Immunohistochemical expression of cytokeratin-19 in non small cell lung carcinomas - an experience from a tertiary care hospital in Lahore

ABSTRACT

Previous literature reveals a significant recognition of Cytokeratin [CK] 19 as a reliable tumour marker in epithelial malignancies. With the hypothesis that CK 19 is extensively released by the tumour cells in patients with non small cell lung carcinomas [NSCLCs], this study was designed to assess [1] the clinicopathological characteristics of lung cancer in this sub-region [2] the pattern of immunohistochemical expression of CK-19 in different NSCLC subtypes with respect to their histological grades. A cross-sectional descriptive study comprising of detailed account of clinical data of 225 patients presenting with NSCLCs. After H/E staining, immunohistochemistry [IHC] was performed using prediluted ready to use mouse monoclonal antibody to CK 19. Our findings of the study revealed that the mean age of the patients was 45 years with the male to female ratio being 51. Most prevalent type seen was squamous cell carcinoma [SCC] and adenocarcinoma [AC] in males and females respectively. Some cases were not easily classifiable as squamous or adenocacinoma and hence they are classified as NSCLs Unclassified. SCC was commonly associated with smoking in both genders. Immunohistochemical staining of the histological tissue sections of 93.7% NSCLCs demonstrated a varying immunopositivity while showing strong, diffuse to focal cytoplasmic staining of the tumour cells. A significant association [p=0.001] was found between the increasing grades of malignancy and the strength of CK-19 expression. Supporting the previous literature, we have also come across that CK-19 is credibly expressed in patients with NSCLCs and may be applied as a reasonably reliable immunohistochemical marker. In future the patients over expressing CK-19 histologically might constitute potential candidates to be followed up through non invasive serial serum levels estimation intended for assessment of tumour burden in recurrence or advanced disease