Risk Factors for Recurrent VIN
Abstract & Commentary
Synopsis: Multifocal, high-grade VIN is likely to recur.
Source: Küppers V, et al. J Reprod Med 1997;42:140-144.
Küppers and colleagues report the results of primary treatment of 84 patients with vulvar intraepithelial neoplasia (VIN), and they established a uniform protocol for the treatment of VIN in 1990. In hairbearing areas, CO2 laser excision or cold knife excision was performed. In non-hairbearing areas, CO2 laser ablation was performed. Laser vaporization was usually confined to a depth of less than 2 mm, and laser excision was usually confined to a depth of 4 mm.
Küppers et al reviewed various known and proposed risk factors for VIN recurrence. The two most predictive variables they identified were the degree of VIN and the presence of multifocality. That is, patients with VIN III were much more likely to recur than patients with VIN I or II. Likewise, patients who were treated for multifocal lesions were much more likely to recur than those with unifocal lesions. Women with both VIN III and multifocal lesions almost always recurred (94%).
Menopausal status and smoking were not predictive of recurrence of VIN. However, the numbers of both postmenopausal women and nonsmoking women in their study was small.
CO2 laser therapy was compared to cold knife excisional therapy. No differences in recurrence rates were identified if only those patients with negative excisional margins were included. However, when all knife excision cases were compared to CO2 laser cases, there was a much higher rate of recurrence among knife excision cases because so many excised lesions had positive margins.
COMMENT BY KENNETH NOLLER, MD
There is no doubt that VIN and invasive cancer is occurring at younger and younger ages. No longer is it rare to see a teenager with VIN III. In fact, in this series the patients with VIN III were on average almost six years younger than the women treated for VIN I-II.
Unfortunately, all of us who treat VIN with some frequency recognize that there is a high recurrence rate. Therefore, it is important to be certain that the initial treatment is both as complete as possible (free margins),and as minimal as possible to avoid disfigurement. Fortunately, the CO2 laser appears to be the ideal instrument to accomplish both of these aims. Because the laser should always be used with colposcopy, it is possible to identify the edges of the lesion and remove it completely. Likewise, the CO2 laser causes the least disfigurement (if properly used) of any of the treatment methods. This articleand several others reported elsewhere found that CO2 laser therapy was at least as good as, and probably superior to, local excision.
I am concerned about the ability of future clinicians to treat VIN with the CO2 laser. Because we no longer use the laser frequently in the treatment of VIN, few individuals are receiving the training that is necessary to be able to perform CO2 laser treatment of VIN safely and effectively. This would certainly be unfortunate since the laser appears to have many benefits over excision.
Although smoking was not a predictor of VIN recurrence in this study, more than two-thirds of the patients treated for VIN by Küppers et al were smokers. The association between smoking and invasive cancer of the vulva is well known, with a two- to four-fold increase in invasive disease among smokers when compared to nonsmokers. Perhaps smoking is the reason why so many young women are developing VIN, as compared to previous decades, since, unfortunately, young women comprise the largest group of smokers in the United States today.