Quantitative analysis of HLA DR expression and lymphocytic infiltrate in laryngeal cancer including clinical and morphological correlations.

HLA DR antigen expression in tumor cells and lymphocytic infiltrates at the tumour periphery were investigated in 68 laryngeal carcinomas. The tissue sections were studied by a quantitative method using computer image analysis system. The highest number of CD45RO+ cells was observed in the groups of the lowest clinical stage. There were statistically significant differences between the groups in the number of T cells, whereas no differences were found in HLA DR+ cancer cell number, B cell number or mitosis count. Statistical analysis revealed a significant correlation between T-cell number at the periphery of the tumour and the number of cancer cells showing HLA DR expression. The results of the analysis, using Cox proportional hazard model with selected factors, showed that only HLA DR expression in cancer cells had a significant effect on survival, whereas the number of CD45RO+ and CD20+ cells, histological grade and mitosis count did not contribute further to prognostic information. To our knowledge, this is the first time that HLA DR expression and its correlation with lymphocytic infiltration have been shown by a quantitative method in laryngeal cancer.