CYTOGENETIC FINDINGS IN METASTASES FROM COLORECTAL-CANCER

Eighteen tumor samples from 11 patients with metastatic colorectal can cer were cytogenetically analyzed after shortterm culturing. Of the 13 metastases examined, 11 were from lymph nodes, I from the peritoneum and I from the lung. In 5 of the 11 patients, matched samples from the primary tumor and lymph node metastases were analyzed. Cytogenetic si milarities between the primary and secondary lesions were found in all 5 cases, indicating that many of the chromosomal aberrations presumab ly occurred before disease spreading took place. Compared with the pri maries, the metastases appeared to exhibit decreased clonal heterogene ity but, concurrently, an increase in the karyotypic complexity of ind ividual clones. Among the aberrations recurrently found in metastatic lesions were del(1)(p34), i(17)(q10), -18, -Y, -21, +7 and +20, all of which have been seen repeatedly in previous series of primary colorec tal carcinomas, and del(10)(q22) and add(16)(p13), which so far have n ot been associated with primary tumors and which may play a particular pathogenetic role in the metastatic process. (C) 1997 Wiley-Liss, Inc .