In a retrospective cohort study reported in JAMA Oncology, Montagna et al found that patients with breast cancer with nodal downstaging after neoadjuvant chemotherapy had a low rate of axillary recurrence, with no difference observed for staging with targeted axillary dissection vs sentinel lymph node biopsy (SLNB). The findings suggest that axillary lymph node dissection (ALND) can be omitted in this setting.
Study Details
The study included 1,144 consecutive patients with stage II to III biopsy-proven node-positive (N1-3) breast cancer enrolled from sites in 11 countries between April 2013 and December 2020. All patients had achieved nodal pathologic complete response as determined by targeted axillary dissection or SLNB after receipt of neoadjuvant chemotherapy.
A total of 666 patients underwent staging with SLNB with dual-tracer mapping, and 478 underwent targeted axillary dissection as a combination of SLNB with localization and retrieval of the clipped lymph node. The primary outcome measures were 3- and 5-year rates of any axillary recurrence.
Key Findings
Receipt of nodal irradiation was more common in the targeted axillary dissection group vs the SLNB group (85% vs 78%, P = .01). The clipped node was successfully retrieved in 97% of targeted axillary dissection cases and 86% of SLNB cases (without localization). The mean number of sentinel lymph nodes retrieved was three (±2) in the targeted axillary dissection group vs four (±2) in the SLNB group (P < .001); the mean number of total lymph nodes removed was 3.95 (±1.97) vs 4.44 (±2.04), respectively (P < .001).
At 3 and 5 years, rates of axillary recurrence in the total population were 0.65% (95% confidence interval [CI] = 0.29%–1.30%) and 1.0% (95% CI = 0.49%–2.00%). At 3 years, the cumulative incidence of axillary recurrence was 0.5% in the targeted axillary dissection group vs 0.8% in the SLNB group (P = .55).
At 3 and 5 years in the total population, rates of locoregional recurrence were 1.5% and 2.7%, and rates of any invasive recurrence were 7.5% and 10%. At 3 years, no significant differences between the targeted axillary dissection group and the SLNB group were observed for cumulative incidence of locoregional recurrence (0.8% vs 1.9%, P = .19) or any invasive recurrence (7.3% vs 7.8%, P = .60).
The investigators concluded, “The results of this cohort study showed that axillary recurrence was rare in this setting and was not significantly lower after targeted axillary dissection vs SLNB. These results support omission of ALND in this population.”
Walter P. Weber, MD, of the Breast Center, University Hospital of Basel, Switzerland, is the corresponding author for the JAMA Oncology article.
Disclosure: The study was supported by a grant from the National Cancer Institute. For full disclosures of the study authors, visit jamanetwork.com.
