Evidence map›Paper›PMID 42000785›Full record

ArticleScientific reports2026

Extrapancreatic extension modifies chemotherapy benefit in resected pancreatic ductal adenocarcinoma: a population-based cohort study.

Shuai Liang, Xiaolin Dou, Xuejun Gong, Hongqin Jiang, Wei Wei

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Article in Scientific reports, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

5 authors.

Shuai LiangDepartment of General Surgery, Xiangya Hospital of Central South University, No. 87 Xiangya Road, Changsha, 410008, Hunan Province, China.
Xiaolin DouDepartment of General Surgery, Xiangya Hospital of Central South University, No. 87 Xiangya Road, Changsha, 410008, Hunan Province, China.
Xuejun GongDepartment of General Surgery, Xiangya Hospital of Central South University, No. 87 Xiangya Road, Changsha, 410008, Hunan Province, China.
Hongqin JiangXiangya Nursing School, Central South University, Changsha, 410008, Hunan Province, China.
Wei WeiDepartment of General Surgery, Xiangya Hospital of Central South University, No. 87 Xiangya Road, Changsha, 410008, Hunan Province, China. weiweicsu@outlook.com.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

The effect of extrapancreatic extension (EPE) on the benefit of chemotherapy remains unclear. We analyzed 22,045 surgically treated patients with resected PDAC from the SEER database (2004–2022). Variable importance was assessed using Random Survival Forest models with SHAP and permutation methods. Cox proportional hazards models evaluated survival associations and EPE-chemotherapy interactions on multiplicative and additive scales, with Fine-Gray competing risk models for sensitivity analyses. Variable importance analysis identified chemotherapy, EPE, and N stage as the most influential prognostic factors. Chemotherapy absence increased disease-specific mortality (adjusted HR 1.45, 95% CI 1.39–1.52, p < 0.001), while EPE conferred additional risk (adjusted HR 1.25, 95% CI 1.19–1.31, p < 0.001). Notably, within the EPE stratum, chemotherapy absence increased mortality risk by 83% (adjusted HR 1.83, 95% CI 1.75–1.91) versus 34% (adjusted HR 1.34, 95% CI 1.23–1.46) in non-EPE patients. EPE patients receiving chemotherapy achieved comparable adjusted 3-year disease-specific survival to non-EPE patients without chemotherapy (39.5% vs 35.0%). Significant multiplicative interaction (HR 1.37, 95% CI 1.24–1.50, p < 0.001) and additive interaction (RERI 0.63, 95% CI 0.51–0.76, p < 0.001) were observed, with consistent patterns across tumor size categories validated in competing risk analyses. This population-based analysis revealed EPE as an independent adverse prognostic factor in resected PDAC and a significant EPE-chemotherapy interaction on both multiplicative and additive scales across tumor size categories. Despite conferring worse prognosis, EPE-positive patients receiving chemotherapy achieved survival comparable to that of EPE-negative patients without chemotherapy, underscoring the importance of ensuring receipt of chemotherapy in EPE-positive disease. These findings support the need to re-evaluate the role of EPE in staging systems; however, prospective validation is warranted.

Indexed as

Carcinoma, Pancreatic DuctalPancreatic NeoplasmsAgedCohort StudiesFemaleHumansMaleMiddle AgedNeoplasm StagingPrognosisProportional Hazards ModelsSEER ProgramChemotherapyExtrapancreatic extensionInteraction analysisPancreatic ductal adenocarcinomaSEER

Identifiers

PMID42000785
PMCPMC13250076

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