Although rare, the rate of squamous cell carcinoma of the anus (SCCA) is rising globally. Most patients present with nonmetastatic disease and are curable with appropriate treatment, which has evolved significantly over the last several decades. Before the 1970s, SCCA was managed with radical surgery, resulting in a permanent colostomy. Researchers found that preoperative treatment with chemotherapy and concurrent radiation could achieve a pathologic complete response. After this observation, definitive therapy shifted from radical surgery to sphincter-preserving chemoradiation. Investigations into the necessity of chemotherapy and the optimal regimen found that chemotherapy with mitomycin-C and 5-fluorouracil is required for cure. Further studies evaluating the addition of induction or maintenance chemotherapy, monoclonal antibody therapy, or higher radiation doses have demonstrated no significant benefit to disease control. Advanced radiation delivery with intensity-modulated radiotherapy techniques is now considered the standard of care because of its prospectively determined, favorable acute toxicity profile compared with 3-dimensional conformal radiation. It is important to note that chemoradiation treatment response may be slow (up to 26 weeks) and should be assessed through serial clinical examinations. Today, surgical management of SCCA is reserved only for the lowest risk, early stage tumors or for recurrent/persistent disease. Current studies are evaluating radiation dose de-escalation in early stage disease and radiation dose escalation and the addition of immune checkpoint inhibitors in locally advanced cancers. In reviewing how and why modern-day treatment of SCCA was established, the objective of this report is to reenforce adherence to current treatment paradigms to assure the best possible outcomes for patients.

中文翻译：

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肛门癌治疗的当前治疗和未来方向

虽然罕见，但肛门鳞状细胞癌 (SCCA) 的发病率在全球范围内呈上升趋势。大多数患者存在非转移性疾病，并且可以通过适当的治疗治愈，这在过去几十年中发生了显着变化。在 1970 年代之前，SCCA 通过根治性手术进行管理，导致永久性结肠造口术。研究人员发现，术前化疗和同步放疗可以达到病理完全缓解。在此观察后，确定性治疗从根治性手术转变为保留括约肌的放化疗。对化疗的必要性和最佳方案的调查发现，治愈需要用丝裂霉素-C和5-氟尿嘧啶化疗。进一步研究评估增加诱导或维持化疗、单克隆抗体治疗、或更高的辐射剂量已证明对疾病控制没有显着益处。与 3 维适形放射相比，采用调强放射治疗技术的先进放射递送现在被认为是护理标准，因为它具有前瞻性确定的、有利的急性毒性特征。值得注意的是，放化疗反应可能很慢（长达 26 周），应通过一系列临床检查进行评估。如今，SCCA 的手术治疗仅用于风险最低的早期肿瘤或复发/持续性疾病。目前的研究正在评估早期疾病中的辐射剂量降低和辐射剂量升高以及在局部晚期癌症中添加免疫检查点抑制剂。