Liquid biopsy of HPV DNA in cervical cancer.

BACKGROUND: A blood test to serve as a tumor marker for cervical cancer would be useful to clinicians to guide treatment and provide an early signal for recurrence. The development of droplet digital PCR has enabled the detection of HPV DNA in patient serum, providing a potential marker for cervical cancer. OBJECTIVES: To report on a blood-based test for HPV-specific E7 and L1 genes, which may serve as a tumor marker to guide treatment and detect early recurrence in cervical cancer. STUDY DESIGN: Pre-treatment plasma samples were investigated from 138 Hong Kong Chinese women with primary invasive squamous cell carcinoma and adenocarcinoma of the cervix with tumor samples expressing HPV16 or HPV18. Two genes specific to the human papillomavirus, E7 and L1, were measured in cell free DNA (cfDNA) extracted from plasma using droplet digital PCR. Analysis of detectable E7 and L1 levels was performed to investigate the potential of liquid biopsy of E7 and L1 as a clinically useful molecular biomarker. RESULTS: The majority of patients had HPV16 (71.7%), squamous cell carcinoma (78.3%) and stage IB-II disease (82.6%). HPV E7 and L1 sequences were detected in plasma cfDNA from 61.6% (85/138) of patients. Patients with high viral load (defined as ≥20 E7 or L1 copies per 20 µL reaction volume) had increased risk of recurrence and death at 5 years on univariate analysis but not multivariate analysis. CONCLUSIONS: HPV DNA can be quantitatively detected with the use of cfDNA. This has the potential to provide a clinically useful tumor marker for patients with cervical cancer that can aid in post-treatment surveillance and estimating the risk of disease relapse.

Liquid biopsy of PIK3CA mutations in cervical cancer in Hong Kong Chinese women.

INTRODUCTION: Cervical cancer is the fourth most common female cancer worldwide. The prognosis for women with advanced-stage or recurrent cervical cancer remains poor and response to treatment is variable. Standardized management protocols leave little room for individualization. We report on a novel blood-based liquid biopsy for specific PIK3CA mutations as a clinically useful biomarker in patients with invasive cervical cancer. METHODS: One hundred seventeen Hong Kong Chinese women with primary invasive cervical cancer and their pre-treatment plasma samples were investigated. Two PIK3CA mutations, p.E542K and p.E545K were measured in cell free DNA (cfDNA) extracted from plasma using droplet digital PCR. This liquid biopsy of PIK3CA in cervical cancer was correlated to clinico-pathological features to verify the potential of PIK3CA as a clinically useful molecular biomarker for predicting disease prognosis and monitoring for progression. RESULTS: PIK3CA mutations, either p.E542K or p.E545K, were detected in plasma cfDNA from 22.2% of the patients. PIK3CA mutation status was significantly correlated to median tumor size (p<0.01). PIK3CA mutations detected in the plasma were significantly associated with decreased disease-free survival and overall survival (p<0.05). CONCLUSIONS: As a liquid molecular biopsy, analysis of circulating PIK3CA mutations shows promise as a way to refine risk stratification of individual patients with cervical cancer, and provides a platform for further research to offer individualized therapy with the purpose of improving outcomes.

Dysregulated microRNAs and their predicted targets associated with endometrioid endometrial adenocarcinoma in Hong Kong women.

The objective of this study, a parallel study to global gene expression profiling, was to identify dysregulated microRNAs (miRNAs) associated with endometrioid endometrial adenocarcinoma (EEC), examine their correlation with clinico-pathological characteristics and identify predicted target genes of the dysregulated miRNAs. Using real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR), profiling of miRNA expression was performed in 30 EECs and 22 normal counterparts in which genome-wide gene expression had been previously profiled and reported. Clustering analysis identified 30 miRNAs which were significantly dysregulated in EEC. The expression of a sub-group of miRNAs was significantly correlated with clinico-pathological characteristics including stage, myometrial invasion, recurrence and lymph node involvement. By searching for predicted miRNA targets that were linked to the dysregulated genes previously identified, 68 genes were predicted as candidate targets of these 30 dysregulated miRNAs. miR-205 was significantly overexpressed in EECs compared with normal controls. After transfection of a miR-205 inhibitor, the expression of miR-205 in endometrial cancer cell line RL95-2 cells decreased whereas its predicted target gene, JPH4, showed increased protein expression. JPH4 seems to be a real miR-205 target in vitro and in vivo, and a candidate tumor suppressor gene in EEC. Based on this study in EEC, miRNAs predicted to be involved in tumorigenesis and tumor progression have been identified and placed in the context of the transcriptome of EEC. This work provides a framework on which further research into novel diagnosis and treatment of EEC can be focused.