[Efficacy of ruxolitinib and prognostic factors in patients with myelofibrosis stratified by age].

Objective: To explore differences in the efficacy and safety of ruxolitinib in patients with myelofibrosis by age and to identify prognostic factors by analyzing clinical features and characteristics of chromosomes and gene mutations. Methods: This study retrospectively analyzed 188 patients with myelofibrosis who received ruxolitinib in the Department of Hematology, Qilu Hospital, Shandong University from January 1, 2017, to July 1, 2024. According to age at diagnosis, the patients were divided into the middle-aged group (≤55 years), young elderly group (56-65 years), and elderly group (>65 years). Clinical features, the characteristics of chromosomes and gene mutations, and the efficacy and safety of ruxolitinib treatment were compared across the three age groups. Independent factors influencing overall survival were identified through Cox proportional risk regression analysis. Results: Before treatment, the elderly group had more underlying comorbidities, a heavier symptom burden, higher leukocyte count, higher proportion and frequency of JAK2 mutations, and lower proportion of CALR mutations. The incidence of nondriver gene mutations was significantly higher in the young elderly group. After ruxolitinib treatment, the degree of reduction in spleen size did not differ significantly among the three groups. The length of the palpable spleen below the left costal margin reduced by more than 50% from baseline in 50.9% (27/53) of the patients in the middle-aged group, 43.5% (27/62) in the young elderly group, and 45.5% (20/44) in the elderly group (P=0.720). No significant difference was observed among the three groups in the degree of reduction in Myeloproliferative Neoplasm Symptom Assessment Form (10-item version) score (P=0.153), with a reduction in total symptom score by more than 50% achieved by 54.0% (27/50), 60.3% (41/68), and 66.7% (34/51) of the patients from the three groups, respectively (P=0.429). The most common hematological adverse events were anemia and thrombocytopenia, while the most common nonhematological adverse events were electrolyte disturbance, elevated transaminase activity, and pulmonary infection. Multivariate analysis indicated that in ruxolitinib-treated patients with myelofibrosis, poor overall survival was independently predicted by increased age, reduced hemoglobin, percentage of bone marrow blasts ≥ 1%, absence of JAK2 mutations, chromosomal abnormalities, ≥2 high-molecular-risk mutations, and TP53 mutations. Conclusions: Patients with myelofibrosis stratified by age exhibited heterogeneous clinical features and gene mutation profiles but similar efficacy of ruxolitinib treatment and occurrence of adverse events.