Epidemiological and clinical characteristics and outcome of monoclonal gammopathy of renal significance-related lesions in Latin America.

BACKGROUND: Monoclonal gammopathy of renal significance (MGRS)-related lesions are infrequent entities. There are no publications on these disorders in Latin America (LA). The aim of this study was to describe epidemiological and clinical characteristics of these patients in LA. METHODS: We performed a multicentre retrospective study. Patients with diagnosis of MGRS between 2012 and 2018 were included. Epidemiological and clinical data were collected from clinical records. RESULTS: Twenty-seven patients from Chile, Argentina, Ecuador and Uruguay were included. Half debuted with a nephrotic syndrome, and 32% required dialysis. Proliferative glomerulonephritis with monoclonal immunoglobulin deposits was found in 33%, amyloidosis in 26% and monoclonal immunoglobulin deposition disease also in 26%. The immunoglobulin most frequently found in renal biopsies was IgG kappa. In 67% a paraprotein was found. Twenty patients received an anti-plasma cell regimen, and 3 a rituximab-based regimen (IgM-MGRS). Renal response (RR) was achieved in 56%. Early treatment (≤3 months) was associated with higher RR (75% vs 43%). Three patients relapsed within 21.5 months, and 3 progressed: 1 to multiple myeloma, 1 to systemic amyloidosis and another to systemic light-chain deposition disease. Two patients died, both due to infection during induction treatment. CONCLUSION: There was a higher than expected frequency of patients requiring dialysis. The most common MGRS-related lesion was PGNMD. Early treatment was associated with better response. As a rare disease, increasing awareness and promoting early diagnosis are necessary in LA to improve outcomes. SUMMARY AT A GLANCE A collection of 27 cases of MGRS from Latin America with information on epidemiology, clinical characteristics, treatment and outcome of patients diagnosed of MGRS-related renal lesions.

Primary plasma cell leukemia in Latin America: demographic, clinical, and prognostic characteristics. A study of GELAMM group.

Primary plasma cell leukemia (pPCL) is an infrequent and aggressive plasma cell disorder. The prognosis is still very poor, and the optimal treatment remains to be established. A retrospective, multicentric, international observational study was performed. Patients from 9 countries of Latin America (LATAM) with a diagnosis of pPCL between 2012 and 2020 were included. 72 patients were included. Treatment was based on thalidomide in 15%, proteasome inhibitors (PI)-based triplets in 38% and chemotherapy plus IMIDs and/or PI in 29%. The mortality rate at 3 months was 30%. The median overall survival (OS) was 18 months. In the multivariate analysis, frontline PI-based triplets, chemotherapy plus IMIDs and/or PI therapy, and maintenance were independent factors of better OS. In conclusion, the OS of pPCL is still poor in LATAM, with high early mortality. PI triplets, chemotherapy plus IMIDs, and/or PI and maintenance therapy were associated with improved survival.

Patients Age 40 Years and Younger With Multiple Myeloma Have the Same Prognosis as Older Patients: An Analysis of Real-World Patients' Evidence From Latin America.

PURPOSE: Multiple myeloma (MM) is a highly heterogeneous, incurable disease most frequently diagnosed in the elderly. Therefore, data on clinical characteristics and outcomes in the very young population are scarce. PATIENTS AND METHODS: We analyzed clinical characteristics, response to treatment, and survival in 103 patients with newly diagnosed MM age 40 years or younger compared with 256 patients age 41-50 years and 957 patients age 51 years or older. RESULTS: There were no statistical differences in sex, isotype, International Scoring System, renal involvement, hypercalcemia, anemia, dialysis, bony lesions, extramedullary disease, and lactate dehydrogenase (LDH). The most used regimen in young patients was cyclophosphamide, bortezomib, dexamethasone, followed by cyclophosphamide, thalidomide, dexamethasone and bortezomib, thalidomide, dexamethasone. Of the patients age 40 years or younger, only 53% received autologous stem-cell transplant (ASCT) and 71.1% received maintenance. There were no differences in overall survival (OS) in the three patient cohorts. In the multivariate analysis, only high LDH, high cytogenetic risk, and ASCT were statistically associated with survival. CONCLUSION: In conclusion, younger patients with MM in Latin America have similar clinical characteristics, responses, and OS compared with the elderly.

Treatment and Survival Outcomes of Waldenstrom Macroglobulinemia in Latin American Patients: A Multinational Retrospective Cohort Study.

PURPOSE: Waldenstrom Macroglobulinemia (WM) is a rare lymphoma with distinct clinical features, and data from Latin American patients are lacking. Therefore, we aim to investigate the clinical, therapy, and outcome patterns of WM in Latin America. METHODS: We retrospectively analyzed patients with WM diagnosed between 1991 and 2019 from 24 centers in seven Latin American countries. The study outcomes were overall survival (OS) and progression-free survival (PFS). RESULTS: We identified 159 cases (median age 67 years, male 62%). Most patients (95%) were symptomatic at diagnosis. The International Prognostic Scoring System for WM (IPSSWM) at diagnosis was available in 141 (89%) patients (high-risk 40%, intermediate-risk 37%, and low-risk 23%). Twenty-seven (17%) patients were tested for MYD88L265P, with 89% (n = 24 of 27) carrying the mutation. First-line and second-line therapies were administered to 142 (89%) and 53 (33%) patients, respectively. Chemoimmunotherapy was the most commonly used first-line (66%) and second-line (45%) approach; only 18 (11%) patients received ibrutinib. With a median follow-up of 69 months, the 5-year OS rate was 81%. In treated patients, the 5-year OS and PFS rates were 78% and 59%, respectively. High-risk IPSSWM at treatment initiation was an independent risk factor for OS (adjusted hazard ratio: 4.73, 95% CI, 1.67 to 13.41, P = .003) and PFS (adjusted hazard ratio: 2.43, 95% CI, 1.31 to 4.50, P = .005). CONCLUSION: In Latin America, the management of WM is heterogeneous, with limited access to molecular testing and novel agents. However, outcomes were similar to those reported internationally. We validated the IPSSWM score as a prognostic factor for OS and PFS. There is an unmet need to improve access to recommended diagnostic approaches and therapies in Latin America.

Different outcomes for transplant-eligible newly diagnosed multiple myeloma patients in Latin America according to the public versus private management: a GELAMM study.

The aim of this study was to describe clinical and survival characteristics of transplant-eligible multiple myeloma (MM) patients in Latin America (LA), with a special focus on differences between public and private healthcare facilities. We included 1293 patients diagnosed between 2010 and 2018. A great disparity in outcomes and survival between both groups was observed. Late diagnosis and low access to adequate frontline therapy and ASCT in public institutions probably explain these differences. Patients treated with novel drug induction protocols, followed by autologous stem cell transplantation (ASCT) and maintenance, have similar overall survival compared to that published internationally.