Anal intraepithelial neoplasia best treated by electrocauterization
medwireNews: Electrocauterization is better than topical treatments for treating anal intraepithelial neoplasia (AIN) in HIV-positive men who have sex with men (MSM), Dutch study findings suggest.
Compared with imiquimod and topical fluorouracil, electrocautery was associated with higher complete response (CR) rates (39 vs 24 vs 17%, respectively and fewer Grade 3-4 side effects (18 vs 43 and 27%, respectively).
However, recurrence rates were generally high, affecting 22% at 24 weeks, 46% at 48 weeks, and 67% at 72 weeks.
The median time to recurrence was 24 weeks with topical fluorouracil and 48 weeks for both imiquimod and electrocautery, but this significant difference was lost by week 72.
"To our knowledge, this is the largest prospective study on AIN treatment and the first one comparing currently available treatment options," say the study's investigators in The Lancet Oncology.
Olivier Richel and colleagues (Academic Medical Center, Amsterdam) note that although screening for AIN is still under discussion, it is a known precursor for anal cancer, rates of which are rising in HIV-positive MSM.
Between August 2008 and December 2010, Richel and team conducted an open-label, randomized trial involving 388 HIV-positive MSM who were screened and then followed up for AIN using high-resolution anoscopy.
A total of 246 (63%) men were found to have any grade of AIN, and 156 were randomly assigned to receive 16 weeks' treatment with imiquimod (self-applied three times a week), topical fluorouracil (self-applied twice a week), or electrocauterization performed every 4 weeks in the outpatient setting for up to five times.
Only patients who showed a CR or PR after 4 weeks were followed up in the trial; those showing progression or persistent high-grade AIN were referred for further treatment outside the study.
The most common side effects were pain, bleeding, itching.
Data suggests that high-grade AIN was associated with a successful response to treatment whereas low-grade AIN was not. This might suggest a "wait-and-see" policy is best for patients with low-grade AIN, the researchers say, although the study was not powered to determine this.
"Our data also suggest that imiquimod may be the best choice for peri-anal AIN," Richel et al add, noting that further study is needed as this was not a prespecified analysis and patient numbers were small.
There are three take-home messages from the trial, write Ulrike Wieland (University of Cologne, Germany) and Alexander Kreuter (Helios St Elisabeth Hospital Oberhausen, Germany) in an accompanying commentary.
"First (repetitive) ablative treatment such as electrocautery should currently be deemed the first-line option for intra-anal high-grade AIN," they say.
"Second, topical imiquimod seems to be superior for per-anal AIN. Third, in view of the high recurrence rates, regular post-treatment follow-up visits are mandatory."
By Sara Freeman, medwireNews Reporter