Nodal Surgery for Patients ≥ 70 Undergoing Mastectomy for DCIS? Choose Wisely

Area of Science:

• Oncology
• Surgical Oncology
• Breast Cancer Research

Background:

• Choosing Wisely guidelines discourage routine sentinel lymphadenectomy (SLNB) for early-stage HR+/HER2- breast cancer in women aged 70 and older.
• The utility of SLNB in women aged 70 and older with ductal carcinoma in situ (DCIS) undergoing mastectomy remains unclear.
• This study evaluates axillary surgery rates and nodal positivity in this specific patient population.

Purpose of the Study:

• To determine if sentinel lymphadenectomy (SLNB) can be safely omitted in women aged 70 and older with ductal carcinoma in situ (DCIS) undergoing mastectomy.
• To assess the impact of axillary surgery on treatment decisions in this demographic.
• To evaluate rates of upstaging to invasive cancer and nodal positivity (pN+) in older women with DCIS.

Main Methods:

• Retrospective analysis of the National Cancer Database (2012-2020) for females aged 70 and older with DCIS undergoing mastectomy.
• Assessment of upstaging rates to invasive cancer (≥pT1) or nodal positivity (pN+).
• Subset analysis for estrogen receptor-positive (ER+) patients and evaluation of adjuvant therapies based on nodal status.

Main Results:

• Of 9,030 patients, 21% upstaged to ≥pT1. Axillary surgery was performed in 86%, primarily SLNB (65%).
• Post hoc analysis indicated 93% of all patients and 97% of ER+ DCIS patients could have avoided axillary surgery.
• Nodal positivity was low (0.3% without upstaging, 12% with upstaging to ≥pT1), with minimal pN2-3 disease. Node-positive patients had higher adjuvant therapy use, but recommendations for chemotherapy/radiation were often absent.

Conclusions:

• Axillary surgery can likely be omitted for the majority of patients aged 70 and older undergoing mastectomy for ER+ DCIS.
• Omission of axillary surgery may also be considered for patients with ER- DCIS.
• Future guidelines could incorporate preoperative imaging to better identify patients who would benefit from axillary surgery, similar to the SOUND trial approach.