What is anal cancer?

It is an uncommon type of cancer, which occurs in the anal canal. The anal canal is a short tube enclosed by muscle at the end of your rectum through which stool leaves your body. Cancer starts when some of the body cells divide without stopping and as it grows, it may stay in the nearby tissues or spread to other body parts. Anal cancer starts just inside or at the cells around the anal opening.


It starts when a genetic mutation turns healthy, normal cells into abnormal cells. Healthy cells multiply and grow at a set rate and die at a set time. Unusual cells multiply and grow out of control and they don’t die. The build-up of abnormal cells forms a tumour. Cancer cells occupy nearby tissues and may separate from the initial tumour to spread to other body parts. Anal cancer is closely linked to a sexually transmitted infection called HPV. As HPV is detected in most anal cancers, it is thought to be the most common cause of anal cancers.

Risk factors

HPV is considered to be the most typical cause of anal cancer, but apart from this, other risk factors can cause anal cancer, such as

  • Older age (55 and older)
  • Multiple sex partners
  • Smoking
  • History of cervical, vulvar or vaginal cancer
  • Feeble immune system due to chemotherapy, organ transplant or HIV
  • Prior pelvic radiation therapy for prostate, bladder, rectal or cervical cancer


  • Practicing safer sex may reduce the chance of HIV and HPV, two sexually transmitted viruses that can increase the risk of anal cancer
  • HPV vaccines have been shown to lower the risk of HPV infection and anal cancer both
  • Smoking is linked to many kinds of cancers, including anal canal cancer. Don’t start smoking and quit if you currently smoke


Sometimes anal cancers don’t have any symptoms. We have mentioned the symptoms that have been seen in many people with anal cancer, but these could be caused because of other less serious conditions as well. If you notice any of the symptoms, do consult an anal cancer doctor.

  • Bleeding from the rectum or anus
  • Discharge, pus or mucous from the anus
  • Change in bowel movement
  • Pain in the anal area
  • Swollen lymph glands in the groin or anal area
  • Narrowing of the stools
  • A mass or growth in the anal opening


Early-stage anal cancers have high cure rates. There are three basic types of anal cancer treatment

  • Surgery- an operation to remove the cancer
  • Chemotherapy- drugs to kill the cancer
  • Radiation therapy- high-dose X-rays to kill cancer cells

Combination therapy with chemotherapy and radiation therapy is considered the gold standard for most anal cancers. Sometimes, early-stage or tiny tumours may be removed surgically without the need for further treatment. For advanced cancers, major surgery is required to remove the tumours.

If you have anal cancer or feel you are at high risk, you can consult the best anal cancer doctor in Kolkata, Dr. Purnendu Bhowmik.