Researchers conducting a retrospective study identified extramedullary (EM) lesions as a possible indicator of poor prognosis in patients with multiple myeloma (MM) treated in the first line with bortezomib. The study’s results were recently published in the journal Frontiers in Oncology.
MM with EM involvement (EMM) is characterized by tumor cells that have colonized tissue away from the primary tumor site. EM lesions are those related to tumor cells present in adjacent bone (EM-bone related; EMB) or they can be outside of bone as extraosseous lesions (EME).
This retrospective analysis included patients seen at the First Affiliated Hospital of the Medical School of Zhejian University in Hangzhou, China. Included patients had newly diagnosed symptomatic or active MM, and they were treated in the first-line setting with a bortezomib-based regimen. Treatment efficacy was assessed by multiple metrics and with respect to evidence of EM disease, according to results of multiple imaging approaches.
There were 357 patients included in the analysis, among whom 80 (22.4%) had evidence of EM lesions upon initial diagnosis. These included 70 patients who had EMB lesions and 10 who had EME lesions. Most patients (53 patients) with EMB lesions showed single-site involvement. Patients who had EMM showed higher rates of high serum hemoglobin (≥10 g/dL) and serum lactate dehydrogenase (>245 u/L) levels than did patients without EMM. Patients with EMM also frequently showed early-stage Revised International Staging System scores.
Patients with EMM had a significantly poorer progression-free survival (PFS; P =.014) and overall survival (OS; P =.032), compared to patients who did not have EMM. However, PFS and OS rates were similar for patients without EMM and patients who had evidence of only a single site of EMB. Multivariate analysis demonstrated that evidence of multiple EMB sites and/or presence of EME appeared to be independent factors for prognosis with both PFS and OS in these patients.
In an analysis of imaging methods, imaging by positron-emission tomography/computed tomography showed the highest rates of detection of EMM among imaging methods that were used (P =.015). However, for detection of EME there was not a significant difference between imaging methods.
The researchers noted possible limitations to this analysis of prognostic factors included a lack of pathological confirmation to determine the absence of EM lesions in some organs, the retrospective nature of the study, and a low proportion of patients (fewer than 20%) who received autologous stem cell transplantation. The researchers concluded a prospective clinical trial should be performed to thoroughly evaluate the EMM diagnosis and treatment.
He J, Yue X, He D, et al. Multiple extramedullary-bone related and/or extramedullary extraosseous are independent poor prognostic factors in patients with newly diagnosed multiple myeloma. Front Oncol. 2021;11:668099. doi:10.3389/fonc.2021.668099