Myeloproliferative neoplasm Medical Services in China

Myeloproliferative neoplasms (MPNs) are a group of clonal hematopoietic stem cell disorders characterized by the overproduction of mature blood cells—primarily red blood cells, white blood cells, and/or platelets—in the bone marrow. The classic Philadelphia chromosome–negative MPNs include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). These conditions arise from acquired somatic mutations—most commonly in the JAK2 gene (present in >95% of PV and ~60% of ET/PMF cases), but also in CALR and MPL—leading to constitutive activation of the JAK-STAT signaling pathway and uncontrolled myeloid proliferation. While the exact triggers remain unclear, aging is the strongest epidemiologic correlate: MPNs predominantly affect adults over age 60, with median diagnosis ages ranging from 60 to 65 years. Incidence estimates vary globally but average approximately 1–2 cases per 100,000 person-years for PV and ET, and 0.5–1.5 per 100,000 for PMF. Prevalence is higher due to chronic disease course—estimated at 22–57 per 100,000 for PV and ET, and up to 10 per 100,000 for PMF. Risk factors include advancing age, male sex (slightly higher incidence in PV and PMF), and possibly environmental exposures such as ionizing radiation or benzene; however, no strong hereditary pattern or modifiable lifestyle risk has been consistently established. Importantly, MPNs are not contagious nor caused by infection. Quality of life is significantly impacted—not only by physical symptoms (e.g., fatigue, pruritus, night sweats, early satiety, bone pain, splenomegaly-related discomfort) but also by psychological burden, including anxiety about thrombotic events, disease progression to acute myeloid leukemia (10–20% lifetime risk in PMF), and treatment-related side effects. Patients often report impaired work productivity, sleep disruption, and social withdrawal. Symptom burden correlates poorly with blood counts, underscoring the importance of patient-reported outcomes in clinical assessment. Long-term management focuses on risk stratification (age, prior thrombosis, mutation profile, blood counts), cytoreduction (hydroxyurea, interferon-alpha, ruxolitinib), anticoagulation, and supportive care—including phlebotomy in PV and transfusion support in advanced myelofibrosis. With modern therapies, many patients live for decades, especially those with ET or low-risk PV; however, PMF carries a more variable prognosis, with median survival ranging from 1.5 to 15+ years depending on molecular and clinical risk factors.

Myeloproliferative neoplasms (MPNs) are a group of clonal hematopoietic stem cell disorders characterized by excessive production of mature blood cells—most commonly erythrocytes, granulocytes, or platelets. The three classic BCR-ABL1–negative MPNs include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). Treatment is risk-adapted, aiming to reduce thrombotic and hemorrhagic complications, alleviate constitutional symptoms, prevent disease progression (e.g., to accelerated phase or blast-phase acute myeloid leukemia), and improve quality of life and overall survival.

Conservative management forms the cornerstone of early-stage or low-risk MPN care. For low-risk PV (age <60 years, no prior thrombosis) and low-risk ET (age <60 years, no prior thrombosis or JAK2 mutation-associated high platelet count), observation with regular clinical and laboratory monitoring (CBC every 3–6 months, serum ferritin, LDH, uric acid) may be appropriate. Lifestyle modifications—including smoking cessation, weight optimization, hypertension and diabetes control, and avoidance of estrogen-containing contraceptives—are strongly recommended to mitigate cardiovascular risk. Phlebotomy remains first-line conservative therapy in PV: target hematocrit <45% is maintained via scheduled venesection (typically 250–500 mL weekly or biweekly until goal achieved), followed by maintenance phlebotomy as needed. Iron deficiency induced by repeated phlebotomy must be monitored but generally not supplemented unless symptomatic anemia develops, as iron repletion may exacerbate erythropoiesis and thrombotic risk. Low-dose aspirin (75–100 mg daily) is indicated for nearly all PV patients without contraindications (e.g., major bleeding history or active peptic ulcer disease) and for most ET patients—particularly those with microvascular symptoms (e.g., erythromelalgia, transient ischemic attacks) or JAK2 V617F positivity—to reduce thrombotic events by up to 60%.

Pharmacologic therapy is initiated based on risk stratification. High-risk PV (age ≥60 years or prior thrombosis) and high-risk ET (same criteria plus cardiovascular risk factors) require cytoreduction. First-line agents include hydroxyurea—a ribonucleotide reductase inhibitor that effectively controls blood counts and reduces thrombosis risk—with long-term safety supported by decades of clinical use. Alternative cytoreductive agents include interferon-alpha (IFN-α), particularly pegylated formulations (e.g., peginterferon alfa-2a), which demonstrate molecular response rates (reduction in JAK2 V617F allele burden) and favorable tolerability in younger patients and those desiring pregnancy preservation. Ruxolitinib, a JAK1/JAK2 inhibitor, is FDA- and EMA-approved for intermediate- or high-risk PMF and for PV patients resistant/intolerant to hydroxyurea. It significantly improves splenomegaly, constitutional symptoms (e.g., night sweats, weight loss, pruritus), and quality-of-life metrics, though it does not eliminate the malignant clone or consistently reduce allele burden. Additional agents under investigation or used off-label include busulfan (especially in elderly patients), pipobroman, and novel agents such as fedratinib and pacritinib for specific MF subpopulations (e.g., thrombocytopenic MF). Antifibrotic and disease-modifying strategies remain investigational; allogeneic hematopoietic stem cell transplantation (allo-HSCT) is currently the only potentially curative modality—but reserved exclusively for fit patients with high-risk PMF or post-MPN AML due to substantial treatment-related mortality (15–30%).

Surgical intervention has no primary role in MPN management. Splenectomy may be considered in select PMF or post-PV/ET MF patients with massive, symptomatic splenomegaly refractory to medical therapy (e.g., ruxolitinib), severe cytopenias due to hypersplenism, or mechanical complications (e.g., gastric compression, left upper quadrant pain). However, splenectomy carries significant risks—including overwhelming postsplenectomy infection (OPSI), pulmonary hypertension, rapid disease acceleration, and increased thrombotic risk—and should only be performed after multidisciplinary evaluation at experienced centers. Laparoscopic approaches are preferred when feasible, and lifelong penicillin prophylaxis and pneumococcal/meningococcal/H. influenzae vaccination are mandatory preoperatively.

China offers distinct advantages in MPN care, anchored in its rapidly evolving hematology infrastructure. Over 30 national MPN referral centers—including Peking University People’s Hospital, Shanghai Ruijin Hospital, and the First Affiliated Hospital of Sun Yat-sen University—participate in prospective registries (e.g., China MPN Registry) and multicenter clinical trials evaluating novel JAK inhibitors, interferon regimens, and combination therapies. Chinese regulatory approval pathways (NMPA) have accelerated access to ruxolitinib and recently approved fedratinib, with biosimilar development enhancing affordability. Integrated traditional Chinese medicine (TCM) is frequently incorporated adjunctively—not as monotherapy, but as evidence-informed supportive care: standardized herbal formulas (e.g., Bushen Huoxue decoction) have demonstrated adjunctive benefits in reducing fatigue and improving hematopoietic recovery in randomized controlled trials, though rigorous pharmacokinetic interaction studies with conventional agents remain ongoing. Moreover, China’s centralized electronic health record systems facilitate longitudinal monitoring of clonal dynamics (e.g., serial NGS-based minimal residual disease tracking), enabling earlier detection of progression.

Recovery and long-term management emphasize patient empowerment and structured surveillance. Patients should undergo comprehensive baseline assessment—including bone marrow biopsy with cytogenetics, next-generation sequencing (for ASXL1, SRSF2, U2AF1, EZH2, IDH1/2), and imaging (abdominal ultrasound or MRI for splenomegaly)—to inform prognosis and therapeutic decisions. Annual physical exams, CBC, LDH, and liver/kidney function tests are standard; bone marrow evaluation is repeated only upon clinical suspicion of progression (e.g., worsening cytopenias, increasing blasts >5%, new cytogenetic abnormalities). Psychosocial support is integral: MPNs carry high symptom burden and anxiety related to uncertainty of progression; cognitive behavioral therapy and peer-led support groups—increasingly available through platforms like the China MPN Alliance—are associated with improved coping and adherence. Patients must avoid nonsteroidal anti-inflammatory drugs (NSAIDs) due to bleeding risk, maintain hydration (especially during travel or illness), and promptly report signs of thrombosis (e.g., unilateral leg swelling, chest pain, sudden dyspnea) or transformation (e.g., persistent fever, night sweats, unexplained weight loss >10% in 6 months, progressive cytopenias). With contemporary risk-adapted strategies, median survival exceeds 15–20 years for PV and ET, and 5–7 years for intermediate-2/high-risk PMF—underscoring the importance of early diagnosis, precision risk stratification, and sustained multidisciplinary engagement.