Lasers in Gynecology

The August 2024 issue of Obstetrics & Gynecology included a Clinical Expert Series authored by Drs. Cheryl Iglesia, Jennie Eunsook Choi, and Yona Tadir, with a section discussing laser treatment for vulvar lichen sclerosus.1 Unfortunately, the discussion missed several crucial points in the evaluation of CO2 laser as treatment for lichen sclerosus. First, the authors briefly describe a study, “…with the primary outcome of histopathologic change…” left uncited in the article. This study, by Mitchell et al,2 a prospective, double-blind, randomized, sham-controlled trial, was the first to incorporate sham-laser treatment as a control in a study of CO2 laser for lichen sclerosus and found no significant change between pretreatment and posttreatment histopathologic samples. In the study, the sham group demonstrated statistically significant improvement in subjective symptoms, underscoring a strong placebo effect with laser therapy. These findings were mirrored in a more recent study using low-dose laser as the placebo laser dose, showing improvement on visual analog scale scores in both groups.3 Without a sham-laser control, the unblinded patient may have bias in subjective measure reporting. In addition, the high cost of laser treatment raises concern for confirmation bias in both investigators and patients.2 Second, there was no discussion of the paramount importance of histology in evaluating an experimental treatment in a condition with malignant potential and overlap with a benign condition also potentially affected by this modality—genitourinary syndrome of menopause. Subjective scales cannot differentiate between improvement of genitourinary syndrome of menopause and decreased inflammation related to lichen sclerosus. In addition, lichen sclerosus is a premalignant condition, with an approximately 5% increased risk of vulvar squamous cell carcinoma. A recent systematic review indicated that squamous cell carcinoma risk is significantly decreased with use of ultrapotent topical corticosteroid treatment related to decreased chronic inflammation.4 Given these concerns, it is not sufficient to base treatment efficacy on subjective measures. Histologic changes should be the primary outcome in evaluation of any treatment for vulvar lichen sclerosus. This is especially prudent given that topical corticosteroids are well studied, readily available, and cost effective and have demonstrated decreased risk of malignant transformation. These points are crucial in analysis and recommendations regarding past and future studies on laser in the treatment of lichen sclerosus.