Challenges in Myelodysplastic/Myeloproliferative Neoplasms (MDS/MPN)

Allogeneic stem cell transplantation may overcome the adverse impact of myelofibrosis on the prognosis of myelodysplastic syndrome

Purpose

Myelofibrosis (MF) may serve as a poor prognostic factor in myelodysplastic syndromes (MDS). This study explored the impact of allogeneic hematopoietic stem cell transplantation (allo-HSCT) on the outcome of MDS patients with MF.

Patients and Methods

Three hundred and sixteen MDS patients were enrolled in this retrospective study. Based on the degree of MF, we divided the patients into 2 groups: grade 0–1 (MF-0/1) and grade 2–3 (MF-2/3) groups. The clinical features, treatments, and prognosis in MDS patients with MF were analyzed.

Results

Forty-three (13.6%) patients were diagnosed as MF-2/3. Complex karyotypes were more common in the MF-2/3 compared to MF-0/1 groups (P = 0.002). The overall response rate (ORR) of cytoreduction was 49.0%, along with 53.3% in the MF-0/1 and 16.7% in MF-2/3 groups (P = 0.017). In total, 141 patients underwent allo-HSCT, including 121 in the MF-0/1 and 20 in MF-2/3 groups. The median time to neutrophil reconstruction was 12 (range: 7–34) and 14 (range: 10–45) days (P = 0.005), and platelet reconstruction was 14 (range: 8–68) and 18 (range: 8–65) days (P = 0.045) in the MF-0/1 and MF-2/3 groups, respectively. However, the cumulative incidence of neutrophil and platelet engraftment achieved at day + 30 was not different between the two groups (P = 0.107, P = 0.303, respectively). Non-relapse mortality, relapse, and acute and chronic graft-versus-host disease were similar between the two groups (all P > 0.05). Among patients with allo-HSCT, the 2-year overall survival (OS) was 68.5% (95% CI: 60.1–76.9%) and 68.4% (95% CI: 47.4–89.4%) in the MF-0/1 and MF-2/3 groups, respectively, (P = 0.636). Among patients without allo-HSCT, the 2-year OS was 49.9% (95% CI: 40.7–59.1%) and 19.2% (95% CI: 0–39.6%) in the MF-0/1 and MF-2/3 groups, respectively, (P = 0.002). In multivariate cox analysis, complex karyotype was an unfavorable factor for relapse (HR, 4.16; P = 0.006), disease-free survival (DFS) (HR, 2.16; P = 0.020), and OS (HR, 2.47; P = 0.009) post-transplantation.

Conclusion

Patients with MF-2/3 have more complex karyotypes and lower ORR of cytoreduction in MDS. Among patients without allo-HSCT, patients with MF-2/3 have a worse prognosis than those with MF-0/1. However, the adverse impact of MF on prognosis may be overcome by allo-HSCT.

Favorable outcome of a patient with an unclassifiable myelodysplastic syndrome/myeloproliferative neoplasm treated with allogeneic hematopoietic stem cell transplantation

The entity myelodysplastic syndrome/myeloproliferative neoplasm overlap syndrome is characterized by the coexistence of both myeloproliferative and myelodysplastic features in the bone marrow. Risk assessment and treatment recommendations have not been standardized, and clinicians rely on updated patient studies and reviews to make decisions for treatment approaches. Histopathological features have traditionally been important, although in the last decade, several studies have reported mutational profiles of this rare disease. Here, we present a case, wherein the patient presented with leukocytosis and the diagnostic work-up revealed features of myelodysplastic syndrome/myeloproliferative neoplasm overlap syndrome. Mutational profiling revealed mutations in four genes associated with myeloid malignancies, namely, EZH2, CUX1, TET2, and BCOR. After initial therapy with hydroxyurea and interferon-α, the patient underwent allogeneic hematopoietic stem cell transplantation, with reduced intensity conditioning and a matched sibling donor. He had no signs of relapsed disease 2 years after the transplant. Based on the patient outcome, we summarize the diagnostic and therapeutic approaches for patients diagnosed with myelodysplastic syndrome/myeloproliferative neoplasm overlap syndrome, and review the current literature, emphasizing the role of genetic mutations and allogeneic hematopoietic stem cell transplantation. Larger and more detailed clinical studies are strongly needed to optimize and standardize diagnostic and therapeutic approaches for this disease.

Ruxolitinib Plus Decitabine Effectively Treats Myelodysplastic Syndrome/Myeloproliferative Neoplasm, Unclassifiable, by Decreasing the Variant Allele Frequency of KRAS

Myelodysplastic syndrome/myeloproliferative neoplasm, unclassifiable (MDS/MPN-U) is a subtype of MDS/MPN that exhibits a combination of the features of both MDS and MPN. To date, no curative treatment is available for MDS/MPN-U; however, previous studies have suggested a potential survival advantage for ruxolitinib and hypomethylating agents. We reported a case of a JAK2-negative but KRAS-positive MDS/MPN-U patient treated with ruxolitinib plus decitabine. After treatment, the patient’s clinical symptoms were moderated, and the size of the spleen and the peripheral blood cell counts were reduced. These effects might be due to the regimen’s ability to reduce STAT5 activation and upregulate microRNA-181c to downregulate the variant allele frequency (VAF) of KRAS.

Myelodysplastic/myeloproliferative neoplasm, unclassifiable (MDS/MPN-U): More than just a "catch-all" term?

The clinicopathology of MDS and MPN are not mutually exclusive and for this reason the category of myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN) exists. Several sub-entities have been included under the MDS/MPN umbrella, including MDS/MPN-unclassifiable (MDS/MPN-U) for those cases whose morphologic and clinical phenotype do not meet criteria to be classified as any other MDS/MPN sub-entity. Though potentially regarded as a wastebasket diagnosis, since its integration into myeloid disease classification, MDS/MPN-U has been refined with increasing understanding of the mutational and genomic events that drive particular clinicopathologic phenotypes, even within MDS/MPN-U. The prototypical example is the identification of SF3B1 mutations and its durable association with MDS/MPN with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T), an entity previously buried within, but now a separate category outside of MDS/MPN-U. Continued and enhanced study of those entities under MDS/MPN-U, a perhaps provisional category itself, is likely to progressively identify commonality between many "unclassifiables" to establish a new classifiable diagnosis.