A randomised phase II study of continuous versus stop-and-go S-1 plus oxaliplatin following disease stabilisation in first-line chemotherapy in patients with metastatic gastric cancer

Objectives We compared continuous versus stop-and-go chemotherapy after disease stabilisation with induction chemotherapy in the first-line treatment of metastatic gastric cancer (MGC). Methods MGC patients who achieved disease control after 6 cycles of S-1/oxaliplatin (SOX) were randomised to receive either continuous SOX until progression (continuous arm) or to have a chemotherapy-free interval followed by SOX reintroduction at progression (stop-and-go arm). The primary end-point was overall survival (OS). Results Of the 250 patients enrolled, 247 participated in the induction phase. Of these, 121 patients were randomised to the continuous arm (n = 59) or the stop-and-go arm (n = 62). Progression-free survival (PFS) was significantly longer in the continuous arm than in the stop-and-go arm (10.5 versus 7.2 months; hazard ratio [HR] 0.55, 95% CI, 0.37–0.81; P = 0.002). Duration of disease control (DDC) and OS, however, were comparable between the two arms: median DDC, 10.5 versus 11.3 months, HR 0.92 (95% CI, 0.62–1.36; P = 0.674); median OS, 22.6 versus 22.7 months, HR 0.78 (95% CI, 0.50–1.23; P = 0.284). Adverse events including grade ≥3 fatigue (28.8% versus 8.1%; P = 0.003) and sensory neuropathy (25.4% versus 9.7%; P = 0.022) occurred more frequently in the continuous arm than in the stop-and-go arm. Quality of life (QOL) including global health status, physical/role functioning and other symptom scores significantly favoured the stop-and-go arm. Conclusion Compared with the stop-and-go strategy, maintenance chemotherapy improved PFS but not DDC and OS and had a negative impact on QOL, suggesting the stop-and-go strategy may be an appropriate option in MGC patients following induction chemotherapy.