Influence of Race and Nutritional Status on the Long Term Event Free Survival in Childhood Acute Lymphoblastic Leukemia (ALL): A 14-year Follow-up with a Reduced BFM-Based Treatment Protocol (GBTLI ALL-93)

Background: Different event-free survival rates (EFS) of childhood ALL treatment regarding race, were published in the literature. However, a better consensus exists considering the bad prognosis of undernutrition. Taking into account the social economic reality of a low-income country such as Brazil, the systematic evaluation of these variables is of utmost importance, while inserted in a modern ALL treatment protocol.

Objective: To compare, prospectively, the long-term EFS rates of previously untreated children with ALL, according to race and nutritional status at diagnosis.

Methods: Patients were classified as Low Risk and High Risk according to NCI Criteria.

Treatment schedule: Low Risk group: Remission induction therapy with DEXA 6mg/m²/d × 28 days, VCR 1.5 mg/m²/wk × 4, Daunomycin 25 mg/m²/wk × 4, L-ASP 10.000 U/m²/dose × 8, Ara-C 75mg/m²/dose × 8 and TIT therapy (day 0,28 and 42). Intensification therapy with MTX 2g/m²/wk × 4, 24 h continuous infusion with LCV rescue 15mg/m^2/dose × 4, 6MP-50mg/m² d × 21days and TIT therapy (x 4). Re-induction therapy: Dexa 6mg/m² d × 21days, VCR 1.5mg/m²/wk × 4, L-ASP 10.000 U/m²/d × 4, 6-MP 50mg/m²/d × 14days, Ara-C 75 mg/m²/d × 4 and TIT therapy (x3). Central randomization was done for maintenance therapy duration (130 vs 103 wk). Maintenance: 6-MP 50mg/m²/d, MTX 25mg/m2/wk and TIT therapy every 8 weeks during all treatment. No CNS radiation was done. For High Risk patients, an induction intensification with intermediate dose of AraC (750 mg/m2/d × 6) was introduced, as well as, a rotational maintenance therapy with different pair of drugs were proposed (AraC 750mg/m2 × 4/Asp 6 000 U; Dexa/VCR/wk × 3 and 6-MP 75 mg/m2/d × 21 days/MTX 40 mg/m2/wk × 3). Prophylatic CNS radiation(18Gy) was done at wks 19–21 of therapy.

Statistical analysis: EFS is defined as the time from diagnosis till any failure, relapse, death, or the development of a second malignancy. Continuous complete remission duration (CCR) is defined as EFS, contingent upon induction of a complete remission. EFS and CCR rates have been estimated by Kaplan and Meier’s method.

Results: From October 1993 to September 1999, 867 patients were consecutively enrolled in the protocol GBTLI ALL-93. Fourteen pts were excluded (1.5%), due to wrong diagnosis or previous corticosteroid treatment. 853 pts were evaluated in this study. 447 pts were classified as Low Risk group (52%) and 406(48%) as High Risk. According to race, 226 pts (26.5%)were classified as black and 627 (73.5%) as white. Overall undernutrition was diagnosed among 7.0 % of the patients. In the black population 10.4% were undernourished, comparing with 5.7% in the white group. The 14yrs-EFS for all the study patients is 80% ± 2% and 55% ± 2.5% for the Low Risk and High Risk pts, respectively. Concerning race, the 14yrs-EFS is of 71.7% ± 4.5% for the black children, comparatively to 83% ± 2.1% for the white ones (p=0.01). According to the nutritional status, the EFS is of 70.2%± 1.7% and 53.0%± 6.8% for the nourished and undernourished children, respectively. Malnutrition had the worst desfavorable impact among the High Risk pts, with a 14yrs-EFS of 40.1% ± 8.7%, compared to those without malnutrition of 57.8% ± 2.7% (p = 0.05). Social and economical issues directly involved with treatment, were provided by means of free medical attention and drugs supplies. Treatment abandon was < 1%.

Conclusion: The black race and undernutrition had significant adverse effect on the long-term EFS among the patients of this study.