In Reply We appreciate the opportunity to respond to the comments provided by the authors of these 2 letters regarding our article.¹ The overall message of the letter from Leeds and Fang seems to be that there are important limitations to consider when using the National Cancer Data Base (NCDB) for research and when interpreting the findings from such studies. Regarding the letter from Renehan et al, the main issue seems to be that contemporary European guidelines contraindicate local excision as a management strategy for squamous cell carcinoma of the anal canal (SCCAC), and they too cite additional limitations associated with the use of NCDB data.

中文翻译：

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国家癌症数据库评估早期肛门癌治疗结果的局限性-答复

回覆我们很高兴有机会回应这2封信的作者对我们文章的评论。¹利兹和方的来信的总体信息似乎是，在使用美国国家癌症数据库（NCDB）进行研究以及解释此类研究结果时，需要考虑一些重要的限制。关于Renehan等人的来信，主要问题似乎是当代欧洲指南禁止将局部切除作为肛管鳞状细胞癌（SCCAC）的治疗策略，并且它们也引用了与使用NCDB数据相关的其他限制。