Anal cancer is a cancerous condition where malignant cells develop in the anus. It is a very rare type of cancer. The anus is where the stool leaves your body which is made up of outer layers of skin and the end of your large intestine. The anal canal is part of the anus between the rectum and the canal opening. The prognosis is poor due to chances of metastasis to a distant part of the body through lymph nodes. It is most commonly diagnosed in men over 60 years of age and in women over 50 years.