ABSTRACT
INTRODUCTION: Protein p16 has been extensively studied as a potential biomarker for precursor lesions to distinguish cervical Intraepithelial neoplasia (CIN) from their mimics. However, the use of p16 as prognostic biomarker for diagnosis of cervical cancer and precancer is controversial. This study focuses on the assessment of peer-reviewed scientific data related to the use of p16 to predict disease severity and its controversies. METHODS: We reviewed publications in MEDLINE/PubMed assessing the clinical, diagnostic and prognostic significance of p16 in CIN and cervical cancer; we included publications from 2009 to June 2017. RESULTS: The use of p16 as a prognostic marker is still unreliable, although it could be a useful tool for diagnosis of Cervical Intraepithelial Neoplasia lesions with undetermined morphology. Moreover, p16 appears to be a specific marker of high-risk oncogenic HPV infection. CONCLUSION: This review shows the potential utility and drawbacks of p16 for clinical practice and the diagnosis of cervical cancer. Further studies are required to substantiate the role of p16 in conjunction with other more sensitive and specific biomarkers for diagnosing CIN and predicting its progression.
INTRODUÇÃO: A proteína p16 tem sido estudada como um biomarcador potencialmente específico de lesões cervicais precursoras e como uma forma de diferenciar as lesões parecidas com Neoplasia intra-epitelial cervical (NIC). Contudo existem várias controvérsias sobre a utilização de p16 como um biomarcador prognóstico e como uma ferramenta para o diagnóstico de câncer cervical e de lesões pré-câncer. O objetivo deste estudo foi a revisão de dados científicos por pares de bases, relacionados com a utilização da p16 e suas controvérsias. MÉTODOS: O estudo foi projetado como uma revisão da literatura das publicações do Medline/PubMed que avaliam o significado clínico, diagnóstico ou prognóstico do p16 em lesões de NIC e no câncer cervical no período de janeiro de 2009 a junho de 2017. RESULTADOS: o uso do p16 como um marcador prognóstico ainda não é confiável, apesar de que a p16 poderia ser uma ferramenta útil para o diagnóstico em lesões de NIC com morfologia indeterminada. Além disso, a p16 parece ser um marcador específico de infecção por HPV de alto risco oncogênico. CONCLUSÃO: A presente revisão mostra a potencial utilidade da proteína p16, bem como os inconvenientes para uso clínico-patológico e diagnóstico no câncer cervical. Contudo são necessários mais estudos para fundamentar o papel da p16 em conjunto com os outros biomarcadores mais sensíveis e específicos para diagnosticar NIC e prever a sua progressão.
Subject(s)
Humans , Biomarkers, Tumor , Uterine Cervical Neoplasms/diagnosis , Uterine Cervical Dysplasia , Papillomavirus InfectionsABSTRACT
Although several studies have evaluated the role of p16INK4a as a diagnostic marker of cervical intraepithelial neoplasia (CIN) and its association with disease progression, studies regarding the role of p16INK4a in human immunodeficiency virus (HIV)-infected patients remain scarce. The present study was designed to determine the potential utility of p16INK4a as a diagnostic marker for CIN and invasive cervical cancer in HIV-positive and negative cervical specimens. An immunohistochemical analysis of p16INK4a was performed in 326 cervical tissue microarray specimens. Performance indicators were calculated and compared using receiving operating characteristics curve (ROC)/area under the curve. In HIV-1-negative women, the percentage of cells that was positive for p16INK4a expression was significantly correlated with the severity of CIN (p < 0.0001). A ROC curve with a cut-off value of 55.28% resulted in a sensitivity of 89%, a specificity of 81%, a positive predictive value of 91% and a negative predictive value of 78%. HIV-seropositive women exhibited decreased expression of p16INK4a in CIN2-3 specimens compared with HIV-negative specimens (p = 0.031). The ROC data underscore the potential utility of p16INK4a under defined conditions as a diagnostic marker for CIN 2-3 staging and invasive cervical cancer. HIV-1 infection, however, is associated with relatively reduced p16INK4a expression in CIN 2-3.