Molecular genetics in allogeneic blood stem cell transplantation for myelodysplastic syndromes

Myelodysplastic Syndromes: New Methods of Diagnosis, Prognostication, and Treatment

BACKGROUND

Myelodysplastic syndromes (MDS) are malignant diseases arising from hematopoietic stem cells. Their overall incidence is 4 cases per 100 000 persons per year, and they are usually diagnosed when evaluating cytopenia. The median survival time is three years. Myelodysplastic syndromes take a variable course; one-quarter of patients go on to develop acute leukemia.

METHODS

This review is based on publications retrieved by a selective search of the literature from 2013 to 2022, including relevant guidelines, in the PubMed database. The time period was chosen to reflect developments since the publication of the latest EHA guidelines in 2013.

RESULTS

The gold standard of diagnosis is cytomorphology of the blood and bone marrow, supplemented by banding cytogenetics, histomorphology, and somatic mutation analyses. The new classification proposed by the WHO incorporates the molecular and cytogenetic findings. The Molecular International Prognostic Scoring System (IPSS-M), which takes somatic mutations into account, is now available as an aid to prognostication. Quality of life evaluation with standardized instruments is helpful in many ways. Low-risk patients are treated supportively with erythrocyte transfusions and iron chelation therapy. Erythropoietin-a can be given to patients whose erythropoietin level is less than 200ng/mL, lenalidomide to those with a 5q deletion, and luspatercept to those with an SF3B1 mutation. High-risk patients should be evaluated as early as possible for allogeneic hematopoietic stem cell transplantation with curative intent. 5-azacytidine improves outcomes in patients for whom stem cell transplantation is not suitable.

CONCLUSION

Once a precise diagnosis has been established, new prognostic instruments such as the IPSS-M enable risk-adapted treatment based on the biological aspects of the patient's disease as well as his or her age and comorbidities.

Pre-transplantation cytoreduction does not benefit advanced myelodysplastic syndrome patients after myeloablative transplantation with grafts from family donors

BACKGROUND

The role of pre-hematopoietic stem cell transplantation (HSCT) cytoreduction with either induction chemotherapy (IC) or hypomethylating agents (HMAs) in treating advanced myelodysplastic syndrome (MDS) remains debatable. We aimed to evaluate pre-HSCT strategies by comparing the endpoints related to disease control between advanced MDS patients with pre-HSCT cytoreduction and those with best supportive care.

METHODS

We described 228 consecutive advanced MDS patients who received HSCT from a haploidentical donor (HID, n = 162) or matched related donor (MSD, n = 66) with uniform myeloablative conditioning regimens between January 2015 and December 2018. Of these 228 patients, 131 (57.5%) were treated exclusively with pre-HSCT best supportive care (BSC), 49 (22.5%) were given HMA, and 48 (21.1%) received both IC and HMA. Propensity score-matching analysis, multivariate analyses, and subgroup analyses were performed to elucidate the impact of pre-HSCT strategies on transplant outcomes.

RESULTS

The 3-year relapse-free survival (RFS) rates were 78.2% and 70.0% for the BSC and cytoreduction cohorts (P = 0.189) and were 78.2%, 66.7%, and 73.2% for the BSC, HMA, and HMA+IC groups, respectively (P = 0.269). A propensity score-matching analysis confirmed that the 3-year RFS rates were 81.9%, 87.5%, and 66.9% for BSC, cytoreduction complete remission (CR), and cytoreduction non-CR groups, respectively (P = 0.051). Multivariate analyses demonstrated that pre-HSCT cytoreduction, older patient age, monosomal karyotype, and interval between diagnosis and HSCT were poor prognostic factors for RFS. In the subgroup analyses, BSC was associated with longer RFS compared to cytoreduction among the younger patients, those with international prognostic scoring system intermediate-2/high risk at diagnosis, and those with intermediate/poor cytogenetics.

CONCLUSIONS

Different pre-HSCT therapies did not yield discrepant post-HSCT outcomes. No benefit in terms of post-HSCT outcomes were correlated with pre-HSCT cytoreduction in advanced MDS even for cytoreduction CR patients. Early referral to HSCT is essential for advanced MDS patients.

Prediction of Response and Survival Following Treatment with Azacitidine for Relapse of Acute Myeloid Leukemia and Myelodysplastic Syndromes after Allogeneic Hematopoietic Stem Cell Transplantation

To provide long-term outcome data and predictors for response and survival, we retrospectively analyzed all 151 patients with relapse of myeloid neoplasms after allogeneic hematopoietic stem cell transplantation (allo-HSCT) who were uniformly treated with first-line azacitidine (Aza) salvage therapy at our center. Patients were treated for molecular (39%) or hematologic relapse (61%), with a median of 5 cycles of Aza and at least one donor lymphocyte infusion in 70% of patients. Overall response was 46%, with 41% achieving complete (CR) and 5% achieving partial remission. CR was achieved after a median of 4 cycles and lasted for a median of 11 months (range 0.9 to 120 months). With a median follow-up of 22 months (range: 1 to 122 months), the 2-year survival rate was 38% ± 9%, including 17 patients with ongoing remission for >5 years. Based on results from multivariate analyses, molecular relapse and time to relapse were integrated into a score, clearly dividing patients into 3 subgroups with CR rates of 71%, 39%, and 29%; and 2-year survival rates of 64%, 38%, and 27%, respectively. In the subgroup of MDS and secondary AML, receiving upfront transplantation was associated with superior response and survival, and therefore pretransplant strategy was integrated together with relapse type into a MDS–sAML-specific score. Overall, Aza enables meaningful responses and long-term survival, which is a predictable with a simple-to-use scoring system.