title: Understanding molecular markers in recurrent oral squamous cell carcinoma treated with chemoradiation.
abstract: BACKGROUND
  Oral cancer accounts for approximately 2.1% of all cancers worldwide. In India, oral squamous cell carcinoma (OSCC) is the most common cancer with half a million new cases diagnosed every year. More than 50% of patients eventually develop local recurrence or metastasis usually within the first 2-years following completion of treatment. It is beneficial to analyze the prognostic significance of Cyclin D1, p53 and EGFR which are critical mediators in the pathogenesis of OSCC. The objective of this study was to assess the association of expression of these markers with recurrence and pattern of recurrence in OSCC patients undergoing chemoradiation.
  
  
  METHODS
  A Total 290 OSCC cases of locally advanced stage (III, IV) oral cancer with World Health Organization (W.H.O.) performance status of grade 0/1 in the year 2009-2012 were enrolled in the study. Treatment response was assessed according to W.H.O. criteria. Cyclin D1, EGFR and p53 expression in tumor tissue was estimated by immunohistochemical (IHC) method and quantified as percentage positive nuclei.
  
  
  RESULTS
  During the 2-years follow up, 56 (19.3%) patients recurred, out of which, 47 (83.9%) were locoregional and 9 (16.1%) distant sites. On correlating, χ2test showed significant (P< 0.05 orP< 0.01 orP< 0.001) association of marker expressions (Cyclin D1, EGFR and p53) with recurrence. The strong positive expressions of all three markers showed significant association with early time of recurrence. The multivariate logistic regression analysis showed significant (P< 0.05 orP< 0.01 orP< 0.001) association of recurrence with primary site, differentiation, Cyclin D1 and p53 expressions indicating these as an independent predictors of recurrence in OSCC. The Cyclin D1, EGFR and p53 expressions also showed significant (P< 0.001) poor survivals (OS, DFS and RFS) in patients with positive/strong positive expressions than negative expression suggesting their prognosis in OSCC.
  
  
  CONCLUSIONS
  Our results signifies that tumors over expressing Cyclin D1, EGFR and p53 are resistant to chemoradiation and are associated with increased risk of locoregional recurrence and metastasis in OSCC patients undergoing chemoradiation.
authors.affiliation: Department of Radiotherapy, King George's Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Seema
authors.initials: S
authors.lastname: Gupta
authors.affiliation: Department of Radiotherapy, King George's Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Vandana Singh
authors.initials: VS
authors.lastname: Kushwaha
authors.affiliation: Department of Radiotherapy, King George's Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Verma
authors.affiliation: Department of Radiotherapy, King George's Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Huma
authors.initials: H
authors.lastname: Khan
authors.affiliation: Department of Radiotherapy, King George's Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: M L B
authors.initials: ML
authors.lastname: Bhatt
authors.affiliation: Department of Pathology, RMLIMS, Lucknow, Uttar Pradesh, India.
authors.forename: Nuzhat
authors.initials: N
authors.lastname: Husain
authors.affiliation: Clinical and Experimental Medicine Division, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India.
authors.forename: Mahendra Pal Singh
authors.initials: MP
authors.lastname: Negi
authors.affiliation: Clinical and Experimental Medicine Division, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India.
authors.forename: Vivek Vidyadhar
authors.initials: VV
authors.lastname: Bhosale
authors.affiliation: Clinical and Experimental Medicine Division, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India.
authors.forename: Ashim
authors.initials: A
authors.lastname: Ghatak
keywords: Cancer Research; Medicine; Oncology