[Treatment of acute promyelocytic leukemia (APL) with all-trans retinoic acid (ATRA): a report of five-year experience].

From January 1986 to April 1991, 100 consecutive patients with APL received oral ATRA at a dose of 60-100 mg/d alone or in combination with chemotherapy. In 84 cases treated with ATRA, 74 (88.1%) achieved CR; in the 16 cases treated with combined therapy, the CR Rate was 75%. Among the 50 patients followed up for a median of 36 months, 10 used ATRA (Group B) as continuation therapy, 10 chemotherapy (Group C), and 30 cases ATRA and chemotherapy alternatively (Group A). The mean survival was 8, 9, 21 months, respectively. For the 29 cases who died, the overall 3-year survival rate was higher in the group A (46.7%) than in the group B and C. ATRA did not provoke or aggravate DIC, nor did it cause bone marrow hypoplasia. The main side effects were dryness of the lip or skin, headache, nausea or vomiting and liver dysfunction. Severe scrotum exfoliative dermatitis with ulceration was seen in one case. In vitro induction of differentiation, GM-CFU, L-CFU assay and cytogenetic studies were performed. The results were discussed together with clinical observation regarding the mechanism of action of ATRA on APL. ATRA used as an inducer of differentiation is an alternative effective drug in the induction of remission in de novo APL as well as in cases in relapse.