Cytogenetic studies in acute promyelocytic leukemia: a survey of secondary chromosomal abnormalities.

A series of 105 patients with acute promyelocytic leukemia (APL) has been cytogenetically investigated at the Department of Hematology of the Saint-Louis Hospital (Paris) between 1977 and 1990. Sixty-two patients were examined at diagnosis, 32 in relapse, and 11 both at diagnosis and in relapse. The typical t(15;17)(q22;q12) or variants of this translocation were observed in all but four patients. The t(15;17) was the only change in 47 cases at diagnosis and in 21 examined in relapse. The most frequent secondary change was trisomy 8 (17% at diagnosis). More or less complex chromosomal abnormalities in addition to t(15;17) were present in six patients at diagnosis, and in 17 patients in relapse. Rearrangements of 2q35-q37 and del(11p) were observed only in relapse and may thus be nonrandom secondary changes. Cytogenetic studies performed on 19 patients treated with all-trans retinoic acid did not indicate that this treatment induces chromosomal abnormalities.