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