Primary Tumor Size and Tumor-Vessel Interface Following Capecitabine and Temozolomide for Pancreatic Neuroendocrine Tumor

Authors

Jin Guo
Kever A Lewis
Laura Prakash
Priya Bhosale
Ajaykumar Morani
Matthew H G Katz
Ching-Wei D Tzeng
Naruhiko Ikoma
Rebecca Snyder
Michael P Kim
Chandrikha Chandrasekharan
Arvind Dasari
James C Yao
Jeffrey E Lee
Jessica E Maxwell
Daniel M Halperin

Language

English

Publication Date

2-12-2026

Journal

Current Oncology

DOI

10.3390/curroncol33020111

PMID

41744875

PMCID

PMC12939116

PubMedCentral® Posted Date

2-12-2026

PubMedCentral® Full Text Version

Post-print

Abstract

Capecitabine/temozolomide (CAPTEM) is an established regimen for patients with metastatic pancreatic neuroendocrine tumors (PanNET) that is being increasingly used for tumor volume reduction in patients with borderline anatomically resectable disease. We sought to understand the response of the primary tumor, defined as changes in the tumor–vascular interface (TVI). This is a retrospective, single-institution study of patients with locally advanced or metastatic PanNET treated with CAPTEM between 2010 and 2020. RECISTv1.1 measurements and TVI assessments of the primary tumor were performed on pre- and post-therapy images. Patients with locally advanced or metastatic PanNET at presentation (n = 47) were included. CAPTEM was given for a median of 11 cycles. The most common site of metastatic disease was the liver (n = 38). An objective radiographic response in the primary tumor was observed in 6.4% (95% CI 1.7–18.6%) with clinical benefit in 70.2% (95% CI 54.9–82.2%). TVI was modified from >180° to ≤180° in 16.2% (95% CI 6.0–45.5%). Paired analysis of patients pre- and post-CAPTEM did not demonstrate a statistically significant shift in TVI with treatment (p = 0.134). A total of four patients had a change from an unresectable primary tumor to an anatomically resectable tumor following CAPTEM. In patients with locally advanced or metastatic PanNET, treatment with CAPTEM is associated with low radiographic response rates and changes in TVI. The degree to which these changes may correlate with surgical resection rates or R0 resections is not known. Extending these investigations in a cohort of PanNET patients offered CAPTEM for neoadjuvant intent could be helpful to understand whether these phenomena persist in that context.

Keywords

pancreas neuroendocrine tumors, capecitabine, temozolomide, surgical management

Published Open-Access

yes

Recommended Citation

Guo, Jin; Lewis, Kever A; Prakash, Laura; et al., "Primary Tumor Size and Tumor-Vessel Interface Following Capecitabine and Temozolomide for Pancreatic Neuroendocrine Tumor" (2026). Faculty, Staff and Student Publications. 5984.
https://digitalcommons.library.tmc.edu/uthgsbs_docs/5984