# Sentinel Lymph Node Biopsy in Low-Risk Breast Cancer in Patients ≥ 70 Years: How Wisely are We Choosing?

## TL;DR

This study examines how well doctors followed guidelines to avoid unnecessary surgery in older breast cancer patients and found that most still had the procedure, though radiation use increased.

## Contribution

The study evaluates real-world adherence to Choosing Wisely guidelines on de-escalating sentinel lymph node biopsy in older breast cancer patients and identifies factors influencing treatment decisions.

## Key findings

- SLNB rates decreased annually after 2016 but 68.7% of eligible patients still underwent the procedure in 2021.
- Omitting SLNB was associated with increased adjuvant radiation therapy rates (+15.0% annual increase).
- Older age and higher comorbidities predicted lower likelihood of undergoing SLNB.

## Abstract

The Choosing Wisely (CW) guidelines in 2016 recommended against routine sentinel lymph node biopsy (SLNB) for women 70 years and older with early-stage, low-risk breast cancer. We sought to examine trends in SLNB before and after CW guidelines along with the subsequent impact on adjuvant therapy.

The National Cancer Database was used to identify women aged 70 years and older with clinical stage I, ER/PR+, HER2− breast cancer between 2010 and 2021. We evaluated annual percent change (APC) in rates of SLNB by Joinpoint log-linear regression and used a multivariable logistic regression model to identify predictors of receipt of SLNB in the post-CW cohort. We also assessed rates of adjuvant chemotherapy and radiation stratified by receipt of SLNB in the post-CW cohort.

Our study demonstrated an annual decrease in the percentage of women undergoing SLNB after 2016, with an APC of −4.1% (p < 0.001); however, a majority of patients meeting de-escalation criteria (68.7%) still underwent SLNB in 2021. Women older than 75 (OR 0.31, 95% CI 0.30–0.32) and with a Charlson–Deyo score of 3 or greater (OR 0.65, 95% CI 0.60–0.70) were least likely to undergo SLNB, while treatment at nonacademic centers was associated with SLNB (OR 1.70, 95% CI 1.63–1.76). Post-CW, there were no significant change in rates of adjuvant chemotherapy. However, receipt of adjuvant radiation therapy significantly increased in patients for whom SLNB was omitted with an APC of +15.0%, with each additional year of diagnosis after 2016 associated with increased odds of radiation receipt (OR 1.14, 95% CI 1.11–1.17).

Though there has been significant progress made in de-escalating surgical management of early-stage breast cancer in older patients, most patients are still undergoing SLNB. Moreover, patients in whom SLNB is being omitted appear more likely than before to receive adjuvant radiation. More work is needed to provide quality, uniform and cost-effective care for all patients.