A systematic literature review identified only a single randomized trial comparing any of the surgical approaches. In that trial, 30 women with high-grade VIN were randomly assigned to receive carbon dioxide (CO2) laser ablation versus ultrasound surgical aspiration (USA). There were no statistically significant differences in disease recurrence, painful dysuria or burning, adhesions, or eschar formation between the two treatments after 1 year of follow-up. Scarring was observed in 5 of 16 women treated with laser ablation and 0 of14 women treated with USA (P < .01), but consequences of the scarring on sexual function or quality of life were not reported.[Level of evidence 1iiDii] The trial was too small to draw reliable conclusions about the relative efficacy of these surgical techniques. The remainder of the surgical literature is derived from case series and is prone to important study biases.[Level of evidence 3iiiD]
Whatever procedure is used, patients are at substantial risk of recurrence, particularly when the lesions are high grade or multifocal. The most common sites of recurrence are the perianal skin, presacral area, and clitoral hood. About 4% of patients treated for VIN subsequently develop invasive cancer.[8,9]
Because of the physical and psychosexual morbidity associated with many vulvar surgical procedures, nonsurgical approaches have been studied. Some of these approaches, including topical 5-fluorouracil, gamma-interferon, bleomycin, and trinitrochlorobenzene, have been largely abandoned because of intolerable local side effects, such as pain, irritation, and ulceration, or high recurrence rates.[10,11] Photodynamic therapy, using topically applied 5-aminolevulinic acid as the sensitizing agent for 635 nm laser light, has also been studied. However, data are limited to small case series with variable response rates.[12,13][Level of evidence: 3iiiDiv]
More recently, among women with high-grade VIN, substantial response rates and acceptable tolerability were reported for topical imiquimod 5%, an immune-response modifier with activity in HPV 6/11-associated vulvar condylomata. Three randomized placebo-controlled trials (including a total of 104 patients) with clinical response as their primary endpoints.[Level of evidence: 1iDiv] have been reported in either peer-reviewed-journal or abstract format.[14,15,16,17] The results of these trials were summarized in a systematic review. At 5 to 6 months, the complete and partial response rates in patients were 36 of 62 and 18 of 62 in the combined imiquimod arms versus 0 of 42 and 1 of 42 in the combined placebo arms (relative risk [RR], 11.95; 95% confidence interval [CI], 3.21–44.51).