PHF6 mutation is associated with poor outcome in acute myeloid leukaemia

Mutation of plant homeodomain finger protein 6 (PHF6) occurs in approximately 3% of acute myeloid leukaemia (AML) cases. Although it was reported to be associated with poor prognosis, it was not confirmed by other groups. Recently, propensity score matching has provided an effective way to minimise bias by creating two groups that are well balanced with respect to baseline characteristics, providing more convincing results, which has an advantage, especially for rare subtype studies. To provide further evidence on the role of PHF6 mutation, we performed a retrospective propensity score-matched cohort study to assess the therapeutic responses and survival outcomes of AML patients with PHF6 mutation compared with those without PHF6 mutation after balancing age, sex and risk categories.

A total of 22 patients with PHF6 mutation from 801 consecutive newly diagnosed AML cases in our center were identified, and 43 patients with the PHF6 wild-type genotype were successfully matched at a 1:2 ratio.

AML harbouring PHF6 mutation was associated with a lower complete remission (CR) rate (41% vs. 69%; OR = 3.64, 95% CI 1.10, 12.10; p = 0.035) and shorter median overall survival (OS) (6.0 vs. 39.0 months; p < 0.001) and event-free survival (EFS) (2.0 vs. 11.0 months; p = 0.013) compared with PHF6 wild-type patients. Further multivariate analysis supported that PHF6 mutation was an independent risk factor for overall survival in AML (HR = 8.910, 95% CI 3.51, 22.63; p < 0.001). In addition, allogeneic haematopoietic stem cell transplantation (allo-HSCT) seemed to ameliorate the poor prognosis of AML with PHF6 mutation in this study.

Our data revealed that PHF6 mutation was associated with a lower chemotherapy response and shorter survival, suggesting that PHF6 mutation is a predictor of poor prognosis in AML.