The Revised International Staging System (R-ISS) was recently introduced in order to improve risk stratification over that provided by the widely used standard International Staging System. In addition to the parameters of the standard system, the R-ISS incorporates the presence of chromosomal abnormalities detected by interphase fluorescence in situ hybridization [t(4;14), t(14;16) and del17p] and elevated serum lactate dehydrogenase. The R-ISS was formulated on the basis of a large dataset of selected patients who had participated in clinical trials and has not been validated in an independent cohort of unselected patients. Thus, we evaluated the R-ISS in 475 consecutive, unselected patients, treated in a single center. Our patients were older and more often had severe renal dysfunction than those in the original publication on the R-ISS. As regards distribution by group, 18% had R-ISS-1, 64.5% R-ISS-2 and 18% R-ISS-3. According to R-ISS group, the 5-year survival rate was 77%, 53% and 19% for R-ISS-1, -2 and -3, respectively (P<0.001). The R-ISS could identify three groups with distinct outcomes among patients treated with or without autologous stem cell transplantation, among those treated with either bortezomib-based or immunomodulatory drug-based primary therapy and in patients ≤65, 66–75 or >75 years. However, in patients with severe renal dysfunction the distinction between groups was less clear. In conclusion, our data in consecutive, unselected patients, with differences in the characteristics and treatment approaches compared to the original International Myeloma Working Group cohort, verified that R-ISS is a robust tool for risk stratification of newly diagnosed patients with symptomatic myeloma.

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Renal failure (RF) is a common and severe complication of symptomatic myeloma, associated with significant morbidity and mortality. Such patients are commonly excluded from clinical trials. Bortezomib/dexamethasone (VD)-based regimens are the backbone of the treatment of newly diagnosed MM patients who present with severe RF even those requiring dialysis. We analyzed the outcomes of 83 consecutive bortezomib-treated patients with severe RF (eGFR < 30 ml/min/1.73 m 2 ), of which 31 (37%) required dialysis. By IMWG renal response criteria, 54 (65%) patients achieved at least MRrenal, including CRrenal in 35% and PRrenal in 12%. Triplet combinations (i.e., VD plus a third agent) versus VD alone were associated with higher rates of renal responses (72 vs. 50%; P 5 0.06). Fifteen of the 31 (48%) patients became dialysis independent within a median of 217 days (range 11-724). Triplets were associated with a higher probability of dialysis discontinuation (57 vs. 35%). Serum free light chain (sFLC) level 11,550 mg/L was associated with lower rates of major renal response, longer time to major renal response, lower probability, and longer time to dialysis discontinuation. Rapid myeloma response (PR within the first month) was also associated with higher rates of renal response. Patients who became dialysis-independent had longer survival than those remaining on dialysis. In conclusion, VD-based triplets are associated with a significant probability of renal response and dialysis discontinuation, improving the survival of patients who became dialysis independent. Rapid disease response is important for renal recovery and sFLCs are predictive of the probability and of the time required for renal response.

Monoclonal immunoglobulin deposition disease (MIDD) is characterized by non-organized immunoglobulin-fragments along renal basement membranes with subsequent organ deterioration. Treatment is directed against the immunoglobulin-producing clone. We treated 18 MIDD patients with bortezomib-based regimens (12 received bortezomib-dexamethasone, 6 bortezomib-dexamethasone with cyclophosphamide). Eleven (61%) patients achieved a hematologic response, but only 6 (33.3%) reached to a complete (CR) or very good partial response (VGPR). Regarding renal outcomes 77.8 and 55.6% had ≥30 and ≥50% reduction of proteinuria, respectively, but 33.3% ended up in end-stage renal disease (ESRD). Among patients with CR or VGPR, median eGFR improvement was 7.7 ml/min/1.73 m and none progressed to ESRD, but no significant renal recovery was observed in patients achieving a partial response or less, with 50% progressing to dialysis. Pretreatment eGFR seems to influence renal prognosis. Bortezomib-based treatment is considered an effective approach in MIDD and reaching to a deep hematologic response (≥VGPR) conditionally controls further renal declining.