Detection and quantitation of human papillomavirus DNA in primary tumour and lymph nodes of patients with early stage cervical carcinoma

Fifteen Chinese women with early stage cervical squamous cell carcinoma (14 stage IB, one stage IIA) were retrospectively analysed for the correlation between human papillomavirus (HPV) load in primary tumour and the presence of HPV DNA in histologically tumour-free pelvic lymph nodes. HPV16 DNA was detected from majority (12/15) of primary tumours, with a viral load ranging from 12 to 1800 copies per cell. Of the 156 histologically tumour-free pelvic lymph nodes, 41 (26.3%) were positive for HPV DNA. The levels of viral load detected in histologically tumour-free lymph nodes were low and most were not detectable by the less sensitive consensus PCR GP5+/6+. Among patients without histological evidence of nodal involvement, the presence of HPV DNA in lymph nodes was associated with a significantly higher viral load in primary tumour (mean [interquartile range] = 800 [600-1450] versus 40 [19-70] copies per cell, P = 0.016). Three of the four patients with recurrence had histological evidence of lymph node metastases. In contrast, none of the seven patients with HPV DNA-positive lymph nodes but without histologically evidence of nodal involvement developed recurrence. The results of this study suggest that the presence of HPV DNA in histologically tumour-free lymph nodes do not have prognostic significance. The HPV DNA detected from lymph nodes may have originated from circulating necrotic tumour cells or those internalized by scavengers, which was easier to be detected when the viral load per tumour cell was high.