Anal Cancer

ANAL CANCER

Anal cancer is an uncommon type of cancer that occurs in the anal canal and anus.

Symptoms

•            Bleeding from the anus or rectum

•            Pain in the anus

•            A mass or growth in the anal canal

•            Anal itching

Risk factors

•            Older age: Most cases of anal cancer occur in people age 50 and older.

•            Many sexual partners: People who have many sexual partners over their lifetimes have a greater risk of anal cancer.

•            Anal sex: People who engage in receptive anal sex have an increased risk of anal cancer.

•            Smoking: Smoking cigarettes may increase your risk of anal cancer.

•            History of cancer: Those who have had cervical, vulvar or vaginal cancer have an increased risk of anal cancer.

•            Human papillomavirus (HPV): HPV infection increases your risk of several cancers, including anal cancer and cervical cancer. HPV infection is a sexually transmitted infection that can also cause genital warts.

•            Drugs or conditions that suppress your immune system: People who take drugs to suppress their immune systems (immunosuppressive drugs), including people who have received organ transplants, or those who have HIV — the virus that causes AIDS.

Tests to diagnose Anal cancer

•            Digital rectal examination (DRE): An exam of the anus and rectum. The doctor inserts a lubricated, gloved finger into the lower part of the rectum to feel for lumps or anything else that seems unusual.

•            Proctoscopy: A procedure to look inside the rectum and anus to check for abnormal areas, using a proctoscope. A proctoscope is a thin, tube-like instrument with a light and a lens for viewing the inside of the rectum and anus.

•            Endo-anal or endorectal ultrasound: A procedure in which an ultrasound transducer (probe) is inserted into the anus or rectum and used to bounce high-energy sound waves (ultrasound) off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram.

•            Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer. If an abnormal area is seen during the anoscopy, a biopsy may be done at that time.

•            MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).

•            PET scan (positron emission tomography scan): A procedure to find malignant tumour cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and takes a picture of where glucose is being used in the body. Malignant tumour cells show up brighter in the picture because they are more active and take up more glucose than normal cells do.

Stages of Anal Cancer

•            Stage 0: In stage 0, abnormal cells are found in the mucosa (innermost layer) of the anus. These abnormal cells may become cancer and spread into nearby normal tissue.

•            Stage I: Tumour is 2 centimetres or smaller.

•            Stage II: Tumour 2 to 5 cm in size, or more than 5 cm but with no other spread

•            Stage III: The tumour is 5 cm or smaller and has spread to lymph nodes near the anus or groin, or has spread to nearby organs, such as the vagina, urethra, or bladder. Stage III also includes the tumours that have spread to lymph nodes.

•            Stage IV: Tumour has spread to other parts of the body, such as the liver or lungs.

Treatment of Anal Cancer

Three types of standard treatment are used:

Surgery Local resection: A surgical procedure in which the tumour is cut from the anus along with some of the healthy tissue around it. Local resection may be used if the cancer is small and has not spread. This procedure may save the sphincter muscles so the patient can still control bowel movements. Tumours that form in the lower part of the anus can often be removed with local resection.

Abdominoperineal resection: A surgical procedure in which the anus, the rectum, and part of the sigmoid colon are removed through an incision made in the abdomen. The doctor sews the end of the intestine to an opening, called a stoma, made in the surface of the abdomen so body waste can be collected in a disposable bag outside of the body. This is called a colostomy. Lymph nodes that contain cancer may also be removed during this operation. This procedure is used only for cancer that remains or comes back after treatment with radiation therapy and chemotherapy.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy:

• External radiation therapy uses a machine outside the body to send radiation toward the area of the body with cancer.

• Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer.

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy).