Rectal Paps, High Resolution Anoscopy, and Treatment of HPV related disease.
20% of HIV negative gay men
50-80% of HIV positive gay men
Anal Cancer: 5070 cases (2008), and 5290 (2009)
Anal Cancer Deaths: 680 (2008), and 710 (2009)
Anal cancer incidence climbing 2% per year since the 1970’s
The squamous cells of the rectum are the same cells as the cervix.
The HPV viruses that cause rectal warts, rectal dysplasia and rectal cancer are the same
HPV viruses that cause cervical dysplasia and cervical cancer in women.
Since widespread use of cervical Pap screening in women,
cervical cancer has decreased 70% over the past 50 years.
We should be able to achieve this with rectal disease too.
Who?
Rectal Paps recommended yearly for all HIV positive men,
and every 2-3 years for gay men older than 40
(rectal cancer rare younger than 40 years old).
Also recommended for any patient with history of rectal warts,
and all women with history of cervical disease.
What?
There are 40 strains of the HPV virus that infect the anus,
some of which cause typical rough, bumpy warts
(which never cause cancer but look horrible)
and several strains that are flat in appearance and easily overlooked,
but over time can cause enough damage to the cells to result in pre-cancer
(anal intraepithelial neoplasia, AIN) or cancer.
How?
If Pap results show any abnormality(ASCUS/atypical squamous cells of undetermined
significance, LSIL/low-grade squamous intraepithelial lesions, HSIL/high-grade squamous
intraepithelial lesions, etc), the next step is high resolution anoscopy (HRA).
The patient is placed lying on his side. A vinegar soaked pad is placed inside the rectum
for a couple of minutes (which results in any HPV related changes turning white and
becoming easily seen). The rectum is then examined using a high power
microscope (colposcope). Any abnormalities are then biopsied and sent to the lab for a
pathologist to review. Why biopsy and not treat then and there?
Because appearance to the eye of lesions can be deceiving,
and something may actually be better (AIN-1, requiring no treatment)
or worse (carcinoma, requiring surgery in an operating room).
Based on the pathology results, the following treatments are done at the next visit:
If no lesions found, repeat Pap in 6 months.
Warts, treat chemically, or ablated with hyfracator or infrared coagulator (IRC).
AIN-1, not treated (these usually resolve on their own). Repeat Pap and HRA in six months.
AIN-2,3, ablation with IRC. Repeat PAP and HRA in six months.
Cancer, surgery and possible chemotherapy/radiation therapy.