Thalidomide and POEMS syndrome: a cautious step forward

Update on the Diagnosis and Treatment of POEMS (Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal Gammopathy, and Skin Changes) Syndrome: A Review

Importance

POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) syndrome is a rare plasma cell disorder characterized by demyelinating peripheral neuropathy and clonal plasma cell proliferation. Clinical manifestations are believed to be associated with a surge of inflammatory and angiogenic mediators, including interleukins and vascular endothelial growth factor (VEGF), elicited by clonal and polyclonal plasma cells. The clinical manifestations of POEMS syndrome can be debilitating; therefore, early diagnosis is essential. This review discusses several aspects of POEMS syndrome and includes the most recently published findings, with a special emphasis on diagnosis and treatment strategies.

Observations

POEMS syndrome may be underdiagnosed because of its rarity, and it can be mistaken for chronic inflammatory demyelinating polyneuropathy; this misdiagnosis may lead to delayed therapy and progressive worsening of symptoms, especially neuropathy. Therefore, in addition to measurement of the VEGF level, patients with a monoclonal protein detected in blood and/or urine and neuropathy should be evaluated for POEMS syndrome with use of imaging to assess whether sclerotic bone lesions, effusions, and organomegaly are present. Clinical trials are scant, and treatment is largely based on small case series in which plasma cell-directed therapies, borrowed from the myeloma armamentarium, were used. High-dose melphalan and autologous hematopoietic cell transplantation may be offered to eligible patients. Lenalidomide and dexamethasone can be prescribed for patients who are ineligible for transplants. The main goals of therapy are to attain complete hematologic and VEGF responses and to reduce symptoms, although it may take up to 3 years for neurologic deficits to be ameliorated.

Conclusions and Relevance

POEMS syndrome should be considered in the differential diagnosis for patients who have peripheral neuropathy and paraproteinemia among other multisystem manifestations. The syndrome can be debilitating if not recognized early in its course; thus, appropriate diagnosis and treatment are important for optimal clinical outcomes.

Characteristics of 1946 Cases of POEMS Syndrome in Chinese Subjects: A Literature-Based Study

POEMS syndrome is a rare paraneoplastic disorder characterized secondary to a rare plasma cell dyscrasia. Here, we aimed to analyze the clinical characteristics of large sample cases of POEMS in Chinese subjects through making a review of the Chinese literature. Four databases were electronically searched from inception until October 2016. Case reports and case series were identified. Six hundred studies with 1946 participants were identified. The first case was reported in 1986, and the number of reported cases peaked in 2009 and 2010. The top seven provinces on the number of reported cases were in the south-east area of China. The top three departments on the number of published papers and reported cases were ordinally department of Neurology, Hematology, and Endocrinology. The ratio of male to female was about 2.23. The range of age onset was from 10 to 81 years with the mean age of 46.39 (SD, 12.10 years). The initial symptoms of POEMS with peripheral neuropathy, edema and effusions, endocrinopathy, skin changes, and organomegaly accounted for 60.44, 15.72, 9.87, 8.05, and 2.13%, respectively, and subsequently acquired above symptoms as the prevalence was 99.49, 81.91, 75.56, 77.08, and 83.09%, respectively. The present study would help to understand the clinical presentations of POEMS syndrome in the Chinese population.

A prospective phase II study of low dose lenalidomide plus dexamethasone in patients with newly diagnosed polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome

Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome is a rare plasma dyscrasia without standard treatment. This phase II prospective trial evaluates the safety and response of 12 cycles of low dose lenalidomide (10 mg) plus dexamethasone (Rdex) in patients with newly diagnosed POEMS syndrome. Forty-one patients (28 men) were enrolled and the median age at diagnosis was 49 years (range, 21-70 years). Twenty-one patients (46%) achieved complete hematologic response and the neurologic response rate was 95%. The median serum vascular endothelial growth factor (VEGF) declined from 5155 pg/mL (range, 534-14 328 pg/mL) to 832 pg/mL (95-6254 pg/mL) after therapy. The overall VEGF response rate was 83%, and the median time to response was 2 months, with a mean VEGF reduction of 43% at the first month. In terms of clinical response, Rdex substantially relieved extravascular volume overload, organomegaly, and pulmonary hypertension. No treatment-related deaths occurred and no patients suffered from lenalidomide-related grade 3 or above adverse events. After a median follow-up of 34 months, median overall survival (OS) and progression-free survival (PFS) were not reached, with an estimated 3-year OS and PFS of 90% and 75%, respectively. In conclusion, Rdex was active with high hematologic, VEGF and organ response rate and well tolerated for patients with newly diagnosed POEMS syndrome. This trial was registered at www.clinicaltrials.gov as #NCT01816620.

POEMS Syndrome: Therapeutic Options

Treatment of polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome should be directed at the underlying plasma cell clone with risk-adapted therapy based on the extent of the plasma cell disorder. Radiation therapy is effective for patients with a localized presentation, without bone marrow involvement, and 1 to 3 bone lesions. Patients with disseminated disease should receive, preferably, high-dose chemotherapy with peripheral blood transplantation. Low-dose melphalan and dexamethasone or new agents used in myeloma are also effective. The most promising agent is lenalidomide, which could be given before high-dose therapy or radiation to get rapid neurologic responses.