Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada.
Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
Int J Colorectal Dis. 2021 Jun;36(6):1111-1122. doi: 10.1007/s00384-021-03846-5. Epub 2021 Jan 24.
Patients with stage I anal squamous cell carcinoma (SCC) have been underrepresented in landmark trials showing superiority of chemoradiotherapy over radiotherapy for definitive treatment. This review aims to elucidate whether definitive treatment with radiotherapy versus chemoradiotherapy is associated with differences in survival and treatment-related toxicity outcomes in patients with stage I anal SCC.
Medline, EMBASE, and CENTRAL were searched as of November 2020 to identify studies comparing outcomes of radiotherapy versus chemoradiotherapy for non-operative treatment of patients with stage I anal SCC. The primary outcomes were 5-year overall survival and 5-year disease-free survival. The secondary outcome was treatment-related toxicities. A pairwise meta-analysis was performed using an inverse-variance random-effects model.
From 2174 citations, 5 retrospective studies with 415 patients treated with radiotherapy and 3784 patients treated with chemoradiotherapy were included. Patients treated with chemoradiotherapy had an increased 5-year overall survival (RR 1.18, 95% CI 1.10-1.26, p < 0.00001, I = 0%) but no significant difference in 5-year disease-free survival (RR 1.01, 95% CI 0.92-1.11, p = 0.87, I = 0%). Treatment-related toxicities could not be meta-analyzed due to heterogeneity. Limited data from individual studies suggested an increased frequency of select toxicities with chemoradiotherapy.
Radiotherapy may be an appropriate alternative to chemoradiotherapy for patients with stage I anal SCC who may be unable to tolerate chemotherapy-related toxicity; however, chemoradiotherapy remains the gold standard. Larger prospective studies comparing strategies for this select patient population are needed to clarify whether treatment can be de-escalated.
在显示放化疗优于单纯放疗作为确定性治疗的里程碑式试验中，I 期肛门鳞癌（SCC）患者代表性不足。本综述旨在阐明在 I 期肛门 SCC 患者中，与单纯放疗相比，放化疗作为确定性治疗是否与生存和治疗相关毒性结局的差异相关。
截至 2020 年 11 月，通过 Medline、EMBASE 和 CENTRAL 检索比较非手术治疗 I 期肛门 SCC 患者放疗与放化疗结局的研究。主要结局为 5 年总生存率和 5 年无病生存率。次要结局为治疗相关毒性。采用逆方差随机效应模型进行成对荟萃分析。
从 2174 条引文，纳入了 5 项回顾性研究，共纳入 415 例接受放疗和 3784 例接受放化疗的患者。接受放化疗的患者 5 年总生存率增加（RR 1.18，95%CI 1.10-1.26，p<0.00001，I=0%），但 5 年无病生存率无显著差异（RR 1.01，95%CI 0.92-1.11，p=0.87，I=0%）。由于异质性，无法对治疗相关毒性进行荟萃分析。来自个别研究的有限数据表明，放化疗毒性的选择性频率增加。
对于可能无法耐受化疗相关毒性的 I 期肛门 SCC 患者，放疗可能是放化疗的合适替代方法；然而，放化疗仍是金标准。需要更大规模的前瞻性研究来比较这种特定患者人群的治疗策略，以明确是否可以降低治疗强度。
