1295 Prognostic Impact of Chromosome 7 Losses in High-Grade TP53 Mutated Myeloid Neoplasms

Document Type

Conference Proceeding

Publication Date

3-1-2025

Publication Title

Lab Investig

Abstract

Background: TP53 mutation (TP53MUT) and chromosome 7 loss (-7/7q) are both independently considered as adverse prognostic factors in high-grade (HG) myeloid neoplasms (MN). Whether the co-occurrence of -7/7q further worsens the poor prognosis of TP53MUT is unclear. To answer this, we evaluated the differential impact of -7/7q in HG TP53MUT MN. Design: We identified 322 patients with TP53MUT MN carrying ≥1 TP53MUT at a VAF ≥3% diagnosed between 2014-2024 across 10 centers with blasts ≥10% at diagnosis. Baseline clinical, pathological, cytogenetic and somatic information was extracted while stratifying patients by -7/7q status. The primary endpoint was to compare 24-month overall survival (OS24). Additional end-points included complete response to first-line (CR1) therapy per ELN 2022 guidelines (Table 1 footnote). Descriptive and outcome analyses were conducted in Stata 18 using flexible parametric (FP) and non-parametric survival methods. Results: The median age at diagnosis was 68.4 years. There was no difference in baseline characteristics stratified by -7/7q status (see Table 1). Patients with -7/7q were marginally more likely to harbor complex karyotype (P = .09) with significantly greater proportion harboring -17/17p (46.2% vs. 33.8%; P = .031) and TP53 VAF>25% (85.6% vs. 76.4%; P = .042) compared to those without -7/7q. The median duration of follow up (from diagnosis of TP53MUT MN to study exit) was 6.2 months (range: 0.0–72.8 months) with 77.0% receiving frontline non-intensive therapies, mostly HMA-based. First-line response was evaluable in 251 patients with 28.7% achieving CR, 24.7% had partial response, and 46.6% had non-response/stable-progressive disease. -7/7q was not associated with inferior frontline response (P = .35) in the entire cohort as well as in the intensively-treated subgroup (P = .92). Significantly greater proportions of those lacking -7/7q went on to receive alloSCT (20.7% vs. 11.1%; P = .023). In the entire cohort OS24 analysis, -7/7q was associated with inferior overall survival (HR = 1.5 [1.2–2.0]; Pfpm = .002; N = 298). In separate analysis by blast count and therapies, the adverse impact was restricted only to those subgroups with either high blast count or intensive therapy (See figure 1). [Formula presented] [Formula presented] Conclusions: Presence of -7/7q adversely impacts the prognosis of TP53MUT MN, an effect which is accentuated in patients receiving intensive chemotherapy and ≥ 20% blast count at diagnosis, supporting its prognostic utility in this context.

Volume

105

Issue

3 Supplement

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