In general, cancer can be defined as the diseases characterized by uncontrolled growth of normal cells. As cancers grow, they may invade surround tissues (local invasion) or they may continue their growth by spreading to other parts of the body (metastasis).
Anus or the anal canal is the short segment where stool is disposed out of the body as a result of bowel movements.
Anal cancer is developed from the cells right around the anal opening or directly within. The most frequent cancer type seen here is the squamous cell cancer. Other rare cancer types may also occur in the anal canal, therefore, proper evaluation and treatment options must be decided by your physician.
Presence of cells that are starting to become malign or that have potential to turn into malign cancer but yet to advance into deep layers of the skin are called high degree anal intraepithelial neoplasia. This situation suggests that anal caner will develop in the patient, however, it is not an anal cancer and its treatment is different than anal cancer. Presence of such condition must be evaluated by the colorectal surgeon and follow-up and treatment of the patient must be guided accordingly.
What is the incidence rate of anal cancer?
In the USA, approximately 6.000 new anal cancer is diagnosed and this constitutes almost 1-2% of all intestinal cancers. It can be said that anal cancer may develop 1 in every 600 people, this rate for colorectal cancer is 1 in every 20 people. However, on the contrary to some other cancer types, it is worth highlighting that incidence rate of anal cancer increases every year.
Who are under risk?
Risk factors are aspects that cause increased incidence rate for a specific disease. Anal cancer is frequently accompanied by an infection related to human papilloma virus (HPV). HPV may cause papillomas (Condyloma( in anus and genital regions for both men and women, however, presence of papillomas is not a must for cancer development. Anal cancer risk is increased in patients especially with cervical cancer, which develop due to HPV.
Risk factors for anal cancer;
Age 55 or over
Presence of sexually transmitted diseases
Having more than one sex partner
Weakened immune system (chemotherapy, transplantation patients, HIV patients)
Chronic local infections (long term anal fistulas, open wounds around anus)
Having received radiotherapy around pelvic region
Anal canal adenocancer case in a patient with long term untreated perianal fistula
Anal canal adenocancer
Anal cancer in a patients who is thought to have long term hemorrhoidal disease
Can anal cancer be prevented?
Very few cancer types can be completely prevented, however, avoiding abovementioned risk factors and having regular examinations can reduced anal cancer development risk. Use of condom can reduce HPV infections, if not completely preventing them. HPV infection vaccinations are shown to reduce anal cancer development risk for both men and women.
It is recommended that people in high risk group for anal cancers share their conditions with their physicians and be kept under closer observation. Treatment of the anal regions that have a potential to turn into cancer is very important for the prevention of development of anal cancer.
What are the symptoms of anal cancer?
In the most anal cancer cases, early diagnosis is possible as the region can be easily seen and accessed by the physician.
Symptoms of anal cancer;
Rectal or anal bleeding
Formation of mass in anal opening
Continuous or repetitive pain or itch in anal region
Change in bowel movements (having more or less defecation) or need for straining more
Reduced stool diameter
Flow from the anus
Having enlarged lymph nodes in anal region or groin area
Most of these symptoms may be seen in less important conditions like hemorrhoids, however, these should not be taken for granted and such symptoms should never be neglected. In case such symptoms emerge, a colorectal surgeon must evaluate.
How anal cancer is diagnosed?
Anal cancer is generally detected during the examination of patients with abovementioned complaints or symptoms. However, they may be diagnosed incidentally during annual routine examinations or colorectal cancer screening programs. Abnormal formations can be easily seen by anal examination or anoscopy. If an abnormal area is seen in the anus, biopsy must be performed for diagnosis. If the biopsy result is anal cancer, additional tests will be required to determine the stage of the disease.
How anal cancer is treated?
Effective treatment that will completely remove the disease is possible for most of the anal cancer patients. There are 3 main treatment methods in anal cancer treatment.
Surgery; surgical removal of cancer,
Radiotherapy; destroying cancer cells with high dose of x-rays,
Chemotherapy; using drugs to destroy cancer cells.
Today, combined treatments where radiotherapy and chemotherapy are used together are considered as standard treatment method for most anal cancers. Rarely, additional treatment may not be necessary for a very small or early-stage cancer that is surgically removed (local excision). In the past, larger scale operations were required for surgical treatment of anal cancer and these resulted in colostomy, storing the stool by creating an intestinal opening into the abdominal wall.
Will I have colostomy as well?
Today, most of the patients treated for anal cancer do not required colostomy. However, if there is insufficient response to treatment, if tumor relapses after the treatment or in the presence of an unusual anal cancer, permanent colostomy may be required by removing rectum and anus.
How is the period after the anal cancer treatment?
Most of the anal cancers can be successfully treated with combination treatments and cancers that relapse after the treatment can be surgically removed and treated if they are diagnosed early. Therefore, it is crucial to have regular controls after the treatment.