The choice of serum-free light chain analysis method could potentially have clinical consequences for myeloma patients.

Multiple myeloma (MM) is a disease, that at times poses diagnostic and monitoring challenges. Over the last decades laboratory methods have been expanded with serum free light chain (FLC) analysis. Alerted by two index cases with clinical impact due to failure of the FLC analysis to indicate a disease progression, we aimed to identify any clinical consequences due to known differences between FLC analysis methods. We applied two FLC analysis methods (Freelite Binding Site [FBS] and N-Latex Siemens [NLS]) on all patients with MM and monoclonal gammopathy of uncertain significance diagnosed/followed up at Södra Älvsborg Hematology Unit, from April to December 2022. From a total of 123 patients with malignant plasma cell disorder, we identified five cases (4.1%) where solely the FBS method, as opposed to NLS, urine and serum electrophoresis, could support diagnosis or detect progression. The consequences of this discrepancy included not only change of diagnosis or delayed therapy but also change of treatment. Our findings indicate that a stronger awareness of the potential weaknesses of different FLC methods is needed, which calls for a closer collaboration between clinical chemists and hematologists.

Improved survival in myeloma patients-a nationwide registry study of 4,647 patients ≥75 years treated in Denmark and Sweden.

The prevalence of multiple myeloma (MM) is increasing in Nordic countries and the rest of the western world. Patients aged ≥75 years at diagnosis constitute an increasing proportion of all MM patients, but are underrepresented in randomized clinical trials. There is an urgent need for studies of the characteristics, treatment and outcome in this cohort. We present data from two nationwide population-based registries of all MM patients diagnosed in Denmark from January 1, 2005 until February 18, 2020, and in Sweden from January 1, 2008 until December 31, 2019, including treatment data for patients diagnosed until 2018 (Denmark) and 2019 (Sweden). In total 4,647 patients were ≥75 years at diagnosis, compared to 7,378 younger patients. Patients ≥75 years, accounting for approximately 40% of all MM patients, are a distinct cohort with more advanced disease at diagnosis, reflected by higher International Staging System (ISS) stage, and a higher proportion have renal failure and anemia. We found a more gradual introduction of modern medications in the older cohort than in the younger, despite simultaneous changes in guidelines. Compared to the cohorts in randomized controlled trials that guide the treatment of non-transplant eligible patients, we found a higher proportion of patients ≥75 years and presenting with ISS III in the real-world populations. Nevertheless, response rates and survival are increasing, indicating that modern treatment regimens are effective and well tolerated also in elderly MM patients in real-world populations.

Regional differences in treatment and outcome for myeloma patients in Sweden: A population based Swedish myeloma register study.

BACKGROUND: We wanted to evaluate if health care for multiple myeloma (MM) patients is equal in different regions of Sweden. AIM: To study differences in survival for MM depending on health care region and early use of modern treatment. METHODS AND RESULTS: Data from the Swedish Myeloma Register from patients diagnosed between 2008 and 2017 was used. Cohorts were defined by the six healthcare regions (labeled A-F) in Sweden and modern initial treatment was defined as including certain drug combinations. To adjust for time to treatment bias, survival analyses were performed also for patients alive 6 months after diagnosis. In all treated MM patients (n = 5326), we observed a superior overall survival (OS) for region A compared to all other regions (p < .01 for all respectively). After adjusting for time to treatment there was also a superior survival in the region with highest use of modern initial treatment (region A) compared to the regions defined in the study as having intermediate and low use (p < .01 for both). In patients receiving autologous stem cell transplantation (ASCT) a superior survival was observed for region A compared to all regions besides region B. Similar results were seen when adjusting for a time to treatment bias. In patients not receiving ASCT, 75 years or older and adjusted for time to treatment bias, a difference was noted only between region A and E (log rank p = .04, HR 1.2, CI 1.00-1.44, p = .06). In multivariate analyses including age, international staging system stage and time period of diagnosis, differences in survival remained for patients receiving ASCT between region A versus C, D, E and F (p = .01, p < .01, p < .01, p = .03). CONCLUSION: We observed a superior survival in region A for patients receiving ASCT. Explanations may be higher usage of modern initial treatment or regional residual confounding. For patients not receiving ASCT, 75 years or older, differences in survival could be adjusted for.

Outcome data from >10 000 multiple myeloma patients in the Danish and Swedish national registries.

OBJECTIVE: We describe real-world evidence (RWE) from the nationwide Swedish and Danish registries that provide important information on incidence and outcome in multiple myeloma (MM). METHOD: First line treatment data on more than 10.000 MM patients from Denmark and Sweden between 2005-2018 are presented. Key results from research conducted within the Swedish and Danish myeloma registries are summarized, describing subgroups of patients with comorbidity, myeloma complications, and early relapse. RESULTS: We show that national guidelines, generated on results from randomized clinical trials (RCTs) are rapidly implemented and improve overall survival (OS). We find that both the incidence of MM and the median age at diagnosis is higher in national registries compared to results from referral centres, indicating a more complete coverage. This highlights the need of validation of prognostic scoring systems and indices in e.g., SMM and high-risk MM in a real- world-population. We show that these subgroups are unlikely to be captured in RCTs with narrow inclusion and exclusion criteria, that they have worse survival, and are in need of new treatment approaches. CONCLUSION: National registries that include all MM patients are an important source of knowledge on epidemiology, treatment and outcome with implications for the planning of MM care. Despite the introduction of new and better treatments, rapidly implemented in our countries, our registries uncover subgroups of patients that still have inferior outcome. Our RWE can help to identify important research questions to be studied in further clinical trials also in patients currently not included in RCTs.