Helical tomotherapy and systemic targeted therapies in solitary plasmacytoma: Pilot study

Solitary bone plasmacytoma: Long-term clinical outcomes in a single center

BACKGROUND

A solitary plasmacytoma is classified into a solitary plasmacytoma of the bone (SBP) and a solitary extramedullary (soft tissue mass) plasmacytoma, based on the site of the lesion. Despite the high local control rate with radiotherapy, approximately half of patients' conditions progress to multiple myeloma (MM) within 3-5 years after diagnosis, with SBP having a worse prognosis.

PATIENTS AND METHODS

We retrospectively assessed the treatment and outcomes of patients with SBP in a hospital in China from 2008 to 2021. Twenty-four patients treated over 13 years with SBP were enrolled in this retrospective study.

RESULTS

The most common sites for SBP were the axial skeleton and femur. The M protein was detected in 11 patients (46 %), of which 8 (33 %) had light chains, 2 (8 %) had immunoglobulin G kappa and 1 (4 %) had immunoglobulin D kappa. Flow cytometry revealed that 5 patients (21 %) had minimal bone marrow involvement. The treatment included chemotherapy, surgery, and radiotherapy in 18 (75 %), 12 (50 %), and 9 (38 %) patients, respectively, of whom 13 (54 %) received combined treatment. Over a median follow-up period of 67.2 months, 9 patients (38 %) developed MM in a median time of 101.5 months. The 5- and 10-year progression-free survival rates were 67.3 % and 37.4 %, respectively. One patient died due to pneumonia without progression and the other died due to relapse.

CONCLUSION

This study confirmed the high rate of progression of SBP to MM, indicating a need for adjunct chemotherapy for the management of SBP.

The paradoxical pharmacological mechanisms of lenalidomide and bortezomib in the treatment of multiple myeloma

The combination of bortezomib (Velcade, PS-341) and lenalidomide (Revlimid) for the treatment of multiple myeloma was proved by USA Food and Drug Administration in 2006. Lenalidomide prevents the proliferation of multiple myeloma cells through binding to cereblon and promoting the ubiquitinational degradation of IKZF1 (Ikaros)/IKZF3 (Aiolos). However, the proteasome inhibitor bortezomib would inhibit the ubiquitinational degradation of IKZF1/IKZF3. How bortezomib could not block the antiproliferative effect of lenalidomide on multiple myeloma cells, which is the paradoxical pharmacological mechanisms in multiple myeloma. In this review, we summarized recent advances in molecular mechanisms underlying the combination of bortezomib and lenalidomide for the treatment multiple myeloma, discussed the paradoxical pharmacological mechanisms of lenalidomide and bortezomib in the treatment of multiple myeloma.

Solitary Plasmacytoma Treated by Lenalidomide-Dexamethasone in Combination with Radiation Therapy: Clinical Outcomes

PURPOSE

The study evaluates the results of the concurrent use of lenalidomide-dexamethasone with intensity modulated radiation therapy (IMRT) for solitary plasmacytoma in terms of toxicity and outcome.

METHODS AND MATERIALS

Forty-six patients were treated for histologically proven solitary plasmacytoma (SP) between June 2007 and June 2018 in our Department (Curie Institute, Paris, France). All patients received IMRT. The median total dose was 40 Gy (range, 40-46). Prescription of concurrent lenalidomide-dexamethasone with radiation therapy was left to the discretion of the referring hematologist-oncologist and started the first day of radiation therapy for 4 cycles.

RESULTS

Twenty-seven solitary plasmacytoma were treated with IMRT alone and 19 with lenalidomide-dexamethasone in association with IMRT. At 5 years, the local control, multiple myeloma-free survival (MMFS), and progression-free survival (PFS) rates were 96.3%, 85.4%, and 60%. MMFS and PFS were significantly higher in the IMRT plus lenalidomide-dexamethasone group compared with IMRT alone group (100% vs 77.1%, P = .02 and 81.7% vs 48.4%, P = .047, respectively). No major toxicity was found in either group.

CONCLUSIONS

Lenalidomide-dexamethasone in association with IMRT in the treatment of solitary plasmacytoma is safe and improves MMFS and PFS. Further prospective and comparative studies are needed to confirm these results.

Radiation Therapy for Solitary Plasmacytoma and Multiple Myeloma: Guidelines From the International Lymphoma Radiation Oncology Group

PURPOSE

To develop guidelines for the work-up and radiation therapy (RT) management of patients with plasma cell neoplasms.

METHODS AND MATERIALS

A literature review was conducted covering staging, work-up, and RT management of plasma cell neoplasms. Guidelines were developed through consensus by an international panel of radiation oncologists with expertise in these diseases, from the International Lymphoma Radiation Oncology Group. RT volume definitions are based on the International Commission on Radiation Units and Measurements.

RESULTS

Plasma cell neoplasms account for approximately one-fifth of mature B-cell neoplasms in the United States. The majority (∼95%) are diagnosed as multiple myeloma, in which there has been tremendous progress in systemic therapy approaches with novel drugs over the last 2 decades, resulting in improvements in disease control and survival. In contrast, a small proportion of patients with plasma cell neoplasms present with a localized plasmacytoma in the bone, or in extramedullary (extraosseous) soft tissues, and definitive RT is the standard treatment. RT provides long-term local control in the solitary bone plasmacytomas and is potentially curative in the extramedullary cases. This guideline reviews the diagnostic work-up, principles, and indications for RT, target volume definition, treatment planning, and follow-up procedures for solitary plasmacytoma. Specifically, detailed recommendations for RT volumes and dose/fractionation are provided, illustrated with specific case scenarios. The role of palliative RT in multiple myeloma is also discussed.

CONCLUSIONS

The International Lymphoma Radiation Oncology Group presents a standardized approach to the use and implementation of definitive RT in solitary plasmacytomas. The modern principles outlining the supportive role of palliative RT in multiple myeloma in an era of novel systemic therapies are also discussed.

Primary pancreatic plasmacytoma: a rare case report

BACKGROUND

Extramedullary plasmacytoma is a very rare tumor derived from plasma cells and found outside the bone marrow. Most have been identified in patients with the more aggressive anaplastic form of the disease. Only a few cases of primary pancreatic plasmacytoma have been reported.

CASE PRESENTATION

We present a case of a 56-year-old man in whom a pancreatic mass was found incidentally. The lesion was determined to be a pancreatic plasmacytoma after distal pancreatectomy. There are no indications of clinical, laboratory or imaging findings of multiple myeloma nor any association with plasmacytoma in any other places, so the diagnosis of primary pancreatic plasmacytoma was made.

CONCLUSION

Primary pancreatic plasmacytoma is rare and the diagnosis is difficult before surgery.