Impact of immunotherapy use in patients with stage IV pancreatic carcinoma

Background: Most patients with pancreatic cancer have non-resectable disease at the time of diagnosis and usually die within 6-12 months. Despite indications in other solid tumors, the role of immunotherapy (IO) is unknown for late stage, advanced pancreatic cancer. Methods: Using the National Cancer Database (NCDB), cases of Stage IV pancreatic cancers diagnosed in the period of 2014-2016 with at least 30-day follow up were retrospectively analyzed. The following clinical demographics were included: age (younger than 70 vs. older than 70), sex (male vs. female), race (whites vs. others), insurance (uninsured vs. insured), type of institution (academic vs. nonacademic), liver metastasis (yes vs. no), lung metastasis (yes vs. no), external beam radiation (yes vs. no), systemic chemotherapy (yes vs. no) and IO (yes vs. no). survival analysis was performed using Kaplan-Meier curves and Log-rank tests. Multivariable Cox proportional hazard models and propensity score matching analysis were also utilized. A P value <0.05 was considered significant. Results: Among 25,596 eligible cases, 163 patients were treated with IC). A significant association between the use of IO and several clinical demographics (age <70, academic institution, adenocarcinoma, lung metastasis, radiation, chemotherapy) was noted. Chemotherapy was administered in 133 (82%) and 16,342 (64%) of cases in the IO and non-IO groups, respectively. Use of IO was associated with improved overall survival (OS) in both univariate and multivariate analyses (P<0.0001 for each). Median OS (in months) was 12.2 in the IO group vs. 5.8 in the non-IO group. Landmark analysis in the IO group showed 12 and 24-month survival of 51.0% and 20.0% respectively, as compared with 28.2% and 11.9% in the non-IO group. Propensity score matching analysis also demonstrated a trend toward improved OS in IO group (P=0.0753). Median survival was 12.2 and 8.9 months, respectively. Conclusions: This retrospective data analysis using a large cancer database suggests that use of IO could improve survival in patients with advanced pancreatic cancer. More studies will be needed in the future to validate these results.