Long-term outcomes of definitive radiotherapy-based comprehensive treatment for inoperable stage I-III non-metastatic pancreatic cancer / 中华放射肿瘤学杂志

ABSTRACT

Objective:To analyze long-term outcomes of inoperable non-metastatic pancreatic cancer patients treated with definitive radiotherapy-based comprehensive treatment.Methods:Clinical data of 168 patients with medically unfit, refusal to surgery or inoperable non-metastatic pancreatic cancer treated with radiotherapy-based comprehensive treatment in PLA General Hospital between January 2016 and December 2020 were retrospectively analyzed. Survival outcomes,prognostic factors and patterns of treatment failure were analyzed in the radiotherapy ( n=95) and combined chemoradiotherapy ( n=73) groups. The survival analysis was conducted by Kaplan-Meier method. The survival curve was compared by log-rank test. Independent prognostic factors were identified by Cox proportional harzard model. Results:With a median follow-up of 20.2 months in the entire group, the median overall survival (OS) and median progression-free survival (PFS) were 18.0 and 12.3 months. The corresponding median OS and median PFS after receiving radiotherapy were 14.3 and 7.7 months. The 1-, 2-and 3-year OS rates were 72.1%, 36.6% and 21.5%, and the 1- and 2-year local control rates were 82.6% and 64.3%, respectively. The median OS for stage Ⅰ, stage Ⅱ and stage III were 27.1, 18.0 and 17.0 months, respectively. There was no significant difference in the median OS of patients with localized disease (stage Ⅰ-Ⅱ) between the radiotherapy and combined chemoradiotherapy groups (21.1 vs. 20.4 months, P=0.470). In patients with locally advanced disease (stage Ⅲ), combined chemoradiotherapy group showed better median OS compared with radiotherapy group (19.2 vs. 13.8 months, P=0.004). Clinical stage, CA19-9 before radiotherapy, comprehensive treatment and biological effective dose (BED 10) were identified as the independent prognostic factors for OS ( P=0.032, 0.011, 0.003 and 0.014). The cumulative 1- and 2-year actuarial rates of treatment failure, local-regional recurrence and distant metastasis were 48% and 74.4%, 15.0% and 27.4%, 23.6% and 33.1%, respectively. Liver metastasis (16.1%, 27/168) and local recurrence (11.9%, 20/168) were the primary patterns of treatment failure. Conclusions:Definitive radiotherapy-based comprehensive treatment effectively prolongs long-term survival in patients with inoperable non-metastatic pancreatic cancer. Definitive radiotherapy can be an alternative treatment option with curative intent for patients with localized pancreatic cancer who are medically unfit or refuse to undergo surgery. The combination of radiotherapy and chemotherapy remains an effective treatment choice for locally advanced unresectable pancreatic cancer.