Anal cancer is a rare but serious type of cancer that develops in the tissues of the anal canal. The anus is the final part of the gastrointestinal tract, and cancer can develop either in the lining of the anus or in the surrounding area. Early diagnosis and treatment are critical for prognosis and patients’ quality of life.
Causes and Risk Factors
The main risk factors for anal cancer include:
1. HPV Infection (Human Papillomavirus):
– HPV is the main causative factor, as it is directly associated with the development of cancers in areas of the body exposed to the virus.
2. Individuals with a weakened immune system:
– Patients with HIV or those receiving immunosuppressive therapy have an increased risk due to their reduced ability to fight infections and cancerous changes.
3. History of sexually transmitted infections (STIs):
– The presence of other STIs increases the risk of HPV infection and, consequently, the risk of developing anal cancer.
4. People who engage in passive or active anal sex:
– Sexual behaviours involving anal intercourse increase the risk of infection with HPV and other viruses linked to the development of anal cancer.
5. Individuals with a history of cervical, vulvar, or vaginal cancer:
– Women with a history of cancer in these areas have an increased risk of developing anal cancer, possibly due to a shared causative factor (HPV).
6. Smoking:
– Smokers have an increased risk of developing anal cancer, as smoking weakens the immune system and facilitates the development of cancer cells.
7. Older age:
– Age over 50 is a risk factor, as anal cancer occurs more often in older individuals.
8. Women:
– Women have a slightly higher risk compared to men, especially if they have a history of HPV or other gynaecological cancers.
Symptoms of Anal Cancer
Symptoms of anal cancer may include:
– Bleeding from the anus: A common symptom often mistaken for haemorrhoids.
– Pain or pressure in the anus: There may be discomfort, especially during bowel movements.
– Changes in bowel habits: Constipation, diarrhoea, or a feeling of incomplete evacuation.
– Mass or lump in the anus: Lumps may be visible or felt by touch.
– Unusual discharge from the anus: Mucus or pus discharge.
Diagnosis of Anal Cancer
Anal cancer is diagnosed through:
– Anoscopy: Using a special instrument to examine the inside of the anus.
– Biopsy: Removing a tissue sample for analysis.
– Imaging tests: Endoanal ultrasound, MRI, or CT scan to assess the extent of the cancer.
Regular Screening and Monitoring with High-Resolution Anoscopy (HRA)
For people in high-risk groups, high-resolution anoscopy (HRA) is a critical tool for the early diagnosis and prevention of anal cancer. HRA allows the detection of precancerous lesions and other abnormalities in the anus using a specialised high-resolution microscope.
Benefits of HRA:
– Early Detection of Lesions: Identifies small lesions that may be precancerous or cancerous, allowing timely intervention.
– Accurate Diagnosis: Provides a clear image of the area, assisting in accurate diagnosis and appropriate treatment.
– Guidance for Biopsy: Guides targeted biopsies from suspicious areas.
Who is HRA recommended for?
HRA is mainly recommended for people at high risk for anal cancer, such as:
– Individuals with HPV infection.
– Patients with HIV or under immunosuppressive therapy.
– People with a history of STIs or sexual activity involving anal intercourse.
– Individuals with a history of gynaecological cancers.
Frequency of HRA screening:
– High-risk individuals are recommended to undergo annual screening.
– Frequency can be adjusted based on each patient’s condition.
Treatment of Anal Cancer
Treatment depends on the stage of the cancer and may include:
– Surgery: Removal of the cancer and affected tissues.
– Radiation therapy: Destroys cancer cells and shrinks tumours.
– Chemotherapy: Uses drugs to destroy cancer cells, usually combined with radiation therapy.
Prevention
Prevention of anal cancer includes:
– HPV vaccination: Reduces the risk of infection and cancer development.
– Regular screening: For high-risk individuals, regular screening with HRA and other diagnostic tests is recommended.
– Use of condoms: Reduces the risk of HPV and other STIs.
– Avoiding smoking: Improves general health and reduces cancer risk.
Conclusion
Anal cancer develops slowly, in multiple stages. Early diagnosis and prevention are vital for managing anal cancer. If you belong to high-risk groups, you should undergo regular screening for the diagnosis and treatment of precancerous dysplasias to prevent anal cancer.
Anal Cancer: Frequently Asked Questions
Anal cancer is rare except in high-risk groups. Homosexual men have an incidence 20 times higher than the general population. About 50% of HIV-positive homosexual men will develop precancerous anal dysplasia in their lifetime. 10% of them will eventually develop anal cancer.
- People with frequent anal intercourse
- Dysplasia or cancer of the lower female genital tract
- HIV (10% risk of anal cancer)
- Immunosuppression (kidney transplant – biological agents)
- Anal warts and HPV infection
- Inflammatory bowel diseases
- Multiple sexual partners
Yes, anal cancer can be prevented if precancerous lesions are diagnosed early and treated effectively. HPV infection and its progression to anal cancer are much more common among homosexual men and people with weakened immune systems, so these groups should be regularly screened.
Primary prevention involves vaccinating young men and women under 26 years old and high-risk groups even at older ages. Secondary prevention consists of early diagnosis of precancerous lesions with cytology and high-resolution anoscopy. Early diagnosis identifies and treats precancerous lesions (dysplasia – HSIL).
Anal cancer presents as a painful hard mass in the anus that bleeds. Diagnosis is confirmed with biopsies, and its extent is determined by endoanal ultrasound and MRI.
Anal cancer is more common in women with a history of significant dysplasia or cancer of the external genital organs (cervix, vagina, vulva).
