An anal carcinoma is a cancer of the intestinal outlet. It is a malignant tumour which can be treated well in most cases. Untreated, however, it can lead to incontinence (loss of control over bowel movements) and even death.
The disease is rare and benign tumours of the anus are much more common. Symptoms may include pain during bowel movement, foreign body sensation and bleeding at the bowel outlet. If the doctor’s examination leads to the suspicion of anal carcinoma, the diagnosis is confirmed or excluded by taking a sample. The chance of survival and the treatment options depend on the size and spread of the cancer.
There is no clear cause of anal carcinoma, but it has been shown that various risk factors are associated with the disease. In more than 80% of patients, an infection with certain viruses (HPV = human pappiloma viruses) can be detected, which are considered to be the cause of various cancers. These viruses are transmitted through unprotected sexual intercourse.
The use of condoms offers protection against infection with these viruses. Other risk factors that favour anal carcinoma are sexually transmitted diseases, a high number of sexual partners (over 10) and passive anal intercourse, especially in men. However, women are more often affected by anal carcinoma overall. A weakened immune system, as in AIDS or after organ transplantation, also increases the risk. In addition, smokers are at increased risk of developing the disease.
In order to diagnose anal carcinoma, the physical examination and the medical interview (anamnesis) are most important. If one goes to the doctor because of symptoms such as swelling at the rectal outlet or problems with bowel movements, the doctor will ask various questions about the symptoms as well as possible further diseases. A complete anamnesis also includes an interview on sexual behaviour.
These very intimate questions can be very important for the doctor in making an assessment. By specifically examining the anal region, including palpation of the rectum with the finger, the doctor can often already make a diagnosis. In order to confirm or disprove it, a tissue sample may be taken next and examined.
In the case of anal carcinoma, this can also help to determine the type of cancer cells and the degree of degeneration. Once the diagnosis is confirmed, various examinations are then carried out to determine whether the cancer has already spread to other parts of the body. In addition to palpation of the lymph node regions, these usually include an ultrasound of the anal canal, a rectal endoscopy and computer tomography (sectional imaging with X-rays in the “tube”) of the abdominal cavity and the chest.
Tumour markers can be determined in the blood of anal carcinoma patients during follow-up examinations after therapy, since an increase in tumour markers can be an indication of a recurrence of the disease. They are not suitable for diagnosing the disease, since an elevation does not necessarily have to be caused by cancer. In addition, the values can also be inconspicuous in patients with the disease.