P53 IMMUNOSTAINING AND IMAGE CYTOMETRY DNA ANALYSIS IN PRECANCEROUS AND CANCEROUS SQUAMOUS EPITHELIAL LESIONS OF THE LARYNX

Background: Squamous epithelial cancer can develop from progressive ep ithelial changes connoted dysplasias. Histopathologic evaluation/gradi ng of these lesions is difficult and gives poor information concerning the risk for progression to cancer. Squamous cell carcinoma of the he ad and neck (SCCHN) frequently show p53 alteration and DNA-ploidy aber ration. Could these markers be used as indicators for malignancy risk in the larynx? Methods: Immunohistochemical staining (IHC), with the C M-1 antibody against p53, and image cytometry (ICM) DNA analysis were performed in 60 lesions from 12 patients-and 21 controls-who were init ially seen with laryngeal lesions prior to cancer in situ (cis) or inv asive cancer diagnosis at the same site. Results: All but one of the i nvasive cancers, and 77% of the lesions which preceded cancer or cance r in situ, showed positive p53 immunostaining, as compared with only 1 0% of the controls. All but one of the invasive cancer lesions, and 77 % of the precancerous lesions, showed aberrant DNA-ploidy results, whe reas all controls were diploid. When DNA and p53 analysis were combine d, only one of the lesions preceeding cis or invasive cancer was negat ive. Conclusions: Both p53 immunoreactivity and DNA-ploidy aberration appear to be early events in the multistep process of squamous epithel ial carcinogenesis. Immunohistochemical staining p53 analysis and ICM DNA analysis does increase the diagnostic sensitivity for cancerous an d true precancerous lesions in the larynx. (C) 1997 John Wiley & Sons, Inc.