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Potential Treatment Options

Prepared using information provided by Drs Irving Salit & Jill Tinmouth, AIN Screening specialists, Toronto General Hospital                                                                  

Last Updated: January 2014


For classification of Anal Squamous Intraepithelial (AIN):


For level 2 Moderate high grade changes (AIN2) and level 3 Severe high grade changes (AIN3), the Toronto General Hospital clinic offers treatments with the intent to try to get rid of these worrisome cells and allow normal cells to grow back. The treatments are the same as the treatments used to destroy anal warts.


5 treatments are available:

1) TCA acid application: 4-6 monthly appointments where the doctor paints on a strong acid to the high grade areas/lesions. Quick, very mild discomfort but inconvenient due to the number of appointments necessary. 65-70% effective with 1 course of treatment (4-6 appointments).


2) IRC laser: Each high grade area is burned with a laser, leaving a scab that will heal. Since we use heat to burn, lidocaine or freezing must be injected into the area. The injection is the most uncomfortable part; it will feel like a bee string for about 5 seconds. Once the lidocaine takes effect, you should not feel much during the treatment. When the lidocaine wears off, we expect you to feel some mild-moderate anal discomfort and have some bleeding with bowel movements for up to a week after. Serious complications that happen about 2% of the time include infection or the formation of an abscess (pus) that will require antibiotics and/or may require a surgeon to drain the abscess. 65-70% effective with 1 course of treatment (IRC-ing each lesion at separate appointments). We do not have the capacity/equipment for sedation in our clinic, so you are awake during the treatment.


3) Self-applying a cream (Aldara/Vyloma/Efudex) into the anal canal: You apply a cream into the anal canal 1-3 times a week for 16 weeks (using gloves to protect the skin on your finger). This is the most convenient method since you apply the cream yourself. The creams are meant to destroy the bad cells. This causes local irritation, pain and discomfort. Irritation means its working.The patient adjusts the frequency of applying the cream depending on comfort. So it’s about finding the right frequency/timing so you are able to continue applying the cream. This method while the most convenient requires that you be responsible for your own treatment. Effective about 50% of the time.


4) Surgery: Under sedation (you are asleep), the surgeon will remove/cut/burn all the warty areas in the anal canal. Biopsies will also be taken as “mapping biopsies” to determine the extent of High Grade disease.


5) Watchful Waiting or Surveillance: For some people that have high grade changes all around the anal canal that would not be able to tolerate treatment or people that do not want to pursue a form of treatment at this time.


Dr Jill Tinmouth quotes high grade changes at Level 3 Severe (AIN3) have a likelihood of progressing to anal cancer about 15% over 8-10 years (cancer would be Level 4).

We suspect the likelihood of Level 2 (AIN2) progressing to cancer slightly less.

With this information some people choose not to pursue active treatment but prefer to be monitored (examined with periodic biopsies) every 6-12 months with the intention to catch cancer early if the high grade changes ever progress.

=> We only recommend this option after all treatment options have been exhausted.


The best screening tool for Anal Cancer and /or Anal Intraepithelial Neoplasia (AIN) is via High Resolution Anoscopy (HRA):

Please speak to your primary care medical team about this screening technique.


HRA Screening Clinics in Canada:

TORONTO: Toronto General: Drs Irv Salit and Jill Tinmouth

MONTREAL: Hôpital Notre-Dame du Centre Hospitalier de l’Université de Montréal: Dr Francois Coutlée

VANCOUVER: St Paul’s Hospital in Vancouver: Dr Natasha Press

OTTAWA: Dr Marina Straszak-Suri, Centrepointe Medical Consultants

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