SO-5 Disease-free survival as surrogate for overall survival in neoadjuvant chemo(radio)therapy treatment of esophageal or gastro-esophageal junction carcinoma: An analysis of 4518 individual patients and 22 trials

The use of disease-free survival (DFS) as a surrogate endpoint for overall may speed up clinical research in cancer trials. Validation DFS OS neoadjuvant treatment oesophageal and gastro-oesophageal junction is still uncertain. We used Individual patient data from network meta-analysis chemotherapy or chemoradiotherapy esophageal gastro-esophageal carcinoma (MANATEC-02). Eligible trials were randomized closed to accrual before 2015, comparing followed by surgery (CTS) versus alone (S), (CRTS) S CTS CRTS, first-line an locally advanced with, adenocarcinoma squamous cell carcinoma. approach individual trial level correlation was used: at the level, estimated Kendall’s tau R2 determined with two-stage copula model. Leave-one-trial out crossvalidation applied. A multi-state Markov model evaluate time between recurrence death each trial. Both available 4518 patients (22 30 MANATEC-02 study), 2222 comparison, 1908 CRTS 388 CRTS. 3440 (76.1%) had event 3303 (73.1%) died. Among events, 1235 corresponded deaths. For vs S, median 16.6months [95% CI 15.8 – 17.4] 12.0 [11.4 - 12.9]. 30.1months [27.8 33.2] 21.9months [20 24.7]. CTC RCTC, 28.6months [25.5 33.6] [17.3 27.4]. Using unadjusted Clayton model, 0.73 0.74] 0.97 [0.97 0.97] 0.75 [0.75 0.76] 0.98 [0.98 0.98] RCTC 0.91 [0.91 0.91] 0.96 [0.96 0.96] RCTC. sojourn state shorter older (started recruitment 1995) more recent trials: mean 10.7 months 10.1 11.3] 16.7 15.4 17.6]. validated studying be useful when delays recurrences become larger.