Impact of Initial FDG-PET/CT and Serum-Free Light Chain on Transformation of Conventionally Defined Solitary Plasmacytoma to Multiple Myeloma

• Published in: Clinical cancer research Vol. 20; no. 12; pp. 3254 - 3260
• Main Authors: FOUQUET, Guillemette, GUIDEZ, Stéphanie, BERTHON, Céline, TERRIOU, Louis, COITEUX, Valérie, MACRO, Margaret, DECAUX, Olivier, FACON, Thierry, HUGLO, Damien, LELEU, Xavier, HERBAUX, Charles, VAN DE WYNGAERT, Zoé, BONNET, Sarah, BEAUVAIS, David, DEMARQUETTE, Hélène, ADIB, Salim, HIVERT, Bénédicte, WEMEAU, Mathieu
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Association for Cancer Research 15.06.2014
• Subjects: Aged; Antineoplastic agents; Biological and medical sciences; Biomarkers, Tumor - analysis; Bone Neoplasms - metabolism; Bone Neoplasms - mortality; Bone Neoplasms - pathology; Cell Transformation, Neoplastic - metabolism; Cell Transformation, Neoplastic - pathology; Female; Fluorodeoxyglucose F18; Follow-Up Studies; Genetics; Hematologic and hematopoietic diseases; Humans; Immunodeficiencies. Immunoglobulinopathies; Immunoglobulin Light Chains - metabolism; Immunoglobulinopathies; Immunopathology; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Life Sciences; Male; Medical sciences; Middle Aged; Multiple Myeloma - metabolism; Multiple Myeloma - mortality; Multiple Myeloma - pathology; Neoplasm Staging; Pharmacology. Drug treatments; Plasmacytoma - metabolism; Plasmacytoma - mortality; Plasmacytoma - pathology; Positron-Emission Tomography - methods; Prognosis; Radiopharmaceuticals; Retrospective Studies; Survival Rate; Tomography, X-Ray Computed - methods; Radionuclide study; Immunopathology; Biological fluid; 2-deoxy-2-fluoroglucose; Radiodiagnosis; Solitary plasmacytoma; Malignant hemopathy; Light peptide chain; Myeloma; Immunoglobulinopathy; Lymphoproliferative syndrome; Medical imagery; Serum; Computerized axial tomography; Positron emission tomography; Cancer; Emission tomography
• ISSN: 1078-0432; 1557-3265
• DOI: 10.1158/1078-0432.ccr-13-2910

Solitary plasmacytoma (SP) is a localized proliferation of monoclonal plasma cells in either bone or soft tissue, without evidence of multiple myeloma (MM), and whose prognosis is marked by a high risk of transformation to MM. We studied the impact of FDG-PET/CT (2[18F]fluoro-2-deoxy-D-glucose positron emission tomography-computed tomography) on the risk of transformation of SP to overt MM among other markers in a series of 43 patients diagnosed with SP. Median age was 57.5 years; 48% of patients had an abnormal involved serum-free light chain (sFLC) value, and 64% had an abnormal sFLC ratio at diagnosis. Thirty-three percent had two or more hypermetabolic lesions on initial PET/CT, and 20% had two or more focal lesions on initial MRI. With a median follow-up of 50 months, 14 patients transformed to MM with a median time (TTMM) of 71 months. The risk factors that significantly shortened TTMM at diagnosis were two or more hypermetabolic lesions on PET/CT, abnormal sFLC ratio and involved sFLC, and to a lesser extent at completion of treatment, absence of normalized involved sFLC and PET/CT or MRI. In a multivariate analysis, abnormal initial involved sFLC [OR = 10; 95% confidence interval (CI), 1-87; P = 0.008] and PET/CT (OR = 5; 95% CI, 0-9; P = 0.032) independently shortened TTMM. An abnormal involved sFLC value and the presence of at least two hypermetabolic lesions on PET/CT at diagnosis of SP were the two predictors of early evolution to myeloma in our series. This data analysis will need confirmation in a larger study, and the study of these two risk factors may lead to a different management of patients with SP in the future. .