Objectives: This study aimed to investigate the clinical characteristics, treatment outcomes, and factors influencing treatment success in patients with denosumab (Dmab)-related osteonecrosis of the jaw (DRONJ). Patients and Methods: This retrospective cohort study included the patients who were diagnosed with DRONJ and treated at the authors’ affiliated hospital, between August 2019 and August 2024. The patients were divided into the three groups; Group 1, low-dose Dmab; Group 2, transition from bisphosphonates (BPs) to low-dose Dmab; Group 3, high-dose Dmab. Differences in clinical characteristics among the groups were compared. Surgical outcomes were classified into three categories: complete healing, partial healing, and no healing. “Treatment success” was defined as the combined proportion of complete and partial healing. Results: A total of 178 DRONJ patients were included in this study. Most of DRONJ occurred in osteoporosis patients. In patients treated with lowdose Dmab, prior BP use resulted in the development of MRONJ within a shorter period after Dmab administration but did not affect disease severity or treatment outcomes. Overall postoperative healing outcomes were favorable at 3 months after DRONJ treatment. The overall treatment success rate was 81.5%; Group 1, 85.0%; Group 2, 82.8%; Group 3, 53.8%, P=0.027). Multiple regression analysis demonstrated that Dmab dosage was a significant factor influencing treatment success, whereas age, treatment duration, lesion location, and DRONJ stage were not (odds ratio, 5.13; 95% confidence interval, 1.19-22.14; P=0.028). Conclusion The earlier onset in the BP to Dmab transition group may be attributable to the cumulative duration of antiresorptive therapy. Patients treated with high-dose Dmab demonstrated poorer prognosis and more frequent recurrence after MRONJ treatment compared with those treated with low-dose Dmab or BP to Dmab transition therapy. herefore, these findings need to be considered for treatment of DRONJ.

Mutations in the calreticulin gene, CALR, have recently been discovered in subsets of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF). We investigated Korean patients with ET and PMF to determine the prevalence, and clinical and laboratory correlations of CALR/JAK2/MPL mutations. Among 84 ET patients, CALR mutations were detected in 23 (27.4%) and were associated with higher platelet counts (P=0.006) and lower leukocyte counts (P=0.035) than the JAK2 V617F mutation. Among 50 PMF patients, CALR mutations were detected in 11 (22.0%) and were also associated with higher platelet counts (P=0.035) and trended to a lower rate of cytogenetic abnormalities (P=0.059) than the JAK2 V617F mutation. By multivariate analysis, triple-negative status was associated with shorter overall survival (HR, 7.0; 95% CI, 1.6-31.1, P=0.01) and leukemia-free survival (HR, 6.3; 95% CI, 1.8-22.0, P=0.004) in patients with PMF. The type 1 mutation was the most common (61.1%) type among all patients with CALR mutations, and tended toward statistical predominance in PMF patients. All 3 mutations were mutually exclusive and were never detected in patients with other myeloid neoplasms showing thrombocytosis. CALR mutations characterize a distinct group of Korean ET and PMF patients. Triple-negative PMF patients in particular have an unfavorable prognosis, which supports the idea that triple-negative PMF is a molecularly high-risk disease.
Adult ; Aged ; Aged, 80 and over ; Calreticulin/*genetics ; Disease-Free Survival ; Female ; Gene Frequency ; Genetic Association Studies ; Humans ; Janus Kinase 2/*genetics ; Male ; Middle Aged ; Mutation/genetics ; Primary Myelofibrosis/*genetics/mortality ; Receptors, Thrombopoietin/*genetics ; Republic of Korea ; Thrombocythemia, Essential/*genetics/mortality ; Young Adult