Quantitative Analysis of Cell-Free Epstein-Barr Virus DNA in Plasma of Patients with Nonnasopharyngeal Head and Neck Carcinomas

Abstract

Purpose: We investigated the detectability of EBV DNA in the plasma of patients with non-nasopharyngeal head and neck carcinomas (NNHNC). Previous studies have shown that EBV is present in the tumor tissue of some NNHNC.Experimental Design: We recruited 101 patients with NNHNC and 48 healthy controls. Blood samples were taken from controls and patients before treatment. Tumor tissue samples were tested for the presence of EBV in the first 69 patients by in situ hybridization for small EBV-encoded RNA (EBER). Plasma EBV DNA was measured by real-time quantitative PCR in patients and controls.Results: Squamous cell carcinoma (SCC) was the commonest histology (78 patients) followed by lymphoepithelial carcinoma (8 patients). EBER was detected in tumor cells in 7 of 69 patients tested. All of the EBER-positive tumors were lymphoepithelial carcinoma. Two controls (2 of 48; 4.2%) had detectable plasma EBV DNA. Plasma EBV DNA was detected in all of the patients with EBER-positive tumors, and in 23 of 94 (24.5%) patients with tumors of EBERnegative or unknown status. The proportion of plasma EBV DNA-positive cases in either group was significantly higher than that in the control group (P < 0.0027). Plasma EBV DNA concentrations in patients with EBER-positive tumors (median, 3827 copies/ml) were significantly higher than those in the controls (median, 0 copy/ml; P ‫؍‬ 0.0001). Of patients with SCC, 21 (26.9%) had detectable plasma EBV DNA (median concentration, 34 copies/ml). Plasma EBV DNA concentrations in the whole group of patients with SCC (median, 0 copy/ml; interquartile range, 0 -4 copies/ ml) were also significantly higher than those in the controls (P ‫؍‬ 0.001).Conclusions: Our data indicate that plasma EBV DNA reflects tumoral EBER status, and it may be of use as a tumor marker for EBER-positive NNHNC. The biological and clinical significance of low levels of circulating EBV DNA in the minority of patients with EBER-negative tumors remain to be elucidated.

Quantitative analysis of cell-free Epstein-Barr virus DNA in the plasma of patients with peripheral T-cell and NK-cell lymphomas and peripheral T-cell proliferative diseases

“…However, some of our patients with EBER-negative tumor cells demonstrated low levels of EBV DNA in their plasma. This finding corresponds to a previous report showing a slight increase in plasma EBV DNA in a significant proportion of patients with EBER-negative squamous cell carcinoma of the head and neck regions (Yu et al, 2004). Additionally, three patients in our study who had undetectable EBV genome in tumor cells and circulating lymphocytes showed EBV DNA in the plasma (29 copies/ml, 69 copies/ml, and 920 copies/ml).…”

“…A high level of cell-free EBV DNA in plasma was detected in patients with EBV-associated disease such as nasopharyngeal carcinoma, Hodgkin's lymphoma, extranodal NK-T-cell lymphoma, nasal type, post-transplant lymphoproliferative disease, Burkitt's lymphoma, lymphoepithelial carcinoma, and infectious mononucleosis (Chan et al, 2003;Gallagher et al, 1999;Green et al, 1998;Lei et al, 2000Lei et al, , 2002Lit et al, 2004;Lo et al, 1999;Yu et al, 2004). The concentration in positive samples varied from 24 copies/ml to more than 600,000 copies/ml, while the samples from healthy individuals were usually negative.…”

Optimization of circulating cell-free DNA recovery for KRAS mutation and HPV detection in plasma

“…Increasing evidence shows that DNA alterations in tumour tissue can be detected in blood using cfDNA [2,3,[7][8][9][10][11]. However, the fraction of tumour-origin DNA in cfDNA can be very low since cfDNA is derived from both tumour and non-tumour cells.…”

“…In this regard, the use of circulating free DNA (cfDNA) from plasma or serum as an alternative and additional source of DNA to test cancer specific genetic alterations is an attractive proposition [5,6]. Recent advances in PCR (Polymerase Chain Reaction) based technology have allowed the analysis of specific genetic (point mutations in EGFR [7,8], KRAS [8], BRAF [9]) and epigenetic alterations (such as HPV [10] and EBV [11]) in cfDNA isolated from patients' plasma or serum. These genes are of particular importance in determining the response to a variety of novel agents in clinical use and in the development of cancer treatment.…”

Circulating DNA as a Biomarker for Early Detection of Cancer: A Brief Update with an Emphasis on Lung Cancer~!2010-06-09~!2010-08-03~!2010-09-06~!

“…Such studies have indicated a good correlation between restricted expression at the tissue level and the occurrence of detectable levels of candidate biomarkers in serum/plasma DNA. In this connection, the circulating methylated DNA approach has been applied as a biomarker in various forms of cancer, including pancreatic [19,20,24,25], ovarian [26][27][28][29], prostate carcinoma [30][31][32][33][34], hepatocellular carcinoma [35][36][37][38], esophageal adenocarcinoma [39,40], colorectal carcinoma [8,41,42], breast [3,[43][44][45], head and neck squamous cell carcinoma [46][47][48], non-Hodgkin lymphoma [49], and lung cancer [10,16,18,[50][51][52].…”