Acute myeloid leukemia (AML) is a highly heterogeneous hematologic malignancy characterized by the proliferation of myeloid blasts. Bone marrow fibrosis (BMF), characterized by increased deposition of reticulin or collagen fibers, can occur in AML. International authoritative guidelines do not mention AML patients with BMF and the reported studies are inconsistent. Therefore, we retrospectively analyzed the clinical data of newly diagnosed AML patients in our hospital and compared the clinical characteristics, gene mutations and prognosis of AML patients with or without BMF. We found AML patients with BMF tended to be older, were more prone to hepatosplenomegaly, their level of β2-MG was higher and they often had karyotypes associated with a poor prognosis. The proportion of AML patients without BMF was high in the intermediate-risk group and low in the high-risk group. The mutation rates of ASXL1 and TET2 genes were higher and that of CEBPA was lower in the BMF group. Multivariate analysis showed BMF had independent prognostic significance. AML patients without BMF had higher CR/CRi rate, and the time of hematopoietic recovery in patients achieving CR/CRi was longer in BMF group. The degree of BMF, prognostic level and blasts in peripheral blood were independent risk factors for CR/CRi in newly diagnosed AML. AML patients in the BMF group, especially those with BMF ≥ 2, had a lower OS rate. In age<60 years old group, the higher the degree of BMF was, the shorter the median survival time and the lower the OS rate. In age ≥ 60 years old group, the median survival time in the BMF-1 and the BMF-2/3 groups was shorter. For AML with low, intermediate and high risk, there was always a lower OS rate in patients with BMF. The median survival of AML patients decreased with an increasing degree of BMF in different risk stratifications. BMF had no effect on OS of AML patients with HSCT. In conclusion, AML patients with BMF have a poor prognosis, and BMF was an independent prognostic factor for OS. The assessment of BMF was of great significance for the treatment efficacy and prognosis of newly diagnosed AML.

Background: Myeloid sarcoma (MS) is a rare hematological tumor that presents with extramedullary tumor masses comprising myeloid blasts. A controversial issue is whether MS involving normal hematopoietic sites (liver, spleen, and lymph nodes) should be excluded in future studies. We aimed to compare MS characteristics and outcomes involving hematopoietic and non-hematopoietic sites and construct a prognostic nomogram exclusively for the latter.

Methods: Data from patients diagnosed with MS between 2000 and 2018 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. According to the primary site, patients were classified as having MS involving hematopoietic sites (hMS) or non-hematopoietic sites (eMS). Clinical characteristics and survival outcomes were compared between the two groups using Wilcoxon, chi-square, and log-rank tests. Cox regression analysis was used to identify eMS prognostic factors to establish prognostic nomograms. The models’ efficiency and value were assessed using receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA).

Results: In total, 694 patients were enrolled, including 86 with hMS and 608 with eMS. There were no sex, race or marital status distribution differences between the two groups. Patients with eMS had better overall and cancer-specific survival rates than those with hMS. Additionally, prognostic factor effects differed between the two groups. Patients with eMS were randomly divided into the training (number of patiens, n=425) and validation cohorts (n=183). Age, first primary tumor, primary site, and chemotherapy were used to establish nomograms. The C-index values of overall survival (OS) and cancer-specific survival (CSS) nomograms were 0.733 (validation: 0.728) and 0.722 (validation: 0.717), respectively. Moreover, ROC, calibration curves, and DCA confirmed our models’ good discrimination and calibration ability and potential clinical utility value.

Conclusion: Our study described the differences between patients with eMS and those with hMS. Moreover, we developed novel nomograms based on clinical and therapeutic factors to predict patients with eMS’ 1-, 3- and 5-year survival rates.

Sinusoidal Obstruction Syndrome (SOS) is a life threatening HSCT complication and it can rapidly evolve in Multiple Organ Dysfunction Syndrome, with a mortality exceeding 80%. Early treatment with defibrotide is the leading factor for efficacy. Its prophylactic use is recommended in the pediatric setting, but its value isn’t validated for adults, although factors for individual risk assessment are debated. We here present a real-world experience of Defibrotide prophylaxis in adults at very high risk of SOS. We treated with prophylactic Defibrotide and Ursodeoxycholic Acid seven patients receiving allogeneic HSCT for high risk B-ALL, previously treated with single agent Inotuzomab-Ozogamicin. They all had other high risk factors for SOS such as previous hepatotoxicity, previous allo-HSCT, double alkylating conditioning. All patients received Treosulfan-Fludarabine conditioning, Thiotepa was added in 4 patients and 4GyTBI in 2 patients. GvHD prophylaxis included post-transplant cyclophosphamide, rapamycin and mycophenolate. Donor source was PBSC. Five patients received family MMRD transplant, 1 patient a MRD transplant and 1 patient a MUD transplant. Non-severe gastrointestinal bleeding occurred in two patients requiring defibrotide temporarily discontinuation. SOS occurred in 3/7 cases within 21 days after HSCT and no late-onset SOS were diagnosed. SOS caused death in all cases. All three patients were characterized by a common pattern of very high risk factors by prior HSCT, they all received a myeloablative conditioning with Treosulfan-Thiotepa and a MMRD transplant. Defibrotide prophylaxis apparently failed to protect against the development of SOS in those patients treated with a double alkylator-based conditioning regimen, while a possible efficacy for the other high-risk patients is debatable.