ORIGINAL RESEARCH article

Front. Oncol.

Sec. Gastrointestinal Cancers: Colorectal Cancer

Volume 15 - 2025 | doi: 10.3389/fonc.2025.1566569

This article is part of the Research TopicMolecular Epigenetic Mechanisms in Early-Onset Colorectal CancerView all articles

Postoperative Adjuvant Chemotherapy in Patients with Stage II Early Onset Colorectal Cancer: Exploration and Discovery Using Real-world Data and the SEER Database

Provisionally accepted
Shikun  caoShikun cao1yihuan  qiaoyihuan qiao2lijun  wulijun wu1qi  chenqi chen1Kai  TianKai Tian1jipeng  lijipeng li2Chungen  XingChungen Xing1*
  • 1Second Affiliated Hospital of Soochow University, Suzhou, China
  • 2Xijing Hospital, Air Force Medical University, Xi’an, Shaanxi Province, China

The final, formatted version of the article will be published soon.

The incidence of early-onset colorectal cancer (EOCRC) is rising, yet intensive postoperative adjuvant chemotherapy (ACT) often results in overtreatment with minimal prognostic benefit.This study aims to assess the therapeutic necessity of ACT in stage II EOCRC patients and to identify potential ACT candidates.Methods: A total of 296 non-ACT and 50 ACT patients with stage II EOCRC were included from Xijing Hospital (XJCRC), and 2067 non-ACT and 1163 ACT patients were enrolled from the Surveillance, Epidemiology, and End Results (SEER) cohort.To address selection bias and confounding, propensity score matching, inverse probability treatment weighting (IPTW), and multivariate Cox regression analyses were utilized. Survival curves and landmark analysis were employed to compare Overall Survival (OS) differences.Results: Similar OS were observed between ACT and non-ACT groups in both cohorts before and after adjustment for confounders. No significant survival differences were noted in dMMR (P = 0.48), pMMR (P = 0.07), and T3 (P = 0.83) subgroups. However, T4 stage patients receiving ACT demonstrated prolonged survival compared to non-ACT counterparts, particularly after three years (P = 0.007), as identified by landmark analysis.Conclusions: Most stage II EOCRC patients might yield limited benefits from postoperative ACT, with the sole exception of those at T4 stage, who could experience long-term clinical advantages.

Keywords: Early onset colorectal cancer, Adjuvant chemotherapy, Deficient mismatch repair, Survival, Landmark analysis

Received: 25 Jan 2025; Accepted: 14 May 2025.

Copyright: © 2025 cao, qiao, wu, chen, Tian, li and Xing. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Chungen Xing, Second Affiliated Hospital of Soochow University, Suzhou, China

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