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.

Genomic aberrations in cervical adenocarcinomas in Hong Kong Chinese women.

Although the rates of cervical squamous cell carcinoma have been declining, the rates of cervical adenocarcinoma are increasing in some countries. Outcomes for advanced cervical adenocarcinoma remain poor. Precision mapping of genetic alterations in cervical adenocarcinoma may enable better selection of therapies and deliver improved outcomes when combined with new sequencing diagnostics. We present whole-exome sequencing results from 15 cervical adenocarcinomas and paired normal samples from Hong Kong Chinese women. These data revealed a heterogeneous mutation spectrum and identified several frequently altered genes including FAT1, ARID1A, ERBB2 and PIK3CA. Exome sequencing identified human papillomavirus (HPV) sequences in 13 tumors in which the HPV genome might have integrated into and hence disrupted the functions of certain exons, raising the possibility that HPV integration can alter pathways other than p53 and pRb. Together, these provisionary data suggest the potential for individualized therapies for cervical adenocarcinoma based on genomic information.

CHD5 Downregulation Associated with Poor Prognosis in Epithelial Ovarian Cancer.

BACKGROUND: The CHD5 gene located on 1p36 encodes a protein-chromodomain helicase DNA-binding protein 5. CHD5 has been shown to be a tumor suppressor gene candidate. This study investigated the involvement of CHD5 in ovarian cancer and its clinicopathological significance. METHODS: CHD5 expression in ovarian cancer and its counterpart were determined by quantitative RT-PCR. The correlation of CHD5 expression to clinicopathological features of the tumor was analyzed. RESULTS: CHD5 expression was downregulated by at least twofold in 32 of 72 (41%) invasive epithelial ovarian carcinomas when compared to 12 controls in Hong Kong Chinese women. CHD5 downregulation was correlated to clinical status (p < 0.05), but not to patient age, tumor type and grade, recurrence and clinical stage (p > 0.05). Survival analysis showed that patients with CHD5 downregulation in their tumors were associated with shorter disease-free and total survival times compared to those without CHD5 downregulation (p < 0.05). Cox proportional-hazards regression analysis indicated that downregulation of CHD5 is an independent adverse prognostic factor in ovarian cancer. CONCLUSION: This study shows that CHD5 is downregulated in a certain number of ovarian cancers and appears to be an adverse predictor candidate of ovarian cancer disease-free and total survival.

Dissection of PIK3CA Aberration for Cervical Adenocarcinoma Outcomes.

Personalized treatment of genetically stratified subgroups has the potential to improve outcomes in many malignant tumors. This study distills clinically meaningful prognostic/predictive genomic marker for cervical adenocarcinoma using signature genomic aberrations and single-point nonsynonymous mutation-specific droplet digital PCR (ddPCR). Mutations in PIK3CA E542K, E545K, or H1047R were detected in 41.7% of tumors. PIK3CA mutation detected in the patient's circulating DNA collected before treatment or during follow-up was significantly associated with decreased progression-free survival or overall survival. PIK3CA mutation in the circulating DNA during follow-up after treatment predicted recurrence with 100% sensitivity and 64.29% specificity. It is the first indication of the predictive power of PIK3CA mutations in cervical adenocarcinoma. The work contributes to the development of liquid biopsies for follow up surveillance and a possibility of tailoring management of this particular women's cancer.

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.

Osteopontin Fragments with Intact Thrombin-Sensitive Site Circulate in Cervical Cancer Patients.

We investigated whether circulating osteopontin (OPN) could be used as a biomarker for cervical cancer. We employed a monoclonal antibody (mAb 659) specific for the unique and intact thrombin-sensitive site in OPN using an inhibition ELISA. We found significantly higher levels of OPN in 33 cervical cancer patients in both the plasma (mean +/- SD, 612 +/- 106 ng/mL) and serum (424 +/- 121 ng/mL) compared to healthy subjects [409 +/- 56 ng/mL, from 31 plasma samples (P < 0.0001), and 314 +/- 98 ng/mL, from 32 serum samples (P = 0.0002), respectively]. Similar results were obtained when the plasma from a bigger group (147 individuals) of cervical cancer patients (560 +/- 211 ng/mL) were compared with the same plasma samples of the healthy individuals (P = 0.0014). More significantly, the OPN level was highest in stage III-IV disease (614 +/- 210 ng/mL, from 52 individuals; P = 0.0001) and least and non-discriminatory in stage I (473 +/- 110 ng/mL, from 40 individuals; P = 0.5318). No such discrimination was found when a mAb of a different specificity (mAb 446) was used in a similar inhibition ELISA to compare the two groups in the first study; a commercial capture ELISA also failed. The possibility that the target epitope recognized by the antibody probe in these assays was absent from the circulating OPN due to protein truncation was supported by gel fractionation of the OPN found in patients' plasma: 60-64 kDa fragments were found instead of the presumably full-length OPN (68 kDa) seen in healthy people. How these fragments are generated and what possible role they play in cancer biology remain interesting questions.

An update on Mullerian-inhibiting substance: its potential application against ovarian cancer.

Each year, ∼25 000 women are newly diagnosed with ovarian cancer in the USA. The vast majority (>90%) of cases are of epithelial origin. This highly lethal cancer carries a mortality rate of >50% and a high risk of recurrence after conventional, first-line chemotherapy. Müllerian-inhibiting substance (MIS) is a gonadal hormone that causes regression of the Müllerian ducts. A series of studies have demonstrated that MIS also has multiple extra-Müllerian functions including inhibition of epithelial ovarian cancer cells in vitro and in vivo. Accumulating evidence has shown that many human cancers are organized hierarchically and contain a small population of cancer stem cells (CSCs) that are inherently resistant to common chemotherapy and radiation therapy. The effect of MIS on ovarian CSC seems to be particularly useful in rescuing ovarian cancer patients with resistance to conventional treatment. Based on recent studies evaluating MIS, this review updates our current understanding of the molecular genetic aspects of MIS, its pathophysiology, as well as its potential to treat chemoresistant epithelial ovarian cancer.

Dysregulated microRNAs in the pathogenesis and progression of cervical neoplasm.

MicroRNAs (miRNAs) play an important role in a variety of physiological as well as pathophysiological processes, including carcinogenesis. The aim of this study is to identify a distinct miRNA expression signature for cervical intraepithelial neoplasia (CIN) and to unveil individual miRNAs that may be involved in the development of cervical carcinoma. Expression profiling using quantitative real-time RT-PCR of 202 miRNAs was performed on micro-dissected high-grade CIN (CIN 2/3) tissues and compared to normal cervical epithelium. Unsupervised hierarchical clustering of the miRNA expression pattern displayed a distinct separation between the CIN and normal cervical epithelium samples. Supervised analysis identified 12 highly differentially regulated miRNAs, including miR-518a, miR-34b, miR-34c, miR-20b, miR-338, miR-9, miR-512-5p, miR-424, miR-345, miR-10a, miR-193b and miR-203, which distinguished the high-grade CIN specimens from normal cervical epithelium. This miRNA signature was further validated by an independent set of high-grade CIN cases. The same characteristic signature can also be used to distinguish cervical squamous cell carcinoma from normal controls. Target prediction analysis revealed that these dysregulated miRNAs mainly control apoptosis signaling pathways and cell cycle regulation. These findings contribute to understanding the role of microRNAs in the pathogenesis and progression of cervical neoplasm at the molecular level.