Host Nuclear Genome Copy Number Variations Identify High-Risk Anal Precancers in People Living with HIV

Abstract

BACKGROUND: People living with HIV (PLWH) have substantially increased incidence of anal precancer and cancer. There are very little data regarding genomic disturbances in anal precancers among PLWH. Here, we identified specific chromosomal variants in anal squamous intraepithelial lesions. METHODS: We collected 63 anal biopsy specimens (27 low-grade intraepithelial lesions [LSIL] and 36 high-grade intraepithelial lesions [HSIL]) from PLWH obtained as part of anal cancer screening in our NYC-based health system. Data on patient demographics, anal cytological and high-risk human papillomavirus (HR-HPV) diagnoses were collected. Specimens were tested for a panel of chromosomal alterations associated with HPV-induced oncogenesis using Fluorescence In-Situ Hybridization (FISH) and analyses compared the associations of these alterations with clinical characteristics. RESULTS: Gains of 3q26, 5p15, 20q13 and cen7 were detected in 42%, 31%, 31%, and 19% of HSIL compared to 7%, 0%, 4%, and 0% of LSIL, respectively. Where at least one abnormality was seen, 89% had a 3q26 gain. In lesions with 5p15 gains, 20q13 gains co-occurred in 91% of cases, while cen7 gain only co-occurred with the other three alterations. Sensitivity and specificity of any alteration to predict HSIL was 47% (95% CI: 30-65%) and 93% (95% CI: 76%-99%) respectively. CONCLUSIONS: Genomic alterations seen in HPV-associated cancers may help distinguish anal LSIL from HSIL. 3q26 amplification may be an early component of anal carcinogenesis, preceding 5p16, 20q13 and/or chr7. IMPACT: We share insights on potential genomic biomarkers for discriminating high-risk anal precancers.