Small cell rectal cancer: a therapeutic challenge

A generally well 71-year-old man presented to his general practitioner with altered bowel habit and haematochezia. Colonoscopy revealed a malignant-appearing rectal mass, with histological features of extrapulmonary small cell carcinoma (EPSCC) of the rectum. Imaging demonstrated limited stage disease with a threatened circumferential resection margin. He was treated with a modified platinum chemoradiotherapy regimen for small cell lung cancer with an excellent response. Unfortunately, his cardiac function precluded surgery at the time and the patient subsequently developed hepatic metastases with local disease recurrence, and died 15 months following his initial diagnosis. Rectal EPSCC is a rare diagnosis, and this case represented a challenge for the multidisciplinary team given the limited evidence base. Medical therapy reflects extrapolation of small cell lung cancer treatment and the role of surgery is less clearly defined given aggressive and refractory disease is common. Immunotherapy, however, represents an exciting development for metastatic disease.