Evidence map›Paper›PMID 41658037›Full record

ArticleSurgical case reports2026

Pathological Complete Response Achieved with Colorectal Cancer-Based Chemotherapy for Locally Recurrent Cecal Neuroendocrine Carcinoma after Surgery: A Case Report.

Kana Kajisako, Taro Tanabe, Naho Nishibayashi, Sachiko Ishida, Suguru Ogihara, Takahiro Hobo, Koji Kobayashi, Hirokazu Toshima, Ken Shimada, Noboru Yokoyama and 1 more

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.

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0citing papers 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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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

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4 · The record

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5 · Who and what money

Authors and funding

11 authors.

Kana KajisakoDigestive Diseases Center, Showa Medical University Koto Toyosu Hospital, Tokyo, Japan.
Taro TanabeDigestive Diseases Center, Showa Medical University Koto Toyosu Hospital, Tokyo, Japan.
Naho NishibayashiDigestive Diseases Center, Showa Medical University Koto Toyosu Hospital, Tokyo, Japan.
Sachiko IshidaDigestive Diseases Center, Showa Medical University Koto Toyosu Hospital, Tokyo, Japan.
Suguru OgiharaDigestive Diseases Center, Showa Medical University Koto Toyosu Hospital, Tokyo, Japan.
Takahiro HoboDigestive Diseases Center, Showa Medical University Koto Toyosu Hospital, Tokyo, Japan.
Koji KobayashiDepartment of Oncology, Showa Medical University Koto Toyosu Hospital, Tokyo, Japan.
Hirokazu ToshimaDepartment of Oncology, Showa Medical University Koto Toyosu Hospital, Tokyo, Japan.
Ken ShimadaDepartment of Oncology, Showa Medical University Koto Toyosu Hospital, Tokyo, Japan.
Noboru YokoyamaDigestive Diseases Center, Showa Medical University Koto Toyosu Hospital, Tokyo, Japan.
Haruhiro InoueDigestive Diseases Center, Showa Medical University Koto Toyosu Hospital, Tokyo, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

introductionPrimary neuroendocrine carcinoma (NEC) of the colon is extremely rare, accounting for only 0.2% of all colorectal malignancies, and is associated with a poor prognosis. Early diagnosis is often challenging, as endoscopic biopsies are frequently misinterpreted as adenocarcinoma. Although platinum-based regimens such as etoposide plus cisplatin or irinotecan are commonly used, no standard chemotherapy protocol has been established. We report a case of locally recurrent cecal NEC that responded remarkably to a colorectal cancer-based chemotherapy regimen, achieving a pathological complete response. CASE PRESENTATION: A 52-year-old man presented with severe anemia. Imaging and colonoscopy revealed a cecal tumor initially diagnosed as adenocarcinoma. He underwent laparoscopic right hemicolectomy with lymph node dissection. Final pathology revealed NEC, staged as pT3N2aM0, Stage IIIB. Adjuvant etoposide-cisplatin chemotherapy was initiated. Three months postoperatively, carcinoembryonic antigen (CEA) rose to 44.4 ng/mL, and CT demonstrated a perianastomotic peritoneal nodule and lymphadenopathy, consistent with recurrence. Considering the adenocarcinoma component in the primary tumor and elevated CEA, chemotherapy was switched to a colorectal cancer-based regimen: FOLFOXIRI plus bevacizumab. After 7 cycles, both radiologic regression and normalization of CEA levels were achieved. Resection of the recurrent lesions confirmed a pathological complete response with no residual tumor cells.

conclusionsTo the best of our knowledge, this is the first reported case of cecal NEC achieving pathological complete regression with a colorectal cancer-based chemotherapy regimen. Our findings indicate that colorectal NEC may respond not only to platinum-based regimens but also to colorectal cancer-based regimens. Furthermore, CEA levels may serve as a clinically relevant biomarker to guide chemotherapy selection in this setting.

Indexed as

CEAchemotherapycolon cancerneuroendocrine carcinomapathological complete response

Identifiers

PMID41658037
PMCPMC12872675

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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.