A 60 years old male presented to OPD with bleeding PR. On DRE, growth was felt at by the tip of index finger. On sigmoidoscopy, there was an ulcero-proliferative growth located 6 cm from anal verge. On CECT, liver and lungs were not involved. After chemoradiation, what is the next best step?
Observation an follow up Low anterior resection Abdominoperineal resection Haman's procedure