Myelodysplastic Syndromes and Acute Myeloid Leukemia After Radiotherapy for Prostate Cancer: A Population-Based Study

Myelodysplastic Syndrome Related to Successful Treatment With177Lu-PSMA for Metastatic Castration-Refractory Prostate Cancer

ABSTRACT

177Lu-vipivotide tetraxetan (177Lu-PSMA-617/LuPSMA) received recent EMA approval for metastatic castration-resistant prostate cancer, with promising data for earlier stages. Secondary myeloid neoplasm following exposure to DNA-damaging therapy (therapy-related myelodysplastic syndrome [MDS]) is a rare severe complication of 177Lu-oxodotreotide. We present a 77-year-old man, with synchronous liver, bone, and lymph node metastatic prostate cancer, having developed a low-risk MDS with SF3B1 mutation, 1 month after the sixth administration of LuPSMA. Although on partial metabolic and biological response with PSA nadir at 7 months after therapy, life quality was significantly altered by MDS.

Impact of Advanced External Beam Radiotherapy on Second Haematological Cancer Risk in Prostate Cancer Survivors

AIMS

External beam radiotherapy (EBRT) for prostate cancer (PCa) has rapidly advanced over the years. Advanced techniques with altered dose distributions may have an impact on second haematological cancer (SHC) risks. We assessed SHC risk after EBRT for PCa and explored whether this risk has changed over the years.

MATERIALS AND METHODS

Patients diagnosed with a T1-T3 PCa between 1990 and 2015 were selected from the Netherlands Cancer Registry. Patients treated with EBRT were assigned to EBRT eras based on the date of diagnosis. These eras represented two-dimensional radiotherapy (2D-RT; 1991-1996), three-dimensional conformal radiotherapy (3D-CRT; 1998-2005) or advanced EBRT (2008-2015). Standardised incidence ratios (SIR) and absolute excess risks (AER) were calculated overall and by EBRT era. Sub-hazard ratios (sHRs) were calculated for the comparison of EBRT versus radical prostatectomy and active surveillance.

RESULTS

PCa patients with EBRT as the primary treatment (n = 37 762) had an increased risk of developing a SHC (SIR = 1.20; 95% confidence interval 1.13-1.28) compared with the Dutch male general population. Estimated risks were highest for the 2D-RT era (SIR = 1.32; 95% confidence interval 1.14-1.67) compared with the 3D-CRT era (SIR = 1.16; 95% confidence interval 1.05-1.27) and the advanced EBRT era (SIR = 1.21; 95% confidence interval 1.07-1.36). AER were limited, with about five to six extra cases per 10 000 person-years. Relative risk analysis (EBRT versus radical prostatectomy/active surveillance) showed significant elevation with EBRT versus active surveillance (sHR = 1.17; 95% confidence interval 1.03-1.33; P = 0.017), but not for EBRT versus radical prostatectomy (sHR = 1.08; 95% confidence interval 0.94-1.23; P = 0.281).

CONCLUSION

Increased SHC risks after EBRT for PCa cancer were observed for all EBRT eras compared with the general Dutch male population. Excess risks for EBRT versus other PCa treatment groups were found for only EBRT versus active surveillance.

Second malignancies among older patients with classical myeloproliferative neoplasms treated with hydroxyurea

Patients with classical Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs), including polycythemia vera (PV), essential thrombocythemia (ET), and primary and secondary myelofibrosis (MF), are known to have an increased risk of second malignancies (SMs). Hydroxyurea (HU) is a guideline-recommended cytoreductive therapy for patients at high risk for MPNs. Controversy exists as to whether HU use is associated with a higher risk of SMs, including acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). We conducted a retrospective cohort study of older patients diagnosed with MPN (age ≥66 years) between 2010 and 2017 and included the data in the Surveillance, Epidemiology, and End Results Medicare-linked database. Multivariable competing risk analyses adjusting for patient characteristics were used to assess the impact of HU on the development of SM. We identified 4023 patients (1688 with PV, 1976 with ET, and 359 with MF) with a median age of 77 (interquartile range [IQR], 71-83) years at the time of MPN diagnosis. After a median follow-up of 3.25 (IQR, 2.10-5.00) years, 489 patients developed an SM (346 solid, 73 lymphoid, and 70 myeloid malignancies). The cumulative incidence probability of SM was 19.88% (95% confidence interval [CI], 17.16%-22.75%) among 2683 HU users and 22.31% (95% CI, 17.51%-27.47%) among 1340 nonusers, respectively (Gray's test, P < .01). We did not identify significant differences in the incidence of solid or hematologic SMs, including AML/MDS (hazard ratio, 1.33; 95% CI, 0.77-2.29; P = .30), between HU users and nonusers. Our results suggest that the use of HU does not increase the risk of SM in older patients with MPN.

Case report: Identification of acute promyelocytic leukemia during osimertinib resistance followed by granulocyte colony-stimulating factor and pembrolizumab

Background

The occurrence of acute promyelocytic leukemia (APL) during the management of lung cancer is rare and life-threatening. It was mainly reported to be secondary to chemoradiotherapy. A few studies reported an increased incidence of therapy-related acute promyelocytic leukemia (t-APL) after gefitinib became available.

Case presentation

We reported a patient who developed thrombocytopenia after receiving oral osimertinib in combination with intensity-modulated radiotherapy (IMRT). For half a year, she had an unrecoverable low platelet count, which progressed to concomitant leukopenia and the transient appearance of orthochromatic normoblasts in the peripheral blood test, indicating a dormant myeloid disorder. Due to simultaneous resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI), pembrolizumab and granulocyte colony-stimulating factor (G-CSF) were administered, revealing prominent signs of hematological malignancy in a peripheral blood test that was later identified as t-APL.

Conclusion

In general, patients undergoing EGFR-TKI combined with local radiotherapy should be concerned about their hematological assessment. If patients exhibit unrecoverable abnormalities in routine blood tests, a secondary nonsolid malignancy other than myelosuppression should be considered, and further lung cancer treatment should be discontinued.

Association between radiotherapy and risk of second primary malignancies in patients with resectable lung cancer: a population-based study

BACKGROUND

The most common form of treatment for non-metastatic lung cancer is surgery-based combination therapy, which may also include adjuvant radiotherapy or chemotherapy. Second primary malignancies (SPMs) are uncommon but significant radiation side effects in patients with resectable lung cancer, and SPMs have not been adequately investigated. Our study aims to assess the correlations of radiotherapy with the development of SPMs in patients with resectable lung cancer.

METHODS

We screened for any primary malignancy that occurred more than five years after the diagnosis of resectable lung cancer. Based on the large cohort of the Surveillance, Epidemiology and End Results database, radiotherapy-correlated risks were estimated using the Poisson regression analysis and the cumulative incidence of SPMs was calculated using Fine-Gray competing risk regression analysis.

RESULTS

Among the 62,435 patients with non-metastatic lung cancer undergoing surgery, a total of 11,341 (18.16%) patients have received radiotherapy. Our findings indicated that radiotherapy was substantially related to a high risk of main second solid malignancies (RR = 1.21; 95%CI, 1.08 to 1.35) and a negligible risk of main second hematologic malignancies (RR = 1.08; 95%CI, 0.84 to 1.37). With the greatest number of patients, the risk of acquiring a second primary gastrointestinal cancer was the highest overall (RR = 1.77; 95 percent CI, 1.44 to 2.15). The cumulative incidence and standardized incidence ratios of SPMs revealed similar findings. Furthermore, the young and the elderly may be more vulnerable, and the highest risk of acquiring most SPMs was seen more than ten years after lung cancer diagnosis. Additionally, more attention should be paid to the second primary gastrointestinal cancer in young individuals with resectable lung cancer.

CONCLUSION

After receiving radiotherapy, an increased risk of developing second primary solid and gastrointestinal cancers was observed for patients with resectable lung cancer. The prevention of SPMs associated with radiotherapy requires further attention.

Assessment of Second Primary Cancer Risk Among Men Receiving Primary Radiotherapy vs Surgery for the Treatment of Prostate Cancer

IMPORTANCE

Shared decision-making is an important part of the treatment selection process among patients with prostate cancer. Updated information is needed regarding the long-term incidence and risk of second primary cancer after radiotherapy vs nonradiotherapy treatments, which may help to inform discussions of risks and benefits for men diagnosed with prostate cancer.

OBJECTIVE

To assess the current incidence and risk of developing a second primary cancer after receipt of radiotherapy vs nonradiotherapy treatments for prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used the Veterans Affairs Corporate Data Warehouse to identify 154 514 male veterans 18 years and older who had localized prostate cancer (tumor stages T1-T3) diagnosed between January 1, 2000, and December 31, 2015, and no cancer history. A total of 10 628 patients were excluded because of (1) incomplete treatment information for the year after diagnosis, (2) receipt of both radiotherapy and a surgical procedure in the year after diagnosis, (3) receipt of radiotherapy more than 1 year after diagnosis, (4) occurrence of second primary cancer or death within 1 year or less after diagnosis, (5) prostate-specific antigen value greater than 99 ng/mL within 6 months before diagnosis, or (6) no recorded Veterans Health Administration service after diagnosis. The remaining 143 886 patients included in the study had a median (IQR) follow-up of 9 (6-13) years. Data were analyzed from May 1, 2021, to May 22, 2022.

MAIN OUTCOMES AND MEASURES

Diagnosis of a second primary cancer more than 1 year after prostate cancer diagnosis.

RESULTS

Among 143 886 male veterans (median [IQR] age, 65 [60-71] years) with localized prostate cancer, 750 (0.5%) were American Indian or Alaska Native, 389 (0.3%) were Asian, 37 796 (26.3%) were Black or African American, 933 (0.6%) were Native Hawaiian or other Pacific Islander, 91 091 (63.3%) were White, and 12 927 (9.0%) were of unknown race; 7299 patients (5.1%) were Hispanic or Latino, 128 796 (89.5%) were not Hispanic or Latino, and 7791 (5.4%) were of unknown ethnicity. A total of 52 886 patients (36.8%) received primary radiotherapy, and 91 000 (63.2%) did not. A second primary cancer more than 1 year after prostate cancer diagnosis was present in 4257 patients (3.0%), comprising 1955 patients (3.7%) in the radiotherapy cohort and 2302 patients (2.5%) in the nonradiotherapy cohort. In the multivariable analyses, patients in the radiotherapy cohort had a higher risk of second primary cancer compared with those in the nonradiotherapy cohort at years 1 to 5 after diagnosis (hazard ratio [HR], 1.24; 95% CI, 1.13-1.37; P < .001), with higher adjusted HRs in the subsequent 15 years (years 5-10: 1.50 [95% CI, 1.36-1.65; P < .001]; years 10-15: 1.59 [95% CI, 1.37-1.84; P < .001]; years 15-20: 1.47 [95% CI, 1.08-2.01; P = .02).

CONCLUSIONS AND RELEVANCE

In this cohort study, patients with prostate cancer who received radiotherapy were more likely to develop a second primary cancer than patients who did not receive radiotherapy, with increased risk over time. Although the incidence and risk of developing a second primary cancer were low, it is important to discuss the risk with patients during shared decision-making about prostate cancer treatment options.

CSF3R T618I mutant myelodysplastic/myeloproliferative neoplasm in the elderly: An age-related disease with unfavorable prognosis

We reported two MDS/MPN-U and one CMML patients with CSF3R T618I mutation. There were two males and one female, with a median age of 84 years. Three patients presented with leukocytosis and anemia, two with thrombocytopenia, and one with monocytosis. In all the patients, bone marrow showed hypercellularity with myeloid or erythroid predominant trilineage hematopoiesis and dysplasia. Two cases carried -7/-7q abnormalities. In addition to CSF3R T618/I mutation, each case carried 3–5 additional somatic mutations. The median survival was only 2 months. These rare patients were characterized by old age, high mutation rates, clonal hematopoiesis-associated mutations, clonal evolution, and unfavorable prognosis.

Therapy-related myeloid neoplasms in 109 patients after radiation monotherapy

Therapy-related myeloid neoplasms (t-MNs) are a late complication of cytotoxic therapy and are defined as a distinct entity by the World Health Organization. Although the link between chemotherapy exposure and risk of subsequent t-MN is well described, the association between radiation monotherapy (RT) and t-MN risk is less definitive. We analyzed 109 consecutive patients who developed t-MNs after RT and describe latencies, cytogenetic profile, mutation analyses, and clinical outcomes. The most common cytogenetic abnormality was a clonal abnormality in chromosome 5 and/or 7, which was present in 45% of patients. The median latency from RT to t-MN diagnosis was 6.5 years, with the shortest latency in patients with balanced translocations. One-year overall survival (OS) was 52% and 5-year OS was 22% for the entire cohort. Patients with chromosome 5 and/or 7 abnormalities experienced worse 1-year OS (37%) and 5-year OS (2%) compared with other cytogenetic groups (P < .0001). Sixteen patients underwent net-generation sequencing; ASXL1 and TET2 were the most commonly mutated genes (n = 4). In addition, 17 patients underwent germline variant testing and 3 carried pathogenic or likely pathogenic germline variants. In conclusion, patients with t-MN after RT monotherapy have increased frequencies of chromosome 5 and/or 7 abnormalities, which are associated with poor OS. In addition, pathogenic germline variants may be common in patients with t-MN after RT monotherapy.

Challenging the concept of de novo acute myeloid leukemia: Environmental and occupational leukemogens hiding in our midst

Myeloid neoplasms like acute myeloid leukemia (AML) originate from genomic disruption, usually in a multi-step fashion. Hematopoietic stem/progenitor cell acquisition of abnormalities in vital cellular processes, when coupled with intrinsic factors such as germline predisposition or extrinsic factors such as the marrow microenvironment or environmental agents, can lead to requisite pre-leukemic clonal selection, expansion and evolution. Several of these entities have been invoked as "leukemogens." The known leukemogens are numerous and are found in the therapeutic, occupational and ambient environments, however they are often difficult to implicate for individual patients. Patients treated with particular chemotherapeutic agents or radiotherapy accept a calculated risk of therapy-related AML. Occupational exposures to benzene, dioxins, formaldehyde, electromagnetic and particle radiation have been associated with an increased risk of AML. Although regulatory agencies have established acceptable exposure limits in the workplace, accidental exposures and even ambient exposures to leukemogens are possible. It is plausible that inescapable exposure to non-anthropogenic ambient leukemogens may be responsible for many cases of non-inherited de novo AML. In this review, we discuss the current understanding of leukemogens as they relate to AML, assess to what extent the term "de novo" leukemia is meaningful, and describe the potential to identify and characterize new leukemogens.

Three Synchronous Primary Extranodal Mantle Cell Lymphomas Involving Torus Tubarius, Posterior Nasopharynx, and Base of the Tongue 65 Years After Treatment of Chronic Sinusitis with Nasopharyngeal Radium Irradiation

Patient: Male, 81

Final Diagnosis: Mantle cell lymphoma

Symptoms: Dificulty in swallowing and pain in the right ear

Medication: —

Clinical Procedure: Otorhinolaryngology panendoscopy • biopsy of the tumors

Specialty: Otolaryngology

Epidemiology of acute myeloid leukemia: Recent progress and enduring challenges

Acute myeloid leukemia (AML) is a malignant disorder of the bone marrow which is characterized by the clonal expansion and differentiation arrest of myeloid progenitor cells. The age-adjusted incidence of AML is 4.3 per 100,000 annually in the United States (US). Incidence increases with age with a median age at diagnosis of 68 years in the US. The etiology of AML is heterogeneous. In some patients, prior exposure to therapeutic, occupational or environmental DNA-damaging agents is implicated, but most cases of AML remain without a clear etiology. AML is the most common form of acute leukemia in adults and has the shortest survival (5-year survival = 24%). Curative therapies, including intensive chemotherapy and allogeneic stem cell transplantation, are generally applicable to a minority of patients who are younger and fit, while most older individuals exhibit poor prognosis and survival. Differences in patient outcomes are influenced by disease characteristics, access to care including active therapies and supportive care, and other factors. After many years without therapeutic advances, several new therapies have been approved and are expected to impact patient outcomes, especially for older patients and those with refractory disease.

Myeloid disorders after autoimmune disease

Autoimmune diseases (ADs) are associated with an increased risk not only of lymphoproliferative disorders but also of myeloid malignancies. The excess risk of myelodysplastic syndromes and/or acute myeloid leukemia is observed across several AD types, including systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disorders, multiple sclerosis, among others. The risk of developing myeloid neoplasms (MNs) is dependent on several variables, including the specific AD type, chronicity and severity of the AD, type and duration of exposure of disease modifying anti-rheumatic drugs or cytotoxics/immunosuppressives, and genetic predisposition risk. Putative triggering factors linking AD to elevated MN risk include AD-directed medications, shared genetic susceptibilities between the two disease entities, and chronic immune stimulation or bone marrow infiltration by the AD. Molecular mechanisms underpinning leukemogenesis remain largely speculative and warrant further investigation. Leukemias arising in patients with AD are not always 'therapy-related' in that MNs may develop in certain AD subtypes even among patients with no prior therapy exposure. Only a few studies have attempted to determine factors associated with MN development in AD but failed to demonstrate consistent characteristic clinical or paraclinical features. These reports have failed to demonstrate a clear correlation between individual agent exposure and subsequent leukemia development due to the low rates of therapy exposure compounded by the rarity of MN occurrence. Notwithstanding, the leukemogenic potential is best documented with agents such as azathioprine, cyclophosphamide, and mitoxantrone; this risk of MN development does not appear to be shared by biologic approaches such as anti-tumor necrosis factors-alpha inhibitors. In this article, we discuss plausible biologic mechanisms underlying MN pathogenesis in AD and review the data available on the development of MNs in patients with AD.

Risk of subsequent myeloid neoplasms after radiotherapy treatment for a solid cancer among adults in the United States, 2000-2014

Although increased risk of acute myeloid leukemia (AML) has been observed after chemotherapy and radiotherapy, less is known about radiotherapy-related risks of specific AML subtypes and other specific myeloid neoplasms. We used the US population-based cancer registry data to evaluate risk of myeloid neoplasms among three cohorts of cancer survivors initially treated with radiotherapy only. We included 1-year survivors of first primary thyroid (radioiodine only, stages I-IV; N = 49 879), prostate (excluding stage IV; N = 237 439), or uterine corpus cancers (stage I-II; N = 16 208) diagnosed during 2000-2013. We calculated standardized incidence ratios (SIRs) and excess absolute risks (EARs). Thyroid cancer survivors had significantly elevated risks of total AML (SIR = 2.77, 95% CI: 1.99-3.76), AML with cytogenetic abnormalities (SIR = 3.90, 95% CI: 1.57-8.04), AML with myelodysplasia-related changes (SIR = 2.87, 95% CI: 1.05-6.25), and BCR-ABL1-positive chronic myelogenous leukemia (CML) (SIR = 5.38, 95% CI: 2.58-9.89). Irradiated prostate and uterine corpus cancer survivors were at elevated risk for total AML (SIR = 1.14, 95% CI: 1.03-1.27 and SIR = 1.77, 95% CI: 1.01-2.87, respectively), AML with cytogenetic abnormalities (SIR = 2.52, 95% CI: 1.84-3.37 and SIR = 7.21, 95% CI: 2.34-16.83, respectively), and acute promyelocytic leukemia (SIR = 3.20, 95% CI: 2.20-4.49 and SIR = 8.88, 95% CI: 2.42-22.73, respectively). In addition, prostate cancer survivors were at increased risk of BCR-ABL1-positive CML (SIR = 2.11, 95% CI: 1.52-2.85). Our findings support the importance of diagnostic precision in myeloid neoplasm classification since susceptibility following radiotherapy may vary by myeloid neoplasm subtype, thereby informing risk/benefit discussions in first primary cancer treatment.

Risk of myeloid neoplasms after radiotherapy among older women with localized breast cancer: A population-based study

Background

There are inconsistent and limited data regarding the risk of myeloid neoplasms (MN) among breast cancer survivors who received radiotherapy (RT) in the absence of chemotherapy. Concern about subsequent MN might influence the decision to use adjuvant RT for women with localized disease. As patients with therapy-related MN have generally poor outcomes, the presumption of subsequent MN being therapy-related could affect treatment recommendations.

Methods

We used the Surveillance, Epidemiology, and End Results (SEER)–Medicare linked database to study older women with in-situ or stage 1–3 breast cancer diagnosed 2001–2009 who received surgery. Chemotherapy and RT were ascertained using Medicare claims, and new MN diagnoses were captured using both SEER registry and Medicare claims. We excluded women who received chemotherapy for initial treatment, and censored at receipt of subsequent chemotherapy. Competing-risk survival analysis was used to assess the association between RT and risk of subsequent MN adjusting for relevant characteristics.

Results

Median follow-up for 60,426 eligible patients was 68 months (interquartile range, 46 to 92 months), with 47.6% receiving RT. In total, 316 patients (0.52%) were diagnosed with MN; the cumulative incidence per 10,000 person-years was 10.6 vs 9.0 among RT-treated vs non-RT-treated women, respectively (p = .004); the increased risk of subsequent MN persisted in the adjusted analysis (hazard ratio = 1.36, 95% confidence interval: 1.03–1.80). The results were consistent in multiple sensitivity analyses.

Conclusions

Our data suggest that RT is associated with a significant risk of subsequent MN among older breast cancer survivors, though the absolute risk increase is very small. These findings suggest the benefits of RT outweigh the risks of development of subsequent MN.

Hypomethylating agent therapy use and survival in older patients with chronic myelomonocytic leukemia in the United States: A large population-based study

BACKGROUND

Despite the approval of azacitidine in 2004 and the approval of decitabine in 2006 in the United States for chronic myelomonocytic leukemia (CMML), the overall survival (OS) benefit with hypomethylating agent (HMA) therapy is unclear.

METHODS

Older adults (age ≥ 66 years) who had been diagnosed with CMML from 2001 to 2011 were selected from the Surveillance, Epidemiology, and End Results-Medicare database, and propensity score matching was used to match patients who had been diagnosed after HMA approval (2007-2011) and had received HMA treatment with patients diagnosed before HMA approval (2001-2003). Cox proportional hazards models with the matched sample were used to assess the change in OS. A second matched cohort of patients who did not receive HMA after approval and patients diagnosed before HMA approval was used to evaluate survival change attributable to other potential differences between the 2 time periods, such as improved supportive care.

RESULTS

Among 1378 older adults diagnosed with CMML, the median OS was 13 months, and 18.8% received HMAs. In the primary matched analysis, with 225 HMA users diagnosed in 2007-2011 and 395 patients diagnosed in 2001-2003, the median OS times were 17 and 11 months, respectively (hazard ratio, 0.72; 95% confidence interval [CI], 0.58-0.91; P = .005). In a secondary analysis, the risk of death did not differ between 395 propensity score-matched HMA nonusers diagnosed in 2007-2011 and 484 patients diagnosed in 2001-2003 (hazard ratio, 1.09; 95% CI, 0.91-1.32; P = .34).

CONCLUSIONS

Despite limited evidence, HMAs are commonly used to treat older CMML patients. The use of HMAs was associated with a 28% reduction in the risk of death in adjusted analyses. Improvements in supportive care do not appear to account for temporal improvements in OS. Cancer 2017;123:3754-3762. © 2017 American Cancer Society.

Comparison of clinical outcomes and prognostic utility of risk stratification tools in patients with therapy-related vs de novo myelodysplastic syndromes: a report on behalf of the MDS Clinical Research Consortium

While therapy-related (t)-myelodysplastic syndromes (MDS) have worse outcomes than de novo MDS (d-MDS), some t-MDS patients have an indolent course. Most MDS prognostic models excluded t-MDS patients during development. The performances of the International Prognostic Scoring System (IPSS), revised IPSS (IPSS-R), MD Anderson Global Prognostic System (MPSS), WHO Prognostic Scoring System (WPSS) and t-MDS Prognostic System (TPSS) were compared among patients with t-MDS. Akaike information criteria (AIC) assessed the relative goodness of fit of the models. We identified 370 t-MDS patients (19%) among 1950 MDS patients. Prior therapy included chemotherapy alone (48%), chemoradiation (31%), and radiation alone in 21%. Median survival for t-MDS patients was significantly shorter than for d-MDS (19 vs 46 months, P<0.005). All models discriminated survival in t-MDS (P<0.005 for each model). Patients with t-MDS had a significantly higher hazard of death relative to d-MDS in every risk model, and had inferior survival compared to patients with d-MDS within all risk group categories. AIC Scores (lower is better) were 2316 (MPSS), 2343 (TPSS), 2343 (IPSS-R), 2361 (WPSS) and 2364 (IPSS). In conclusion, subsets of t-MDS patients with varying clinical outcomes can be identified using conventional risk stratification models. The MPSS, TPSS and IPSS-R provide the best predictive power.