Anal cancer is an uncommon malignant growth of the anal skin. It presents with anal pain and discharge. Clinical examination may reveal ulceration around the anus, associated anal warts and sometime fungating growth of friable tissue.
The cause of anal cancer is exposure to the human papilloma virus, particularly HPV types 16 and 18. Immunosuppression through HIV / AIDS infection or medically through the use of drugs can be associated with more aggressive anal cancer.
Patients with anal cancer require consultation to determine which lifestyle and medical factors may have contributed to the anal malignancy. Examination is to determine whether the anal canal is anatomically normal and to determine the extent of cancerous tissue growth. Given that the anal cancer commonly spreads to the lymph nodes of the groin, clinical examination will also requires palpation of this area.
Management of anal cancer usually involves colonoscopy and an examination under anaesthetic. These procedures allow exclusion of abnormalities from the rest of the colon and then biopsy of the anal lesion. Imaging, in the form of a CT scan, is required to check the chest and abdomen for spread of the tumour.
Anal cancer is treated with chemoradiotherapy. The treatments are given concurrently and are successful in most at curing the tumour. For those who develop recurrent disease, surgery is required to remove the rectum and anus. This operation is called an abdominoperineal resection.
To avoid anal cancer, the Gardasil vaccine is important early in life to prevent the serious strains of HPV causing dysplasia, the precursor change before anal cancer itself develops. If dysplasia has been diagnosed then it can be kept under surveillance by specialist physicians who monitor the anus with high resolution microscopes called anoscopes.