Two Cases of Unresectable Advanced Rectal Cancer with a Long-Term Survival for Which Pathological Complete Response Was Achieved through Neoadjuvant Effective Chemotherapy

We report 2 unusual cases of Stage IV rectal cancer for which pathological complete response was achieved with neoadjuvant chemotherapy(NAC)consisting of a combination of 5-fluorouracil(5-FU), oxaliplatin, Leucovorin(mFOLFOX6)or irinotecan(FOLFIRI), and bevacizumab, without radiotherapy. Case 1: A 65-year-old man was diagnosed as having rectal cancer with an invasive carcinoma of the prostate and lymph node metastasis. He refused to undergo surgery and received NAC instead. After NAC with mFOLFOX6 and FOLFIRI was performed, CT scan and colonoscopy revealed no evidence of disease. The subsequent result was compatible with a complete pathological response. The patient is currently alive 4 years after the first chemotherapy, without evidence of recurrence and adjuvant chemotherapy. Case 2: A 75-year-old man was diagnosed as having rectal cancer with an invasive carcinoma of the bladder and lymph node metastasis. After providing neoadjuvant bevacizumab-containing chemotherapy, low anterior resection of the rectum was performed. Operative findings showed that the tumor was only ulcer and the lymph nodes were not enlarged. The subsequent results indicated that pathological findings revealed no cancer and a complete pathological response. In conclusion, the survival benefits from NAC are still unclear for patients with an initially unresectable rectal cancer. We report 2 rare cases of rectal cancer with long survival and a complete pathological response after neoadjuvant chemotherapy.