Contribution of Human papillomavirus in neuroendocrine tumors from a series of 10,575 invasive cervical cancer cases

Aims: Neuroendocrine tumors (NET) of the cervix are rare tumors with a very aggressive course. The human papillomavirus (HPV) has been linked to its etiology. The objective of this study is to describe HPV prevalence and genotype distribution of NET. Methods and Results: Forty-nine tumors with histological neuroendocrine features were identified among 10,575 invasive cervical cancer (ICC) cases from an international study. HPV DNA detection was done using SPF10/DEIA /LiPA(25) system. Immunohistochemical (IHC) staining for neuroendocrine markers (chromogranin A, synaptophysin, CD56) and for p16(INK4a) as a surrogate for HPV transforming infection was performed. In 13 samples with negative IHC for all 3 neuroendocrine markers studied, it was possible to conduct electron microscopy (EM). NET represented 0.5% of the total ICC series and HPV was detected in 42 out of 49 samples (85.7%, 95% CI: 72.8%, 94.1%). HPV16 was the predominant type (54.8%), followed by HPV18 (40.5%). p16(INK4a) overexpression was observed in 38/44 cases (86.4%). Neuroendocrine IHC markers could be demonstrated in 24/37 (64.9%) cases. EM identified neuroendocrine granules in 8 samples with negative IHC markers. Conclusions: Our data confirms the association of cervical NET with HPV and p16(INK4a) overexpression. Specifically, HPV16 and 18 accounted together for over 95% of the HPV positive cases. Current HPV vaccines could largely prevent these aggressive tumors.