ABSTRACT
OBJECTIVE: The aim of this study was to determine the pathological complete response rates in a group of locally advanced rectal cancer patients who underwent chemoradiotherapy (CRT) after treatment with induction folinic acid and 5‑florouracil (FOLFOX) chemotherapy and the relationship between the complete response and positron emission tomography‑computed tomography (PET‑CT). MATERIALS AND METHODS: The files of 239 patients who were diagnosed with rectal cancer between January 2008 and January 2012 were evaluated retrospectively. Of these, there were 24 locally advanced rectal cancer patients who met the following criteria: They were administered CRT after receiving four courses induction oxaliplatin, FOLFOX and they underwent PET‑CT for staging and for the evaluation of their response to FOLFOX treatment. Of these 24 patients, 20 operable patients were included in the study. RESULTS: The pathological complete response was obtained in seven patients (35%) who were operated on and then given induction four courses FOLFOX chemotherapy and CRT. We determined that age, gender, clinical stage at diagnosis and PET‑CT before and after induction chemotherapy were not predictive of the pathological complete response to tumor fluorodeoxyglucose uptake activity. CONCLUSION: The rates of pathological complete response were increased in locally advanced rectal cancer patients who underwent short‑term induction chemotherapy. Although the PET‑CT has retained its importance in predicting pathological complete response, there is still a need for studies with a larger number of patients and long‑term follow‑ups.