Pattern of disease progression during third-line or later chemotherapy with nivolumab associated with poor prognosis in advanced gastric cancer: a multicenter retrospective study in Japan

Background Accelerated tumor growth during immunotherapy in pre-existing measurable lesions, hyperprogressive disease (HPD), has been reported. However, progression of non-measurable lesions and new lesions are frequently observed in patients with advanced gastric cancer (AGC). Methods This retrospective study involved AGC patients at 24 Japanese institutions who had measurable lesions and received nivolumab after ≥ 2 lines of chemotherapy. HPD was defined as a ≥ two-fold increase in the tumor growth rate of measurable lesions. The pattern of disease progression was classified according to new lesions in different organs and ascites appeared/increase of ascites. Results Of 245 patients, 147 (60.0%) showed progressive disease (PD) as the best response and 41 (16.7%) showed HPD during nivolumab monotherapy. There was no significant difference in overall survival (OS) between patients with HPD and those with PD other than HPD (median OS 5.0 vs 4.8 months; hazard ratio [HR] 1.0, 95% confidence interval [CI] 0.6–1.5; p = 1.0). Fifty-three patients developed new lesions in different organs and 58 had appearance/increase of ascites; these patients showed shorter OS than those without each of these features (median OS 3.3 vs 7.1 months, HR 1.8, 95% CI 1.2–2.7, p = 0.0031 for new lesions, and 3.0 vs 7.8 months, HR 2.6, 95% CI 1.8–3.8, p