Vol. 8, Issue 2, Part A (2025)

Background: Next to adenocarcinoma, squamous cell carcinoma (SCC) of the lung is the commonest histologic subtype in non-small cell lung cancer (NSCLC). Study aimed to analyse clinicopathological and immunohistochemical profile of Non-small cell lung cancer (NSCLC).

Patients and Methods: A total of 470 cases of NSCLC were diagnosed based on cytology, out of which 288 cases were subjected to bronchial biopsy. NSCLC were collected for immunohistochemical with p63, ck5/6, TTF-1 and Napsin-A markers in a study period of 3 years.

Results: Among 288 biopsies, 152 cases were well differentiated Adenocarcinoma (ADC), and 99 cases were well differentiated SCC and 37 cases were diagnosed as poorly differentiated NSCLC (probably ADC (n=28) and probably SCC (n=9)). Out of 28 cases diagnosed as poorly differentiated ADC, 26 cases were positive to TTF-1, Napsin-A and negative for p63, ck5/6, diagnosed as ADC and 2 were positive to p63, ck5/6 and negative to TTF-1, Napsin-A, diagnosed as SCC. Out of 9 cases of SCC, 6 were positive to p63, ck5/6 and negative to TTF-1, Napsin-A were diagnosed as SCC and 3 cases were positive to TTF-1 and Napsin-A and negative to p63 and ck5/6, diagnosed as ADC. TTF1 and Napsin-A had 100% specificity to ADC and TTF-1 is more sensitive than Napsin-A. p63 were positive in 100 out of 107 cases of SCC (Sensitivity 93.5%) and negative in all ADC (Specificity 100%). ck5/6 was positive in 83 out of 107 cases (Sensitivity 77.4%) and negative in all ADC (Specificity100%). All ck5/6 positive cases also positive to p63. Three SCC cases which are positive for p63 were negative to ck5/6. p63 and ck5/6 shows 100% specificity to SCC and higher sensitive than ck5/6.

Conclusion: Immunohistochemistry with TTF-1, Napsin-A, p63 and ck5/6 markers can be used in subtyping of poorly differentiated carcinomas. TTF-1 and Napsin-A are highly specific for ADC and TTF-1 has high sensitivity than Napsin-A. p63 and ck5/6 are highly specific for SCC and p63 has higher sensitivity than ck5/6.