Long-term prognoses and outcomes of axillary lymph node recurrence in 2,578 sentinel lymph node-negative patients for whom axillary lymph node dissection was omitted: results from one Japanese hospital

Background Axillary dissection omission for sentinel lymph node-negative patients has been a practice at Cancer Institute Hospital, Japanese Foundation for Cancer Research since 2003. We examined the long-term results of omission of axillary dissection in sentinel lymph node-negative patients treated at our hospital, as well as their axillary lymph node recurrence characteristics and outcomes. Methods Our study included 2,578 patients with cTis or T1-T3N0M0 primary breast cancer for whom dissection was omitted because they were sentinel lymph node negative. The median observation period was 75 months. Results In sentinel lymph node-negative patients for whom dissection was omitted, the rates of axillary lymph node recurrence, distant recurrence, and breast cancer mortality were 0.9, 2, and 1 %, respectively. Eighteen patients underwent additional dissection if axillary lymph node recurrence was observed at the first recurrence. Four triple-negative (TN) patients experienced distant recurrence after additional dissection. All four patients were administered anticancer agents after axillary lymph node recurrence and experienced recurrence within 1 year of additional dissection. The axillary lymph node recurrence rate was 0.8 % for luminal and 4.5 % for TN subtypes. Conclusions The long-term prognoses of patients for whom dissection was omitted owing to negative sentinel lymph node metastases were similar to those reported previously—low recurrence and mortality rates. The frequency of axillary lymph node recurrence and the post-recurrence outcome differed between luminal and TN cases, with recurrence being more frequent in patients with the TN subtype. TN patients also had poorer prognoses, even after receiving additional dissection and anticancer agents after recurrence.