Immunohistochemical analysis and prognostic value of cathepsin D determination in laryngeal squamous cell carcinoma

Cathepsin D, a protease with the capability of degrading matrix proteins, i s implicated in the process of breast and colorectal cancer invasion and me tastasis. Biochemical studies in laryngeal cancer have shown a potential pr ognostic significance of cathepsin D content determination. We studied immu nohistochemical positivity of cathepsin D in tumor epithelium and stroma of 61 surgical specimens of squamous cell laryngeal cancer. Immunohistochemic al reaction was quantitatively assessed using a PC-based image analysis sys tem SFORM-VAMS. The results were correlated to clinical and morphological p arameters and survival. Immunohistochemical positivity was noted in neoplas tic cells and tumor stroma. Significant prognostic value for cathepsin D wa s established separately for epithelial tumor component and tumor stroma us ing log-rank test, the Cox proportional hazards regression model, and C4.5 machine learning system. In all groups, patients above the median cathepsin D staining showed significantly shorter survival time. C4.5 machine learni ng system extracted cutoff values for the decision tree that defines the pr obabilities of patients survival and death with high sensitivity (92.8% ali ve, 73.6% dead), 100% specificity, and 86.9% accuracy. This makes immunohis tochemical cathepsin D estimation an independent prognostic parameter in la ryngeal carcinomas within a 5-year period from the time of tumor surgery.