CLONAL CHROMOSOME-ABERRATIONS ACCUMULATE WITH AGE IN UPPER AERODIGESTIVE TRACT MUCOSA

Short-term cultured non-neoplastic upper aerodigestive tract (UAT) muc osa samples from 36 patients with squamous cell carcinoma of the head and neck (SCC) and 53 patients with benign UAT disorders were cytogene tically analyzed. The cell cultures were divided into two series: in s eries A, cells were cultured in a medium stimulating outgrowth of mese nchymal cells; whereas the cultured cells in series B were of epitheli al morphology. Series A was further subdivided into three different ag e groups (less than or equal to 15 years, 16-59 years, and greater tha n or equal to 60 years) of non-SCC patients and one SCC group. Series B was composed of two groups; one with and one without SCC. Among the non-SCC patients in series A, there was an increase with age in the fr equency of cells/sample with numerical and structural chromosomal chan ges as well as in the incidence of clonal chromosomal aberrations. No differences could, however, be detected between cancer patients and ag e-matched controls. In series B, the frequency of cells/sample with nu merical changes and the incidence of clonal numerical aberrations were significantly higher among SCC patients. Three main conclusions could be drawn. First, the frequencies of clonal and non-clonal chromosome aberrations in UAT mucosa were age dependent. Second, the cytogenetic support for the validity of the field cancerization hypothesis was res tricted to increased levels of numerical chromosome changes in epithel ial cell cultures from cancer patients, Third, clonal chromosome aberr ations, including autosomal and sex chromosome aneuploidies as well as structural rearrangements, are not restricted to neoplastic mucosal c ells.