Response criteria for myelofibrosis with myeloid metaplasia, which was recently proposed by the European Myelofibrosis Network (EUMNET)
1. Complete response | Complete response in anemia, splenomegaly, constitutional symptoms, and platelet and leukocyte count |
| i. Complete response in anemia: hemoglobin level at least 120 g/L for transfusion-independent patients or at least 110 g/L for transfusion-dependent patients (applicable only for patients with baseline hemoglobin level below 100 g/L). | |
| ii. Complete response in splenomegaly: spleen not palpable. | |
| iii. Complete response in constitutional symptoms: absence of constitutional symptoms (fever, drenching night sweats, or a minimum 10% weight loss). | |
| iv. Complete response in platelet count: platelet count 150-400 × 109/L. | |
| v. Complete response in leukocyte count: leukocyte count 4-10 × 109/L. | |
| 2. Major response | Any response in both anemia and splenomegaly without progression in constitutional symptoms or complete response in anemia without progression in splenomegaly or partial response in anemia in a baseline transfusion-dependent patient combined with response in constitutional symptoms without progression in splenomegaly or any response in splenomegaly combined with response in constitutional symptoms without progression in anemia. |
| i. Partial response in anemia: either a minimum 20-g/L increase in hemoglobin level or more than 50% decrease in transfusion requirement. | |
| ii. Partial response in splenomegaly: either a minimum 50% decrease in spleen size if baseline is no more than 10 cm from LCM or a minimum 30% decrease if baseline is at least 10 cm from LCM. | |
| iii. Partial response in platelet count: a minimum 50% decrease in platelet count if baseline above 800 × 109/L or platelet count increase by at least 50 × 109/L if baseline below 100 × 109/L. | |
| iv. Partial response in leukocyte count: a minimum 50% decrease in leukocyte count if baseline above 20 × 109/L or leukocyte count increase by at least 1 × 109/L if baseline below 4 × 109/L. | |
| v. Progression in anemia: a hemoglobin decrease of at least 20 g/L or a minimum 50% increase in transfusion requirement or becoming transfusion dependent. | |
| vi. Progression in splenomegaly: a minimum 50% increase in spleen size if baseline no more than 10 cm from LCM or a minimum 30% increase if baseline greater than 10 cm from LCM. | |
| vii. Progression in constitutional symptoms: appearance of constitutional symptoms. | |
| 3. Moderate response | Complete response in anemia with progression in splenomegaly or partial response in anemia without progression in splenomegaly or any response in splenomegaly without progression in anemia and constitutional symptoms. |
| 4. Minor response | Any leukocyte- or platelet-based response without progression in anemia, splenomegaly, or constitutional symptoms. |
| 5. No response | None of the above. |
| 6. Histologic response | The panel of experts recommended that a histologic response should include assessment of both age-adjusted bone marrow cellularity and fibrosis. The need for both adequate biopsy specimen and good quality reticulin/collagen staining was underscored. Furthermore, general assessment and scoring of grades of fibrosis is to be done in areas of hematopoiesis after assessing the quality of the reticulin stain by detection of normal staining in vessel walls as internal controls. |
| 7. Cytogenetic response | Major cytogenetic response: failure to detect a cytogenetic abnormality in cases with a pre-existing abnormality. |
| Minor cytogenetic response: a 50% or greater reduction in abnormal metaphases. |
1. Complete response | Complete response in anemia, splenomegaly, constitutional symptoms, and platelet and leukocyte count |
| i. Complete response in anemia: hemoglobin level at least 120 g/L for transfusion-independent patients or at least 110 g/L for transfusion-dependent patients (applicable only for patients with baseline hemoglobin level below 100 g/L). | |
| ii. Complete response in splenomegaly: spleen not palpable. | |
| iii. Complete response in constitutional symptoms: absence of constitutional symptoms (fever, drenching night sweats, or a minimum 10% weight loss). | |
| iv. Complete response in platelet count: platelet count 150-400 × 109/L. | |
| v. Complete response in leukocyte count: leukocyte count 4-10 × 109/L. | |
| 2. Major response | Any response in both anemia and splenomegaly without progression in constitutional symptoms or complete response in anemia without progression in splenomegaly or partial response in anemia in a baseline transfusion-dependent patient combined with response in constitutional symptoms without progression in splenomegaly or any response in splenomegaly combined with response in constitutional symptoms without progression in anemia. |
| i. Partial response in anemia: either a minimum 20-g/L increase in hemoglobin level or more than 50% decrease in transfusion requirement. | |
| ii. Partial response in splenomegaly: either a minimum 50% decrease in spleen size if baseline is no more than 10 cm from LCM or a minimum 30% decrease if baseline is at least 10 cm from LCM. | |
| iii. Partial response in platelet count: a minimum 50% decrease in platelet count if baseline above 800 × 109/L or platelet count increase by at least 50 × 109/L if baseline below 100 × 109/L. | |
| iv. Partial response in leukocyte count: a minimum 50% decrease in leukocyte count if baseline above 20 × 109/L or leukocyte count increase by at least 1 × 109/L if baseline below 4 × 109/L. | |
| v. Progression in anemia: a hemoglobin decrease of at least 20 g/L or a minimum 50% increase in transfusion requirement or becoming transfusion dependent. | |
| vi. Progression in splenomegaly: a minimum 50% increase in spleen size if baseline no more than 10 cm from LCM or a minimum 30% increase if baseline greater than 10 cm from LCM. | |
| vii. Progression in constitutional symptoms: appearance of constitutional symptoms. | |
| 3. Moderate response | Complete response in anemia with progression in splenomegaly or partial response in anemia without progression in splenomegaly or any response in splenomegaly without progression in anemia and constitutional symptoms. |
| 4. Minor response | Any leukocyte- or platelet-based response without progression in anemia, splenomegaly, or constitutional symptoms. |
| 5. No response | None of the above. |
| 6. Histologic response | The panel of experts recommended that a histologic response should include assessment of both age-adjusted bone marrow cellularity and fibrosis. The need for both adequate biopsy specimen and good quality reticulin/collagen staining was underscored. Furthermore, general assessment and scoring of grades of fibrosis is to be done in areas of hematopoiesis after assessing the quality of the reticulin stain by detection of normal staining in vessel walls as internal controls. |
| 7. Cytogenetic response | Major cytogenetic response: failure to detect a cytogenetic abnormality in cases with a pre-existing abnormality. |
| Minor cytogenetic response: a 50% or greater reduction in abnormal metaphases. |
Response or disease progression is validated only if it lasts for 1 month or longer