Impact of chemoradiotherapy on the survival of unresectable locally advanced pancreatic cancer: a retrospective cohort analysis

Background: The role of chemoradiotherapy in unresectable locally advanced pancreatic cancer is still unclear.

Methods: Data from patients with unresectable locally advanced pancreatic cancer were extracted from the Surveillance, Epidemiology, and End Results Program database. Univariate and multivariate Cox regression analyses were conducted to identify the independent prognostic factors of survival. Propensity score matching was carried out to minimize the interference of confounding factors. Subgroup analysis was performed to screen the characteristics of patients who would benefit from chemoradiotherapy.

Results: A total of 5002 patients with unresectable locally advanced pancreatic cancer were included. Among them, 2423 (48.4%) received chemotherapy, and 2579 (51.6%) received chemoradiotherapy. The median overall survival of all patients was 11 months. Multivariate Cox analysis showed that age (p < 0.001), marital status (p < 0.001), tumor size (p = 0.001), N stage (p = 0.015) and radiotherapy (p < 0.001) were independent prognostic factors of survival. Both before (HR, 0.817; 95% CI, 0.769-0.868; p < 0.001) and after (HR, 0.904; 95% CI, 0.876-0.933; p < 0.001) propensity score matching, chemoradiotherapy significantly improved the median overall survival of patients from 10 to 12 months. Subgroup analysis showed that chemoradiotherapy was significantly associated with improved survival regardless of sex, primary site or N stage. In addition, the following subgroups all significantly benefited from chemoradiotherapy: age ≥ 50 years, not divorced, grade 2-4, tumor size > 2 cm, adenocarcinoma, mucinous adenocarcinoma and white race.

Conclusions: Chemoradiotherapy is highly recommended for patients with unresectable locally advanced pancreatic cancer.