Neoadjuvant Chemoradiotherapy and Chemotherapy in Patients with Locally Advanced Rectal Cancer

Aims: Evaluate the role of neoadjuvant chemoradiotherapy (CRT) followed by an additional cycle of chemotherapy and total mesorectal excision (TME) in patients with locally advanced rectal cancer on the rate of pathologic complete response (pCR) and tumor downstaging, their impact on survival and evaluation of treatment related toxicity and surgical complications.

Patients and Methods: This prospective phase II trial included 73 patients with histopathologically proven non metastatic rectal adenocarcinoma referred from or admitted at Surgical Oncology Department, Radiotherapy Department, South Egypt Cancer Institute, and Clinical Oncology Department, Assiut University, Egypt, from March 2012 to September 2013. Radiotherapy (1.8 Gy, 5 days a week over 5 weeks, total dose 50.4 Gy, 3 D conformational technique) was given in combination with intravenous oxaliplatin 50 mg/m2 once weekly for 5 weeks and oral capecitabine 825 mg/m2 twice daily on each day of radiation. After completion of CRT, patients received an additional cycle of chemotherapy consisted of oxaliplatin (130 mg/m2 on day 1) and capecitabine (825 mg/m2, twice per day from day 1 to day 14). Surgery was performed 6–8 weeks after completion of chemoradiotherapy.

Results: Seventy patients (95.9%) underwent surgery. Postoperative pathologic assessment showed an overall downstaging rate of 78.1%, while 16 patients (21.9%) had stationary disease. Complete pathologic response was achieved in 11 patients (15.1%). No tumor progression has been observed. After median follow up period of 26 months (7-30 months), the 2-year overall survival (OS) was 88%, recurrence free survival was 88.7% and distant metastasis free survival was 93.9%. Lower pathologic tumor stage was significantly associated with better OS (P = .002) and recurrence-free survival (P = .001), while pathologic nodal stage and TRG had no significant difference in overall survival, recurrence free survival or distant metastasis free survival. Forty-one patients (56.2%) experienced grade 1-2 toxicity and 5 patients (6.8%) experienced grade 3 toxicity.

Conclusion: Neoadjuvant CRT and one cycle of chemotherapy followed by TME is effective with pCR of 15.1% and overall downstaging rate of 78.1%. In addition to favorable toxicity profile (lower grade 3 and 4 toxic effects as 3 patients developed grade 3 diarrhea and 2 patients developed grade 3 hematological toxicity and lower rate of Grade 1 – 2 diarrhea ; 28.8%) and outcome.