Risk stratification and prognostic factors in patients with unresectable undifferentiated carcinoma of the pancreas

Undifferentiated carcinoma (UC) of the pancreas has been considered a highly aggressive malignancy. However, only a few studies have systematically described the clinical course of UC patients. The aim of this study was to clarify the prognosis and construct a prognostic model for patients with unresectable UC. This study was conducted at 17 institutions in Japan, and a total of 55 patients were analyzed. The median overall survival (OS) of patients with unresectable UC was 3.95 months. In the multivariate Cox proportional hazards (CPH) model, age ≥65 years, Eastern Cooperative Oncology Group performance status (ECOG PS) ≥2, and C-reactive protein (CRP) >10 mg/L were independent prognostic factors for OS (age ≥65 years: hazard ratio [HR], 2.732; 95% confidence interval [CI], 1.353–5.515; ECOG PS ≥ 2: HR, 7.866; 95% CI, 1.981–31.241; CRP >10 mg/L: HR, 1.956; 95% CI, 1.013–3.775). Based on the β coefficients from the CPH model, the prognostic scores were defined as follows: age ≥65 years (3 points), ECOG PS ≥ 2 (6 points), and CRP >10 ml/L (2 points). The final prognostic model was the sum of the points. The derived prognostic model stratified patients into high-risk (score ≥4) and low-risk (score 0–3) groups, with significant differences in OS (1.45 vs. 8.19 months, respectively; p