You are here

FOLFOX4/XELOX in stage II–III colon cancer: Efficacy results of the Italian three or six colon adjuvant (TOSCA) trial

Alberto F. Sobrero, Sara Lonardi, Gerardo Rosati, Maria Di Bartolomeo, Monica Ronzoni, Nicoletta Pella, et al.


Background: Six months of oxaliplatin-based treatment has been the standard of care as adjuvant therapy for stage III colon cancer and an accepted option for high-risk stage II. Given the cumulative neurotoxicity associated to oxaliplatin, a shorter duration of therapy, if equally efficacious, would be advantageous for patients and health-care systems.

Methods: TOSCA was an open-label, phase III, multicenter, non-inferiority trial randomizing patients with high-risk stage II or stage III radically resected colon cancer to receive 3 months or 6 months of FOLFOX4/XELOX. Primary end-point was relapse-free survival.

Results: From June 2007 to March 2013, 3759 patients were accrued from 130 Italian sites, 64% receiving FOLFOX4 and 36% XELOX in either arm. Two thirds were stage III. At the cut-off time for analysis the median time of follow-up was 62 months and 772 relapses or deaths have been observed. The RFS rate at 8 years is 75%. This analysis was done when 82% of the planned number of events was reached, with a power of 72% instead of 80%. The decision to anticipate the analysis was based on the participation to the IDEA joint collaborative analysis of studies sharing this clinical question. The Hazard Ratio of the 3months vs 6 months for relapse/death was 1.14 (95%CI 0.99-1.31, p for non inferiority = 0.253) and the confidence interval crossed the non inferiority limit of 1.20.

Conclusions: TOSCA was not able to demonstrate that 3 months of oxaliplatin-based adjuvant treatment is as efficacious as 6 months. Nevertheless , because the absolute difference in RFS between the two treatment durations is small ( less than 3 % at 5 years ), the decision to complete the whole 6-month program should be individualized based on toxicity and patients’ attitude. This study is registered with Registration Number: NCT00646607. It was supported by a grant from AIFA (Agenzia Italiana del Farmaco) Grant Code FARM5RWTWZ. 

Clinical trial information: NCT00646607

All content © 2017 American Society of Clinical Oncology. All rights reserved.

Search this site

Search form

ECCO2017 symposium webcast: Treatment evolution in advanced GI malignancies

Welcome and introduction - Florian Lordick


Subscribe to our E-Alert to keep up to date with the new items in the Resource Centre

Featured Content

New Book Content

This online Resource Centre has been sponsored by Lilly Oncology

Note that Lilly Oncology has no editorial control over the content of this Resource Centre. The Resource Centre and all content therein has been subject to an independent editorial review.