Improving outcomes for uncommon tumours such as anal cancer can be challenging. Evolution of care tends to be incremental rather than transformative and identifying the specific factors facilitating improvement can be difficult. Outcome from specialist units may be better than that demonstrated in trials, posing challenges for development of future trials.

中文翻译：

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惠特尔肛门癌？

改善诸如肛门癌之类的罕见肿瘤的治疗结果可能具有挑战性。护理的发展往往是渐进的，而不是变革性的，确定促进改善的具体因素可能很困难。专科病房的结果可能比试验结果更好，这对将来试验的发展提出了挑战。