Delivery rate of patients with advanced gastric cancer to third-line chemotherapy and those patients' characteristics: an analysis in real-world setting

Background: Nivolumab has recently become available for third-line chemotherapy of advanced gastric cancer in Japan. The drug is expected to provide long-term survival in some patients. However, not all patients receive third-line therapy. in this study, we investigated the frequency of prescribing and the predictive factors for prescribing of third-line chemotherapy for patients with advanced gastric cancer. Methods: We retrospectively analyzed the medical records of 271 patients with unresected advanced gastric cancer who had started chemotherapy between January 2006 and June 2017 at Kurashiki Central Hospital. Patients' median age was 68 years, and 190 patients were male. We compared baseline characteristics of patients who did or did not receive third-line chemotherapy and, through multivariate logistic-regression analysis, identified potential predictive factors for receiving third-line chemotherapy. Results: Among the 271 patients, 71 (26.2%) received third-line chemotherapy. In the univariate analysis, the rate of receiving this care was significantly related to patients' performance status, cancer histology, and several laboratory variables at baseline. Multivariate analysis revealed that performance status 0 and serum C-reactive protein levels <= 0.6 mg/dL were independent and significant predictive factors for administration of the third-line chemotherapy; adjusted odds ratios of the two factors were 4.17 (95% confidence interval, 2.13-8.15) and 2.46 (1.19-5.08), respectively. Conclusions: in this real-world study, only 26.2% of patients received third-line chemotherapy. Poor performance status and high serum C-reactive protein value at the start of first-line chemotherapy were significantly associated with lower frequency of administration of third-line chemotherapy.