Cytokeratin 8 depicts nodal metastasis in head and neck squamous cell carcinoma.

Background: Nodal involvement in squamous cell carcinoma is an important feature directly associated with the poor prognosis in patients with head and neck squamous cell carcinoma (HNSCC). There are no clear cut indicators available currently to identify the lymph node metastases and overall prognosis in HNSCC. Thus, the current study was conducted to correlate the immunoexpression of cytokeratins (CK) 8, 10, and 14 with lymph node metastases and tumour differentiation in patients with HNSCC.

Material and methods: The study population included 61 retrospective cases of HNSCC with lymph node metastases (n = 31) and without lymph node metastases (n = 30). Expression of CK 8, 10, and 14 was assessed by immunohistochemical staining procedure. Using Pearson's Chi-square test and Spearman's correlation coefficient, the correlation of these markers with lymph node metastases and tumour differentiation was statistically analysed.

Results: The expression of CKs in HNSCC cases was higher than in controls. In nodal metastasis cases, CK 8 expression was noted in >50% of the tumour cells at the invasive tumour front (ITF) (P value 0.008), and in cases without nodal metastasis, <1% or negative expression was noted. CK 10 expression gradually decreased as the tumour grade increased. Association of CK 10 expression and tumour differentiation exhibited statistically significant results (P value 0.03). CK 14 expression was noted in the entire epithelium and at the ITF, strongly in most cases; however, CK 14 did not correlate with the lymph node metastasis and tumour differentiation as well.

Conclusion: We found a strong correlation of CK 8 expression with nodal metastasis in HNSCC, and it can be utilised as a reliable prognostic indicator.