Retrospective analysis of plasmacytoma in Kansai Myeloma Forum Registry

• Published in: International journal of hematology Vol. 112; no. 5; pp. 666 - 673
• Main Authors: Nakaya, Aya, Tanaka, Hirokazu, Yagi, Hideo, Ohta, Kensuke, Shibayama, Hirohiko, Kohara, Takae, Kanda, Junya, Shindo, Maki, Shimura, Yuji, Kosugi, Satoru, Kida, Toru, Kaneko, Hitomi, Imada, Kazunori, Karasuno, Takahiro, Matsuda, Mitsuhiro, Iida, Masato, Adachi, Yoko, Fuchida, Shin-ichi, Uoshima, Nobuhiko, Uchiyama, Hitoji, Takahashi, Ryoichi, Matsui, Toshimitsu, Wada, Katsuya, Kiyota, Miki, Shimazaki, Chihiro, Hino, Masayuki, Kuroda, Junya, Kanakura, Yuzuru, Takaori-Kondo, Akifumi, Nomura, Shosaku, Matsumura, Itaru
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 01.11.2020; Springer Nature B.V
• Subjects: Adult; Aged; Aged, 80 and over; Bone Neoplasms - epidemiology; Bone Neoplasms - mortality; Bone Neoplasms - pathology; Bone Neoplasms - therapy; Chemotherapy; Disease Progression; Female; Hematology; Humans; Immunoglobulin G; Japan - epidemiology; M protein; Male; Medical prognosis; Medicine; Medicine & Public Health; Middle Aged; Monoclonal gammopathy; Multiple myeloma; Multiple Myeloma - etiology; Myeloma; Myeloma Proteins; Oncology; Original Article; Plasmacytoma; Plasmacytoma - epidemiology; Plasmacytoma - mortality; Plasmacytoma - pathology; Plasmacytoma - therapy; Prognosis; Proteins; Radiation therapy; Registries; Retrospective Studies; Statistical analysis; Survival Rate; Japan; Solitary plasmacytoma; Progression to multiple myeloma; Solitary bone plasmacytoma; Extramedullary plasmacytoma
• ISSN: 0925-5710; 1865-3774; 1865-3774
• DOI: 10.1007/s12185-020-02961-3

We retrospectively analyzed 51 patients with solitary plasmacytoma diagnosed from October 2002 to September 2018 from a cohort of 3575 patients with plasma cell dyscrasias registered in the Kansai Myeloma Forum. Twenty-seven patients had solitary bone plasmacytoma (SBP) and 24 had extramedullary plasmacytoma (EMP), with prevalence of 0.8% and 0.7%, respectively. The most frequent M protein was IgG (40%) in SBP, whereas non-secretory proteins were most frequent (50%) in EMP. Five-year overall survival was 78.2% in SBP and 80.8% in EMP ( P  = 0.894). Among patients with SBP, 44% progressed to MM with a median time of 10.5 months (2.4–93.3 months), whereas 8% of EMP patients progressed to MM with a median time of 18.6 months (13.0–24.2 months). The most frequent treatment was radiotherapy (41%) or observation (41%) in SBP, and chemotherapy (54%) in EMP. No statistically significant difference was observed upon univariate analysis of prognostic factors including age, sex, performance status, and IgG M protein. Our results suggest that there are biological differences between SBP and EMP in real-world settings.