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J K Larsen

Publications and source records attributed to J K Larsen.

168 records · Page 10Linked to original sources
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In B-cell chronic lymphocytic leukaemia chromosome 17 abnormalities and not trisomy 12 are the single most important cytogenetic abnormalities for the prognosis: a cytogenetic and immunophenotypic study of 480 unselected newly diagnosed patients.

Of 560 consecutive, newly diagnosed untreated patients with B CLL submitted for chromosome study, G-banded karyotypes could be obtained in 480 cases (86%). Of these, 345 (72%) had normal karyotypes and 135 (28%) had clonal chromosome abnormalities: trisomy 12 (+12) was found in 40 cases, 20 as +12 alone (+12single), 20 as +12 with additional abnormalities (+12complex). Other frequent findings included abnormalities of 14q, chromosome 17, 13q and 6q. The immunophenotype was typical for CLL in 358 patients (CD5+, Slg(weak), mainly FMC7-) and atypical for CLL in 122 patients (25%) (CD5-, or Slg(strong) or FMC7+). Chromosome abnormalities were found significantly more often in patients with atypical (48%) than in patients with typical CLL phenotype (22%) (P < 0.00005). Also +12complex, 14q+, del6q, and abnormalities of chromosome 17 were significantly more frequent in patients with atypical CLL phenotype, whereas +12single was found equally often in patients with typical and atypical CLL phenotype. The cytomorphology of most of the +12 patients was that of classical CLL irrespective of phenotype. In univariate survival analysis the following cytogenetic findings were significantly correlated to a poor prognosis: chromosome 17 abnormalities, 14q+, an abnormal karyotype, +12complex, more than one cytogenetic event, and the relative number of abnormal mitoses. In multivariate survival analysis chromosome 17 abnormalities were the only cytogenetic findings with independent prognostic value irrespective of immunophenotype. We conclude that in patients with typical CLL immunophenotype, chromosome abnormalities are somewhat less frequent at the time of diagnosis than hitherto believed. +12single is compatible with classical CLL, and has no prognostic influence whereas chromosome 17 abnormalities signify a poor prognosis. In patients with an atypical CLL immunophenotype, chromosome abnormalities including +12complex, 14q+, del 6q and chromosome 17 are found in about 50% of the patients, and in particular chromosome 17 abnormalities suggest a poor prognosis.

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Chromosome abnormalities, cellular DNA content, oncogene amplification and growth pattern in agar culture of human neuroblastomas.

The association of ability to grow in vitro, non-random chromosome abnormalities, DNA ploidy and oncogene amplification with prognosis may lead to a better understanding of the biology of neuroblastomas. In a pilot study fresh tumour tissue was obtained from 4 consecutive patients at the Department of Paediatric Surgery, Rigshospitalet, Denmark. Chromosome abnormalities were detected in 3 out of 3 successfully karyotyped tumours, and one or more aneuploid stem lines were detected in 4 out of 4 tumours using flow cytometry. The N-myc oncogene was amplified in 1 out of 3 tumours tested. Continuous cell lines could be established from all 3 advanced stage tumours. This pilot study has shown that fresh tumour tissue can be obtained and successfully studied for various fundamental aspects of the biology of neuroblastomas.

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