Anal Cancer – Anal Warts
There has been a significant increase in the incidence of anal cancer during the last 10 years. This is attributed to the wide spread of HPV infection and other aggravating factors (HIV infection, smoking). It is estimated that the frequency of anal cancer in gay is the same as the frequency of cervical cancer before the advent of cervical cytology. Some subtypes of HPV virus (i.e 16, 18, 31 , 33, 35) are more prone to develop cancer. These subtypes can be detected by PCR test.
Anal cancer does not appear suddenly. For many years it is preceded by precancerous lesions (anal intraepithelial neoplasia – dysplasia) which do not cause any symptoms. HPV aused dysplasias are distinguished in low-grade anal intraepithelial dysplasia (LGAIN) and high-grade anal intraepithelial dysplasia (HGAIN). They can be detected with simple anal cytology (Pap test) in high-risk individuals. If anal cytology results are positive, high resolution anoscopy should follow. The precancerous lesions (HGAIN) are diagnosed with biopsy and can be treated with cauterization without anesthesia.
If the cellular immune system becomes compromised (e.g. HIV infection or immunosuppression -solid organ transplantation), the clearance of the HPV virus from anus is hindered and progression to high-grade dysplasia and anal cancer becomes more probable. Anal cancer is more frequent in groups with a high probability of HPV infection and/or immunodeficiency. HPV virus is detected in approximately 90% of anal cancer specimens. Moreover 90% of HPV positive cases are due to HPV subtypes 16 and 18. Anal cancer incidence in gay population is similar to the incidence of cervical cancer before the advent of anal smear. The lifetime probability of anal cancer detection in seropositive gay is about 10% and that of high-grade dysplasia detection is about 50%.
The Risk factors for acquiring anal cancer are the following:
• 15 or more sexual partners
• Anal intercourse (examination every 2-3 years ) .
• Antecedent cervical dysplasia CIN3.
• Anal warts
• Kidney transplantation, immunosuppressive medication, chronic steroid treatment.
• HIV Infection (annual examination is required)
These groups should be checked regularly by anal cytology. Anal smear does not cause pain and it is carried-out in the proctologist’s office. If anal cytology is positive, then high resolution anoscopy should follow for the localisation of dysplasia and biopsy. Anal cytology has a small diagnostic value and direct high resolution anoscopy without any previous anoscopy has a much higher diagnostic yield. Any enema or douching should be avoided before taking the test. If anal cytology is positive, then high resolution anoscopy should follow for localisation of dysplasia and biopsy.
PROCTOLOGY CLINIC- ATHENS GREECE