Background There is currently no consensus for firstline chemotherapy in patients with advanced gastric cancer (AGC), not eligible to receive trastuzumab.

Purpose To evaluate the efficacy and tolerance of triplets versus doublets by analysing a national gastric cancer registry.

Material and methods Patients with AGC treated with polychemotherapy, excluding trastuzumab, were included from 2008 to 2016. The effect of triplets versus doublets was compared using three methods: Cox proportional hazards regression, propensity score matching (PSM) and coarsened exact matching (CEM).

Results 970 patients were recruited (doublets n=569, triplets n=401). In the Cox model, the use of triplets was associated with better overall survival (OS), hazard ratio (HR) 0.84 (95% CI 0.72–0.98), p=0.035, after adjusting for confounding factors. After PSM, the sample contained 340 pairs. A significant increase in OS(11.14 months (95% CI 9.60–12.68) versus 9.60 months (95% CI 8.44–10.75)) was seen in favour of triplets; HR 0.77 (95% CI 0.65–0.92), stratified log rank test, adjusted for percentile groups of the PSM, p=0.004. The effect appeared to be comparable for anthracycline based triplets (HR 0.78 (95% CI 0.64–0.94)) or docetaxel based triplets (HR 0.78 (95% CI 0.60–1.009)). The trend was similar after applying the CEM algorithm, with a HR of 0.78 (95% CI 0.63–0.97), p=0.03.

Triplet therapy was viable and relative dose intensities exceeded 85%, except for cisplatin in DCX. Triplets had more severe toxicity overall, especially haematological, hepatic and mucosal adverse events.

Conclusion Triplet therapies are feasible in daily practice and are associated with a discreet benefit in efficacy at the expense of a moderate increase in toxicity.

References and/or acknowledgements To the investigators of the AGAMENON study.

No conflict of interest