Treatment of Anal Cancer

Author : Bhadresh Bundela

Stages of anal cancer

The treating oncologist will want to know whether the tumour is localised to the anus or whether it has spread to the local lymph nodes (usually the groin nodes or pelvic nodes) or whether (the minority of cases) it has spread further afield.
Clinical examination supplemented by scanning will assist in this regard. THe treatment is tailored to the extent of the disease at presentation.

Outcomes of anal cancer

If the patient’s disease is not sterilised by the chemo-radiotherapy programme, then the abdo-perineal resection operation is the fall back position (providing that there is no evidence of metastatic disease).

Treatment of anal cancer

For localised disease to the anus, the standard operation has been abdoperineal resection, (see colorectal cancer section) until recently, and even now this is still advised if the anal sphincter has been destroyed by tumour such that the patient will never be continent of faeces again.

However, in recent years it has been realised that there is a high cure rate by chemo-radiotherapy programmes. It had been long recognised that there was a good response rate of the disease to radiotherapy but the demonstrable augmentation of this response rate into a high cure rate by the addition of synchronous chemotherapy (usually 5-fluorouracil and mitomycin – sometimes cis-platinum) is a discovery of the last decade.

The side effects of the chemo-radiotherapy programme are nausea and soreness of the perineum which can be severe (and occasionally it is worthwhile to perform a temporary defunctioning colostomy to avoid faecal soiling over the sore perineum). Nevertheless the therapy programme is considered an advance as, when the side effects settle, the patient is left with an intact anal sphincter and continent in most instances.

The modern radiation system is with high energy linear accelerators and using conformal technology The long term follow-up of radically radiated patients is not as good as surgery (perhaps 40% cure) but, recently, the use of chemotherapy together with both surgery and radiotherapy has led to improved results all round and may allow conservative therapy to substitute operation in some cases – for one has always got radical cystectomy to fall back on if follow-up cystoscopy shows persisting tumour (but against this argument one may be risking that usually sound first principle of oncology which is to go for first time cure).

Many clinical trials are currently in progress. There is no doubt that modern chemotherapy, using drugs such as cis-platinum and gemcitabine can cause a good regression in transitional carcinoma of the bladder and for younger and fitter patients many would now employ it in conjunction with local therapy (surgery or radiotherapy), but frequently in a clinical trial context.