Long-term clinical outcomes in a cohort of patients with solitary plasmacytoma treated in the modern era

Abstract

Background The risk of recurrence of solitary plasmacytoma (SP)/progression to MM is well established, but patient, imaging and treatment factors influencing risk of progression require further evaluation. Methods This is a retrospective analysis of 66 SP patients (23 UK, 43 Brazil) diagnosed 1989–2016. Patient baseline characteristics were recorded. The incidence of progression to MM was calculated, including biochemical and imaging findings and the treatment modality received. Survival estimates were determined by Kaplan-Meier analyses. Results With a median follow-up of 53.6 months the 5 year overall survival (OS) was 90.7% (95%CI 79–96%). The median progression free survival (PFS) from diagnosis was 61 months. Cumulative incidence of progression to MM was 49.9% at 5 years (95% CI 35.6–62.6%) and was significantly higher with bone plasmacytoma (47.2%, 95%CI 31.9–61.1%), than an extramedullary location (8.3%, 95%CI 0.4–32.3%, Gray test p = 0.0095)). The majority of patients with solitary bony plasmacytoma (SBP) received radiotherapy (RT) (51/53, 96.2%) whereas most extramedullary cases were treated with surgical resection (7/13, 53.8%). A small proportion of SBP patients received additional upfront chemotherapy, with 5/6 in remission after a median follow-up (FU) of 10 years. The diagnostic yield of surveillance functional FU imaging without other indications of relapse/progression was low. The positive predictive value of functional FU imaging was high but with a low negative predictive value, especially in cases of suspected relapse/progression. Conclusion Our data suggests functional imaging should be used if clinical suspicion of relapse/progression, rather than a routine surveillance tool, and upfront adjuvant chemotherapy is worthy of prospective evaluation.

Clinical presentation and outcomes of solitary plasmacytoma in a tertiary hospital in the UK

“…Stringent diagnosis of SP might have also had a significant impact on SP survival as demonstrated in the findings of a recent publication by Sharpley et al of a cohort of SP patients treated in the UK and Brazil. 17 The 5-year OS of 97.5% was significantly higher than in our cohort and other previous studies but the median PFS of 61 months was comparable. The reason suggested by the authors include the increased use of sensitive radiological imaging such as whole-body computed tomography / fluorodeoxyglucose positron emission tomography to correctly identify SP thereby excluding high-risk multifocal plasmacytoma/myeloma cases from the cohort.…”

Solitary plasmacytoma of thoracic vertebra in a woman with Lynch syndrome: A case report

“…Randomized clinical trials are needed to reveal more evidence. Patients with SPB and LS should stay in continuous oncologic aftercare due to 49.9% incidence of progression to MM [7].…”

“…Radiological findings are vertebral body osteolysis with pathologic fracture and soft tissue masses with consecutive spinal cord compression [5]. Treatment of choice is symptom control with local radiation, surgical procedures, if necessary, and oncologic aftercare to prevent the turnover to multiple myeloma [7].…”

Confusion, cognitive impairment, and spinal cord compression caused by plasmacytoma: a case report

“…Because of its rarity and multitude of manifestations, plasmacytoma can sometimes be mistaken for other spinal lesions such as metastasis, gliomas, or other hematological malignancies [19][20][21]. First line treatment for plasmacytoma is radiotherapy, corticosteroids, chemotherapy, and/or immunotherapy rather than surgical resection [22]. Cases in the literature have been reported wherein misdiagnosed plasmacytomas have been surgically resected [10,21,23].…”