Clinical presentation and outcomes in light chain amyloidosis patients with non-evaluable serum free light chains.

Hematologic response criteria in light chain (AL) amyloidosis require the difference in involved and uninvolved free light chains (dFLC) to be at least 5 mg/dl. We describe the clinical presentation and outcomes of newly diagnosed amyloidosis patients with dFLC <5 mg/dl (non-evaluable dFLC; 14%, n=165) compared with patients with dFLC ⩾5 mg/dl (evaluable dFLC; 86%, n=975). Patients with non-evaluable dFLC had less cardiac involvement (40% vs 80%, P<0.001), less liver involvement (11% vs 17%, P=0.04) and a trend toward less gastrointestinal involvement (18% vs 25%, P=0.08). However, significantly higher renal involvement (72% vs 56%, P=0.0002) was observed in the non-evaluable dFLC cohort. Differences in treatment patterns were observed, with 51% of treated patients undergoing upfront stem cell transplantation in the non-evaluable cohort compared with 28% in the evaluable dFLC group (P<0.001). Progression-free survival (61 vs 13 months, P<0.001) and overall survival (OS; 101 vs 29 months, P<0.001) were significantly longer in the non-evaluable dFLC cohort. Normalization of involved light chain levels and decrease in dFLC <1 mg/dl (baseline at least 2 mg/dl) were predictive of OS and associated with better dialysis-free survival and may be used for response assessment in patients with non-evaluable FLC levels.

Natural history of t(11;14) multiple myeloma.

Translocation (11;14) on interphase fluorescent in situ hybridization in plasma cells is regarded as a standard risk prognostic marker in multiple myeloma based on studies conducted before introduction of current therapies. We identified 365 patients with t(11;14), and 730 matched controls:132 patients with non-(11;14) translocations and 598 patients with no chromosomal translocation. The median progression-free survival for the three groups were 23.0 (95% confidence interval (CI), 20.8-27.6), 19.0 (95% CI, 15.8-22.7) and 28.3 (95% CI, 25.7-30.6) months, respectively (P<0.01). The median overall survival (OS) for t(11;14), non-(11;14) translocation and no-translocation groups were 74.4 (95% CI, 64.8-89.3), 49.8 (95% CI, 40.0-60.6) and 103.6 (95% CI, 85.2-112.3) months, respectively (P<0.01). Excluding those with 17p abnormality, the median OS in the three groups were 81.7 (95% CI, 67.0-90.7), 58.2 (95% CI, 47.0-76.4) and 108.3 (95% CI, 92.4-140.1) months, respectively (P<0.01). The above relationship held true in patients with age <65 years, international staging system (ISS) I/II stage or those who received novel agent-based induction. Advanced age (hazard ratio (HR): 1.98), 17p abnormality (HR: 2.2) and ISS III stage (HR: 1.59) at diagnosis predicted reduced OS in patients with t(11;14). These results suggest that outcomes of t(11;14) MM are inferior to other standard risk patients.

Clinical utility of the Revised International Staging System in unselected patients with newly diagnosed and relapsed multiple myeloma.

We analyzed the utility of Revised International staging system (RISS) in an unselected cohort of newly diagnosed multiple myeloma (NDMM; cohort 1), and relapsed/refractory multiple myeloma (RRMM; cohort 2) patients. Cohort 1 included 1900 patients seen within 90 days of diagnosis, from 2005 to 2015, while cohort 2 had 887 patients enrolled in 23 clinical trials at Mayo Clinic. The overall survival (OS) and progression-free survival (PFS) was calculated from the time since diagnosis or trial registration. The median estimated follow up was 5 and 2.3 years for Cohorts 1 and 2, respectively. Among 1067 patients evaluable in Cohort 1, the median OS and PFS was 10 and 2.8 years for RISS stage I, 6 and 2.7 years for RISS stage II and 2.6 and 1.3 years for RISS stage III (P<0.0001). Among 456 patients evaluable in Cohort 2, the median OS and PFS was 4.3 and 1.1 years for RISS stage I, 2 and 0.5 years for RISS stage II and 0.8 and 0.2 years for RISS stage III (P<0.0001). In conclusions, RISS gives a better differentiation of NDMM as well as RRMM patients into three survival subgroups and should be used to stratify patients in future clinical trials.