Detection of human papillomavirus type 16 E6/E7 transcripts in histologically cancer-free pelvic lymph nodes of patients with cervical carcinoma.

Human papillomavirus (HPV) 16 E6/E7 mRNAs have been detected in paraffin-embedded sections of histologically cancer-free pelvic lymph nodes from four of six patients with HPV 16-associated cervical cancer. The cDNA obtained from the viral mRNA by reverse transcription was amplified by the polymerase chain reaction (PCR). Transcripts were present in a small but significant proportion (6/42, 14%) of the histologically negative/HPV 16 DNA-positive lymph node blocks; but neither HPV 16 DNA nor transcripts were found in 12 lymph node blocks from two patients whose cervical cancers were not HPV-related. Both of the HPV 16 mRNAs detectable by the PCR primers used in the assay (the E6*I and the full-length E6 transcript) were found in the primary tumors, but the transcription patterns in the lymph nodes were variable. The presence of HPV E6/E7 mRNAs in lymph nodes of patients with HPV-related cancer may be a more sensitive indicator of metastasis than conventional histology. In addition, their detections is likely to be more significant than that of HPV DNA sequences alone. The practical significance of the findings, however, awaits correlation with the ultimate clinical outcome.