Studies question value of certain HNC biomarkers

Source: Dr.Biscuspid.com September 19, 2012 -- Human papillomavirus (HPV) DNA positivity alone, particularly when assessed using polymerase chain reaction methods, is a poor biomarker for HPV-driven head and neck cancers (HNCs), according to two studies published in Cancer Research (September 18, 2012). These studies identified alternative potential markers, including viral load, viral gene expression, and the evaluation of HPV DNA in combination with certain HPV assays. Prior research has established that HPV is a cause of some head and neck cancers, including oropharyngeal cancer, and that patients with HPV-associated disease tend to have a better clinical outcome. Consequently, the proper assessment of the clinical status of individual tumors has become a goal of clinicians treating this disease because HPV at the tumor site does not indicate causal involvement in the cancer. In the first study, Dana Holzinger, PhD, of the division of genome modifications and carcinogenesis at the German Cancer Research Center, and colleagues analyzed the potential of direct and indirect HPV markers to identify patients with HPV-driven tumors. They analyzed 199 oropharyngeal squamous cell carcinoma specimens for HPV DNA, viral load, RNA expression patterns seen in cervical carcinomas, and the p16 protein. They found that the cervical cancer RNA expression pattern and viral load were associated with the lowest risk for death from oropharyngeal cancer. In contrast, a weaker association was found for samples that were HPV DNA-positive or that expressed the p16 protein. "We showed that high viral load and a cancer-specific pattern of viral gene expression are [...]

2012-09-28T13:42:14-07:00September, 2012|Oral Cancer News|

Evaluation of a combined triple method to detect causative HPV in oral and oropharyngeal squamous cell carcinomas: p16 Immunohistochemistry, Consensus PCR HPV-DNA, and In Situ Hybridization

Source: 7thspace.com Recent emerging evidences identify Human Papillomavirus (HPV) related Head and Neck squamous cell carcinomas (HN-SCCs) as a separate subgroup among Head and Neck Cancers with different epidemiology, histopathological characteristics, therapeutic response to chemo-radiation treatment and clinical outcome. However, there is not a worldwide consensus on the methods to be used in clinical practice. The endpoint of this study was to demonstrate the reliability of a triple method which combines evaluation of: 1. p16 protein expression by immunohistochemistry (p16-IHC); 2. HPV-DNA genotyping by consensus HPV-DNA PCR methods (Consensus PCR); and 3 viral integration into the host by in situ hybridization method (ISH). This triple method has been applied to HN-SCC originated from oral cavity (OSCC) and oropharynx (OPSCC), the two anatomical sites in which high risk (HR) HPVs have been clearly implicated as etiologic factors. Methylation-Specific PCR (MSP) was performed to study inactivation of p16-CDKN2a locus by epigenetic events. Reliability of multiple methods was measured by Kappa statistics. Results: All the HN-SCCs confirmed HPV positive by PCR and/or ISH were also p16 positive by IHC, with the latter showing a very high level of sensitivity as single test (100% in both OSCC and OPSCC) but lower specificity level (74% in OSCC and 93% in OPSCC).Concordance analysis between ISH and Consensus PCR showed a faint agreement in OPSCC (kappa = 0.38) and a moderate agreement in OSCC (kappa = 0.44). Furthermore, the addition of double positive score (ISHpositive and Consensus PCR positive) increased significantly the specificity of HR-HPV detection on [...]

2012-02-29T17:24:29-07:00February, 2012|Oral Cancer News|
Go to Top