MHC CLASS-I ANTIGENS AND TUMOR-INFILTRATING LEUKOCYTES IN LARYNGEAL-CANCER - LONG-TERM FOLLOW-UP

Alteration in MHC class I expression may be used by cancer cells to av oid immune destruction. Much experimental evidence supports this idea, although survival studies are very scarce. To investigate whether the presence or absence of HLA-A, -B and -C antigens in laryngeal carcino ma influences survival, a series of 60 primary laryngeal tumours treat ed surgically and normal tissues were evaluated in frozen sections for the expression of MHC class I antigens and tumour-infiltrating leucoc ytes (CD3, CD4, CD8, CD11b, CD1, CD20 and CD16), using monoclonal anti bodies and the APAAP technique. Long-term follow-up from the patients is available, ranging from 6 to 10 years. Thirteen tumours presented t otal HLA-ABC loss, five selective losses of HLA-A antigens and one abs ence of HLA-B antigens. Total losses were statistically associated wit h several clinical and pathological parameters, but there were no diff erences regarding tumour-infiltrating leucocytes. After conducting a p rospective study, only T and N staging and scoring according to Giant' s malignancy classification were found to be independently related to patients' outcome. From our data, we conclude that neither complete lo ss of HLA class I antigens nor tumour-infiltrating leucocytes appear t o influence survival in squamous cell carcinoma of the larynx.