Cathepsin D concentration in primary laryngeal cancer: correlation with clinico-pathological parameters, EGFR status and prognosis

Sixty-three patients with primary laryngeal squamous-cell carcinoma were followed up for a median of 33 months after surgery. Cathepsin D (Cath D) concentration was assayed using a solid phase 2-site immunoradiometric assay in which the first monoclonal antibody (MAb) was coated on the ELISA solid phase and the second one, MIG8 radiolabeled with I125-EGF, was used as the tracer. The median value of Cath D (13.8 pM/mg protein) was chosen as cut-off. Cath D 2 median value was closely related to neck lymph node involvement at presen- tation and to a short metastasis-freesurvival (MFS) and actual overallsurvival (0s).The 5-yearMFSwas 7I%for patientswith Cath D < median value tumors as compared with 0% for patients with Cath D 2 median value tumors. Lymph node status at presentation was not related to a short MFS and 0s. Cox’s univariate regression analysis using Cath D as a continu- ousvariableshowedthatCathDlevelsarecorrelatedwithneck lymph node metastasis, On multivariate analysis, Cath D status proved to be an independent factor for predicting a short MFS. Cath D assay may prove to be particularlyuseful in identifying laryngealcancer patients who, with or without neck lymph node involvement at presentation, are at high risk of metastatic disease and poor outcome.