Outcomes and patterns of failure in solitary plasmacytoma: A multicenter Rare Cancer Network study of 258 patients

• DOI: 10.1016/j.ijrobp.2005.06.039
• Publication Date: 2005-10-18T11:21:02Z
• Authors: Mahmut Ozsahin; Richard W. Tsang; Philip Poortmans; Yazid Belkacémi; Michel Bolla; Fazilet Öner Dinçbas; Christine Landmann; Bernard Castelain; Jeroen Buijsen; Jürgen Curschmann; Sidney P. Kadish; Anna Kowalczyk; Yavuz Anacak; Josef Hammer; Tan D. Nguyen; Gabriela Studer; Rachel Cooper; Meriç Sengöz; Luciano Scandolaro; Abderrahim Zouhair
• Keywords: Male; 0301 basic medicine; Analysis of Variance; prognostic factors; solitary plasmacytoma; Bone Neoplasms; Radiotherapy Dosage; Middle Aged; Disease-Free Survival; 3. Good health; multiple myeloma; 03 medical and health sciences; Treatment Outcome; Disease Progression; Humans; Female; Multiple Myeloma; radiotherapy; Plasmacytoma; Retrospective Studies

To assess the outcomes and patterns of failure in solitary plasmacytoma (SP).The data from 258 patients with bone (n = 206) or extramedullary (n = 52) SP without evidence of multiple myeloma (MM) were collected. A histopathologic diagnosis was obtained for all patients. Most (n = 214) of the patients received radiotherapy (RT) alone; 34 received chemotherapy and RT, and 8 surgery alone. The median radiation dose was 40 Gy. The median follow-up was 56 months (range 7-245).The median time to MM development was 21 months (range 2-135), with a 5-year probability of 45%. The 5-year overall survival, disease-free survival, and local control rate was 74%, 50%, and 86%, respectively. On multivariate analyses, the favorable factors were younger age and tumor size <4 cm for survival; younger age, extramedullary localization, and RT for disease-free survival; and small tumor and RT for local control. Bone localization was the only predictor of MM development. No dose-response relationship was found for doses >30 Gy, even for larger tumors.Progression to MM remains the main problem. Patients with extramedullary SP had the best outcomes, especially when treated with moderate-dose RT. Chemotherapy and/or novel therapies should be investigated for bone or bulky extramedullary SP.