Curative-Intent Chemoimmunotherapy in Stage IIB Triple-Negative Breast Cancer in a Patient on Chronic Peritoneal Dialysis: A Case Report and Literature Review

Triple-negative breast cancer (TNBC) is an aggressive subtype associated with higher recurrence rates and inferior survival compared with hormone receptor-positive disease. The addition of immune checkpoint inhibition to neoadjuvant chemotherapy has improved pathologic complete response (pCR) and event-free survival in early-stage TNBC and is now the standard of care for high-risk disease. However, patients with end-stage renal disease (ESRD) requiring dialysis were excluded from pivotal clinical trials, leaving limited evidence to guide treatment in this population. We report the case of a 41-year-old woman with clinical stage IIB (cT2N1M0) TNBC and ESRD on chronic peritoneal dialysis who received modified neoadjuvant chemoimmunotherapy based on the KEYNOTE-522 regimen. Chemotherapy dosing was individualized for renal failure, including flat-dose carboplatin and dose-reduced anthracycline and cyclophosphamide, while pembrolizumab was administered at standard dosing. She completed neoadjuvant therapy and 16 of 17 planned pembrolizumab cycles (final cycle omitted due to toxicity) with overall manageable adverse effects. Surgical pathology following lumpectomy and sentinel lymph node biopsy demonstrated pCR (residual cancer burden score of 0). At one-year follow-up, she remains without evidence of recurrence. This case demonstrates the feasibility of delivering curative-intent TNBC chemoimmunotherapy in a patient undergoing peritoneal dialysis and highlights the importance of multidisciplinary coordination in managing malignancy in patients with advanced renal disease.