- Types of Metastatic Carcinoma:
- breast cancer
- renal cell ca
- prostatic cancer
- lung carcinoma
- thyroid cancer:
- may cause heavy bleeding if disturbed (consider need for embolization prior to biopsy or ORIF);
- iodine radioisotope scan can be useful for following metatasis;
- ref: Images in Clinical Medicine. Metastasis from Thyroid Carcinoma
- multiple myeloma
- Work Up:
- determine the diagnosis:
- the most important consideration in managing a patient w/ an apparent bone lesion is to determine whether the lesion
represents a metstatic lesion, a primary bone tumor (sarcoma), or infection;
- obviously, an elderly patient w/ advanced breast, lung, or prostate cancer which has spread to other organs does not
require further diagnostic work up of a new bone lesion;
- in contrast, a middle aged patient who has been "cured" of prior breast carcinoma, will require a methodical work up of a
new bone lesion;
- for instance, a new pathologic osseous lesion in a patient previously treated with radiation, could occur
from radiation induced sarcoma rather than a new metastatic lesion;
- ref: Evaluation of the patient with carcinoma of unknown origin metastatic to bone.
- history and physical exam:
- new onset pneumonia, wheezing, or worsening of asthma may indicate lung ca;
- hematuria or flank pain points to renal carcinoma;
- change in bowel function or occult blood in the stool suggests rectal ca;
- carcinoma of the breast, testicles, rectum, prostate, or thyroid may be suggested by the presence of a mass on PE;
- indicated if the primary origin of the tumor is in doubt;
- if metastatic carcinoma is suspected, then the work up concentrates on the etiology (ie breast, lung, prostate, as well as
other mets) rather than biopsy;
- Evaluation of the patient with carcinoma of unknown origin metastatic to bone.
- Presentation and staging of metastatic bone disease.
- hypercalcemia should be ruled out in any patient w/ a bone lesion;
- most commonly used drugs are pamidronate and zoledronic acid (4 or 8 mg infused over five minutes and is
treatment of choice);
- hematuria will help rule out renal ca;
- ESR helps rule out multiple myeloma or infection;
- radiographic studies:
- radiographic work up should include either a bone scan or a skeletal survey;
- CT scan is the study of choice for detection of pulmonary, abdominal, pelvic, and retroperitoneal metastasis;
- most skeletal metastases cause bone destruction and appear osteolytic on the roentgenogram;
- occasionally, the tumor cells provoke osteoblastic response, & x-ray show increased density (common w/ prostate ca);
- r/o pending fracture:
- always rule out pending frx of the proximal femur and proximal humerus;
- pathologic frx of the proximal femur is amoung the most devastating devasting complications of metastatic carcinoma,
since patients will have constant pain and will not be able to leave the hospital bed;
- Treatment Options:
- osteoclast inhibiting agents:
- indications for treatment: patients w/ an abnormal bone scan and a CT or MRI showing bone destruction even if there is normal
findings on plain x-rays;
- theory is that osseous metastasis and subsequent erosions will in part require recruitment of osteoclasts;
- bisphosphonates: (etidronate, pamidronate, clodronate)
- of these pamidronate is the most frequently used (given as a once-monthly infusion over 1 - 2 hours);
- aminobisphosphonate: fosamax;
- w/ metastatic lytic disease consider:
- pamidronate: 90 mg IV over 2 hours;
- zoledronic acid: 4 mg IV delivered over fifteen minutes every three to four weeks;
- Reduction in new metastases in breast cancer with adjuvant clodronate treatment.
- Bisphosphonates as anticancer drugs.
- Biochemical markers and skeletal metastases.
- radiation therapy
- DVT prophylaxis
- Thromboembolism After Intramedullary Nailing for Metastatic Bone Lesions
- management of metastatic disease to the spine
- surgical fixation:
- w/ pathologic frx or pending frx, hardware failure/loss of fixation is more common w/ renal cell carcinoma because
patients tend to have long term survival and persistent local tumor osteolysis is common;
- as noted by Wedin R, et al (1999), endoprosthetic reconstruction has a lower failure rate than osteosynthetic devices;
- ref: Failures after operation for skeletal metastatic lesions of long bones.
- humeral IM nailing: (see humeral nailing technique)
- Metastatic bone disease. A study of the surgical treatment of 166 pathologic humeral and femoral fractures.
- Treatment of pathologic fracture of the humerus.
- prophylactic femoral IM nailing
- acetabular reconstruction:
- in the report by Marco RA, et al (2000), 55 patients with metastatic disease of the acetabulum were treated with operative
acetabular reconstruction combined with a total hip replacement;
- 9 of the 18 patients who could not walk preoperatively regained the ability to walk;
- 14 of the 17 patients who originally were able to walk in the community retained that ability;
- median period of survival was nine months;
- patients w/ visceral metastases had a median period of survival of 3 months compared w/ 12 months for patients
w/o visceral metastases;
- 14 (25 percent) of the 55 patients had moderate local progression of the disease, and five of these patients had failure
of the fixation;
- 14 early complications developed in twelve (22 percent) of the patients;
- ref: Functional and Oncological Outcome of Acetabular Reconstruction for Treatment of Metastatic Disease.
- pathologic fracture
- pathologic hip fracture:
- main issues involve low potential for fracture healing and possibility of concomitant lesions in the femoral shaft;
- w/ femoral neck or base of femoral neck fracture consider hemiarthroplasty;
- if metastatic lesions are present in the femoral shaft then consider long stemed prosthesis;
- Modular prostheses in metastatic bone disease of the proximal femur.
- Head and neck replacement endoprosthesis for pathologic proximal femoral lesions.