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

Abstract

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, nonmeasurable 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. K E Y W O R D S amyloidosis, multiple myeloma, plasma cell neoplasms 1 | INTRODUC TI ON Multiple myeloma (MM) is defined as a plasma cell disorder with infiltration of clonal plasma cells in bone marrow and organ damage due to hypercalcemia, anemia, renal failure, or bone lesions. 1 The myeloma plasma cells usually produce a serum or urine paraprotein called M protein. The M protein is measured either as a whole antibody (heavy and light chains) or as the individual parts. 2 With

Case of non‐secretory multiple myeloma eventually diagnosed by 18F‐FDG PET/CT

“…Several studies have reported that the diagnostic sensitivity of serum FLC assay for NSMM is within the range of 68%-86%, suggesting that serum FLC assay is highly recommended for the diagnosis of "serum free light chain-only myeloma". 10,11 In conclusion, this case suggests that we should consider NSMM as one of the differential diagnoses for inflammatory disorders, including those presenting without CRAB symptoms. 18 F-FDG PET/CT can detect bone lesions with high sensitivity and specificity so that it can be a valuable tool for the diagnosis of NSMM.…”

“…This case was found to be “serum free light chain‐only myeloma” with an abnormal κ/λ ratio. Several studies have reported that the diagnostic sensitivity of serum FLC assay for NSMM is within the range of 68%–86%, suggesting that serum FLC assay is highly recommended for the diagnosis of “serum free light chain‐only myeloma” 10,11 …”

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

“…There are few data on the incidence in a real‐world population. In 2019, a study of 4325 patients with MM from the SMR found that 253 patients (6%) had oligo‐secretory and 136 (3%) had non‐secretory MM 29 . The median survival for secretory MM was 42.7 months, oligo‐secretory MM 38.6 months and non‐secretory MM 44.6 months (ns).…”

A case report: Nonsecretory multiple myeloma presenting with bone pain

“…It is often caused by bone pain, which can occur in a single or multiple parts of the body, most commonly in the vertebral body, skull, ribs, pelvis, and proximal long bone. [ 8 , 9 ] Multiple osteolytic lesions can be seen in the affected bones, causing pathological fractures, vertebral collapse, spinal cord compression, etc, [ 10 , 11 ] which are easily misdiagnosed as osteoporosis, fracture, cervical and lumbar diseases, and bone metastatic cancer. As a rare disease in clinical practice, the misdiagnosis rate of NSMM is as high as 80%, among which bone pain ranks first among all misdiagnosed symptoms.…”