Long-term outcomes after autologous stem cell transplantation for patients with POEMS syndrome (osteosclerotic myeloma): a single-center experience

The POEMS syndrome (polyradiculoneuropathy, organomegaly, multiple endocrinopathies, monoclonal protein, skin changes) is a rare disease associated with a plasma cell dyscrasia. Patients with disseminated POEMS can be treated with high-dose therapy and autologous stem cell transplantation (ASCT). While clinical improvement is nearly universal in these patients, the long-term outcomes after transplantation are unclear. We therefore assessed the long-term clinical outcomes of 59 POEMS patients treated with ASCT at our institution. With a median follow-up of 45 months, 14 patients have progressed with a progression-free survival of 98% and 75% at 1 and 5 years, respectively. Factors associated with progression have included an IgG-λ monoclonal component (hazard ratio HR 7.5; 95% confidence interval CI, 2.3-28.3; P = .0008), fluorodeoxyglucose-avid lesions on baseline positron emission tomography (HR 6.4; 95% CI, 1.2-120; P = .03), lack of complete hematologic response (HR 5.4; 95% CI, 1.8-16.7; P = .003), and patients aged 50 years or younger at transplantation (HR 4.4; 95% CI, 1.3-20; P = .01). The most common progression events have been radiologic followed by rising VEGF. Symptomatic progression has been rare. Most patients could be salvaged with immunomodulatory drugs or radiation. The 5-year survival is 94%. Herein, we describe a system of monitoring response and progression among patients with POEMS after ASCT.