Acute promyelocytic leukemia, study of predictive factors for Differentiation Syndrome, single center experience

Reports about patients with acute promyelocytic leukemia from the Middle East are few; in this study we are reporting our single center experience of treating 29 patients over 6 years. Acute promyelocytic leukemia treatment response is markedly improved after the introduction of ATRA. Treatment related complication is still an important issue particularly Differentiation Syndrome. Prediction to its occurrence has been tried by other groups. We aimed to study all the possible predictive factors of acute promyelocytic leukemia. Our chemotherapy induction protocol is AIDA protocol which includes ATRA 45 mg/m2/d in divided doses every12 h, and Idarubicin 12 mg/m2/d IV on days 3, 5, 7, and 9. Differentiation Syndrome occurred in 48.3% of patients and was mainly presented by pulmonary symptoms in 55.2%, 6 cases died during induction. None of the predictive factors studied showed a statistically significant difference between patients who developed Differentiation Syndrome and those who did not. Differentiation Syndrome did not affect overall survival. Cox regression showed an inverse yet a non significant association between PETHEMA and overall survival probability (P = 0.168). In conclusion, Differentiation Syndrome has no clear predictive factor to date. The best approach is to hold ATRA and give dexamethasone which is quite effective as reported in the literature. PETHEMA risk model has a moderately significant prognostic value.