Molecular characterization of lung carcinomas: A study on diagnostic, predictive, and prognostic markers using immunohistochemical analysis at a tertiary care center in Uttarakhand, India

Shalinee Rao1, Michael Leonard Anthony1, Nilotpal Chowdhury1, Rajesh Kathrotia2, Mayank Mishra3, Manisha Naithani4, Girish Sindhwani3, Neha Singh1
1Department of Pathology and Laboratory Medicine, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India
2Department of Physiology, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India
3Department of Pulmonary Medicine, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India
4Department of Biochemistry, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India
DOI: 10.4103/jcar.jcar_14_21


INTRODUCTION: Focused studies in different geographic regions would delineate the underlying biological differences and molecular alterations in non-small cell lung cancer (NSCLC) worldwide. Previous studies in literature have documented limited characterization by studying a minimal number of biological markers. This study was done to evaluate expression of multiple immunomarkers including diagnostic, prognostic, and predictive markers in NSCLC for its characterization.
MATERIALS AND METHODS: This was an observational study conducted on 60 consecutive cases of NSCLC. Immunomarkers comprising of p63, p40, TTF-1, napsin A, B-Raf, c-Met, phospho-AKT (P-AKT), PTEN, anaplastic lymphoma kinase (ALK), epidermal growth factor receptor (EGFR) and K-Ras, synaptophysin, chromogranin and pan-cytokeratin were evaluated on paraffin-embedded tissue sections of NSCLC.
RESULTS: Age of patients with NSCLC in our study ranged from 35 to 90 years, and 93.3% of them were chronic smokers. 93.3% of cases presented in late stages (Stages III and IV) and 78% of cases were squamous cell carcinoma (SCC). EGFR positivity was noted in 83.3% of cases. ALK was positive in one case while C-Met and PTEN immunopositivity was noted in only two cases. Ten cases showed positivity for K-Ras and 90% of these were SCC. Ten cases were positive for B-Raf and 80% of these were SCC. 30% of cases showed immunopositivity for P-AKT. None of the molecular markers was found to have statistically significant correlation with clinicopathological parameters.
CONCLUSION: SCC is the predominant histological subtype of NSCLC in the region of Uttarakhand, India, with a high proportion of cases harboring EGFR mutation. Variable expression of K-Ras, P-AKT, ALK 1, and PTEN in NSCLC signifies that molecular profile of every case is individualistic and independent. We attribute this to ethnicity, influence of implicated substance or metabolite in tobacco, and variable mutations incurred in tumor cells over a period of time.

Keywords: Characterization, immunoexpression, molecular profile, non-small cell lung cancer