Abstract: Objective To investigate the prevalence, feature and specific prognostic relevance of p16 gene deletion in Chinese adult patients with Philadelphia-negative B- lineage acute lymphoblastic leukemia (B-ALL). Methods Clinical data of 210 newly diagnosed B-ALL patients were analyzed retrospectively. According to the p16 gene status at diagnosis, 61 cases were divided into the p16 gene deletion group and 149 cases were divided into the p16 non-deletion group. The clinical data, immune phenotypes, cytogenetics, molecular characteristics and prognosis were compared between two groups of patients. Results The proportion of patients with p16 gene deletion accompanied with CD20-positive were significantly higher in p16 gene deletion group compared with those of p16 non-deletion patients (47.5% vs. 30.8%, χ2=5.238, P＜0.05).There were no significant differences in the other immunophenotypes and cytogenetics between the two groups (P＞0.05).There were no significant differences in the transplant rate and complete remission of hematopoietic stem cells between the two groups. The recurrence rate was significantly higher in the p16 gene deletion group than that of p16 non-deletion group(χ2=12.027，P＜0.05). Among the 79 patients with relapse, 4 patients were not detected p16 gene deficiency at the initial stage, while p16 gene deletion was detected at the time of relapse. There were lower overall survival (OS) and disease freesurvival (DFS) in the p16 gene deletion group than those of p16 non-deletion group (Log-rank χ2=16.715 and 21.237，P＜0.05). Among the patients of p16 gene deletion, the patients received allogenic hematopoietic stem cell transplantation (AlloHSCT) showed a better OS and DFS compared with those of patients with chemotherapy (Log-rank χ2=25.316 and χ2=20.637，P＜0.05). There were lower values of OS and DFS in patients with CD20-positive than those of patients with CD20-negative in p16 gene deletion group (Log-rank χ2=7.782 and χ2=5.733，P＜0.05). Conclusion There are higher rate of CD20-positive and poor prognosis in patients with p16 gene deletion. Hematopoietic stem cell transplantation can significantly improve the prognosis of patients with p16 gene deletion.

Key words: gene deletion, genes, p16, precursor B-cell lymphoblastic leukemia-lymphoma, antigens, CD20