What is the role of surgery in multiple myeloma?

Role of Surgery in Multiple Myeloma

Surgery plays a critical adjunctive role in multiple myeloma for specific skeletal complications—primarily pathological fractures, spinal instability, spinal cord compression, and intractable pain—but is not a primary treatment modality for the disease itself. 1, 2

Primary Indications for Surgical Intervention

Spinal Complications

• Surgery is indicated for spinal cord compression to prevent permanent neurological deficits, requiring rapid diagnosis and treatment. 1, 3

• Vertebral instability or unstable spinal fractures require surgical fixation to restore axial skeleton integrity. 2, 4

• Anterior laminectomy is useful when vertebral instability or bone particles are compressing the spinal cord. 1

• Approximately 8-10% of multiple myeloma patients develop neurological deficits requiring surgical consideration. 5

Long Bone Fractures

• Surgery is indicated for fixation of pathological fractures of long bones to restore function and mobility. 2, 4

• Impending fractures of long bones warrant prophylactic surgical stabilization. 1

• For limited bone involvement, filling the cavity with bone cement and stabilizing with plate or nail construct is recommended. 4

• For extensive involvement, en bloc resection with endoprosthetic replacement or graft-prosthetic composite reconstruction is necessary. 4

Minimally Invasive Procedures

Vertebroplasty and Kyphoplasty

• Balloon kyphoplasty is the treatment of choice for painful vertebral compression fractures, with approximately 80% of patients experiencing pain relief. 2, 6

• Kyphoplasty is associated with reduced rates of cement leakage compared to vertebroplasty. 2

• These procedures should be considered for vertebral compression fractures with persistent pain after 3 months of conservative treatment. 6

• Vertebroplasty and kyphoplasty can reduce local pain without interfering with subsequent systemic antimyeloma therapy programs. 3

Surgical Approach and Technique

Pre-operative Assessment

• Complete imaging workup including whole-body low-dose CT is standard for evaluating lytic lesions, with MRI of the affected area to assess bone marrow involvement and soft tissue extension. 4

• PET/CT may be useful for better definition of disease extent and metabolic activity. 4

• Laboratory tests including complete blood count, renal function, calcium levels, and myeloma markers are necessary. 4

Surgical Principles

• The surgical approach should aim for a final, load-stable solution that accounts for the frequent long-term course of the disease, rather than temporary measures. 5

• Internal fixation using plate or intramedullary nail with cement augmentation enhances fixation stability. 4

• Hybrid stabilization procedures combining bone cement and various implants are commonly employed for extremity lesions. 5

• Intra-lesional curettage should remove all visible abnormal tissue, with specimens collected for histopathological examination. 4

Clinical Context and Outcomes

Disease Prevalence in Surgical Populations

• Multiple myeloma is the most common etiology for emergency spine surgery in patients with no prior cancer diagnosis, accounting for 51% of urgent surgical cases for pathological vertebral fractures in one large series. 7

• Multiple myeloma is the most frequent spinal tumor, accounting for approximately 15% of all spinal malignancies. 5

• More than 50% of all multiple myeloma patients sustain pathological fractures during their disease course. 5

Survival and Prognosis

• Surgical treatment in multiple myeloma patients shows favorable survival (37% at five years), which is better than patients with metastatic bone disease and must be considered when planning surgical interventions. 8

• Patients with a single bone lesion, negative bone marrow biopsy, no paraproteinaemia, or Salmon-Durie stage I have better survival probability. 8

Integration with Systemic Therapy

Timing Considerations

• Systemic anti-myeloma therapy should be resumed as soon as wound healing permits following surgery. 4

• Radiotherapy is often recommended after surgery but may delay systemic anti-myeloma therapies that include radiosensitizing drugs. 2

• Bisphosphonate therapy should be continued post-operatively to reduce bone resorption. 4

Adjuvant Treatments

• Adjuvant radiation therapy should be considered based on surgical margins and disease characteristics. 4

• Radiotherapy is indicated for extremely painful lytic lesions and prevention of pathological fractures when surgery is not performed. 2

• A dose of 3000 cGy in 10-15 fractions is typically effective for painful osteolytic lesions. 2

Common Pitfalls to Avoid

• Never perform surgery without adequate pre-operative imaging and systemic disease assessment, as this can lead to inadequate treatment planning. 4

• Avoid treating multiple myeloma patients surgically as though they have simple bone metastases, as the oncological therapy and survival times differ significantly. 8

• Ensure reconstruction provides immediate stability to allow early mobilization, as delayed mobilization increases morbidity. 4

• Consider the patient's overall disease status and prognosis when planning the extent of surgery, as overly aggressive procedures may not be warranted in poor-prognosis patients. 4

Solitary Plasmacytoma Exception

• For solitary bone plasmacytoma, local radiotherapy (45-50 Gy to the involved field) is the treatment of choice, not surgery. 1

• Surgery is recommended for solitary bone plasmacytoma only when there is vertebral instability or for fixation of a long bone. 1

• For extramedullary plasmacytoma of the upper aerodigestive tract with good resection potential, surgery is appropriate. 1