Musculoskeletal Oncology & Therapy

• This presentation discusses musculoskeletal oncology and therapy considerations, given by David Clever, MD, PhD on March 26, 2025.
• One should always seek a diagnosis when planning a patient’s treatment.

Terms & Conditions

• The information presented is for learning purposes.
• If confused, asking questions and sharing feedback should be encouraged.

Overview of Musculoskeletal Oncology

• Includes:
• Introduction
• History Gathering
• Physical Exam
• Workup & Treatment
• Imaging
• Histology
• Surgical Principles

Diagnosis of Musculoskeletal Issues

• Treatment approach relies on an accurate diagnosis.
• Benign conditions may not need surgery.
• Metastatic carcinoma, lymphoma/myeloma, sarcoma, necessitating wide resection, can be present.
• 1. 7 million new carcinoma cases occur annually in the US, with over half a million leading to metastatic carcinoma in bone.
• Approximately 1,600 to 2,000 bone sarcomas and about 14,000 soft tissue sarcomas are diagnosed each year.
• For patients over 40 with malignant bone tumors, consider metastatic carcinoma, myeloma, and lymphoma rather than sarcoma.
• Metastatic carcinoma is more likely to spread to bone compared to soft tissue.
• In adults with soft tissue masses, sarcoma is more probable than metastatic soft tissue carcinoma.
• Failure to diagnose carcinoma properly could result in inadequate treatment, with implications for staging, systemic therapy, and radiation.
• A missed sarcoma diagnosis may lead to limb loss, loss of life, and other adverse outcomes.

Diagnostic Process

• Clinical history factors: age, location, and symptom patterns.
• Imaging techniques include X-rays, CT scans, and MRIs.
• Biopsies can be percutaneous/needle or open.

Patterns

• Under 30 years: Ewing, Osteoid osteoma, NOF, SBC, Osteochondroma, ABC, Giant CT, Geode infection, Chondroblastoma
• Over 30 years: Metastasis, Myeloma, NOF, SBC, osteochondroma, Enchondroma, ABC, Chondrosarcoma, Giant CT, Geode infection

History and Exam

• Key questions for a physical exam:
• Is there pain?
• Is there a known cancer diagnosis? If so, when was diagnosed?
• Was the setting a clinic or hospital?
• Was there a fracture with preceding pain?
• Was the clinic finding incidental or related to specific symptoms?
• It's important to check for other injuries during the physical examination.

Imaging

• Assessments typically involve X-rays of the whole bone.
• CT or MRI may be used for tumors.
• Can use CT scans of the chest, abdomen, and pelvis.
• Unknown Primary cases:
• Primary organ carcinomas
• Visceral Mets
• Bone mets: Spine, ribs, pelvis, hips
• With a Known Primary can:
• Re-stage
• Rule out second primary tumor

Staging Imaging

• Nuclear Medicine Bone Scan (T-99)
• Asymptomatic mets (wider field of view than CT C/A/P)
• Skeletal Survey
• X-ray vs. CT
• For Multiple Myeloma
• PET/CT – whole body staging (difficult for inpatient)
• Whole body vs. eyes-to-thighs
• Also evaluates for visceral and nodal mets

Imaging Features

• Key factors include Location, matrix formation, border, and periosteal reaction.

Benign Bone Tumors

• Benign bone tumors range in pathology, with some being indolent and others bordering on malignancy.

Indolent (Observation)

• Indolent lesions include osteoma (bone island), osteochondroma/enchondroma, and fibroosseous lesions such as NOF (non-ossifying fibroma) or fibrous dysplasia.

Benign Bone Tumor - Excision/Curettage

• These may include osteochondroma/ enchondroma, osteoid osteoma, bone cysts (solitary, ABC), and fibroosseous lesions.

Benign Aggressive

• Chondroblastoma/ CMF, osteoblastoma, and giant cell tumors.

Malignant Bone Tumors

• Osteosarcoma, Ewing’s Sarcoma, Chondrosarcoma, and Metastatic Disease.

Operative Treatment Goals - Primary Sarcoma

• Primary objective: cure and remove the tumor via wide resection.

Operative Treatment Goals - Metastases

• The goal is to relieve pain, restore function, and stabilize the skeleton through intralesional surgery.

Overview of Common Locations

• Most common locations: Axial is greater than appendicular
• Includes: Spine, Pelvis & Sacrum, Ribs, Sternum & Clavicle, Femur, Humerus, and Tibia

Operative Treatment Goals

• Estimation of survival
• Expected response to other treatment
  • Local: Radiotherapy
  • Systemic: Chemotherapy, Hormone therapy, or Immune therapy
• Principles of poly-trauma: mobilize

Estimation of Survival

• Extent of disease
• Tumor type
  • breast, myeloma: >2-3 years
  • prostate, renal: 1-2 years
  • lung: 6 months
• Surgery may be warranted with only 2-3 month survival

Metastatic Disease

• Tumors metastatic to bone (USA Cancer Statistics):
• Breast
• Prostate
• Lung
• Renal
• Thyroid

Goals of Surgery

• Treat or prevent fracture, pain relief, and improving quality of life.
• Minimize disruption to systemic therapy/chemo
• Should conduct immediate fixation and local control and construct should tolerate post-op radiation.
• Metal and cement can be used for immediate fixation.
• It is important to describe the lesion, treatment plan, and whether to stabilize or replace, which according to type and extent.

Local Control Fail

• Wide excision and limb salvage or amputation is determined
• Surgery is almost always part of treatment for Primary Malignant Bone Tumors

Surgical Alternatives

• Amputation
  • Better tumor control
  • Fewer complications
  • Functional deficit
• Limb Salvage
  • Increased potential for local recurrence
  • Extensive surgery with more complications
  • Better functional result

Limb Salvage vs. Amputation

• A viable alternative is comparable tumor control and functional results superior to amputation and prosthetic fitting.

History cont.

• Limb salvage needs systemic disease evaluation and staging with CBC, chemistry profile, UA, CXR, chest CT, and bone scan.

Most Common Symptoms

• Pain is constant, present at night and worsening as compared to painless soft tissue sarcoma.
• Mass is enlarging and tender.
• May have "traumatic" onset
• Tipping point is analogous to "new" arthritis diagnosis

Limb Salvage Techniques

• Arthrodesis, arthroplasty, and segmental reconstruction

Soft Tissue Sarcoma Facts

• Any new soft tissue mass in an adult
• Growing
• Painful (often aren’t)

Therapy Considerations

• Resection:
  • What tissue is resected? Bone, Muscle, Capsule
  • What tissue is reconstructed? Not all things need reconstruction

Soft Tissue Sarcoma

• What needs worked up??
• Any new soft tissue mass in an adult
• Growing
• Painful (often they aren’t)

Therapy Considerations

• Post Operative Motion and Weight Bearing depends on Timing
• What are we waiting for?
  • Muscle Healing
  • Capsule Healing
  • Bone Healing
    • Allograft Bone, Autograft Bone, Vascularized Bone
  • Metal – cemented or ingrowth surface
  • Upper or lower extremity
• How do we monitor healing

Soft Tissue Sarcoma Treatment

• Surgery, Radiation, and Chemo/Immunotherapies are more experimental

Osseointegration Technique

• Direct bony ingrowth or ongrowth to metallic implant which protrudes through skin
  • Allowing for direct connection of implant to prosthesis
• Variety of implant styles
• Applied to variety of amputation sites
• Prosthesis can be traditional or myoelectric

Why Osseointegration

• Problems with Socket Prostheses
  • Not for short residual limbs
  • Skin breakdown
  • Difficulty donning/doffing
  • Limited range of motion
  • Rotational control
  • Weight gain/loss
• Socket replacement

Osseointegration History

• In the 1990s Rickard Branemark expanded father’s work aiming to aid amputees
• OPRA (Osseointegrated Prosthesis for the Rehabilitation of Amputees) (TM) Implant System – FDA Approved

OPRATM Osseointegrated Prosthesis

• Modular Design
  • Fixture: Anchoring element inside bone
  • Abutment: Skin penetrating connection
  • Axor II TM: Connection between abutment and prosthesis
  • Prosthesis

Osseointegration History

• Titanium integration to bone was discovered 1962 in Switzerland while studying microcirculation in bone of animal models: Early human applications

Osseointegration Case Example

• 26 y Male with Synovial Sarcoma; College student had Limb Salvage, Local Recurrence Sciatic Neuroma and Skin blistering despite prosthetic modification; not wearing prosthesis and harder to get to class.
• 2 - Contouring and Abutment: Shape and thin muscle, Purse-string suture to femur, Prepare skin flap, Transcutaneous opening for abutment, Placement abutment, Bolster dressing, and Waiting for skin healing before loading prosthesis.