GENETIC PROGRESSION MODEL FOR HEAD AND NECK-CANCER - IMPLICATIONS FORFIELD CANCERIZATION

A genetic progression model of head and neck squamous cell carcinoma h as not yet been elucidated, and the genetic basis for ''field canceriz ation'' of the aerodigestive tract has also remained obscure, Eighty-s even lesions of the head and neck, including preinvasive lesions and b enign lesions associated with carcinogen exposure, were tested using m icrosatellite analysis for allelic loss at 10 major chromosomal loci w hich have been defined previously, The spectrum of chromosomal loss pr ogressively increased at each histopathological step from benign hyper plasia to dysplasia to carcinoma in situ to invasive cancer, Adjacent areas of tissue with different histopathological appearance shared com mon genetic changes, but the more histopathologically advanced areas e xhibited additional genetic alterations, Abnormal mucosal cells surrou nding preinvasive and microinvasive lesions shared common genetic alte rations with those lesions and thus appear to arise from a single prog enitor clone, Based on these findings, the local clinical phenomenon o f field cancerization seems to involve the expansion and migration of clonally related preneoplastic cells.