Evidence map›Paper›PMID 42404091›Full record

ArticleSurgical case reports2026

A Case of Pancreatic Cancer with High Tumor Mutation Burden Showing a Remarkable Response to Pembrolizumab.

Kazuto Takata, Yuki Kitano, Rumi Itoyama, Shigeki Nakagawa, Hideaki Miyamoto, Hirohisa Okabe, Hiromitsu Hayashi, Yasuhito Tanaka, Masaaki Iwatsuki

Abstract readCase Reports
In one paragraph

Article in Surgical case 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.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

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

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Kazuto TakataDepartment of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
Yuki KitanoDepartment of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
Rumi ItoyamaDepartment of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
Shigeki NakagawaDepartment of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
Hideaki MiyamotoDepartment of Gastroenterology and Hepatology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
Hirohisa OkabeDepartment of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
Hiromitsu HayashiDepartment of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
Yasuhito TanakaDepartment of Gastroenterology and Hepatology, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
Masaaki IwatsukiDepartment of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

introductionPancreatic cancer (PC) is an aggressive malignancy with limited therapeutic options and generally poor responsiveness to immune checkpoint inhibitors (ICIs). Microsatellite instability-high (MSI-High) and tumor mutation burden-high (TMB-High) phenotypes are rare, each occurring in approximately 1% of PC cases, but may predict improved response to ICIs. We report a case of recurrent PC harboring both MSI-High and markedly elevated TMB, in which pembrolizumab achieved an exceptional and durable response. CASE PRESENTATION: A 72-year-old man presented with appetite loss, and contrast-enhanced CT revealed a large pancreatic tail tumor invading the stomach, colon, spleen, and left kidney. Fine-needle biopsy confirmed adenocarcinoma. Despite initial modified FOLFIRINOX therapy showing progressive disease, subsequent gemcitabine plus nab-paclitaxel achieved partial response (PR). However, gastrointestinal bleeding due to gastric invasion necessitated surgery. The patient underwent extensive resection, including distal pancreatectomy with splenectomy, total gastrectomy, partial colectomy, nephrectomy, adrenalectomy, and portal vein resection and reconstruction using the left renal vein. Pathology demonstrated well-differentiated ductal adenocarcinoma with multiorgan invasion and portal vein tumor thrombus (ypT3N1M0, Stage IIB, Evans Grade IIb). Although adjuvant chemotherapy was considered, it could not be initiated because of persistent postoperative diarrhea and delayed recovery of the patient's general condition. Four months after surgery, recurrence was detected in the para-aortic lymph nodes, with suspected peritoneal dissemination causing right hydronephrosis, accompanied by elevated carbohydrate antigen 19-9 (CA19-9). Comprehensive genomic profiling using the surgically resected tumor specimen revealed MSI-High status and extremely high TMB (75 mutations/Mb), and genomic alterations in

conclusionsThis case highlights the potential for exceptional and durable response to pembrolizumab in PC characterized by concurrent MSI-High and markedly elevated TMB. Given the rarity of these biomarkers and the typically poor prognosis of PCs, early genomic profiling may facilitate personalized treatment strategies and improve outcomes in selected patients.

Indexed as

comprehensive genomic profilingimmune checkpoint inhibitorsmicrosatellite instability–highpancreatic cancertumor mutation burden–high

Identifiers

PMID42404091
PMCPMC13333211

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.