A Randomized Phase II Trial of Consolidation Chemotherapy after Preoperative Chemoradiation versus Chemoradiation alone for Locally Advanced Rectal Cancer: KCSG CO 14-03

Publication date: Available online 12 April 2018
Source:International Journal of Radiation Oncology*Biology*Physics
Author(s): Sun Young Kim, Jungnam Joo, Tae Won Kim, Yong Sang Hong, Jeong Eun Kim, In Gyu Hwang, Beom Gyu Kim, Keun-Wook Lee, Ji-Won Kim, Ho-Suk Oh, Joong Bae Ahn, Dae Young Zang, Dae Yong Kim, Jae Hwan Oh, Ji Yeon Baek
PurposePreoperative chemoradiation followed by total mesorectal excision (TME) in locally advanced rectal cancer is the standard of care. To date, the role of consolidation chemotherapy after chemoradiation has rarely been addressed through randomized trial. This study aims to evaluate the efficacy of chemoradiation followed by consolidation chemotherapy compared with chemoradiation alone.Methods and MaterialsPatients with adenocarcinoma of rectum and cT3-4NanyM0 were enrolled. In arm A (control arm), we planned chemoradiation (50.4 Gy/28 fractions) with capecitabine followed by TME. In arm B, two cycles of capecitabine and oxaliplatin (CapOx) 1 week were administered after the completion of chemoradiation before TME (capecitabine, 1,700 mg/m²/day from day 1 to 14; oxaliplatin, 100 mg/m² on day 1 every 3 weeks). The downstaging rate (the proportion of ypT0 to 2 and ypN0M0) was the primary endpoint, which was to be tested with a one-sided type-I error of 15% and 85% power.ResultsFrom September 2014 to February 2016, 110 (arm A, 56; arm B, 54) patients were randomized and 108 (arm A, 55; arm B, 53) started chemoradiation. TME was conducted per protocol in 96 patients (arm A, 52; arm B, 44). In arms A and B, downstaging was achieved in 21.2% and 36.4% (P = 0.077) and the pathologic complete response rate was 5.8% and 13.6% (P = 0.167), respectively. Grade ≥3 adverse events occurred in 3.6% in arm A and 9.4% in arm B during the preoperative treatment phase and 1.9% and 9.0% during the postoperative recovery phase, respectively.ConclusionConsolidation chemotherapy with two cycles of CapOx demonstrated a marginal improvement in the downstaging rate. However, a phase III trial of this strategy is discouraged because of high drop-out rate and safety issues.

Teaser

Preoperative chemoradiation followed by 6-8 weeks of rest until total mesorectal excision is the standard of care in locally advanced rectal cancer. This randomized phase II study suggested pathologic downstaging could be marginally improved with consolidation chemotherapy after preoperative chemoradiation before total mesorectal excision.


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