The Latin-American Experience in POEMS Syndrome: A Study of the GELAMM (Grupo de Estudio Latinoamericano de Mieloma Múltiple).

Introduction: POEMS syndrome is a rare paraneoplastic syndrome caused by an underlying plasma cell disorder. The acronym refers to the following features: polyradiculoneuropathy, organomegaly, endocrinopathy, monoclonal paraproteinemia, and skin changes.

Methods: The study was conducted at 24 hematological centers across 8 Latin-American countries. The study included a total of 46 patients {median age was 52 years (interquartile range [IQR]: 42-61.5), 30 males and 16 females} fulfilling the POEMS syndrome criteria diagnosed over a period of 12 years (January 1, 2011, through July 31, 2023). Epidemiological and clinical data were collected in an ad hoc database sent to the members of GELAMM, as well as the Kolmogorov-Smirnov test and Kaplan-Meier estimates.

Results: All patients had polyneuropathy and monoclonal gammopathy; 89% had bone marrow plasma cell infiltration, 33% had sclerotic bone lesions. Only 10 patients underwent vascular endothelial growth factor (VEGF) testing in plasma samples. The paraproteinemia was IgG λ in 32% and IgA λ in 30%. 59% patients presented with cutaneous changes, mainly hyperpigmentation, 54% had organomegaly, and 74% endocrinopathy. The median interval from symptom onset to diagnosis was 7.7 months (IQR: 4.0-12.6). 69% of patients received a single line of treatment. The median follow-up period was 25 months (IQR: 9.37-52.0) and the 2-year overall survival rate was 100%. All patients who underwent transplantation (43%) are alive, with a median follow-up of 45.62 months (IQR: 15.46-70).

Conclusion: This study investigates POEMS syndrome in Latin America and presents an initial overview of the disease in the region. VEGF usage is recommended for accurate diagnosis, but only 7 hematology centers in the region used it. Survival rate in Latin America is comparable with those observed internationally.