Comorbidities in multiple myeloma and implications on survival: A population-based study.

High proportion of patients with multiple myeloma suffer from comorbidities which may alter clinical management. Therefore, our aims were to evaluate the prevalence of comorbidities and their impact on survival. We included patients diagnosed with multiple myeloma 1990-2013 in Sweden and all diagnoses from each patient from 1985. A total of 13 656 patients with multiple myeloma were included in the study, thereof 7404 (54%) had comorbidity at diagnosis. The risk of death was increased for those with one comorbidity at diagnosis compared to those without any comorbidity (hazard ratio = 1.19; 95% confidence interval:1.14-1.25); this risk was higher for those with two (1.38; 1.30-1.47) and three or more comorbidities (1.72; 1.62-1.83). Furthermore, the risk of death was increased in patients with prior history of cancer, arrhythmia, heart failure, diabetes mellitus, cerebrovascular disease, chronic lung disease, psychological disease, peptic ulcer, neurological disease, peripheral vascular disease, chronic kidney disease, dementia, and inflammatory bowel disease. This large study shows that over 50% of multiple myeloma patients have a comorbidity at diagnosis and survival decreased with increasing numbers of comorbidities. This emphasizes the importance of comorbidities when evaluating patients and deciding on treatment strategies for individuals with multiple myeloma.

Outcome and characteristics of non-measurable myeloma: A cohort study with population-based data from the Swedish Myeloma Registry.

OBJECTIVE: We describe survival in patients with oligo- and non-secretory multiple myeloma (MM). We refer to the whole group as non-measurable MM and compare it with secretory MM. METHODS: Oligo-secretory MM was defined as M protein in serum <10 g/L and M protein in urine <200 measured as mg/day, mg/liter or mg/mmol creatinine. If patients had no M protein, they were defined as non-secretory. The groups were also subdivided by Free Light Chains (SFLC) level and ratio. RESULTS: Out of 4325 patients with symptomatic MM in the Swedish Myeloma Registry during 2008-2016 eligible for the study, 389 patients (9%) had non-measurable MM. Out of these, 253 patients (6%) had oligo-secretory and 136 (3%) had non-secretory MM. Median survival for secretory MM was 42.7 months, non-measurable MM 40.2 months, oligo-secretory MM 38.6 months, and non-secretory MM 44.6 months. Difference in overall observed survival was non-significant for all groups when compared with secretory MM. Within non-secretory MM, stem cell transplantation (SCT), 95% being auto-SCT, was significant for superior survival in multivariate analysis (HR 0.048. P = .0015). CONCLUSION: In this population-based study, we found no difference in survival between oligo- or non-secretory MM when compared with secretory MM. SCT appears to be important also for patients with non-secretory disease.

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.

Measurable Residual Disease Testing in Multiple Myeloma Routine Clinical Practice: A Modified Delphi Study.

We used a modified Delphi approach to establish areas of consensus and nonconsensus regarding the utility of determining measurable residual disease (MRD) to assess multiple myeloma (MM) treatment response, which may inform disease management and design of future clinical trials. This modified Delphi study incorporated 2 iterative rounds of surveys to evaluate the opinions of an expert panel of 61 practicing hematological oncologists from across 14 countries in Europe concerning the use of MRD testing in MM management. Survey 1 assessed experts' opinions on MRD testing in different clinical situations and associated challenges. Survey 2 focused on the lack of consensus areas identified in survey 1. Consensus to an individual question was defined a priori as 75% agreement or disagreement by the panel. From the 2 rounds of surveys, the experts reached consensus agreement that MRD testing should be performed in newly diagnosed or relapsed patients who achieved complete response (CR) or better after transplantation. In transplant-ineligible patients, experts recommended MRD testing in those who are ≤70 years old and in CR. If a patient was previously positive on positron-emission tomography and computed tomography (PET/CT), both MRD and PET/CT should be assessed at CR. MRD testing should be performed ≤6 months after transplantation and every 6-12 months in continuously treated patients in CR. There was no consensus on making treatment decisions based on MRD status. MRD testing is an important component of clinical management in MM. Additional data will further clarify the role of MRD in guiding treatment decisions.