Pardanani, Animesh

Abstract We examined the individual prognostic contribution of absolute neutrophil (ANC), lymphocyte (ALC), and monocyte (AMC) counts, on overall (OS), leukemia‐free (LFS), and myelofibrosis‐free (MFFS) survival in essential thrombocythemia (ET). Informative cases ( N = 598; median age 59 years; females 62%) were retrospectively accrued from a Mayo Clinic database: JAK2 59%, CALR 27%, triple‐negative 11%, and MPL 3%; international prognostic scoring system for ET (IPSET) risk high 21%, intermediate 42%, and low 37%; 7% (37/515) had abnormal karyotype and 10% (21/205) adverse mutations ( SF3B1/SRSF2/U2AF1/TP53 ). At median 8.4 years, 163 (27%) deaths, 71 (12%) fibrotic, and 20 (3%) leukemic transformations were recorded. Multivariable analysis resulted in HR (95% CI) of 16.5 (9.9–27.4) for age > 70 years, 3.7 (2.3–6.0) for age 50–70 years, 2.4 (1.7–3.3) for ANC ≥8 × 10 9 /L, and 1.9 (1.4–2.6) for ALC <1.7 × 10 9 /L. The corresponding HR‐based scores were 4, 2, 1, and 1, resulting in an new 4‐tiered AgeAncAlc (AAA; triple A) risk model: high (5–6 points; median survival 8 years; HR 30.1, 95% CI 17.6–54), intermediate‐2 (4 points; median 13.5 years; HR 12.7, 95% CI 7.1–23.0), intermediate‐1 (2–3 points; median 20.7 years; HR 3.8, 95% CI 2.3–6.4) and low (0–1 points; median 47 years). The AAA model (Akaike Information Criterion [AIC] 621) performed better than IPSET (AIC 647) and was subsequently validated by an external University of Florence ET cohort ( N = 485). None of the AAA variables predicted LFS while ALC <1.7 × 10 9 /L was associated with inferior MFFS ( p = .01). Adverse mutations ( p < .01) and karyotype ( p < .01) displayed additional prognostic value without disqualifying the prognostic integrity of the AAA model. This study proposes a simple and globally applicable survival model for ET, which can be used as a platform for further molecular refinement. This study also suggests a potential role for immune‐related biomarkers, as a prognostic tool in myeloproliferative neoplasms.

AbstractOverviewSystemic mastocytosis (SM) results from clonal proliferation of mast cells (MC) in extracutaneous organs.DiagnosisThe major criterion is presence of multifocal MC clusters in the bone marrow and/or extracutaneous organs. Minor diagnostic criteria include elevated serum tryptase level, MC CD25/CD2/CD30 expression, and presence of activating KIT mutations.Risk StratificationEstablishing SM subtype as per the International Consensus Classification/World Health Organization classification systems is an important first step. Patients either have indolent/smoldering SM (ISM/SSM) or advanced SM, including aggressive SM (ASM), SM with associated myeloid neoplasm (SM‐AMN), and mast cell leukemia. Identification of poor‐risk mutations (i.e., ASXL1, RUNX1, SRSF2, NRAS) further refines the risk stratification. Several risk models are available to help assign prognosis in SM patients.ManagementTreatment goals for ISM patients are primarily directed toward anaphylaxis prevention/symptom control/osteoporosis treatment. Patients with advanced SM frequently need MC cytoreductive therapy to reverse disease‐related organ dysfunction. Tyrosine kinase inhibitors (TKI) (midostaurin, avapritinib) have changed the treatment landscape in SM. While deep biochemical, histological and molecular responses have been documented with avapritinib treatment, its efficacy as monotherapy against a multimutated AMN disease component in SM‐AMN patients remains unclear. Cladribine continues to have a role for MC debulking, whereas interferon‐α has a diminishing role in the TKI era. Treatment of SM‐AMN primarily targets the AMN component, particularly if an aggressive disease such as acute leukemia is present. Allogeneic stem cell transplant has a role in such patients. Imatinib has a therapeutic role only in the rare patient with an imatinib‐sensitive KIT mutation.