Prospective Randomized Trial of Topical a-Interferon (a -Interferon Gels) for the Treatment of Vulvar Intraepithelial Neoplasia III

Nick M. Spirtos, M.D., Lloyd H. Smith, M.D., Ph.D., and Nelson N. H. Teng, M.D., Ph.D.

Division of Gynecologic Oncology, Department of Gynecology and Obstetrics, Stanford University Medical Center, Stanford, California 94305

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Twenty-one patients were prospectively randomized into a blinded double-armed crossover study comparing a -interferon (a -IFN, 106 IU in a 3.5% aqueous methycellulose base) with and without 1% nonoxynol-9. Nine and twelve patients were randomized to arms with (+N) and without (-N) 1% nonoxynol-9, respectively. Patients applied the gel to affected areas every 8 hr. and were evaluated biweekly. Including those crossed over, 14 patients were treated with -N. Six of fourteen (43%) achieved complete responses: biopsy proven with at least 1 year follow-up (CR). One patient achieved a partial response with at least a 50% reduction in the total surface area of all lesions present (PR). Similarly, 13 patients were treated with +N. Two patients in this group were found to have invasive cancer and one to have HIV and thus were eliminated from statistical analysis. Of the remaining 10 patients, 3 had CRs (30%), 5 had PRs (50%), and 2 failed to respond. There was no significant difference in responses between the two groups. Overall, 14 of 18 (67%) patients demonstrated some response to a-IFN applied topically. These data support the conclusion that a-IFN is an active agent in the treatment of vulvar intraepithelial neoplasia III.


Severe vulvar intraepithelial neoplasia (VIN III) has become more frequently recognized in young, sexually active women (1,2). Management imperitives include (1) exclusion of the existence of an invasive component and (2) removal of all lesions. However, since such lesions are often widespread or multifocal, removal may require resection or vaporization of substantial portions of the vulva, resulting in unavoidable morbidity. The recognition that such lesions may recur even after extensive therapy and that VIN lesions are classically thought to be indolent, carrying a low probability of transition to an invasive lesion, makes some form of conservative therapy very desirable.

The presence of the human papilloma virus (HPV) genome in the vast majority of VIN cases is consistent with epidemologic data suggesting that intraepithelial neoplasms of the lower female genital tract are associated with sexually transmitted agents (3). Interferons, a family of cellular proteins originally detected by their inhibitory effect on viral replication, are attractive potential therapeutic agents for HPV infections. Remissions of vaginal and vulvar condyloma accuminata have been documented in some patients given parenteral or topical human leukocyte interferon (a -interferon) (4,5) . Published reports have also documented the effectiveness of a -interferon (a -IFN) in treating patients with intraepithelial or invasive squamous cell neoplasms of the cervix (6-9). For example, biopsy-proven complete regression of moderate to severe cervical intraepithelial neoplasia (CIN) lesions after 12 weeks of topical a-IFN was reported in three of six patients by Moller et al. (7). Choo et al. (9) reported complete resolution of moderate CIN among two of seven patients treated with intracervical injections of a -IFN. In addition to these data, there are anecdotal reports of therapeutic effects of interferons on VIN lesions (10,11). Consequently, experimental a -IFN treatment of patients with VIN lesions is warranted. Here we report the results of a double-blinded randomized prospective trial of topical a-IFN alone versus a-IFN plus non-oxynol-9 in patients with biopsy-proven VIN III.

Materials and Methods

Beginning on July 1, 1985 and ending on June 30, 1987, twenty-one patients were prospectively randomized into a blinded double-armed crossover study comparing the therapeutic effects of a-IFN (10-6IU/3 in 3.5% aqueous methylcellulose base) with and without 1% nonoxynol-9 (Exovir Inc., Great Neck, NY). Patients were entered into the study only after a histologic diagnosis of VIN III was confirmed in the Department of Pathology at Stanford University Hospital and informed consent obtained. Patients were then instructed to apply the gel every 8 hr. to all lesions and were seen every other week in the Gynecologic Oncology Clinic. As long as a response of consistent diminution in lesion size was observed, the patient was continued on the same drug. If cessation of clinical response was noted over an 8-week period, progression was noted, or a new lesion appeared, the patient was crossed over into the other arm of the study. Prior to the time of crossover, all patients underwent rebiopsy to confirm the diagnosis as well as to rule out an invasive lesion. In those cases in which a complete clinic response was noted, a biopsy of previously affected areas was performed 2 weeks after disappearance of the last lesion and then every 6 months. In those patients who ultimately failed both arms of the treatment protocol, management was individualized.

Of the 21 patients initially enrolled in the study, 9 were randomized to treatment with a-IFN plus nonoxynol-9 (+N) and 12 were randomized to treatment with a-IFN alone (-N). A complete history was obtained and a physical examination performed on each patient. The individual lesions were measured in two dimensions and recorded on an every-other-week basis. At these visits, all symptoms and possible side effects related to the medication were noted. A complete blood count with differential and platelet count was performed on entry into the study and again between 4 and 8 weeks after beginning therapy. A complete response (CR) was considered to have been achieved only when all clinical evidence of disease was noted to be absent and this observation was confirmed for at least 1-year in a previously affected and treated area were considered, for the purposes of this study, to have had a partial response (PR). Patients who did not achieve a CR or a PR were considered treatment failures.

Twelve patients were randomized to treatment wtih -N and 9 patients to treatment with +N. Two patients were crossed over into the -N arm and four patients were crossed over into the +N arm. The total number of patients treated with -N before or after crossover was 14. The total number of patients treated with +N was 13. Three of these patients, however, were eliminated from the statistical analysis: two because invasive lesions were found within 2 months of entry into the study and one because HIV infections was diagnosed. Characteristics and cure rates of the two groups of patients were compared using Fisher's exact test.


The average age in the -N group was 46 years, and in the +N group, 37 years. This difference was not significant. Additionally, the initial average lesions size was 231 mm2 in the -N groups and 237 mm2 in the +N group. This was statistically indistinguishable. No differences were noted between the two groups in the following areas: (1) previous HPV infection; (2) previous gynecologic infection; (3) previous abnormal PAP smears; (4) smoking history; (5) alcohol use; (6) hormonal replacement; (7) symptoms including itching, burning, and pain; (8) previous treatment for VIN III; and (9) adverse side effects from the medication. Four of six patients (67%) in the +N groups and ten of twelve patients (83%) in the -N group presented with symptoms, the most common being itching and burning. A similar number of patients in both groups had been previously treated for VIN III. Three of six patients (50%) in the +N groups (one by cryotherapy and two by local excision) and eight of twelve (67%) in the -N groups (four by excision, and one by excision and laser ablation) had been previously treated. Nine of eleven (82%) patients previously treated for VIN III and four of six (67%) of those not previously responded to therapy.

Of 14 patients in the -N group, there were 6 complete responses (43%), 1 partial response (7%), and 7 failures (50%). Among the 10 patients in the +N group there were 3 complete responses (30%), 5 partial responses (50%), and 2 failures (20%). There was no statistical difference between the number of responders in the two arms of the study. More impressive is the fact that of 18 patients treated, 14 demonstrated a significant response to a-IFN therapy. Of 4 nonresponders, 2 were not crossed over because they moved and were unable to continue in the study.

Among complete responders in the +N group all lesions had resolved by the fourth month (Fig. 1). A similar pattern was noted in the -N groups (Fig. 2). Two patients in the +N groups had no evidence of disease within 4 months of beginninng therapy and negative biopsies after 6 months, but were found to have recurred at their 12-month visit. Two patients from the +N group were crossed over into the -N group. One patient had achieved a partial response to +N, but her response slowed, necessitating crossover, and she ultimately failed to respond to -N. The other patient had no response to either treatment. Four patients were crossed over from the -N to +N group: two subsequently achieved complete responses despite failing the -N regimen, one patient had partial responses to both regimens, and one patient failed both regimens.

There were few side effects associated with treatment in this study. In the +N group, 2 of 6 patients (33%) complained of mild but transient pain which was present only for 2 weeks during therapy. In the -N group, 3 of 12 patients (25%) complained of symptoms related to therapy. One patient (8%) complained of mild discomfort and fever, and two patients (17%) complained of mild pruritis. There was no significant change in any patient's complete blood count, differential, or platelet count.


We have observed dramatic and often rapid responses to topical a -IFN, with total disappearance of some very large, biopsy-proven VIN III lesions. Although no untreated control group was studied, most patients had longstanding lesions which had often failed or recurred after prior therapy. We therefore suggest that topical a-IFN actually mediated the disappearance of these VIN III lesions.

Interferons are derived from a family of genes and several diverse mechanisms of action have been described (review (12)). By inducing a variety of intracellular changes, interferons inhibit replication of viruses, but antiproliferative effects on neoplastic cells have also been described. Potent effects on the natural immune system have been attributed to interferon action, including augmentation of monocyte, macrophage, and natural killer cell cytotoxicity. Enhanced expression of cell surface antigens such as major histocompatibility antigens by neoplastic cells may make them more vulnerable to the effects of the natural immune system. No attempt was made during this study to analyze the contributions of such mechanisms to the resolution of VIN lesions treated with topical a -IFN. Such studies are feasible if biopsies are analyzed during the course of therapy and are planned in the future.

Nonoxynol-9 is a nonionic surfactant and dispersing agent and active ingredient of spermicide gel preparations. Its presence in one arm of this blinded crossover study was intended to allow for possible enhanced absorption of the interferon agent. Although there was no statistical difference in the response rates between the two groups, of four patients cr ossed over from -N to +N, two achieved complete responses, whereas neither of the two crossed over from +N to -N achieved a complete response. This observation may suggest a potential advantage to the addition of nonoxynol-9. However, the small number of patients in these crossover arms precludes meaningful statistical analysis.

In this trial, a-IFN with and without nonoxynol-9 proved to be an effective means to treat VIN III. Overall, 9 of 18 patients (50%) had a complete, histologically proven respnse of at least 1-year duration, and 14 of 18 showed either a partial or a complete response to therapy (78%). This compares favorably to results for topical 5-fluorouracil (5-FU) (Table 1) (1,13,14,15), an antimetabolite commonly used to treat VIN III. However, the morbidity associated with topical a -IFN is insignificant when compared to that associated with 5-FU. In our series, only 5 of 18 patients (28%) described any adverse side effect related to therapy. The complaints were transitory and did not require interruption or discontinuation of therapy. On the other hand, Krupp and Bohm (14) and Lifshitz and Roberts (15) describe universal reactions to 5-FU which include severe pruritis, pain, vulvar edema, and weeping, requiring analgesics, sitz baths, and, in some patients, discontinuation of therapy. In this respect it appears that a-IFN offers an improvement over topical 5-FU. Other medical therapies reported in the literature include topical dinitrochlorobenzene (DNCB) (16) and bleomycin (17). Foster and Woodruff treated six patients, only two of which had VIN III on initiation of therapy, with DNCB and both had complete responses (16). One complained of severe irritation requiring cessation of therapy. Roberts et al. reported dismal results, with only 2 of 12 patients (17%) responding, using topical and intradermal bleomycin (17). The low morbidity associated with the use of topical a-IFN in this study and the high response rate (78%) allow for the conclusion that a -IFN compares favorably to other forms of medical management in the treatment of VIN III.

TABLE 12 - VIN III: Clinical Response Following Treatement with 5-FU



No. of Patients

Complete Responses

Forney et al [13]



0/6 (0%)

Krupp and Bohn [14]



6/8 (75%)

Buscema et al [1]



3/11 (27%)

Lifshitz and Roberts [15]



2/12 (16%)

Although we found no significant difference between the two arms of the study, overall, 50% of the patients considered evaluable had a complete response lasting at least 1 year and another 28% had partial responses. These figures are, if anything, understated since two patients who withdrew from the study were responding to the a -IFN. One had achieved a partial response in less than 2 months and the other had experienced a 39% reduction in lesion size over 3 months. An additional two patients quit and were never crossed over after failing the -N arm of the study. Nevertheless, the medication was well tolerated and patients achieving complete responses did so in less than 4 months. Given these findings, it would be reasonable to increase either the dose or the intensity of a-IFN in hopes of improving response rates.

Results of excisional and ablative techniques used to treat VIN III are difficult to compare with the results obtained in this study because the methodology and follow-up in most reports are insonsistent and incomplete. A review of the world literature through 1985 reveals 902 patients reported in 75 articles treated by excisional or ablative therapy. Within 3 years of completing therapy, 380 (42%) were lost to follow-up; 123 (14%) have documented cures; 85 (9%) have recurred; 306 (34%) were described as cures with follow-up ranging from months to years; and 8 (1%) died (18). Understandably, given this information and the relatively short follow-up in our patients, comparison of topical a-IFN to these other methods of treatment is difficult. Attempts to do so would likely be misleading.

Perhaps an even more important issue is the caution that must be exercised when any form of nonexcisional therapy is used to treat VIN III. Two of twenty-one (9%) patients initially entered into the study were found to have invasive cancer. Interestingly, both patients had been previously treated for VIN as had nine other patients. Thus, 2 of 11 (18%) previously treated patients were found to have invasive lesions. This is substantially higher than the 2% incidence noted by Friedrich et al. (19) or the 4% incidence reported by Buscema et al. (1). These findings mandate careful initial evaluation, follow-up, and excisional biopsy of any suspicious lesion. Our data would suggest this is even more important in the patient with recurrent disease, and in this setting non-excisional therapies must be closely scrutinized.


1. Buscema, J., Woodruff, J.D., Parmley, T., and Genadry, R. Carcinoma in situ of the vulva, Obstet. Gynecol.. 55 225-230 (1980).

2. Bernstein, S. G., Kovacs, B.R., Townsend, D.E., and Morrow, C.P. Vulvar carcinoma in situ Obstet. Gynecol.. 61, 304-307 (1983).

3. Buscema, J., Naghashfar, Z., Swada, E., Daniel, R., Woodruff, J.D., and Shah, K. The predominance of human papilloma virus type 16 in vulvar neoplasia, Obstet. Gynecol., 71, 601-606 (1988).

4. Einhorn, N., Ling, P., and Strander, H.,Systemic interferon alpha treatment of human condylomata acuminata, Acta Obstet. Gynecol.Scand. 62, 285-287 (1983).

5. Vesterinen, E., Meyer, B., Cantell, K., and Parola, E. Topical treatment of flat vaginal condyloma with human leukocyte interferon, Obstet. Gynecol.. 64, 535-538 (1984).

6. Ikic, D., Krusic, J., Kirharajer, V., Knezevic, M., Maricic, Z., Rode, B., Jusic, D., and Soos, E. Application of human leucocyte in patients with carcinoma of the uterine cervix, Lancet 1, 1027-1030 (1981).

7. Moller, B. R., Johannesen, P., Osther, K., Ulmsteen, U., Hastrup, J., and Berg, K. Treatment of dysplasia of the cervical epithelium with an interferon gel, Obstet. Gynecol.. 62, 625-629 (1983).

8. Hsu, C., Choo, Y.C., Seto, W. H., Pang, S. W., Tan, C. Y. H., Merigan, T. C., and Ng, M. G. Exfoliative cytology n the evaluation of interferon of cervical intraepithelial neoplasia, Acta Cytol. 28,111-117 (1984).

9. Choo, Y. C., Hsu, C., Seto, W.H., Miller, D. G., Merigan, T. C., Ng, M. H., and Ma, H. K. Intravaginal application of leukocyte interferon gel in the treatment of cervical intraepithelial neoplasis (CIN), Arch, Gynecol. 237, 51-54 (1985).

10. DePalo, G., Stefanon, B., Rilke, F., Pilotti, S., and Chione, M. Human fibroblast interferon in cervical and vulvar intraepithelial neoplasia associated with viral cytopathic effects. A pilot study, J. Reprod. Med., 30, 404-408 (1985).

11. Slotman, B.J., Helmerhorst, T. J. M., Wijermans, P. W., and Calame, J. J. Interferon alpha in the treatment of intraepithelial neoplasia of the lower genital tract: A case report, Eur. J. Obstet. Gynecol. Reprod. Biol. 27, 327-333 (1988).

12. Kirkwood, J. M., and Ernstoffs, M. S. Interferons in the treatment of human cancer, J. Clin. Oncol. 2, 336-351 (1984).

13. Forney, J. P., Morrow, C. P., Townsend, D. E., and DiSaia, P. J. Management of carcinoma in situ of the vulva, Amer. J. Obstet. Gynecol. 127, 801-806 (1977).

14. Krupp, P. J., and Bohm, J. W. 5-Fluorouracil topical treatment of in situ vulvar cancer, Obstet. Gynecol. 51, 702-706 (1978).

15. Lifshitz, S., and Roberts, J. A. Treatment of carcinoma in situ of the vulva with topical 5-fluorouracil, Obstet. Gynecol. 56, 242-244 (1980).

16. Foster, D. C., and Woodruff, J. D. The use of dinitrochlorobenzene in the treatment of vulvar carcinoma in site, Gynecol. Oncol.11, 330-339 (1981).

17. Roberts, J. A., Watring, W. G., and Lagasse, L. D. Treatment of vulvar intraepithelial neoplasia with local bleomycin, Cancer Clin. Trials 3, 351-354 (1980).

18. Spirtos, N. M., Eisenkop, S. M., Kaiser, S., and Howell, M. Vulvar intraepithelial neoplasia III: A review of the literature, in progress.

19. Friedrich, E. G., Wilkinson, E. J., and Fu, Y. S. Carcinoma in situ of the vulva: A continuing challenge. Amer. J. Obstet. Gynecol. 136, 830-843 (1980).

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