Association of post-operative CEA with survival and oxaliplatin benefit in patients with stage II colon cancer: a post hoc analysis of the MOSAIC trial
Menée auprès de 867 patients atteints d'un cancer du côlon de stade II, cette étude évalue l'association entre le niveau sérique post-opératoire de l'antigène carcino-embryonnaire et la survie sans maladie ou le bénéfice, en termes de survie, de l'ajout d'oxaliplatine à un traitement adjuvant
Background : Adjuvant treatment for stage II colon cancer (CC) can be proposed to patients with high-risk disease. Recently, 2.35 ng/mL carcinoembryonic antigen (CEA) was identified as the best cut-off value. This post hoc analysis of the MOSAIC trial assessed post-operative CEA prognostic value for survival outcomes and predictive value for the addition of oxaliplatin to adjuvant treatment.
Methods : Prognostic and predictive values of post-operative CEA in patients with stage II CC were evaluated with Kaplan–Meier survival curves and Cox model with interaction terms. Disease-free survival (DFS) and overall survival (OS) were estimated.
Results : Among 899 stage II CC patients, post-operative CEA was available in 867 (96.4%); and 434 (48.65%) had a high-risk stage II disease. The 3-year DFS rate was 88.5% and 78.7% in the ≤ 2.35 ng/mL and > 2.35 ng/mL group, respectively (P = 0.006). Use of oxaliplatin showed survival benefit only in patients with high-risk stage II CC and post-operative CEA > 2.35 ng/ml (interaction term P = 0.09 and 0.03 for DFS and OS).
Conclusion : CEA is a strong prognostic factor for DFS and OS in stage II CC. In the MOSAIC trial, only high-risk stage II CC patients with post-operative CEA > 2.35 ng/mL benefited from the addition of oxaliplatin to LV5FU2.
Trial registration : NCT00275210 (January 11, 2006).
British Journal of Cancer , résumé, 2019