The survival benefit of intensified full-dose XELOX chemotherapy concomitant to radiotherapy and then resting-period consolidation chemotherapy in locally advanced rectal cancer

Purpose: To evaluate the effect of an intensified capecitabine and oxaliplatin (XELOX) chemoradiation treatment followed by one cycle of consolidation chemotherapy before surgery in locally advanced rectal cancer (LARC). Methods and Materials: Patients with histologically confirmed, newly diagnosed, locally advanced rectal adenocarcinoma (cT3-T4 and/or cN+) were enrolled. All patients received 3-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) with a dose 50.4Gy in 25 fraction, with two cycles of concurrent XELOX chemotherapy. Thereafter, another cycle of consolidation chemotherapy with XELOX/FLOFOX was administered during the resting period after completion of concurrent chemoradiation (CRT). Tumor response, toxicities, surgical complications, and long-term clinical outcomes were recorded. Results: From January 2011 to December 2013, a total of 96 patients were enrolled in the study. All patients completed the treatment plan of concurrent chemoradiation and consolidate chemotherapy. During concurrent chemoradiation, the incidence of grade 3/4 toxicities was leucopenia (2.1%), thrombocytopenia (4.2%), diarrhea (6.3%). 18 patients (18.8%) developed surgical complications. Pathologic complete response (pCR) was achieved in 20 (20.8%) patients. Tumor down-staging occurred in 69 (71.9%) patients and down-staging of nodes occurred in 47 (49.0%) patients. Of these 96 patients, 5-year local recurrence-free survival, metastasis-free survival, disease-free survival and overall survival rates was 98.9%, 84.7%, 83.7% and 82.1%, respectively, with a median follow-up of 4.24years. Conclusions: The intensified treatment paradigm of XELOX concurrent chemoradiation followed by one cycle of consolidation chemotherapy was well tolerated in our cohort and provided a promising long-term oncologic outcome, which warranted further investigation in a randomize trails.