Management of the axilla after the finding of a positive sentinel lymph node: a proposal for an evidence-based risk-adapted algorithm

Omitting completion axillary lymph node dissection after detection of sentinel node micrometastases in breast cancer: first results from the prospective SENOMIC trial

BACKGROUND

Completion axillary lymph node dissection has been abandoned widely among patients with breast cancer and sentinel lymph node micrometastases, based on evidence from prospective RCTs. Inclusion in these trials has been subject to selection bias, with patients undergoing mastectomy being under-represented. The aim of the SENOMIC (omission of axillary lymph node dissection in SENtinel NOde MICrometases) trial was to confirm the safety of omission of axillary lymph node dissection in patients with breast cancer and sentinel lymph node micrometastases, and including patients undergoing mastectomy.

METHODS

The prospective SENOMIC multicentre cohort trial enrolled patients with breast cancer and sentinel lymph node micrometastases who had breast-conserving surgery or mastectomy at one of 23 Swedish hospitals between October 2013 and March 2017. No completion axillary lymph node dissection was performed. The primary endpoint was event-free survival, with a trial accrual target of 452 patients. Survival proportions were based on Kaplan-Meier survival estimates.

RESULTS

The trial included 566 patients. Median follow-up was 38 (range 7-67) months. The 3-year event-free survival rate was 96.2 per cent, based on 26 reported breast cancer recurrences, including five isolated axillary recurrences. The unadjusted 3-year event-free survival rate was higher than anticipated, but differed between patients who had mastectomy and those who underwent breast-conserving surgery (93.8 versus 97.8 per cent respectively; P = 0.011). Patients who underwent mastectomy had significantly worse tumour characteristics. On univariable Cox proportional hazards regression analysis, patients who had mastectomy without adjuvant radiotherapy had a significantly higher risk of recurrence than those who underwent breast-conserving surgery (hazard ratio 2.91, 95 per cent c.i. 1.25 to 6.75).

CONCLUSION

After 3 years, event-free survival was excellent in patients with breast cancer and sentinel node micrometastases despite omission of axillary lymph node dissection. Long-term follow-up and continued enrolment of patients having mastectomy, especially those not receiving adjuvant radiotherapy, are of utmost importance.

Local treatment of the axilla in early breast cancer: concepts from the national surgical adjuvant breast and bowel project B-04 to the planned intergroup sentinel mamma trial

Local treatment of the axilla in clinically node-negative, early-stage breast cancer patients has been hotly debated after the release of the American College of Surgeons Oncology Group (ACOSOG) Z0011 findings. However, this review does not focus on the 'Z0011-eligible' patients alone, because this subgroup represents a minority of our patients undergoing breast-conserving surgery (BCS) and sentinel lymph node biopsy (SLNB). The following topics are discussed: axillary diagnostics, timing of axillary procedures in the neoadjuvant setting, long-term follow-up of SLNB trials, omission of axillary surgery in randomized trials, management of the involved axilla with low tumor volume, positive sentinel lymph nodes and BCS, involved sentinel lymph nodes and mastectomy, and axillary radiotherapy. Finally, the current innovative study concepts (i.e. Sentinel Node versus Observation after Axillary Ultrasound (SOUND) and Intergroup Sentinel Mamma (INSEMA)) including patients with axillary observation alone in clinically node-negative women are presented.

Prediction of non-sentinel lymph node status in breast cancer patients with sentinel lymph node metastases: evaluation of the tenon score

INTRODUCTION

Current guidelines recommend completion axillary lymph node dissection (cALND) in case of a sentinel lymph node (SLN) metastasis larger than 0.2 mm. However, in 50%-65% of these patients, the non-SLNs contain no further metastases and cALND provides no benefit. Several nomograms and scoring systems have been suggested to predict the risk of metastases in non-SLNs. We have evaluated the Tenon score.

PATIENTS AND METHODS

In a retrospective review of the Swedish Sentinel Node Multicentre Cohort Study, risk factors for additional metastases were analysed in 869 SLN-positive patients who underwent cALND, using uni- and multivariate logistic regression models. A receiver operating characteristic (ROC) curve was drawn on the basis of the sensitivity and specificity of the Tenon score, and the area under the curve (AUC) was calculated.

RESULTS

Non-SLN metastases were identified in 270/869 (31.1%) patients. Tumour size and grade, SLN status and ratio between number of positive SLNs and total number of SLNs were significantly associated with non-SLN status in multivariate analyses. The area under the curve for the Tenon score was 0.65 (95% CI 0.61-0.69). In 102 patients with a primary tumour <2 cm, Elston grade 1-2 and SLN metastases ≤2 mm, the risk of non SLN metastasis was less than 10%.

CONCLUSION

The Tenon score performed inadequately in our material and we could, based on tumour and SLN characteristics, only define a very small group of patients in which negative non-sentinel nodes could be predicted.

Axillary lymph node dissection in early-stage invasive breast cancer: is it still standard today?

Evaluation of axillary lymph node status by sentinel lymph node biopsy (SLNB) and complete axillary lymph node dissection (ALND) are an inherent part of breast cancer treatment. Increased understanding of tumor biology has changed the prognostic and therapeutic impact of lymph node status. Non-invasive imaging techniques like axillary ultrasound, FDG-PET, or MRI revealed moderate sensitivity and high specificity in evaluation of lymph node status. Therefore, they are not sufficient for lymph node staging. Otherwise, the impact of remaining micrometastases and even macrometastases for prognosis and treatment decisions is overestimated. Considering tumor biology, the distinction of axillary metastases in isolated tumor cells (ITC, pN0(i+)); micrometastases (pN1mi), and macrometastases (pN1a) is not comprehensible. Increasing data support the thesis that remaining axillary metastases neither increase the axillary recurrence rate nor decrease overall survival. It is doubtful that axillary tumor cells are capable to complete the complex multistep metastatic process. If applied, axillary metastases are sensitive to systemic treatment and are targeted by postoperative tangential breast irradiation. Therefore, the controversy about the clinical relevance of tumor cell clusters or micrometastases in SLN is a sophisticated but not contemporary discussion. Currently, there is no indication for axillary surgery in elderly patients with favorable tumors and clinically tumor-free lymph nodes. Nonetheless, a rational and evidence-based approach to the management of clinically and sonographically N0 patients with planned breast-conserving surgery and limited tumor size is needed now.

Risk factors for lymphedema after breast cancer treatment

BACKGROUND

As cancer treatments evolve, it is important to reevaluate their effect on lymphedema risk in breast cancer survivors.

METHODS

A population-based random sample of 631 women from metropolitan Philadelphia, Pennsylvania, diagnosed with incident breast cancer in 1999 to 2001, was followed for 5 years. Risk factor information was obtained by questionnaire and medical record review. Lymphedema was assessed with a validated questionnaire. Using Cox proportional hazards models, we estimated the relative incidence rates [hazard ratios (HR)] of lymphedema with standard adjusted multivariable analyses ignoring interactions, followed by models including clinically plausible treatment interactions.

RESULTS

Compared with no lymph node surgery, adjusted HRs for lymphedema were increased following axillary lymph node dissection [ALND; HR, 2.61; 95% confidence interval (95% CI), 1.77-3.84] but not sentinel lymph node biopsy (SLNB; HR, 1.04; 95% CI, 0.58-1.88). Risk was not increased following irradiation [breast/chest wall only: HR, 1.18 (95% CI, 0.80-1.73); breast/chest wall plus supraclavicular field (+/- full axilla): HR, 0.86 (95% CI, 0.48-1.54)]. Eighty-one percent of chemotherapy was anthracycline based. The HR for anthracycline chemotherapy versus no chemotherapy was 1.46 (95% CI, 1.04-2.04), persisting after stratifying on stage at diagnosis or number of positive nodes. Treatment combinations involving ALND or chemotherapy resulted in approximately 4- to 5-fold increases in HRs for lymphedema [e.g., HR of 4.16 (95% CI, 1.32-12.45) for SLNB/chemotherapy/no radiation] compared with no treatment.

CONCLUSION

With standard multivariable analyses, ALND and chemotherapy increased lymphedema risk whereas radiation therapy and SLNB did not. However, risk varied by combinations of exposures.

IMPACT

Treatment patterns should be considered when counseling and monitoring patients for lymphedema.