ESMO WCGC 2013 Report – First results of the PETACC-6 phase III RCT

Review of the presentation by HJ Schmoll EORTC GI Group.  [Preoperative chemoradiotherapy with capecitabine and oxaliplatin vs capecitabine alone in locally advanced rectal cancer: response to the local treatment after chemoradiation and surgery as secondary endpoint]

PETACC-6 is the final trial to investigate the value of oxaliplatin in the pre-operative chemoradiation setting in increasing local complete response rate and reducing further local relapse rate. It is also the final trial to investigate the role of oxaloplatin in decreasing the rate of distant metastases and thereby increasing disease free survival.

An analysis of early secondary endpoints was presented by Dr Schmoll. The addition of oxaliplatin to preoperative fluoropyrimidine based CRT led to increased toxicity; decreased treatment compliance [but did not improve the R0 resection rate]; pathological complete remission (ypTONO) and sphincter preservation. Dr Schmoll explained that this was in accordance with the three previous trials STAR, ACCORD/PRODIGE 2, NSABP R04, with the exception of CAO/ARO/AJO-O4 favouring 5FU plus oxaloplatin. Dr Schmoll explained that only PETACC-6 and CAO/ARO/AJO have randomised oxaloplatin for the post operative adjuvant treatment as well, and are therefore able to answer the most relevant question of the value of oxaloplatin in improving disease free survival. A longer follow up is needed for final disease free survival results.