Multiple HPV genotypes in cervical carcinomas: improved DNA detection and typing in archival tissues.

BACKGROUND: Human papillomaviruses (HPV) have been considered to be the necessary and central agents of cervical carcinoma.

OBJECTIVE: The aim of this study was to determine the prevalence and genotypes of HPV in archival cervical carcinomas.

STUDY DESIGN: The study included 152 paraffin-embedded, formaldehyde-fixed cervical carcinoma specimens. To improve the detection and typing of HPV in archival tissues, we conducted a comprehensive study in which, polymerase chain reaction (PCR)-based methods using E7 type-specific (TS) and L1 modified general primers (MY11/GP6+ and GP5+/GP6+) were employed.

RESULTS: Overall HPV prevalence was 98% in the cervical carcinomas. HPV 16 was detected in 66% of the tumors, HPV 18 in 22%, HPV 31 in 13%, HPV 33 in 9%, and HPV 58 in 9%. Notably, multiple HPV types were present in 44 (28.9%) of the 152 cervical carcinomas. The most common co-infections were HPV types 16/18 (12 cases), followed by HPV types 16/31 (7 cases). Additionally, HPV 18 was more frequent in adenocarcinomas and adenosquamous carcinomas (86%) than in squamous cell carcinomas (15.8%) (P = 0.0002).

CONCLUSIONS: The combination of L1 general primers and E7 type-specific primers can be of use in detecting HPV DNA in archival tissues. The present study showed a high frequency of multiple HPV infections in cervical carcinomas. Hence, relevant HPV typing information in cervical carcinoma is very important for further HPV vaccine design and application.