International Journal of Radiation Oncology*Biology*Physics
Clinical investigationBoneOutcomes and patterns of failure in solitary plasmacytoma: A multicenter Rare Cancer Network study of 258 patients
Introduction
Solitary plasmacytoma (SP) is defined as a proliferation of monoclonal plasma cells without evidence of significant bone-marrow plasma-cell infiltration. It constitutes about 5% of cases of plasma-cell myeloma (1). Two separate entities have been categorized, dependent on the lesion originating in either bone or extramedullary soft tissue (2).
Given the lack of randomized trials in this rare, but radiosensitive, disease (3), recommendations for the choice of treatment have been mainly based on data from retrospective studies, which often had relatively small numbers of patients and a limited ability to make any robust conclusions (4, 5). Only one prospective study included 53 patients (6).
Several studies have shown that radiotherapy (RT) for SP is very effective in providing local control and cure. However, with respect to long-term outcomes, it is known that bone SP progresses more frequently to multiple myeloma (MM) than does soft-tissue SP (7, 8, 9).
No conclusive data have been published on the optimal radiation dose for SP. Many authors have reported a wide range of doses varying from 30 to 66 Gy (10, 11, 12). No evidence has shown whether a radiation dose >30 Gy improves the outcomes. However, most centers use ≥50 Gy to treat SP.
We report the results of a retrospective multicenter study of a large cohort of patients with SP from 19 European and North American centers, aiming to assess the treatment approaches; radiation dose–response effects; and different prognostic factors for survival, progression to MM, and patterns of local failure.
Section snippets
Methods and materials
Between 1977 and 2001, 258 adult patients consecutively treated for bone (n = 206) or extramedullary (n = 52) SP without evidence of MM were collected in a retrospective multicenter study of the Rare Cancer Network. All patients with a new diagnosis of SP and considered candidates for definitive management with curative intent were included in this study. A patient was considered to have SP if the following criteria were met: biopsy-proven solitary lesion, <10% plasma cells in the bone marrow
Local control
Local relapse was observed in 14% of the patients (n = 36), with a median time to local relapse of 20 months (range, 4–149). No regional lymph node relapse was observed. The 5- and 10-year probability of local control was 86% (95% CI, 81–91) and 78% (95% CI, 69–87), respectively. The 10-year local control rate according to radiation dose and other candidate factors is shown in Table 2, Table 3. Local control was better with small tumors (<4 cm) and in patients treated with RT; however, no
Discussion
Prognostic factors, including age, tumor size, and location of origin (extramedullary vs. bone), have been reported to influence the outcomes of SP patients in several series (2, 8, 10, 12, 19, 20, 21, 22).
Despite good local control with RT, patients with bone SP progress to MM more frequently than those with extramedullary SP (7, 10). Many questions remain unanswered about the prognostic factors influencing the outcomes and radiation dose–response relationship, probably because of the limited
References (34)
- et al.
Solitary plasmacytoma of bone and extramedullary plasmacytomatwo different entities?
Ann Oncol
(1995) - et al.
Solitary plasmacytoma of bone and asymptomatic multiple myeloma
Blood
(2000) - et al.
The role of radiation therapy in the treatment of solitary plasmacytomas
Radiother Oncol
(1990) - et al.
Clinical course of solitary plasmacytoma
Radiother Oncol
(1999) - et al.
Solitary plasmacytoma treated with radiotherapyImpact of tumor size on outcomes
Int J Radiat Oncol Biol Phys
(2001) - et al.
Solitary plasmacytoma of bone and soft tissue
Int J Radiat Oncol Biol Phys
(1996) - et al.
Common toxicity criteria: Version 2.0. An improved reference for grading the acute effects of cancer treatment: Impact on radiotherapy
Int J Radiat Oncol Biol Phys
(2000) - et al.
Toxicity criteria of the Radiation Therapy Oncology Group (RTOG) and the European Organization for Research and Treatment of Cancer (EORTC)
Int J Radiat Oncol Biol Phys
(1995) - et al.
Guidelines on the diagnosis and management of solitary plasmacytoma of bone and solitary extramedullary plasmacytoma
Clin Oncol
(2004) - et al.
Solitary bone plasmacytomaOutcomes and prognostic factors following radiotherapy
Int J Radiat Oncol Biol Phys
(1998)
Solitary plasmacytoma of bone and soft tissue
Int J Radiat Oncol Biol Phys
Solitary plasmacytoma of boneMayo Clinic experience
Int J Radiat Oncol Biol Phys
Prognostic value of angiogenesis in solitary bone plasmacytoma
Blood
Comparison of extramedullary plasmacytomas with solitary and multiple plasma cell tumors of bone
J Clin Oncol
Radiotherapy in the treatment of solitary plasmacytoma
Br J Radiol
Extramedullary plasmacytomas and solitary plasma cell tumours of bone
Eur J Haematol
Localised plasmacytomas in TaiwanComparison between extramedullary plasmacytoma and solitary plasmacytoma of bone
Br J Cancer
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