Long-term outcome and axillary recurrence in elderly women (≥70 years) with breast cancer: 10-years follow-up from a matched cohort study

Background and objectives: The oncological benefit of axillary surgery (AS), with sentinel lymph node biopsy (SLNB) or axillary dissection (ALND), in elderly women affected by breast cancer (BC) is controversial. We evaluated AS trends over a 10-year follow-up period as well as locoregional and survival outcomes in this subset of patients. Methods: Patients aged 70 years or older, treated between 1994 and 2008, were selected and divided in two groups, depending on whether or not AS was performed. A (1:1) matched analysis for all relevant clinicopathological features was performed. Outcomes were analyzed using the Kaplan–Meier method and univariate Cox-proportional hazard ratio analysis. Results: A total of 1.748 patients were identified and stratified by age (70–74, 75–79, 80–84). A matched analysis was performed for 252 patients: 122 who underwent AS and 122 who did not. At 10-year follow-up, ipsilateral breast tumor recurrence, distant metastasis and contralateral BC were similar, p = 0.83, p = 0.42 and p = 0.28, respectively. In the no-AS group, a significant increased risk of axillary lymph-node recurrence was identified at 5- and confirmed at 10-years (p = 0.038), without impact on overall survival at 5- and 10-years (p = 0.52). In the non-AS group, higher rate of axillary recurrence at 10-years was observed in patients with poorly differentiated (24.1%, 95% CI 7.2–46.2), highly proliferative (Ki67 ≥ 20%: 17.1%, 95% CI 0.6–33.3) and luminal B tumors (16.8%, 95% CI 5.9–35.5). Conclusions: Axillary staging in elderly women does not impact long-term survival. Tailoring surgery according to tumor biology and age may improve locoregional outcome.