Orthopedic Oncology cases metastatic bone disease1
A 60-year-old female with a history of breast cancer treated 5 years ago with mastectomy, chemotherapy, and radiation is seeing you for knee pain. X-rays of the knee are performed, which show moderate DJD. They also reveal a lesion in the distal femoral shaft. X-rays taken are displayed in Figure 8–39A and B.
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Figure 8–39 A–B
Which of the following tests is not indicated at this time?
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Bone scan
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CT chest/abdomen/pelvis
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Contralateral femur x-rays
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Thyroid studies
Discussion
The correct answer is (C). The patient has a permeative lesion incidentally found on x-rays, with a remote history of nonmetastatic cancer. This lesion could represent the first metastasis of her breast cancer, metastasis of a different primary tumor, or a primary bone lesion. A workup must be started, which includes (but is not limited to) a bone scan, CT chest/abdomen/pelvis, and laboratory studies. Contralateral femur x-rays are not indicated at this point unless she is having pain in that area, or bone scan shows a lesion in that area.
Her extensive workup is negative for primary malignancy. A biopsy is performed
and pathology report is consistent with metastatic breast cancer. An intramedullary nail is placed, and the specimens from the operating room are sent for biopsy. What other information can be obtained from the biopsy?
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Estrogen and progesterone receptor expression
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The duration of time the lytic lesion has been present
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Risk of femoral shaft fracture
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Potential response to radiation
Discussion
The correct answer is (A). In addition to identifying the primary site for this metastatic lesion, biopsy is specifically important in breast cancer metastases because the susceptibility to certain chemotherapeutic agents can be evaluated by testing for various receptor expressions by the tumor cells. For example, Herceptin is a chemotherapeutic agent that will only have an effect in patients with HER2+ breast cancer. Therefore, biopsy of the metastatic lesion can provide important information to drive medical oncologic treatment and prognosis. Importantly, the receptor status of any disease can change through the course of the disease as tumors continue to mutate, which may sometimes open new avenues for treatment. For this reason, any procedure done on a new metastatic bone lesion should include a biopsy of the tissue obtained at the time of surgery.
Objectives: Did you learn...?
To identify and work up metastatic bone disease?
The importance of sending any and all tissue obtained at the time of surgical procedure for biopsy?