Over 150,000 new cases of colon cancer were diagnosed in the US in 2019. Stage and age at diagnosis are important prognostic factors for overall survival (OS). For the age group 70-79, the OS for females with poorly differentiated stage IV colon cancer at 1, 2 and 5 years after surgery is 39%, 15%, and 2%, respectively. We present a case of a 77-year-old female with significant cardiac history. She was diagnosed with stage IV colorectal cancer complicated with enteric fistula. Due to her initial performance status and comorbidities, she was not a candidate for surgery or systemic chemotherapy. Nonetheless, and giving her tumor was microsatellite unstable, she was treated with neo-adjuvant immunotherapy. She achieved complete pathological remission with no evidence of disease found upon surgical resection, for which she eventually qualified due to improvement of performance status. Patient is alive and free of disease 24 months after operation
