Population‐based data on the epidemiology of vulvar lichen sclerosus (LS) are sparse and only few prospective studies have investigated the malignant potential of the disease. We used the nationwide Danish Pathology Registry to first assess the incidence of biopsy‐verified vulvar LS in the period 1997–2022 and second to examine the incidence of vulvar high‐grade squamous precancer and squamous cell carcinoma (SCC) in women with biopsy‐verified vulvar LS (1978–2019) compared with that expected in the general female population. For the latter aim, we computed standardized incidence ratios (SIRs) with 95% confidence intervals (CIs). During our study period, the age‐standardized incidence rate of vulvar LS increased from 5.0 (1997–1998) to 35.7 (2021–2022) per 100,000 person‐years. Compared with the general female population, women with biopsy‐verified vulvar LS had significantly increased rates of vulvar high‐grade squamous precancer (SIR = 8.5; 95% CI: 7.2–10.0) and SCC (SIR = 16.2; 95% CI: 14.2–18.4). The SIRs of vulvar high‐grade squamous precancer and SCC did not vary substantially according to length of follow‐up. This nationwide and population‐based study shows a 7‐fold increase in the incidence of biopsy‐verified vulvar LS since 1997. Data also show that women with biopsy‐verified vulvar LS have 8.5 and 16 times higher than expected incidence of vulvar high‐grade squamous precancer and SCC, respectively. The substantially increased incidence of vulvar high‐grade squamous precancer and SCC following LS is important in relation to the clinical management and follow‐up of LS patients.

中文翻译：

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活检证实的外阴硬化性苔藓：1997-2022年的发病趋势以及外阴鳞状癌前期和鳞状细胞癌的风险增加

关于外阴硬化性苔藓（LS）流行病学的基于人群的数据很少，并且只有少数前瞻性研究调查了该疾病的恶性潜力。我们利用丹麦全国病理学登记处首先评估了 1997 年至 2022 年期间经活检证实的外阴 LS 的发生率，然后检查经活检证实为外阴高级别鳞状细胞癌 (SCC) 的女性的外阴高级别鳞状细胞癌 (SCC) 的发生率外阴 LS（1978-2019）与一般女性人群的预期相比。对于后一个目标，我们计算了具有 95% 置信区间 (CI) 的标准化发生率 (SIR)。在我们的研究期间，外阴 LS 的年龄标准化发病率从每 10 万人年 5.0（1997-1998）增加到 35.7（2021-2022）。与一般女性人群相比，经活检证实外阴 LS 的女性外阴高级别鳞状癌前病变 (SIR = 8.5; 95% CI: 7.2–10.0) 和 SCC (SIR = 16.2; 95% CI: 14.2) 的发生率显着增加–18.4）。外阴高级别鳞状癌前病变和鳞状细胞癌的 SIR 根据随访时间的长短没有显着变化。这项全国性的基于人群的研究显示，自 1997 年以来，经活检证实的外阴 LS 的发生率增加了 7 倍。数据还显示，经活检证实外阴 LS 的女性外阴高级别病变的发生率比预期高 8.5 倍和 16 倍。分别为鳞状癌前期和鳞状细胞癌。 LS 后外阴高级别鳞状癌前病变和鳞状细胞癌的发生率大幅增加，这对于 LS 患者的临床管理和随访具有重要意义。