FOLFOX4 as adjuvant treatment for stage II colon cancer (CC): Subpopulation data from the MOSAIC trial

Abstract

3619 Background: Currently, stage II (Dukes B2) CC patients (pts) are included in clinical trials testing adjuvant chemotherapy as benefit of such treatment remains to be confirmed for these pts. Methods: FOLFOX4 [oxaliplatin/5-Fluorouracil (5FU)/leucovorin (LV)] is the first combination which improves 3-year disease free survival (DFS) (78.2%) when compared with 5-FU/LV (LV5FU2) alone (72.9%) in stage II/III CC as demonstrated in a large phase III randomized study (MOSAIC). The decrease in the risk of recurrence (RRR) is 23% in the overall population (p=0.002) (de Gramont, ASCO 2003). Stage II sub population data are presented here. Results: 40% of the 2246 patients were stage II: 451 in FOLFOX4, and 448 in LV5FU2; main characteristics were well balanced between the 2 groups with respectively for FOLFOX4/LV5FU2 (%): Male 57/52, median age (years) 61/60, colon 57/56, sigmoid 32/34, recto-sigmoid 11/9, KPS ≥ 80%: 88/ 90, Bowel obstruction: 16/19, Tumor perforation: 8/10, T4 (%)19/19, venous invasion: 8/10. The observed reduced risk of recurrence with FOLFOX4 was consistent in both stage II and stage III as shown by a non-significant treatment-by-stage interaction (p=0.77). Overall per patient major safety events on study [incidence of SAE, treatment discontinuation and/or death] were less frequent in stage II (19.8%) than in stage III (25.6%). Conclusion: In the FOLFOX4 arm of MOSAIC, stage II patients benefited from a 20% relative reduction in the risk of recurrence versus those of the LV5FU2 arm with a limited incidence of major safety events. This reflects the favorable benefit-risk of FOLFOX4 in this population. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Sanofi-Synthelabo Sanofi-Synthelabo