NEAR-DIPLOID KARYOTYPES WITH RECURRENT CHROMOSOME-ABNORMALITIES CHARACTERIZE EARLY-STAGE ENDOMETRIAL CANCER

Cytogenetic investigation was attempted on 15 endometrial tumors, When ever possible, a combination of direct harvesting and short-term cultu re (with or without prior methotrexate synchronization) was used. The analysis was successful in 13 cases: 12 carcinomas of stage I and one atypical hyperplasia. Clonal abnormalities were found in 10 tumors, wh ereas the remaining three showed a normal karyotype. The modal chromos ome number was near-diploid. The abnormal karyotypes contained relativ ely simple numerical or structural aberrations in all but one tumor, a serous papillary carcinoma with multiple complex changes as well as c ytogenetic evidence of intratumor heterogeneity. Gain of 1q, trisomy f or chromosomes 2, 7, 10 (this trisomy was shown by in situ hybridizati on to be present also in a large number of interphase cells), and 12, and loss of chromosome 22 were recurrent aberrations; these are also t he cytogenetic anomalies that have been consistently associated with e ndometrial carcinomas in previous studies. The utilization of both dir ect harvesting and short-term culture in several cases increased the f requency with which abnormal karyotypes were found; sometimes aberrati ons were found by the first method but not by the other, and vice vers a. Never were different clonal anomalies found by the two approaches i n the same case. Synchronization of the cultures generally led to chro mosome preparations with more mitoses and of better quality. Again, no different anomalies were found in synchronized and standard cultures from the same tumor.