Additional adjuvant radiotherapy improves survival at 1 year after surgical treatment for pancreatic cancer patients with T4, N2 disease, positive resection margin, and receiving adjuvant chemotherapy

Lili Wu; Yaolin Xu; Yuhong Zhou; Zhaochong Zeng; Yue Fan; Dansong Wang; Wenchuan Wu; Xi Guo; Minzhi Lv; Yuxiu Ouyang; Shisuo Du; Wenhui Lou

doi:10.3389/fonc.2023.1109068

Additional adjuvant radiotherapy improves survival at 1 year after surgical treatment for pancreatic cancer patients with T₄, N₂ disease, positive resection margin, and receiving adjuvant chemotherapy

Front Oncol. 2023 Jul 18:13:1109068. doi: 10.3389/fonc.2023.1109068. eCollection 2023.

Authors

Lili Wu¹, Yaolin Xu^{2

3

4}, Yuhong Zhou⁵, Zhaochong Zeng¹, Yue Fan⁶, Dansong Wang², Wenchuan Wu^{2

3

4}, Xi Guo⁵, Minzhi Lv⁷, Yuxiu Ouyang⁸, Shisuo Du¹, Wenhui Lou^{2

3

4}

Affiliations

¹ Department of Radiotherapy, Zhongshan Hospital Fudan University, Shanghai, China.
² Department of Pancreatic Surgery, Zhongshan Hospital Fudan University, Shanghai, China.
³ Cancer Center, Zhongshan Hospital Fudan University, Shanghai, China.
⁴ Department of General Surgery, Zhongshan Hospital Fudan University, Shanghai, China.
⁵ Department of Medical Oncology, Zhongshan Hospital Fudan University, Shanghai, China.
⁶ Department of Traditional Chinese Medicine, Zhongshan Hospital Fudan University, Shanghai, China.
⁷ Department of Biostatistics, Zhongshan Hospital Fudan University, Shanghai, China.
⁸ Department of Abdominal Tumor Radiotherapy, Guangdong Province Zhongshan City People's Hospital, Zhongshan, Guangdong, China.

Abstract

Background: While adjuvant chemotherapy has been established as standard practice following radical resection of pancreatic ductal adenocarcinoma (PDAC), the role of adjuvant radiation therapy (RT) and which patients may benefit remains unclear.

Methods: This retrospective study included PDAC patients who received pancreatic surgery from April 2012 to December 2019 in Zhongshan Hospital Fudan University. Patients with carcinoma in situ, distant metastasis, and without adjuvant chemotherapy were excluded. Cox proportional hazards modeling of survival were constructed to find potential prognostic factors. Propensity score matching (PSM) and exploratory subgroup analyses were used to create a balanced covariate distribution between groups and to investigate therapeutic effect of radiotherapy in certain subgroups.

Results: A total of 399 patients were finally included, 93 of them receiving adjuvant chemoradiotherapy (C+R+) and 306 of them receiving chemotherapy only. Patients in C+R+ group were more likely to be male patients with T3-4 disease. Lymph node metastases was the only negative prognostic factor associated with overall survival (OS). Additional adjuvant RT was not associated with an OS benefit both before and after PSM. Surprisingly, a trend towards improved OS with RT among patients with either T4, N2 disease or R1 resection becomes significant in patients alive more than 1 year after surgery.

Conclusion: Adjuvant RT was not associated with an OS benefit across all patients, though did show a possible OS benefit for the subgroup with T4N2 disease or R1 resection at 1 year after surgery.

Keywords: chemotherapy; overall survival; pancreatic ductal adenocarcinoma; radiotherapy; surgery.

Grants and funding

This work was supported by the National Nature Science Foundation of China (81773220, 82073479, 82273382、81827807、81972218、81972257、82103409、82272929、82173116), Shanghai ShenKang Hospital Development Centre Project (SHDC2020CR2017B), Program of Shanghai Academic/Technology Research Leader (23XD1400600), China Postdoctoral Science Foundation (2021M690037), Shanghai Sailing Program (21YF1407100), Science and Technology Planning Project of Yunnan Province (202305AF150148), and Shanghai Municipal Health Commission (20224Y0307). The funding agencies had no role in the study design, data collection and analyses, decision to publish, or preparation of the manuscript.