P-032: Clinical Characteristics and Outcome of 30 Patients with Poems Syndrome in Catalonia: Impact of Autologous Stem Cell Transplantation in First Line and at Relapse

Background POEMS syndrome is a rare paraneoplastic disease caused by an underlying plasma cell disorder. The aim of this study is to describe clinical and biological features as well as outcomes in a series of patients in a real-world clinical setting. Methods We retrospectively analyzed 30 patients with POEMS syndrome consecutively diagnosed and treated at 8 hospitals in Catalonia, Spain, between 1996 and 2021. Medical records were reviewed for clinical and lab features at diagnosis, first-line treatment, autologous stem-cell transplantation (ASCT) and outcomes including progression-free (PFS) and overall survival (OS). Diagnosis was stablished according to published diagnostic criteria (Dispenzieri A, Am J Hematol 2011). Median follow up of alive patients was 13 years. Results Median age of the series was 65 years (range, 42-86). The median serum M-spike was 5 g/L. The heavy chain isotype was IgG in 43% of patients and IgA in 40%, while the light chain isotype was lambda in 87%. Four patients had more than 10% bone marrow plasma cells. VEGF was available in 18 patients and 16 of them (88%) had increased levels (3 times greater than the superior limit). All patients presented peripheral neuropathy, and other clinical features included organomegaly (22 patients), extravascular volume overload (22), endocrinopathy (20), skin lesions (18), thrombocytosis (18) osteosclerotic lesions (17), polycythemia (7), papilledema (7), pulmonary hypertension (4), portal hypertension (4), and Castleman disease (7). The median time between onset of symptoms and diagnosis was 6.3 months. Treatment information was available in 29 patients. Four patients had an isolated bone lesion and received only local radiation therapy, with hematologic and clinical response in 2 of them and a 10-year OS of 87%. Twenty-three patients underwent an ASCT: 15 after chemotherapy (with or without additional radiation therapy) and 8 upfront. Median age at the time of ASCT was 54 years. Conditioning prior to ASCT consisted in melphalan 200 mg/m2 in 74% of cases and 140 mg/m2 in 26%. Among 20 evaluable patients for hematologic response, 10 achieved a complete response and 10 obtained a partial response (PR). Eleven (55%) of these hematologic responding patients also obtained a significant organ improvement in a median time of 7 months after ASCT (range, 4–11). Nine patients (41.7%) progressed at a median time of 5 years after transplant, 5 of them received a second ASCT and 3 achieved at least a PR. After the second ASCT, only one patient clinically progressed after 38 months. All the remaining patients remained in response at the last follow-up evaluation. Median PFS and OS of the series were 6 and 12 years, respectively. Conclusions In conclusion, in our experience ASCT proved to be highly effective for patients with POEMS syndrome. When progression is confirmed after the first transplant, a second ASCT may be performed with potential clinical benefit. POEMS syndrome is a rare paraneoplastic disease caused by an underlying plasma cell disorder. The aim of this study is to describe clinical and biological features as well as outcomes in a series of patients in a real-world clinical setting. We retrospectively analyzed 30 patients with POEMS syndrome consecutively diagnosed and treated at 8 hospitals in Catalonia, Spain, between 1996 and 2021. Medical records were reviewed for clinical and lab features at diagnosis, first-line treatment, autologous stem-cell transplantation (ASCT) and outcomes including progression-free (PFS) and overall survival (OS). Diagnosis was stablished according to published diagnostic criteria (Dispenzieri A, Am J Hematol 2011). Median follow up of alive patients was 13 years. Median age of the series was 65 years (range, 42-86). The median serum M-spike was 5 g/L. The heavy chain isotype was IgG in 43% of patients and IgA in 40%, while the light chain isotype was lambda in 87%. Four patients had more than 10% bone marrow plasma cells. VEGF was available in 18 patients and 16 of them (88%) had increased levels (3 times greater than the superior limit). All patients presented peripheral neuropathy, and other clinical features included organomegaly (22 patients), extravascular volume overload (22), endocrinopathy (20), skin lesions (18), thrombocytosis (18) osteosclerotic lesions (17), polycythemia (7), papilledema (7), pulmonary hypertension (4), portal hypertension (4), and Castleman disease (7). The median time between onset of symptoms and diagnosis was 6.3 months. Treatment information was available in 29 patients. Four patients had an isolated bone lesion and received only local radiation therapy, with hematologic and clinical response in 2 of them and a 10-year OS of 87%. Twenty-three patients underwent an ASCT: 15 after chemotherapy (with or without additional radiation therapy) and 8 upfront. Median age at the time of ASCT was 54 years. Conditioning prior to ASCT consisted in melphalan 200 mg/m2 in 74% of cases and 140 mg/m2 in 26%. Among 20 evaluable patients for hematologic response, 10 achieved a complete response and 10 obtained a partial response (PR). Eleven (55%) of these hematologic responding patients also obtained a significant organ improvement in a median time of 7 months after ASCT (range, 4–11). Nine patients (41.7%) progressed at a median time of 5 years after transplant, 5 of them received a second ASCT and 3 achieved at least a PR. After the second ASCT, only one patient clinically progressed after 38 months. All the remaining patients remained in response at the last follow-up evaluation. Median PFS and OS of the series were 6 and 12 years, respectively. In conclusion, in our experience ASCT proved to be highly effective for patients with POEMS syndrome. When progression is confirmed after the first transplant, a second ASCT may be performed with potential clinical benefit.