Background  Comprehensive treatment remains the primary treatment for patients with non-surgical pancreatic cancer, but the optimal treatment modality and outcome are unclear.

  Objective  To analyze the clinicopathological characteristics, treatment modality and prognosis of non-surgical patients receiving radiotherapy-based comprehensive treatment for pancreatic cancer.

  Methods  From January 2016 to December 2020, a total of 230 medically unfit or inoperable pancreatic cancer patients treated with radiotherapy-based comprehensive treatment were enrolled. The median overall survival (mOS) and progression-free survival (mPFS) rates were calculated using the Kaplan-Meier method. Independent prognostic factors were identified by Cox proportional harzard model.

  Results  There were 140 males and 90 females, with a median age of 64 years (range, 33 to 88 years). With a follow-up time of 19.9 months. The mOS and mPFS were 17.1 months and 10.3 months, respectively. The 1-year, 2-year, 3-year, 4-year and 5-year OS were 68.1%, 30.0%, 16.0%, 4.9% and 2.5%, respectively. In patients with localized, locally advanced, and metastatic pancreatic cancer, the median OS were 21.1, 17.0 and 14.1 months, and the mPFS was 14.0, 12.7 and 6.9 months, respectively. There was no significant difference in mOS of patients with localized stage treated with radiotherapy alone (RT) and combined-modality therapy (CMT) (21.1 months vs 19.3 months, P=0.620). Compared with the RT group, the CMT group demonstrated better survival in patients with locally advanced (19.2 vs 11.6 months, P=0.003) and metastatic pancreatic cancer (15.7 months vs 8.0 months, P=0.017). Subgroup analysis of patients in the CMT group showed that the mOS in the induction chemotherapy followed by radiotherapy and consolidation chemotherapy (CT-RT-CT) group, chemotherapy followed by radiotherapy (CT-RT) group and radiotherapy followed by chemotherapy (RT-CT) group were 23.1 months, 16.4 months and 18.0 months, respectively (P=0.007). There was a significant difference in survival of patients with locally advanced stage in above three groups (25.5 months vs 16.4 months and 18.0 months, P=0.034). Clinical stage, baseline CA19-9, treatment modality and radiotherapy site were independent factors affecting patients’ survival (all P<0.05).

  Conclusion  Patients with non-surgical pancreatic cancer have a significantly improved overall survival when treated with radiotherapy-based comprehensive treatment. In patients with localized-stage pancreatic cancer who are medically unfit or inoperable, radiotherapy alone is as effective as a combination of radiotherapy and chemotherapy, indicating that modern radiotherapy can serve as an alternative treatment option for these entities. The combination of radiotherapy and chemotherapy remains the preferred treatment option for patients with locally advanced and metastatic pancreatic cancer, while CT-RT-CT may be a better treatment option for selective patients with locally advanced disease.