Adjuvant interferon for anal condyloma. A prospective, randomized trial.

PURPOSE

The aim of this study was to determine whether interferon combined with surgical excision and fulguration could reduce the unacceptably high rate of recurrence of anal condyloma seen after surgical extirpation.

METHODS

Forty-three patients with anal condyloma were prospectively randomized into two groups. Group I (n = 25) patients underwent surgical excision and fulguration immediately followed by an injection of 500,000 IU (0.1 ml) of interferon alfa-n3 into each quadrant of the anal canal. Group II (n = 18) patients underwent surgical excision and fulguration but then received four injections (0.1 ml) of saline into each quadrant of the anal canal.

RESULTS

After a mean follow-up of 3.8 months, 10 of 43 (23 percent) patients developed recurrent anal condyloma. Only 3 of 25 (12 percent) interferon-treated patients had recurrences vs. 7 recurrences in 18 (39 percent) saline-treated patients (P = 0.046). Interferon was particularly effective in reducing recurrences in patients whose condylomata were present for more than six months (P = 0.04) and those condylomata that contained human papillomavirus DNA subtype 6/11 (P = 0.05).

CONCLUSION

Adjuvant interferon treatment can reduce the high recurrence rate of anal condyloma seen after surgical extirpation.