The Danish Myelodysplastic Syndromes Database: Patient Characteristics and Validity of Data Records

Survival outcomes and healthcare utilization between immigrant patients and Danish-born patients with hematological cancers: a Danish population-based study

Overall survival (OS) for patients with a hematological cancer may differ between immigrant and Danish-born patients due to disparities in socioeconomic status, health literacy, and language proficiency. This cohort study aimed to investigate survival and hospitalization according to immigrant status while controlling for confounders. Patients with newly diagnosed hematological cancer in 2000-2020 were identified in the Danish nationwide hematological registers and stratified into Danish-born, Western, and non-Western patients. Patients were followed from diagnosis until death, 31st December 2021, or emigration, whichever came first. Crude OS, standardized OS, and 5-years OS differences were computed using flexible parametric models and hazard ratios using Cox regression. Number of hospitalization days in the year before and after diagnosis, respectively, were calculated using Poisson regression. A total of 2,241 immigrants and 41,519 Danish-born patients with a hematological cancer were included. Standardized 5-years OS was similar between groups with 58% (95% confidence interval 57-58%) for Danish-born patients, 57% (55-60%) for Western, and 56% (53-58%) for non-Western immigrant patients. Subgroup analyses identified OS differences in selected subgroups. Non-Western immigrant patients had 1.3 (0.5-2.1) more hospitalization days in the year before diagnosis and an adjusted incidence rate ratio of hospitalization days of 1.14 (1.13-1.15) in the year after diagnosis compared with Danish-born patients. In conclusion, there were no overall differences in survival when comparing immigrant patients to Danish-born patients after controlling for relevant confounders. Healthcare utilization was slightly higher among non-Western immigrant patients before and after diagnosis, but differences were small on an individual patient level.

Risk of cancer in relatives of patients with myelodysplastic neoplasia and acute leukemias

BACKGROUND

The risk of cancer among relatives of patients with either myelodysplastic neoplasia (MDS), acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) has not been thoroughly examined.

METHODS

We linked the Danish Civil Registration System with the Danish Cancer Registry, the Danish National Acute Leukemia Registry, and the Danish Myelodysplastic Syndrome Database to estimate the relative risk of cancer among relatives of patients with MDS/AML/ALL. We used standardized incidence ratios (SIRs), i.e., the ratio of observed to expected number of cancers among the relatives as a measure of relative risk.

RESULTS

We identified 13010 first-degree (FDR) and 22051 second-degree (SDR) relatives of 8386 patients with MDS/ALL/AML. Disregarding basal cell carcinoma (BCC), the relative risk for cancer overall was increased in both FDR (SIR=1.3; 95% confidence interval (CI) 1.1-1.4) and SDR (SIR=1.5; 95% CI 1.2-1.8). SIRs among FDRs were statistically significantly increased for malignant melanoma, BCC and for the combined groups of cancers of the male genital organs, urinary tract, and MDS/AML/ALL. Among SDRs, SIRs were statistically significantly increased for malignant melanoma, BCC, and cancers in the digestive organs and peritoneum.

CONCLUSIONS

We observed an increased risk of cancer among FDR and SDR of patients with MDS/AML/ALL.

10-year nationwide trends in incidence, treatment patterns, and mortality of patients with myelodysplastic syndromes in Denmark

Further temporal data on incidence, treatment patterns, and prognosis for patients with myelodysplastic syndromes (MDS) are needed. This study examined 10-year trends in incidence, treatment patterns, and all-cause mortality in a population-based cohort of 2309 MDS patients using Danish nationwide registries (2010-2019). We computed annual incidence rates overall and according to sex and age-groups. We examined temporal changes in the cumulative incidence of MDS specific treatments initiated within one year from diagnosis and temporal changes in the absolute risk of death and five-year adjusted hazard ratios (aHRs) for death, adjusting for age, sex and comorbidity. The age-standardized incidence rate of MDS per 100,000 person-years increased slightly from 5.3 in 2010 to 6.4 in 2019. Between 2010-2012 to 2016-2017, the use of azacitidine increased overall (8% to 22%), in patients with intermediate risk MDS (12% to 34%), and in patients with high-risk MDS (22% to 50%), while it remained stable (around 5%) for patients with low-risk MDS. The five-year aHR for death in the most recent calendar period compared to the earliest calendar period remained unchanged in patients with low-risk MDS, aHR = 0.90 (95% CI, 0.72-1.12) and in patients with high-risk MDS, aHR = 1.19 (95% CI, 0.89-1.61), while survival improved over time among patients with intermediate risk MDS, aHR = 0.67 (95% CI, 0.48-0.92). In conclusion the incidence of MDS slightly increased during a 10-year period in Denmark. The use of azacitidine increased markedly but five-year overall survival remained unchanged.

Treatment patterns in older patients with myelodysplastic syndromes: A population-based analysis reflecting the real world

INTRODUCTION

Treatment for myelodysplastic syndromes (MDS) is complex, options are limited, and insight into consecutive treatments is lacking. We performed this study to assess the outcomes in a real-world cohort of patients with MDS.

MATERIALS AND METHODS

An observational population-based study was performed using the HemoBase registry. Treatment patterns and overall survival (OS) were analyzed with Kaplan-Meier analyses.

RESULTS

In 144 of 280 (51.4%) patients with MDS >50 years, first-line treatment was initiated. The median age was 75.1 years (range: 52.6-92.0); the majority were male (72.2%). Hypomethylating agents (HMA), intensive chemotherapy, lenalidomide, and erythropoiesis-stimulating agents (ESA) were given as first-line treatment to 31.1% (n = 45), 12.5% (n = 18), 2.8% (n = 4), and 53.5% (n = 77) of the population, respectively. The median treatment duration was 5.8 months (95% Confidence Interval [CI]: 1.1-10.4) for HMA, 1.7 months (95%CI: 0.9-2.6) for intensive chemotherapy, 10.8 months (95%CI: 4.7-17.0) for lenalidomide, and 14.8 months (95%CI: 11.4-18.1) for ESA. Consecutive treatments were given to 27.2% of patients. The main reasons for first-line treatment discontinuation were treatment failure (45.8%), toxicity (6.9%), or death (20.1%). Median OS after termination of the initial, second, and third treatment was 5.8 months (95%CI: 3.2-8.5), 9.3 months (95%CI: 0.0-19.6), and 1.0 months (95%CI: 0.0-5.1), respectively.

DISCUSSION

This study shows the treatment outcomes in a real-world population of older patients with MDS. Treatment duration and median OS after treatment discontinuation were relatively limited. There is still an urgent need for new treatment options, strategies to further optimize duration of existing treatments, and communication of realistic treatment goals and expectations, especially for older, higher-risk patients with MDS with a poor prognosis.

Socioeconomic position and clinical outcomes in patients with myelodysplastic syndromes: A population-based cohort study

Low socioeconomic position (SEP) may be associated with adverse outcomes in patients with myelodysplastic syndromes (MDS) inherent to for example, delayed diagnosis or reduced treatment intensity, but firm evidence is limited. In this study, we examined the association between SEP and clinical outcomes. We conducted a population-based cohort study (2010-2018) of 2233 Danish patients with MDS. SEP measures included individual-level information on education, cohabitation status and income retrieved from Statistics Denmark. Associations between SEP measures and disease severity at diagnosis were examined using binomial regression analysis. Using time-to-event analysis, we examined the association between SEP measures and treatment with allogeneic stem cell transplantation (allo-HSCT), risk of progression to acute myeloid leukemia (AML), and death. Estimates were adjusted for covariates selected based on direct acyclic graphs and reported with 95% confidence intervals. Patients with a short education were more likely to be transfusion-dependent at diagnosis (RR = 1.25, 95% CI: 1.04-1.45) and more likely to be diagnosed with higher risk MDS according to the International Prognostic Scoring System (RR = 1.29, 95% CI: 1.03-1.62), than patients with a long education. We found no clear association between SEP and risk of progression to AML. In adjusted models, the 1-year risk of dying was higher in patients with short versus long education (RR = 1.34, 95% CI: 1.08-1.65), in patients with low versus high income (RR = 1.42, 95% CI: 1.14-1.77), and among patients who lived alone compared to those who lived with a partner (RR = 1.15, 0.98-1.35). These associations persisted after 3 years and 5 years of follow-up. Notably, patients with a short education had a markedly lower rate of undergoing treatment with allo-HSCT compared to patients with a long education (HR = 0.51, 95% CI: 0.31-0.84). In conclusion, low SEP and especially short education, were poor prognostic factors for adverse clinical outcomes among patients with MDS.

Positive predictive values of hematological procedure codes in the Danish National Patient Registry - a population-based validation study

Background

The Danish National Patient Registry holds data on hematological procedure codes including date and type of treatment from all hematological departments in Denmark. The validity of the hematological procedure codes remains to be clarified before they are used in epidemiological research.

Patients and Methods

Using the Danish Myelodysplastic Syndromes Database, we identified 897 patients diagnosed with myelodysplastic syndromes or chronic myelomonocytic leukemia treated at five Danish Hospitals between 1 January 2012 and 30 April 2019. From the Danish National Patient Registry, we ascertained information about hematological procedure codes and date of procedure registered on each patient and generated random samples. Using medical record review as the reference standard, we validated procedure codes in the Danish National Patient Registry and calculated positive predictive values (PPVs) with 95% confidence intervals (CIs) for each procedure code.

Results

A total of 523 medical records (99% of the total sample) were available for review. PPVs for specific procedure codes ranged from 71% to 100%. The overall PPV was 91% (95% CI: 88%–92%), reflecting PPVs of 95% (95% CI: 92%–97%) for low‐dose‐chemotherapy, 90% (95% CI: 81%–96%) for high‐dose chemotherapy, 99% (95% CI: 93%–100%) for allogeneic stem cell transplantation, 75% (95% CI: 62%–85%) for immuno‐modulating agents, 80% (95% CI: 74%–85%) for growth factors, and 99% (95% CI: 99%–100%) for bone marrow examination. The accuracy of coding was consistent across geographic regions and year of registration/coding.

Conclusions

Hematological procedure codes reported to the Danish National Patient Registry had high PPVs and are suitable for epidemiological research.