Association of HPV16/18 genotype infection with the Silva pattern classification system in human papilloma virus-associated endocervical adenocarcinomas.

Objective: Persistent high-risk human papillomavirus (HR-HPV) infection is an essential risk factor for HPV-associated adenocarcinomas (HPVA). A three-tier pattern system (the Silva pattern) for endocervical adenocarcinoma (ECA) associated with tumor metastasis and recurrence was described by Elvio G. Silva nearly 10 years ago. However, there are no studies on the association between HPV genotypes and Silva patterns.

Methods: The Silva pattern classification was performed on 240 surgical HPVA specimens according to the 2020 World Health Organization classification of female genital tract cancers. HPV DNA was detected using the SPF₁₀-DEIA-LiPA₂₅ assay for all specimens and an attribution algorithm was used to calculate the attribution rate of HPV16/18.

Results: Out of all HPVA cases, 29 patients (12.1%) were found to have tumors with Silva pattern A, 122 (50.8%) had pattern B tumors, and 89 (37.1%) had pattern C (representing the worst morphological behavior, poorest prognosis and highest risk of mortality). The crude prevalence of HPV16 and 18 was 46.9% and 44.7%, respectively. The attribution of HPV16 in Silva patterns A, B, and C was 58.0%, 51.7%, and 33.8%, respectively (P = 0.123). Similarly, the attribution of HPV18 was found to be 29.8%, 39.7%, and 49.5% in patterns A, B, and C, respectively. Notably, there was a statistically significant positive linear relationship between the prevalence of HPV18 and the Silva pattern from A to C (P = 0.002).

Conclusion: HPV16 and 18 are the most prevalent HPV subtypes in patients with HPVA. HPVA patients who are infected with HPV18 exhibit worse morphological behavior compared to those with the HPV16 genotype.