Evaluation of Immunohistochemical expression of DNA repair proteins and their association with therapeutic outcome among tobacco chewers with oral squamous cell carcinoma

Abstract

Over the years research has been focused on the expression of newlineoncogenes, tumor suppressor genes, proliferative and apoptotic markers. But newlinethe root cause i.e. disruption of repair mechanism has gained momentum only newlinein the recent past with most of the studies pertaining to colon cancer and lung newlinecancer and very few allied to head and neck cancer. Studies on DNA repair newlineprotein expression specifically in OSCC are less. Most of them are multipart of newlinehead and neck cancer studies that include cancers of the oral cavity, pharynx, newlinelarynx, nasal cavity, paranasal sinus and salivary glands. The risk factors newlinediffer in each of these. Therefore, the DNA repair status in oral squamous cell newlinecarcinoma need to be analyzed. Literature review supports the existence of newlinelarge areas of genetically altered field around the tumor proper. This tumor newlineadjacent mucosa with field changes can modify the tumor prognosis. To newlineidentify the field, a number of molecular and genetic studies have been newlinecarried out. Each of these has its own advantages and disadvantages and newlinevery few are used in routine clinical practice. Presently attention is focused on newlineImmunohistochemical analysis which can be instituted into routine clinical newlinepractice. Hence there is a need for a robust and distinctive predictive marker newlineto disclose field cancerization in the tumor associated mucosa. newlineAnalysis of the results revealed that, tobacco related habits are newlinehighly prevalent among oral squamous cell carcinoma individuals. The level of newlineexpression of ERCC1, MSH2 and PMS2 are high in TP followed by controls newlineand least in TAM. From this it can be established that TP is surrounded by newlinefield cancerization that is deficient in DNA repair because of paucities in newlineexpression of DNA repair proteins like ERCC1, and PMS2. The selected newlinestudy group are tobacco chewers who are predisposed for field cancerization.