Outcomes after autologous hematopoietic cell transplantation in POEMS syndrome and comparison with multiple myeloma

Long-Term Outcomes of Autologous Stem Cell Transplantation in Patients with Newly Diagnosed POEMS Syndrome

POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) syndrome is a rare form of plasma cell dyscrasia often treated with high-dose chemotherapy and autologous stem cell transplantation (ASCT). ASCT has resulted in satisfactory and sustained therapeutic outcomes. However, a substantial number of patients eventually experience disease progression, requiring second-line treatment. Therefore, it would be of further benefit to identify patients who will acquire the best long-term survival after ASCT. The aim of this study was to fully reveal the outcomes of patients undergoing ASCT in a large series with long-term follow-up. Long-term outcomes of 239 patients with newly diagnosed POEMS syndrome undergoing ASCT at a single center were evaluated retrospectively. Rates of hematologic complete response (CRH) and vascular endothelial growth factor (VEGF) complete response (CRV) were 57.3% and 68.6%, respectively, with 90.5% of patients achieving an overall clinical response. At a median follow-up of 94 months, the 5-year overall survival (OS) rate was 92.8%, and the 5-year time to next-line treatment (TTNT) rate was 72.2% (median TTNT, 96 months). Patients achieving CRH (5-year TTNT rate, 82.5% versus 60.7%; P < .0001) or CRV (5-year TTNT rate 83.7% versus 54.2%; P < .0001) had better survival outcomes compared to non-CR group patients. Dual hematologic and VEGF complete responses carry further benefit for survival (median TTNT, 129 months versus 68 months; P < .0001). Seven cases of second primary malignancy were recorded, all of which were solid tumors. Front-line ASCT resulted in excellent long-term survival in patients with POEMS syndrome, with the best survival observed in those achieving dual hematologic and VEGF CRs.

A Multicenter Analysis of Clinical Features and Long-Term Outcomes of POEMS Syndrome in Korea

BACKGROUND

POEMS syndrome is a rare form of plasma cell dyscrasia characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal proteins, and skin changes. Owing to its low incidence, there are few reports regarding this syndrome. This multicenter study included 84 patients diagnosed with POEMS syndrome in South Korea.

METHODS

We retrospectively evaluated 84 patients diagnosed with POEMS syndrome at 8 hospitals in South Korea between January 2000 and October 2022. The clinical characteristics and treatment outcomes were analyzed.

RESULTS

The median patient age was 53 years (range, 26-77 years), and 63.1% of the patients were male. All patients had peripheral neuropathy, and 81 (96.4%) had monoclonal plasma cell proliferation. Plasma vascular endothelial growth factor levels were available for 32 patients with a median of 821 pg/mL (range, 26-12,900 pg/mL). Other common features included skin changes (54.2%), volume overload (71.4%), and organomegaly (72.6%). Of the 84 patients, 75 received initial treatment (local radiotherapy, 6 [8.0%]; chemotherapy, 17 [22.7%]; both chemotherapy and local radiotherapy, 9 [12.0%]), upfront autologous stem cell transplantation (ASCT), 43 (57.3%; with induction chemotherapy, n = 12, 16.0%; without induction chemotherapy, n = 31, 41.3%). The median follow-up duration was 40.7 months. The 5-year overall survival (OS) was 78%, and the 5-year progression-free survival (PFS) was 55%. Patients who underwent upfront ASCT and were diagnosed after 2014 had a longer OS and PFS.

CONCLUSION

The demographics of Korean patients with POEMS syndrome were similar to those reported previously. Because of the introduction of new treatment agents and the reduced rate of transplant-related mortality related to ASCT, the treatment outcomes of Korean patients with POEMS syndrome have improved in recent years.

Hematologic malignancies and hematopoietic stem cell transplantation

Paraneoplastic neurologic syndromes are rarely associated with hematologic malignancies. In their rarity, lymphomas are the diseases with more frequent paraneoplastic neurologic syndrome. High-risk antibodies are absent in most lymphoma-associated paraneoplastic neurologic syndromes, with the exception of antibodies to Tr/DNER in paraneoplastic cerebellar degeneration, mGluR5 in limbic encephalitis, and mGluR1 in some cerebellar ataxias. Peripheral nervous system paraneoplastic neurologic syndromes are rare and heterogeneous, with a prevalence of demyelinating polyradiculoneuropathy in non-Hodgkin lymphoma. Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, skin changes (POEMS) is a rare, paraneoplastic syndrome due to an underlying plasma cell disorder. The diagnosis is based on defined criteria, and vascular endothelial growth factor (VEGF), not an antibody, is considered a reliable diagnostic marker that also mirrors therapy response. As with the paraneoplastic neurologic syndromes in solid tumors, therapies rely on cancer treatment associated with immunomodulatory treatment with better response in PNS with antibodies to surface antigens. The best outcome is generally present in Ophelia syndrome/limbic encephalitis with anti-mGluR5 antibodies, with frequent complete recovery. Besides patients with isolated osteosclerotic lesions (where radiotherapy is indicated), hematopoietic stem-cell transplantation is the therapy of choice in patients with POEMS syndrome. In the paraneoplastic neurologic syndromes secondary to immune checkpoint inhibitors, discontinuation of the drug together with immunomodulatory treatment is recommended.

POEMS Syndrome-Clinical Picture and Management. Current Knowledge

POEMS syndrome is a rare form of plasma cell dyscrasia. Difficulties arise already at the stage of making the diagnosis (complex and heterogeneous clinical picture) and continue during the course of treatment (lack of guidelines for therapy, data coming mainly from reports and short series of patients). In this article we review the current state of knowledge on POEMS syndrome diagnostics, clinical characteristics, prognosis, reported treatment outcomes and the emergence of the new therapeutic strategies.

Evidence-based medical treatment of POEMS syndrome

POEMS syndrome is a rare multisystem paraneoplastic disorder due to an underlying low-level plasma cell dyscrasia. Due to its rarity, there are limited data to guide treatment and there are no consensus guidelines. Therapy choices are dictated by patient characteristics, disease factors and local funding arrangements. The goals of therapy are to eradicate the underlying clone in order to improve quality of life and overall survival. Most evidence has been garnered in the front-line setting. Localised disease responds well to radiotherapy, whilst for those with systemic disease, the best outcomes are demonstrated with induction chemotherapy followed up with high-dose melphalan and stem cell rescue if eligible. For transplant-ineligible patients lenalidomide-dexamethasone remains a preferred treatment option. Data in the relapse setting are scarce. Supportive care including management of neuropathy, endocrinopathy, thrombotic risk and anti-infective agents is necessary. Future international collaboration is crucial to define optimal treatment strategies particularly in the relapse setting.