MKSAP quiz: Follow-up for multiple myeloma
A 62-year-old man diagnosed with multiple myeloma 3 weeks ago is found to have multiple lytic lesions in the spine and pelvis on follow-up examination. His vertebral height was maintained. He is receiving bortezomib, lenalidomide, and dexamethasone for myeloma. After physical examination and laboratory studies, what is the most appropriate management?
A 62-year-old man arrives for follow-up consultation for multiple myeloma diagnosed 3 weeks ago. A skeletal survey showed multiple lytic lesions in the spine and pelvis, but the patient's vertebral height was maintained. MRI showed abnormalities in the vertebral bodies but no evidence of spinal cord compression. Myeloma therapy was begun with bortezomib, lenalidomide, and dexamethasone. Medical history is otherwise unremarkable. He takes no other medications.
On physical examination, vital signs are normal. The lower spine is nontender to palpation. The remainder of the physical examination is unremarkable.
Laboratory studies show a serum calcium level of 9.1 mg/dL (2.3 mmol/L) and a serum creatinine level of 0.8 mg/dL (70.7 µmol/L); a complete blood count and serum electrolyte levels are normal.
Which of the following is the most appropriate management of this patient's lytic bone lesions?
A. Dual-energy X-ray absorptiometry
B. Radiation therapy
C. Zoledronic acid
D. Current myeloma treatment
MKSAP Answer and Critique
The correct answer is C. Zoledronic acid. This content is available to MKSAP 18 subscribers as Question 68 in the Hematology and Oncology section. More information about MKSAP is available online.
All patients with multiple myeloma (MM) requiring therapy should be given intravenous bisphosphonates, such as zoledronic acid or pamidronate, in addition to antimyeloma therapy. Zoledronic acid and pamidronate have been shown to prevent new skeletal-related events in patients with MM, but only zoledronic acid has been shown to improve survival. Close monitoring of kidney function and calcium level should be performed in all patients taking zoledronic acid; monitoring for pain and swelling that may be early signs of osteonecrosis of the jaw is also essential. Calcium and vitamin D supplementation is usually given to patients taking intravenous bisphosphonates unless a contraindication exists. Patients with MM are given intravenous zoledronic acid every 3 to 4 weeks. Experts have not reached a consensus on duration of therapy, but indefinite bisphosphonate therapy is often used. It is reasonable to consider remission status, extent of skeletal disease, kidney function, and patient preference when determining the duration of bisphosphonate therapy. In patients who stop therapy, bisphosphonates should be restarted at disease relapse.
In patients with monoclonal gammopathy of undetermined significance and smoldering MM, dual-energy x-ray absorptiometry (DEXA) is performed to evaluate for osteoporosis or osteopenia in determining bisphosphonate therapy. This patient has MM requiring therapy with lytic lesions. Bone density scanning with DEXA is unnecessary to determine treatment.
With the advent of effective antimyeloma therapy, limited use of radiation is recommended to preserve the bone marrow. Radiation therapy is recommended to control pain or prevent impending pathologic fracture or spinal cord compression. In this patient with adequate pain control, no evidence of spinal cord compression, and no neurologic symptoms, radiation therapy is not appropriate.
Patients with MM requiring therapy are at high risk for recurrent skeletal-related events. Therefore, continuing with antimyeloma therapy alone without specifically addressing the bone disease is not adequate.
Key Point
- Zoledronic acid has been shown to prevent new skeletal-related events and improve survival in patients with multiple myeloma requiring therapy.