1. Introduction
Vaginal intraepithelial neoplasia (VaIN) is an uncommon gynecologic disease that accounts for only 1% of all lower genital tract intraepithelial neoplasia.1Human papillomavirus (HPV) infection is implicated as a causative agent of VaIN.2 As with cervical lesions, persistent high-risk HPV (hr-HPV) infection can induce the progression of VaIN to vaginal cancer. Other risk factors include first sexual intercourse at age younger than 17, having more than 5 sexual partners, immunosuppression, smoking, pelvic radiation therapy, exposure to diethylstilbestrol in utero, and history of cervical precancer or cancer.3,4
Epidemiologic information about VaIN is limited, with only one population-based study in the United States in 1977 estimating that VaIN may occur in 0.2- 0.3 per 100,000 women.5 VaIN is often discovered during colposcopy when cervical cancer screening is abnormal. A missed diagnosis of VaIN may occur if colposcope practitioners solely concentrate on examining the cervix and neglect to observe the vagina for potential vaginal lesions. There are currently no screening programs for VaIN except for women who have had a hysterectomy for cervical precancerous lesions or cervical cancer. Thus, the true incidence rates of VaIN may be higher than reported. According to the 2014 WHO classification of tumors of the female reproductive organs (4th Edition)6,VaIN was classified into the low-grade squamous intraepithelial lesion (LSIL), which refers to VaIN1, and high-grade squamous intraepithelial lesion (HSIL), which includes VaIN2 and VaIN3. Compared with cervical intraepithelial neoplasia (CIN), the possibility of VaIN progression to invasive vaginal cancer is much lower, and most VaIN will regress. However, the risk of progression to invasion vaginal cancer remains, especially for HSIL.7-9 Hence, it is crucial to discover vaginal HSIL and treat it promptly prevent vaginal cancer.
Currently, there is no FDA-approved hr-HPV test available for use in vaginal cancer screening. In general population screening, excluding women post-hysterectomy with vaginal stump, both cytological tests and HPV test sample above the surface of cervix. Assessing the sensitivity of cervical cancer screening against VaIN can be helpful in developing an effective screening protocol and managing screen-detected abnormalities. Additionally, in the post-HPV-vaccine era, knowing the prevalence and distribution of HPV genotypes can aid in selecting the most suitable vaccine among the available options to protect against VaIN and vaginal cancer. Due to its rarity, the estimate of accuracy of cervical cancer screening to detect VaIN2 is limited by the availability of few studies.
The present study aims to analyze the clinical data of 1200 VaIN patients at the largest cervical disease center in Fujian province, China. The characteristics and screening history of VaIN were revealed, the result may help better understand and detect VaIN.
2. Materials and Methods