Deletion of CDKN2A/B is associated with inferior relapse free survival in pediatric B cell acute lymphoblastic leukemia.

Considering conflicting data on CDKN2A/B deletion in ALL, this study to assess its prognostic significance as an independent marker in a total of 96 pediatric B and T-ALL cases was planned. The overall frequency of CDKN2A/B deletion was 44% (n = 43) with 36% (30/83) in B-ALL and 100% (13/13) in T-ALL. CDKN2A/B deletion was significantly associated with high WBC count (p = .002) and National Cancer Institute risk (p = .01) in B-ALL. Importantly, CDKN2A/B deletion cases had poor EFS of 42% at 28 months compared to EFS of 90% in rest (p = .0004). Further, relapse free survival was only 56% for cases with CDKN2A/B deletions (n = 25), compared to 100% in control group (p = .001). Moreover, CDKN2A/B deletion was the only risk factor associated with early relapse (p = .01) compared to IKZF1 deletion (p = .73) or occurrence of BCR-ABL1 fusion transcript (p = .26). Thus our study data highlights potential prognostic role of CDKN2A/B deletions in early disease stratification in pediatric B-ALL.