Head and neck squamous cell carcinomas (HNSCC) show diverse clinicopathological features
and are mostly linked with poor outcome. In this study, we tested if the expression
of tumor growth, cell cycle and basement membrane anchorage related biomarkers allow
prognostic and clinicopathological stratification of HNSCC. Archived HNSCC samples
from 226 patients included into tissue microarrays (TMA) were tested using immunohistochemistry.
Histopathological evaluation and the analysis of immunostaining for EGFR, Ki67, p53,
p16ink4 and Collagen XVII proteins were carried out in digital whole slides. Statistical
evaluation was carried out using Pearson's Chi-square test and Kaplan-Meier survival
analysis. In the tested cohort, hypopharyngeal cancers had the least favorable, and
glottic cancers had the most favorable prognosis. High Ki67 positive tumor cell fractions
were associated with significantly worse prognosis and elevated rate of lymph node
metastasis. Both Ki67 and EGFR expression correlated significantly with the tumor
localization. Ki67 index was the highest in the hypopharyngeal region and it proved
to be the lowest in the glottic region. EGFR expression was the highest in the oral
cavity and the lowest in the glottic region. The survival rate of patients with p16ink4-negative
cancer was significantly lower than of those with p16ink4-positive disease. A significant
inverse correlation was found between histological grade and the prognosis of HNSCC.
Our data support that elevated Ki67 positive proliferating cell fractions contribute
to the unfavorable prognosis of hypopharyngeal cancers, while glottic cancers have
the most favorable prognosis because of the lowest Ki67 expression rate.
