Molecular mapping of high-grade cervical intraepithelial neoplasia shows etiological dominance of HPV16.

Women with high-grade cervical intraepithelial neoplasia (HGCIN) frequently present with multiple cervical lesions and multiple concomitant Human papillomavirus (HPV) genotype infections. To elucidate HPV genotype attribution in different regions on the cervix, we performed molecular mapping of cervical disease in women with HGCIN. Thirteen subjects referred to colposcopy for abnormal cervical cancer screening results were included. A cervical smear and biopsies from 4 different areas on the cervix were collected. HPV genotyping using Linear Array (for cytology) or SPF(10) LiPA(25) (for histology) were performed in 13 smears, 52 whole sections from biopsies and 138 tissue regions isolated with laser capture microdissection (LCM). Twelve subjects had a diagnosis of CIN3 and one subject had a diagnosis of CIN2 based on the worst histology found in 4 biopsies. Eight of the 13 smears (62%) showed multiple genotype infections. Four of 13 women (31%) had multiple HPV infections in their biopsies. After performing LCM-PCR, only one woman (8%) had two different carcinogenic HPV types in morphologically distinct, but colliding HGCIN lesions. HPV16 was identified as the causal type in all women with HPV16 in cytology. A large proportion of other HPV types found in cervical smears were not detected at the tissue level. Using tissue-based genotyping and LCM-PCR analysis, we were able to attribute an individual HPV type to each area of CIN lesions. We demonstrate that HPV16 is even more etiologically dominant than previously thought, based on various genotype attribution models.