Successful Breast-Conserving Surgery Following Dose-Modified Neoadjuvant Chemoimmunotherapy in an 86-Year-Old Patient With Locally Advanced Triple-Negative Breast Cancer: A Case Report.

Patients aged ≥ 80 years with breast cancer are underrepresented in clinical trials, resulting in limited evidence regarding optimal treatment strategies, particularly for triple-negative breast cancer (TNBC). We report the case of an 86-year-old woman with locally advanced PD-L1-positive TNBC who presented with a painful 10-cm breast mass with skin invasion, clinically suspected axillary lymph node involvement, and subsequent tumor bleeding. Because of her preserved functional status, intact cognitive function, absence of significant comorbidities, and strong motivation for treatment, dose-modified neoadjuvant chemoimmunotherapy with pembrolizumab, paclitaxel, and carboplatin was administered. The tumor showed a marked response, and after four cycles complete clinical remission was achieved. Breast-conserving surgery with axillary lymph node dissection was subsequently performed, and pathological examination demonstrated a complete pathological response. The patient remains disease-free 15 months after surgery. This case highlights the importance of careful patient selection and individualized treatment planning when considering curative-intent multimodality treatment in very elderly patients with locally advanced TNBC.