Practical prognostic index for survival in patients with unresectable pancreatic cancer treated with gemcitabine or S-1.

Background/aims: We performed this retrospective cohort study to identify prognostic factors for unresectable pancreatic cancer treated with current standard therapy using gemcitabine (GEM) or S-1 and to stratify patients prior to treatment using a prognostic index (PI).

Methodology: We analyzed 182 patients with unresectable pancreatic cancer, who had received GEM or S-1 as first-line chemotherapy. Factors that contributed to the prognosis were identified by univariate and multivariate analysis using a Cox proportional hazards model. The PI was constructed using the factors identified in the multivariate analysis.

Results: By multivariate analysis, performance status (PS), stage, and absolute neutrophil count (ANC) were identified as factors that independently contributed to the prognosis of unresectable pancreatic cancer (P < 0.05). The hazard ratios were 1.69, 3.33, and 1.18, respectively. In addition, PI was calculated using these three factors. Patients were classified into three groups according to the PI values. A significant difference was observed among the survival curves of these three groups (P < 0.05).

Conclusions: We identified three prognostic factors in the population after the introduction of S-1, and have created a simple and useful PI. This index demonstrates the ability to accurately classify advanced pancreatic cancer patients before the start of treatment.