Quite a rare type of condition, anal cancer usually happens due to the uncontrolled proliferation of abnormal cells in the anal canal. The anus is a small opening at the end of the intestines that is attached to the anal canal, a short tube attached at the end of the rectum that facilitates the expulsion of stool from the body. Also Read: Rectal Cancer: Causes, Symptoms And Treatment

anal cancer


Depending upon the type of tumours that give rise to anal cancer, it is subdivided into 6 types. These tumours can be either malignant or benign but if left untreated, the benign ones can turn active and spread to other parts of the body. 

Benign Tumours:

These are non-cancerous tumours that mostly include genital warts, skin tags, polyps and granular cell tumours.

Precancerous Conditions:

Commonly seen in case of Anal Squamous Intraepithelial Neoplasia (ASIL) and Intraepithelial Neoplasia (AIN), although being benign in origin, these tumours become active over time and turn malignant.

Bowen’s Disease:

Also defined as squamous cell carcinoma in situ, this condition is usually characterized by irregular cells on the surface of the anal tissues that haven’t spread onto deeper layers.


A rare form of cancer that arises from the glands that surround the anus.

Squamous Cell Carcinoma:

A most common type of anal cancer, these are chiefly malignant tumours that are caused by abnormal squamous cells that line the anal canal.

Basal Cell Carcinoma:

Quite a rare type of malignant tumour since it affects the skin that is exposed to direct sunlight.


Like any other forms of cancer, the absolute cause of anal cancer is yet to be discovered but it usually happens when a genetic mutation turns normal, healthy cells of the anal tissue into abnormal carcinogenic cells and causes them to grow and multiply at a high rate leading to accumulation of abnormal cells into tumours that slowly metastasize and spread onto nearby tissues. Also Read: Colorectal cancer: What are the causes, symptoms and treatment

Risk Factors

Some researches show that there is a certain risk factor that increases the chances of having anal cancer. These include:

Age: It is commonly seen in people above 50 years.

Multiple Partners: Frequently diagnosed in people involved with multiple partners over their lifetime.

Addiction: People addicted to smoking have a higher risk of anal cancer.

Medical Cancer: Patients with a past medical case of any other form of cancer are more at risk,

Other Infections: Having HPV or Human Papilloma Virus, a sexually transmitted infection increases the risk of anal cancer. The chances of anal cancer also increase if a person is already suffering from HIV or AIDS


The common signs and symptoms of anal cancer are difficult to differentiate since they are quite similar to those of irritable bowel syndrome, haemorrhoids and other gastrointestinal infections, including:

  • Changes in bowel habits
  • Pain, or pressure due to the formation of a lump near the anus
  • Discharge from the anus or itching sensation
  • Thin stools
  • Bleeding from the rectum or anus

Diagnosis And Treatment

It is strictly advised to consult a specialist doctor if you notice any of the above-given signs and symptoms. The doctor usually does a thorough physical check-up of the anus and rectum to find the presence of any lumps or abnormalities. Other diagnostics include:

  • Digital Rectal Exams
  • Imaging Techniques – Ultrasound, MRI-scan, PET-scan, and CT-scan.
  • Anal Pap Smears
  • Biopsy


Although there is no proper cure, the available treatment options usually depend upon the patient’s age and stage of cancer including:

  • Chemotherapy
  • Radiation Therapy
  • Surgery
  • Immunotherapy
  • Supportive Care