人们普遍认为，肿瘤分期和大小会影响局部晚期直肠癌（LARC）对新辅助治疗的反应。迄今为止，关于器官保存的研究包括各种大小和 TNM 分期的肿瘤。本研究的目的是根据每个相关的 TNM 分期和肿瘤大小报告肿瘤反应。纳入了 2014 年至 2021 年接受 LARC 治疗的 cT2-3NxM0 肿瘤患者，这些患者接受新辅助放化疗联合或不联合诱导化疗。在诊断时（cTNM）对肿瘤进行分期并通过盆腔 MRI 计算肿瘤大小。肿瘤大小基于每个肿瘤最长轴上的最大尺寸。临床反应是根据治疗后盆腔 MRI 和手术后的病理反应来定义的。使用 IBM SPSS Statistics™ 版本 20 进行统计分析。432 名患者的数据分析如下：cT2N0 (n = 51)、cT2N (n = 36)、cT3N0 (n = 76)、cT3N (n = 270)。完全或接近完全缓解（cCR 或 nCR）的比率从 cT2N0 ≤ 3 cm 的 77% 到 cT3N  > 4 cm 的 20% 不等。 86% 的 cT2N0 患者、50% 的 cT2N 患者、39% 的 cT3N0 患者和 12% 的 cT3N 患者实现了 2 年器官保留且无复发。根据肿瘤分期和大小，肿瘤反应存在显着差异。肿瘤反应似乎与 TNM 分期和肿瘤大小的增加成反比。这些数据可以支持器官保存计划选择性患者招募的细化和共同决策。© 2024。Springer Nature Switzerland AG。

It is accepted that tumor stage and size can influence response to neoadjuvant therapy in locally advanced rectal cancer (LARC). Studies on organ preservation to date have included a wide variety of size and TNM stage tumors. The aim of this study was to report tumor response based on each relevant TNM stage and tumor size.Patients treated with LARC from 2014 to 2021 with cT2-3NxM0 tumors who received neoadjuvant chemoradiotherapy with or without induction chemotherapy were included. Tumors were staged and tumor size calculated on pelvic MRI at the time of diagnosis (cTNM). Tumor size was based on the largest dimension taken on the longest axis of each tumor. Clinical response was defined on the basis of post-treatment pelvic MRI and pathological response following surgery, when performed. Statistical analysis was performed using IBM SPSS Statistics™, version 20. Data from 432 patients were analyzed as follows: cT2N0 (n = 51), cT2N+ (n = 36), cT3N0 (n = 76), cT3N+ (n = 270).The rate of complete or near-complete response (cCR or nCR) varied from 77% in cT2N0 ≤ 3 cm to 20% in cT3N+ > 4 cm. Organ preservation without recurrence at 2 years was achieved in 86% of patients with cT2N0, 50% in cT2N+, 39% in cT3N0, and 12% in cT3N+.There is significant variation in tumor response according to tumor stage and size. Tumor response appears inversely proportional to increasing TNM stage and tumor size. This data can support both refinement of selective patient recruitment to organ preservation programs and shared decision-making.© 2024. Springer Nature Switzerland AG.