KARYOTYPIC ABNORMALITIES IN TUMORS OF THE PANCREAS

Short-term cultures from 20 pancreatic tumours, three endocrine and 17 exocrine, were cytogenetically analysed. All three endocrine tumours had a normal chromosome complement. Clonal chromosome aberrations were detected in 13 of the 17 exocrine tumours: simple karyotypic changes were found in five carcinomas and numerous numerical and/or structural changes in eight. When the present findings and those previously repo rted by our group were viewed in conjunction, the most common numerica l imbalances among the 22 karyotypically abnormal pancreatic carcinoma s thus available for evaluation turned out to be, in order of falling frequency, -18, -Y, +20, +7, +11 and -12. Imbalances brought about by structural changes most frequently affected chromosomes 1 (losses in 1 p but especially gains of 1q), 8 (in particular 8q gains but also 8p l osses), and 17 (mostly 17q gain but also loss of 17p). Chromosomal ban ds 1p32, 1q10, 6q21, 7p22, 8p21, 8q11, 14p11, 15q10-11, and 17q11 were the most common breakpoint sites affected by the structural rearrange ments. Abnormal karyotypes were detected more frequently in poorly dif ferentiated and anaplastic carcinomas than in moderately and well diff erentiated tumours.