What is Anal Cancer?Anal cancer is a disease in which cancer cells (rapidly dividing cells) originate from the tissues of the anus or anal canal. Aggressive tumours are tumours that grow rapidly and spread to other parts of the body.
What is the Anus?The anus is the outer lower end of the intestine. Once digested, food travels from the stomach to the small intestine. It then travels from the small intestine to the main part of the large intestine called the colon. The large intestine absorbs water and salt from digested food and sends it back to the bloodstream. The rest is waste known as feces or stool. Stool accumulates in the last part of the intestine and then is excreted out of the body through the anus.
Disease EpidemiologyIt is rare cancer. Among all registered cases, half were diagnosed before metastasis (spread of the tumour from its primary focus to other parts of the body). The average age at development of the disease in most cases is 60 years. It is more common in men than in women.
Disease CausesThere is no well-known cause; however, there are several risk factors such as old age, cigarette smoking, having multiple sex partners, anal sex, human papillomavirus infection, having HIV, and a personal or family history of cervical, vaginal, and vulvar cancer.
Signs and SymptomsIn most cases, the patient is asymptomatic and is only diagnosed at an advanced stage of cancer. Some initial warning signs and symptoms:
- Change in bowel habits, constipation, diarrhea, or more frequent urge to pass stool.
- Dark colour stool due to the presence of blood in the stool
- Feeling as if the bowels are not empty after defecation.
- Bleeding from the anus
- Pain in the abdomen
- Un explained weight loss
- Excessive sweating at the night
DiagnosisThe following diagnostic tests and procedures can be used to make a diagnosis. These are
- Endoscopic examination of the anus, rectum, and large intestine. Endoscopy is a procedure that allows the doctor to visualize the internal organs of the body directly through the endoscope.
- Computed tomography (CT-pelvis) helps to differentiate squamous cell cancer of the rectum from anal cancer.
- Biopsy of the lesion/tumour and histopathological examination