RESUMO
BACKGROUND: Human papillomavirus associated anogenital cancers are a significant global burden. The detection of biomarkers (circulating tumour DNA; ctDNA or circulating HPV DNA; cHPV DNA) in blood referred to as "liquid biopsy" may support the early diagnosis and monitoring of affected individuals. METHODS: A systematic review, including meta-analysis of studies available in the literature on the utilization of ctDNA and cHPV DNA as diagnostic, predictive, and monitoring biomarker tests of HPV associated anogenital cancers was performed following the criteria of PRISMA. RESULTS: A total of 31 studies were eligible for systematic review; 20 used cHPV DNA in cervical cancers; 7 used ctDNA in cervical cancer; 5 used cHPV DNA in anal cancer; no eligible studies on vulva, vaginal or penile cancer were available. The meta-analysis identified low sensitivity (0.36) and high specificity (0.96) of cHPV DNA as diagnostic for cervical cancer. Comparatively, there was high sensitivity (0.95) and specificity (1.0) of cHPV DNA for the diagnosis of anal cancer. cHPV DNA and/or ctDNA in cervical cancer were prognostic markers associated with poor clinical outcomes. Additionally, in anal cancer the post treatment detection of cHPV DNA was informative in the prediction of treatment response or progression-free survival. CONCLUSION: ctDNA and cHPV DNA are promising diagnostic and prognostic biomarkers for the detection of anogenital disease. Evolution and refinement of molecular tools is likely to improve performance further. Additionally the comparative absence of studies in the vulval, vaginal and penile context warrants further exploration and research.
