Evidence map›Paper›PMID 42271445›Full record

ArticleRadiation oncology (London, England)2026

The phase I trial of preoperative short-course chemoradiotherapy with S-1/irinotecan and short-course radiation in locally advanced lower rectal cancer (SHOWTIME study).

Ken Kojo, Toshimichi Tanaka, Takahiro Yamanashi, Hirohisa Miura, Keigo Yokoi, Keita Kojima, Kazuko Yokota, Shogo Kawakami, Hiromichi Ishiyama, Keishi Yamashita and 4 more

Abstract readClinical Trial, Phase I
In one paragraph

Article in Radiation oncology (London, England), 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
–field-weighted citation impact
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

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

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

14 authors.

Ken KojoDepartment of Lower Gastrointestinal Surgery, Kitasato University School of Medicine, 1-15-1, Kitasato, Minami Ward, Sagamihara, Kanagawa, 252-0329, Japan. kkojo@kitasato-u.ac.jp.ORCID http://orcid.org/0000-0001-8744-8358
Toshimichi TanakaDepartment of Lower Gastrointestinal Surgery, Kitasato University School of Medicine, 1-15-1, Kitasato, Minami Ward, Sagamihara, Kanagawa, 252-0329, Japan.
Takahiro YamanashiDepartment of Lower Gastrointestinal Surgery, Kitasato University School of Medicine, 1-15-1, Kitasato, Minami Ward, Sagamihara, Kanagawa, 252-0329, Japan.
Hirohisa MiuraDepartment of Lower Gastrointestinal Surgery, Kitasato University School of Medicine, 1-15-1, Kitasato, Minami Ward, Sagamihara, Kanagawa, 252-0329, Japan.
Keigo YokoiDepartment of Lower Gastrointestinal Surgery, Kitasato University School of Medicine, 1-15-1, Kitasato, Minami Ward, Sagamihara, Kanagawa, 252-0329, Japan.
Keita KojimaDepartment of Lower Gastrointestinal Surgery, Kitasato University School of Medicine, 1-15-1, Kitasato, Minami Ward, Sagamihara, Kanagawa, 252-0329, Japan.
Kazuko YokotaDepartment of Lower Gastrointestinal Surgery, Kitasato University School of Medicine, 1-15-1, Kitasato, Minami Ward, Sagamihara, Kanagawa, 252-0329, Japan.
Shogo KawakamiDepartment of Radiation Oncology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami Ward, Sagamihara, Kanagawa, 252-0329, Japan.
Hiromichi IshiyamaDepartment of Radiation Oncology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami Ward, Sagamihara, Kanagawa, 252-0329, Japan.
Keishi YamashitaDivision of Advanced Surgical Oncology, Research and Development Center for New Medical Frontiers, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami Ward, Sagamihara, Kanagawa, 252-0329, Japan.
Yusuke KumamotoDepartment of General-Pediatric-Hepatobiliary Pancreatic Surgery, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami Ward, Sagamihara, Kanagawa, 252-0329, Japan.
Naoki HikiDepartment of Upper Gastrointestinal Surgery, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami Ward, Sagamihara, Kanagawa, 252-0329, Japan.
Takeo SatoResearch and Development Center for Medical Education, Department of Clinical Skills Education, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami Ward, Sagamihara, Kanagawa, 252-0329, Japan.
Takeshi NaitohDepartment of Lower Gastrointestinal Surgery, Kitasato University School of Medicine, 1-15-1, Kitasato, Minami Ward, Sagamihara, Kanagawa, 252-0329, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundA phase I study was conducted to determine the optimal dose of irinotecan in short-course chemoradiotherapy (SCCRT) using S-1/irinotecan and short-course radiotherapy (SCRT) for the development of a new total neoadjuvant therapy (TNT) regimen that is safe, effective, and has a low patient burden for locally advanced rectal cancer (LARC).

methodsThe objective of this study was to ascertain the maximum tolerated dose (MTD) and the recommended dose (RD) of irinotecan in SCCRT for locally advanced rectal cancer. The assessment of dose-limiting toxicity (DLT) was conducted over a 14-day period following treatment administration. The patient received a 14-day course of chemotherapy, with S-1 administered from the first to the fifth day and from the eighth to the twelfth day. Irinotecan was administered on the first and eighth days of treatment. The radiotherapy regimen was initiated with a total dose of 25 Gy, administered in five fractions from the eighth to twelfth day.

resultsFifteen patients received SCRT in conjunction with S-1 and escalating doses of irinotecan (40-60 mg/m²). All patients completed the SCCRT protocol. At a dose of 60 mg/m², DLT occurred in all patients, thereby establishing this dosage as the MTD. At a dose of 50 mg/m², DLT was observed in two of six patients, thereby establishing this dose as the RD. The most prevalent Grade ≥ 3 adverse event was diarrhea. All patients received CapeOX-based consolidation chemotherapy. Among the 11 surgical cases, the R0 resection rate was 100%, with a pathological complete response in 27.3% and downstaging in 90.9%. Three patients demonstrated a complete clinical response and underwent non-operative management.

conclusionThe safety and feasibility of administering SCCRT with S-1/irinotecan at a 50 mg/m² irinotecan dose have been demonstrated. These findings support further investigation of this regimen in a TNT setting for rectal cancer.

trial registrationThe present study was duly registered with the Japan Clinical Trials Registry (jRCT s031210461). URL: https://jrct.mhlw.go.jp/re .

Indexed as

Antineoplastic Combined Chemotherapy ProtocolsChemoradiotherapyRectal NeoplasmsAdultAgedCamptothecinDrug CombinationsFemaleHumansIrinotecanMaleMaximum Tolerated DoseMiddle AgedNeoadjuvant TherapyOxonic AcidTegafurCamptothecinDrug CombinationsIrinotecanOxonic AcidS 1 (combination)TegafurAdvanced rectal cancerChemoradiotherapyTotal neoadjuvant therapy

Identifiers

PMID42271445
PMCPMC13480079

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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.