A comparison of low-dose cytarabine and hydroxyurea with or without all-trans retinoic acid for acute myeloid leukemia and high-risk myelodysplastic syndrome in patients not considered fit for intensive treatment.

Background: The survival of older patients with acute myeloid leukemia has not improved. Few clinical trials have been available for older patients who are not considered fit for an intensive chemotherapy approach.

Methods: Between December 1998 and November 2003, as part of National Cancer Research Institute Acute Myeloid Leukemia 14 Trial, 217 patients, who were deemed unfit for intensive chemotherapy were randomized to receive low-dose cytarabine (Ara-C) (20 mg twice daily for 10 days) or hydroxyurea with or without all-trans retinoic acid (ATRA).

Results: Low-dose ara-C produced a better remission rate (18% vs 1%; odds ratio [OR], 0.15; 95% confidence interval [95% CI], 0.06-0.37; P = .00006) and better overall survival (OR, 0.60; 95% CI, 0.44-0.81; P = .0009), which was accounted for by the achievement of complete remission (CR) (duration of CR: 80 weeks vs 10 weeks for patients with no CR). Patients who had adverse cytogenetics did not benefit. ATRA had no effect. Toxicity scores or supportive care requirements did not differ between the treatment arms.

Conclusions: Older, less fit patients have a poor outcome, and few trials have been conducted in this patient group. Low-dose ara-C treatment was superior to best supportive care and hydroxyurea because it had greater success in achieving CR, and it could represent standard care against which new treatments may be compared in this patient group.