UC Irvine

Background

Tumor protein 53 (TP53) mutations are uncommon in adult patients with acute lymphoblastic leukemia (ALL) and predict a poor outcome.

Methods

TP53 mutation analysis was performed in 164 newly diagnosed adult patients with ALL using a combination of targeted amplicon-based next-generation sequencing and Sanger sequencing.

Results

TP53 mutations were detected in 25 patients (15%), with a median allelic frequency of 42.2% (range, 5.6%-93.8%). The majority of mutations were single-nucleotide variants of missense type and involved the DNA-binding domain. TP53-mutated (TP53^mut ) ALL was found to be significantly associated with older age, lower median white blood cell and platelet counts, lower frequency of Philadelphia chromosome and a higher frequency of low hypodiploid karyotype compared with ALL with wild-type TP53 (TP53^wt ). To evaluate the prognostic effect of TP53 mutations, the authors selected 146 patients with B-cell immunophenotype ALL (24 with TP53^mut and 122 with TP53^wt ) who were uniformly treated with frontline hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (hyper-CVAD)-based regimens; >90% of these individuals also received a monoclonal antibody. Over a median follow-up duration of 15 months, there was no significant difference in the median overall survival, event-free survival, and duration of complete remission noted between patients with TP53^mut ALL and those with TP53^wt ALL.

Conclusions

Hyper-CVAD-based regimens appear to negate the poor prognostic impact of TP53 mutations in patients with adult B-cell immunophenotype ALL. Cancer 2017;123:3717-24. © 2017 American Cancer Society.