Reply to I.A. Voutsadakis et al and A. Goyal et al

External Validation of the SERC Trial Population: Comparison with the Multicenter French Cohort, the Swedish and SENOMIC Trial Populations for Breast Cancer Patients with Sentinel Node Micro-Metastasis

Simple Summary

After the results of many trials, it is now accepted to omit axillary dissection in selected patients with limited axillary involvement. However, the external validity of these trials is questionable. Our study aimed to evaluate the accuracy of the real French population representativity in the SERC (Sentinelle Envahi et Randomisation du Curage) trial population for patients with breast cancer (BC) associated with sentinel node (SN) micro-metastasis and the differences between the studied population and the real French population. The secondary aim was to compare the French and the Swedish populations of patients with SN micro-metastasis. The findings of our study in addition to the previously demonstrated concordance between the SENOMIC (Sentinelle node Micrometastasis) trial and the Swedish National Breast Cancer Registry (NKBC) populations implied that the results of both the SERC and the SENOMIC trials can be applied to both the French and Swedish real populations.

Abstract

Many trials confirmed the safety of omitting axillary dissection in the selected patients treated for early breast cancer. The external validity of these trials is questionable. Our study aimed to evaluate the accuracy of the French population representativity in the SERC trial and the differences between these two populations as well as comparing the French and the Swedish populations (the SENOMIC trial population and the Swedish National Breast Cancer Registry (NKBC) cohort) of patients with sentinel node (SN) micro-metastasis. A higher rate of smaller tumors and grade 1 tumors was observed in the French cohort when compared to the SERC population. Our findings conclude that both French populations show similar characteristics. Positive non-sentinel node (NSN) rates at completion axillary lymph node dissection (ALND) were 10.28 % and 11.3 % in the SERC trial and French cohort, respectively (p = 0.5). The rate of grade 1 tumors was lower in the SENOMIC trial (16.2%) and in the NKBC cohort (17.4%) compared to the SERC trial population (27.3%) and the French cohort (34.4%). Our findings in addition to the previously demonstrated concordance between the SENOMIC trial and the NKBC populations imply that the results of both the SERC and the SENOMIC trials can be applied to both French and Swedish real populations.

Axillary Management in Women with Early Breast Cancer and Limited Sentinel Node Metastasis: A Systematic Review and Metaanalysis of Real-World Evidence in the Post-ACOSOG Z0011 Era

BACKGROUND

After the publication of the Z0011 trial, the American Society of Clinical Oncology published an updated clinical practice guideline stating that clinicians should not recommend axillary lymph node dissection (ALND) for early-stage breast cancer patients with the involvement of one or two sentinel lymph nodes (SLNs). However, these recommendations have been challenged because they were mainly based on data from limited studies. The aim of the current study is to systematically compare the real-world outcomes of SLN biopsy (SLNB) alone and SLNB + ALND in patients with early-stage breast cancers and limited positive SLN metastasis in the post-Z0011 era PATIENTS AND METHODS: We searched articles in the PubMed, EMBASE, and Cochrane library databases. The primary endpoints were overall survival (OS) and disease-free survival (DFS). The secondary endpoints were recurrence rate and the incidence of lymphedema.

RESULTS

One randomized controlled trial and six retrospective studies with 8864 patients were retrieved. For patients with early-stage breast cancer with one or two SLN metastases, receiving SLNB alone showed no significant difference in OS, DFS, and recurrence rate compared with receiving SLNB + ALND. The incidence of lymphedema in patients who received SLNB alone was significantly lower than those who received SLNB + ALND (odds ratio 1.95, 95% confidence interval 1.02-3.71).

CONCLUSIONS

Current real-world evidence proved that the Z0011 strategy is safe with respect to survival outcomes and effective in reducing the incidence of lymphedema. ALND should be avoided in patients with early-stage breast cancer with one or two SLN metastases in the post-Z0011 era.

Prognostic impact of macrometastasis linear size in sentinel node biopsy for breast carcinoma

AIM

The aim of the present study was to evaluate the risk of axillary non-sentinel lymph-node metastases (ALN) in breast cancer patients presenting macrometastasis (Mac-m) in the sentinel lymph node (SN).

MATERIALS AND METHODS

A retrospective series of 1464 breast cancers from patients who underwent ALN dissection following the diagnosis of Mac-m in the sentinel node (SN) was studied. In all the cases the MAC-m linear size was evaluated and correlated with presence or absence of non-SN ALN metastases.

RESULTS

Non-SN metastases were detected in 644∖1464 cases (43.98%). The risk of further axillary metastases ranged from 20.2% (37/183) in cases with Mac-m between 2 and 2.9 mm, to 65.3% (262/401) in cases with Mac-m measuring > 10 mm. The risk of non-SN ALN metastases showed a 3% increase, parallel to each mm increment in SN metastasis size. The data evaluated with the receiver operating characteristic (ROC) curve showed that the Mac-m could be subdivided according to a new cut-off of 7 mm. pT1 tumours, with Mac-m < 7 mm had a risk of non-SN ALN metastases of <30%. Furthermore 109/127 of these (85.8%) had 3 or less non-SN ALN -metastases.

CONCLUSIONS

The present data give a detailed description on the risk of non-SN ALN involvement, that may be useful in the evaluation of breast cancer patients. It is suggested that a Mac-m size of <7 mm is related to a low residual axillary disease burden in breast cancer patients with small (pT1) tumours.