Treatment of Stage II–III Anal Margin Cancer or Stage I–III Anal Canal Cancer
This protocol addresses patients with stage II–III cancer of the anal margin, or stage I–III cancer of the anal canal. These presentations are typically amenable to organ-preserving, definitive treatment using a combined modality approach.
Clinical Scenario
Stage II–III anal margin cancer, or stage I–III anal canal cancer, eligible for definitive non-surgical treatment.
Treatment Approach
The established approach is definitive chemoradiotherapy — radiotherapy delivered concurrently with chemotherapy. The choice of chemotherapy backbone, specific agents, and radiation dose range depend on tumour stage and nodal involvement.
Full regimen details — including agents, scheduling, and dose ranges for each stage — are available in the complete structured protocol.
Clinical Target
Complete response — defined as the absence of tumour and/or ulceration — with clinical tumour response assessed at 26 weeks after completion of chemoradiotherapy.
References
DOI: 10.1016/j.annonc.2021.06.015
- Stage II-III anal margin
- Stage I-III anal canal
- Concomitant 5-FU and MMC with RT is generally recommended [I, A].
- Other options may include 5-FU and cisplatin, and in some cases, other chemotherapy (ChT) combinations can be used.
- CRT for locally advanced anal cancer should be given with an RT dose of >50 Gy; the optimal dose for different tumour stages is not known [III, B].
- The optimal RT dose for primary anal cancer is not known, but doses of at least >45-50 Gy are recommended for T1-2N0 tumours, and doses of 50.4 Gy or higher for T3-4 or N1 tumours [III, B].
- DRE has been the mainstay of determining complete response after treatment, defined as the absence of tumour and/or ulceration.
- Using data from the ACT II trial, the optimum timepoint to assess clinical tumour response after CRT was judged to be 26 weeks [II, B].
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