Purpose

Short-course radiation therapy (SCRT) and nonoperative management are emerging paradigms for rectal cancer treatment. This clinical trial is the first to evaluate SCRT followed by chemotherapy as a nonoperative treatment modality.

Methods

Patients with nonmetastatic rectal adenocarcinoma were treated on the single-arm, Nonoperative Radiation Management of Adenocarcinoma of the Lower Rectum study of SCRT followed by chemotherapy. Patients received 25 Gy in 5 fractions to the pelvis followed by FOLFOX ×8 or CAPOX ×5 cycles. Patients with clinical complete response (cCR) underwent nonoperative surveillance. The primary end point was cCR at 1 year. Secondary end points included safety profile and anorectal function.

Results

From June 2016 to March 2019, 19 patients were treated (21% stage I, 32% stage II, and 47% stage III disease). At a median follow-up of 27.7 months for living patients, the 1-year cCR rate was 68%. Eighteen of 19 patients are alive without evidence of disease. Patients with cCR versus without had improved 2-year disease-free survival (93% vs 67%; P = .006), distant metastasis-free survival (100% vs 67%; P = .03), and overall survival (100% vs 67%; P = .03). Involved versus uninvolved circumferential resection margin on magnetic resonance imaging was associated with less initial cCR (40% vs 93%; P = .04). Anorectal function by Functional Assessment of Cancer Therapy-Colorectal cancer score at 1 year was not different than baseline. There were no severe late effects.

Conclusions

Treatment with SCRT and chemotherapy resulted in high cCR rate, intact anorectal function, and no severe late effects.

NCT02641691.

中文翻译：

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非手术直肠癌治疗短程放疗后化疗：非随机对照试验

目的

短程放射治疗 (SCRT) 和非手术治疗是直肠癌治疗的新兴范例。该临床试验是第一个评估 SCRT 继以化疗作为非手术治疗方式的临床试验。

方法

非转移性直肠腺癌患者接受 SCRT 的下直肠腺癌单臂非手术放射治疗研究，然后进行化疗。患者接受 25 Gy 分 5 次对骨盆进行 FOLFOX ×8 或 CAPOX ×5 周期。临床完全缓解（cCR）的患者接受了非手术监测。主要终点是 1 年时的 cCR。次要终点包括安全性和肛门直肠功能。

结果

从 2016 年 6 月到 2019 年 3 月，19 名患者接受了治疗（21% 的 I 期、32% 的 II 期和 47% 的 III 期疾病）。存活患者的中位随访时间为 27.7 个月，1 年 cCR 率为 68%。19 名患者中有 18 名在没有疾病证据的情况下还活着。与无 cCR 相比，cCR 患者的 2 年无病生存期（93% vs 67%；P  = .006）、无远处转移生存期（100% vs 67%；P  = .03）和总生存期（100 % 与 67%；P  = .03）。磁共振成像中受累与未受累的环切缘与较少的初始 cCR 相关（40% 对 93%；P = .04)。通过癌症治疗功能评估的肛门直肠功能 - 结肠直肠癌评分在 1 年与基线没有差异。没有严重的迟发效应。

结论

SCRT 和化学疗法治疗导致高 cCR 率、完整的肛门直肠功能，并且没有严重的迟发效应。

NCT02641691。