Effectiveness of the Traditional Japanese Herbal Medicine, Yokuinin (Kampo), in the Treatment of Cervical Precancerous Lesions.

Background Human papillomavirus (HPV) infection precedes cervical dysplasia, culminating in cervical cancer. Yokuinin extract, used for treating verruca vulgaris caused by HPV, exhibits potential antitumor activity against cervical cancer and mild cervical dysplasia. We examined the usefulness of Yokuinin in the treatment of cervical precancerous lesions. Methods This retrospective study included 73 female patients with verrucous skin lesions and mildly abnormal cervical cytology diagnosed between April 2019 and August 2021. Of the 73 patients, 34 received Yokuinin treatment whereas 39 did not. The Yokuinin-treated patients received 1.0 g Yokuinin orally divided into three doses daily. Evaluation criteria included retested cervical cytology, time to negative cervical cytology (negative for intraepithelial lesions or malignancies), and side effects. Statistical analyses employed the Mann-Whitney U test and chi-square test, indicating a statistically significant difference (p<0.05). Results Yokuinin-treated patients were significantly more likely to achieve normal cytology (NILM) status (p= 0.0441). Median time to NILM was three months for Yokuinin-treated versus five months for non-Yokuinin-treated group, indicating that the Yokuinin-treated group achieved NILM significantly earlier (p= 0.0011). Additionally, high-risk HPV-positive patients were more likely to develop NILM in a short period after Yokuinin administration, and premenopausal patients also developed NILM in a short period. No adverse effects were associated with Yokuinin administration. Conclusion Yokuinin administration effectively normalized precancerous cervical lesions, with expedited normalization observed in HPV-positive and premenopausal cases. Yokuinin emerges as a promising treatment for cervical precancerous lesions.