BACKGROUND Prospective randomized trials have not yet identified baseline features predictive of organ preservation in locally advanced rectal cancers treated with total neoadjuvant therapy and a selective watch-and-wait strategy. METHODS This was a secondary analysis of the OPRA trial, which randomized patients with stage II-III rectal adenocarcinoma to receive either induction or consolidation total neoadjuvant therapy. Patients were recommended for total mesorectal excision, or watch and wait based on clinical response at 8 ± 4 weeks after completing treatment. Standardized baseline clinical and radiological variables were collected prospectively. Survival outcomes, including total mesorectal excision-free survival, disease-free survival, and overall survival, were assessed by intention-to-treat analysis. Cox proportional hazards models were used to evaluate associations between baseline variables and survival outcomes. RESULTS Of the 324 patients randomized for the OPRA trial, 38 (11.7%) had cT4 tumours, 230 (71.0%) cN-positive disease, 101 (32.5%) mesorectal fascia involvement, and 64 (19.8%) extramural venous invasion. Several baseline features were independently associated with recommendation for total mesorectal excision on multivariable analysis: nodal disease (HR 1.66, 95% c.i. 1.12 to 2.48), extramural venous invasion (HR 1.57, 1.07 to 2.29), mesorectal fascia involvement (HR 1.45, 1.01 to 2.09), and tumour length (HR 1.11, 1.00 to 1.22). Of these, nodal disease (HR 2.02, 1.15 to 3.53) and mesorectal fascia involvement (HR 2.02, 1.26 to 3.26) also predicted worse disease-free survival. Age (HR 1.03, 1.00 to 1.06) was associated with overall survival. CONCLUSION Baseline MRI features, including nodal disease, extramural venous invasion, mesorectal fascia involvement, and tumour length, independently predict the likelihood of organ preservation after completion of total neoadjuvant therapy. Mesorectal fascia involvement and nodal disease are associated with disease-free survival.

中文翻译：

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直肠腺癌器官保留 （OPRA） 试验中成功保留器官的基线 MRI 预测因子。


背景 前瞻性随机试验尚未确定预测接受全新辅助治疗和选择性观察等待策略治疗的局部晚期直肠癌器官保留的基线特征。方法 这是对 OPRA 试验的二次分析，该试验将 II-III 期直肠腺癌患者随机分配接受诱导或巩固全新辅助治疗。建议患者进行全直肠系膜切除术，或在完成治疗后 8 ± 4 周根据临床反应观察和等待。前瞻性收集标准化基线、临床和放射学变量。通过意向性治疗分析评估生存结局，包括直肠系膜切除术无总生存期、无病生存期和总生存期。Cox 比例风险模型用于评估基线变量与生存结局之间的关联。结果 在随机分配到 OPRA 试验的 324 例患者中，38 例 （11.7%） 患有 cT4 肿瘤，230 例 （71.0%） cN 阳性疾病，101 例 （32.5%） 直肠系膜筋膜受累，64 例 （19.8%） 壁外静脉浸润。几个基线特征与多变量分析中全直肠系膜切除术的建议独立相关：淋巴结疾病 （HR 1.66,95% CI 1.12 至 2.48）、壁外静脉浸润 （HR 1.57,1.07 至 2.29），直肠系膜筋膜受累 （HR 1.45,1.01 至 2.09）和肿瘤长度 （HR 1.11,1.00 至 1.22）。其中，淋巴结疾病 （HR 2.02， 1.15 至 3.53） 和直肠系膜筋膜受累 （HR 2.02， 1.26 至 3.26） 也预测较差的无病生存率。年龄 （HR 1.03， 1.00 至 1.06） 与总生存期相关。 结论 基线 MRI 特征，包括淋巴结疾病、壁外静脉浸润、直肠系膜筋膜受累和肿瘤长度，独立预测完成全新辅助治疗后器官保留的可能性。直肠系膜筋膜受累和淋巴结疾病与无病生存率相关。