Pathological complete response after neoadjuvant chemotherapy for rectal cancer with synchronous multiple liver metastases: a report of an unusual case.

BACKGROUND: Systemic chemotherapy for stage IV colorectal cancer has advanced markedly in the recent years. We report an unusual case of 13 synchronous liver metastases for which a pathological complete response was achieved with neoadjuvant chemotherapy (NAC) consisting of a combination of 5-fluorouracil (5-FU), oxaliplatin, leucovorin (mFOLFOX6), and bevacizumab. CASE PRESENTATION: A 44-year-old man was diagnosed with colorectal cancer with synchronous liver metastases. We resected the primary rectal tumor first. Further, after providing NAC for hepatic metastases, lateral segmentectomy and partial resection of the liver were performed. The subsequent result was compatible with a complete pathological response. The postoperative course was uneventful, and the patient is currently alive 5 years after the first surgery without evidence of recurrence and without adjuvant chemotherapy. CONCLUSIONS: For patients with initially resectable colorectal liver metastases, the survival benefits of NAC are still unclear. We report a rare case of 13 synchronous liver metastatic lesions from rectal cancer with a complete pathological response after neoadjuvant bevacizumab-containing chemotherapy.