Purpose: To investigate the efficacy and the optimal dose of topical interferon-alpha in cases of cervical intraepithelial neoplasia (CIN) associated with human papillomavirus (HPV) infection.
Patients and methods: From January 1995 to December 1997, 75 patients with CIN (45 with CIN I-III, and 30 with CIS) associated with HPV infection were treated with local administration of interferon-alpha (group 1). From January 2002 to June 2003, after polymerase chain reaction (PCR) determination of HPV types 6, 11, 16, 18, 31 and 33, treatment with interferon-alpha was administered to 21 patients with CIN I-II (group 2). HPV 16 was found in 11 cases and HPV 31 in 10 cases. In cases of CIS, the interferon treatment followed conization. In all cases interferon was injected intralesionally or at periphery of the conization, 3 times per week at dose of 3 million (m) IU. Ten interferon administrations were given in all of the cases.
Results: In group 1 after 5 administrations the cytological findings returned to normal in 48 (64%) cases, and in 27 (36%) cases only dyskaryotic cells were found. In all cases the cytological findings reverted to normal after 10 administrations of interferon. In 45 cases with CIN I-III treated with interferon only (without conization), biopsy was carried out, and all of the patients were found free of dysplastic lesions. In group 2 the cytological findings of all 21 cases returned to normal after 10 administrations of interferon. As of December 2003, both the cytological and histological findings were negative for CIN and HPV.
Conclusion: These results suggest that treatment with interferon-alpha is an effective therapeutic method for CIN associated with HPV infection, and 10 administrations of 3 mIU constitute the optimal dose.