] 0.91-1.08, p=0.84), DFS (HR 1.04, 95% CI 0.90-1.19, p=0.61), LRR (HR 0.76, 95% CI 0.45-1.20, p=0.31), and AR (HR 1.01, 95% CI 0.99-1.03, p=0.35). Similarly, no significant differences were observed between AxRT and SLNB alone for OS (HR 0.57, 95% CI 0.32-1.02, p=0.06) and DFS (HR 0.52, 95% CI 0.26-1.05, p=0.07). When comparing AxRT and ALND, a trend towards higher OS was observed the AxRT group (HR 0.08, 95% CI 0.67-1.15), but the difference did not reach statistical significance (p=0.35, I2 = 0%). Additionally, no significant differences significance observed for DFS or AR (p=0.13 and p=0.73, respectively) between the AxRT and ALND groups.

Conclusion

Our findings suggest that survival and recurrence rates are not inferior in patients with clinical node-negative early breast cancer and a positive sentinel lymph node who receive SLNB alone compared to those undergoing ALND or AxRT.

Can Axillary Lymph Node Dissection be Omitted in Breast Cancer Patients with Metastatic Sentinel Lymph Nodes Undergoing Mastectomy? A Systematic Review and Meta-Analysis of Real-World Evidence

BACKGROUND

The omission of axillary lymph node dissection (ALND) in patients with breast cancer who have metastatic sentinel lymph nodes (SLNs) undergoing mastectomy remains controversial. This meta-analysis explored the clinicopathological factors affecting the selection of ALND and the influences of ALND on survival outcomes in patients receiving mastectomy with positive SLNs.

METHODS

Eligible studies published prior to 31 December 2022 were selected by searching the Embase, Web of Science and PubMed databases. Pooled analyses were performed using the number of events for clinicopathological parameters and HRs with 95% CIs for survival outcomes including disease-free survival (DFS), overall survival (OS), distant recurrence-free survival (DRFS) and locoregional recurrence-free survival (LRFS).

RESULTS

A total of 10 retrospective studies enrolling only breast cancer patients with limited SLN metastases (no more than 3 positive SLNs or micrometastatic SLNs) undergoing mastectomy were included. Performing ALND in mastectomy patients who had limited SLN metastases was significantly correlated with invasive ductal carcinomas, larger tumors, lymphovascular invasion, higher tumor grade, macrometastatic SLNs, more positive SLNs, extranodal extension, positive surgical margins, negative ER, administration of adjuvant chemotherapy and nonwhite race (P < 0.05). However, performing ALND did not result in significantly longer OS, DFS, LRFS or DRFS (P > 0.05) in these patients.

CONCLUSION

The present meta-analysis indicated that ALND may be safely avoided in patients with breast cancer who had limited SLN metastases undergoing mastectomy. Further well-designed randomized clinical trials are warranted to validate our results.

Prognosis and local treatment strategies of breast cancer patients with different numbers of micrometastatic lymph nodes

BACKGROUND

Lymph node micrometastasis is an important prognostic factor in breast cancer, but patients with different numbers of involved lymph nodes are all divided into the same N1mi stage without distinction. We designed this study to compare the prognosis and local treatment recommendations of N1mi breast cancer patients with different numbers of micrometastatic lymph nodes.

PATIENTS AND METHODS

A total of 27,032 breast cancer patients with T1-2N1miM0 stage from the Surveillance, Epidemiology, and End Results (SEER) database (2004-2019) who underwent breast surgery were included in this retrospective study. Patients were divided into three groups for prognosis comparison according to the number of micrometastatic lymph nodes: N1mi with 1 (Nmi = 1), 2 (Nmi = 2), or more (Nmi ≥ 3) involved lymph nodes. We explored the characteristics and survival outcomes of the population receiving different local treatments, including different axillary surgery types and whether receiving radiotherapy or not. Univariate and multivariate Cox proportional hazards regression analysis were used to compare the overall survival (OS) and breast cancer-specific survival (BCSS) in different groups. Stratified analyses and interaction analyses were also applied to explore the predictive significance of different involved lymph nodes numbers. Propensity score matching (PSM) method was utilized to balance the differences between groups.

RESULTS

Univariate and multivariate Cox regression analysis indicated that nodal status was an independent prognostic factor. After adjustment for other prognostic factors, there was a significant difference in prognosis between Nmi = 1 group and Nmi = 2 group [adjusted hazard ratio (HR) 1.145, 95% confidence interval (CI): 1.047-1.251, P = 0.003], and patients with Nmi ≥ 3 group had a significantly poorer prognosis (adjusted HR 1.679, 95% CI 1.589-2.407; P < 0.001). The proportion of N1mi patients only underwent sentinel lymph nodes biopsy (SLNB) gradually increased from 2010 (P_trend < 0.001). After adjusting for other factors, N1mi patients who underwent axillary lymph nodes dissection (ALND) was associated with significant survival benefit than SLNB (adjusted HR 0.932, 95%CI 0.874-0.994; P = 0.033), the same goes for receiving radiotherapy (adjusted HR 1.107, 95%CI 1.030-1.190; P = 0.006). Further stratified analysis showed that in the SLNB subgroup, radiotherapy was associated with a significant survival benefit (HR 1.695, 95%CI 1.534-1.874; P < 0.001), whereas in the ALND subgroup, there was no significant prognostic difference with or without radiotherapy (HR 1.029, 95%CI 0.933-1.136; P = 0.564).

CONCLUSION

Our study indicates that the increasing number of lymph node micrometastases was associated a worse prognosis of N1mi breast cancer patients. In addition, ALND does provide a significant survival benefit for these patients, while the benefit from local radiotherapy may be of even greater importance.