Outcomes and prognostic factors:
At a median follow up of 70 months (range, 14 to 181 months), the 5-year EFS was 76%±4.4% and the 5-year OS was 78%±4.2% for the whole group. When compared using log-rank test, the 5-year EFS for patients treated in the augmented therapy group was 87% ± 4.9% which is significantly better than the standard therapy group estimate of 67%±6.5% (p=0.03) (Figure.1A). However, there was no statistically significant difference in 5-year OS between the 2 groups 87%±5.1%in augmented vs.71% ±6.2%in standard group, p=0.061) (Figure.1B)
In a univariate analysis model, other factors associated with better EFS and OS were: Response to therapy at day 15 of remission induction and cranial radiation (Appendix Table 2).
Notably, none of the patients (N=21) who received CRT relapsed in both group; the 5-year Relapse free survival (RFS) in patients who received CRT in both groups was 100%± 0%, and in patients who did not receive CRT in augmented and standard therapy group was (94%± 4.2%,62%± 7.7%, P=0.0004), respectively (Figure 2).
In total 79 patients did not received CRT (N=41 in standard therapy, N=38 in augmented therapy). Seventeen (22%) of 79 patients who did not receive CRT had bone marrow or isolated extramedullary relapse. Among these 17 patients, 15/79(19%) were treated in standard therapy group and 2/79 (3%) in the augmented therapy group. (Table 2)