Initial Medical Evaluation
Detecting bone cancer early and accurately is important for effective treatment. This article explains the steps involved in diagnosing bone cancer, from the first signs to determining the extent of the disease.
Persistent symptoms like bone pain, limb swelling, or unexplained fractures often prompt a visit to a primary care physician. These symptoms can be subtle and may worsen over time, indicating a need for medical attention.
During this initial consultation, the doctor takes a thorough medical history, asking detailed questions about symptom onset, family cancer history, and past medical conditions. A physical examination then checks the affected area for tenderness, swelling, or limitations in joint motion.
Initial blood tests may be ordered to assess general health or rule out other conditions with similar symptoms. While not specifically diagnostic for bone cancer, abnormalities in blood cell counts or enzyme levels can suggest further investigation is needed.
Diagnostic Imaging Tests
After initial medical evaluation, doctors use various imaging techniques to visualize bones and surrounding tissues.
X-rays are typically the first imaging test for suspected bone cancer. They reveal changes in bone structure, such as tissue destruction or new bone formation, which can suggest the presence of a tumor.
Following X-rays, magnetic resonance imaging (MRI) provides detailed images of the bone and surrounding soft tissues. MRI shows the precise size and location of a tumor within the bone, and its relationship to nearby nerves, blood vessels, and muscles. This detailed view helps understand the local extent of the potential cancer.
Computed tomography (CT) scans offer cross-sectional images, useful for assessing bone structure in greater detail than X-rays. CT scans also frequently check for spread to other body parts, especially the lungs, which is a common site for metastasis. High-resolution images can detect small nodules in the lungs that might not be visible on other scans.
A bone scan (bone scintigraphy) involves injecting a radioactive tracer that travels to areas of increased bone activity, such as cancer, infection, or healing fractures. The scan highlights these “hot spots,” indicating regions that require further investigation.
Positron emission tomography (PET) scans detect metabolically active cancer cells throughout the body. Often combined with a CT scan (PET-CT), this technique uses a radioactive sugar molecule absorbed more readily by cancer cells. PET-CT identifies both the location and metabolic activity of cancerous lesions, aiding in detecting primary tumors and any spread.
Confirming Diagnosis Through Biopsy
While imaging tests can strongly suggest bone cancer, a definitive diagnosis requires a biopsy. A biopsy involves removing a tissue sample for microscopic examination by a pathologist. This step confirms cancer cells, identifies the specific type of bone cancer, and assesses its grade, which indicates how aggressive the cancer cells appear.
A common type is a needle biopsy, either fine needle aspiration or core needle. A core needle biopsy uses a larger needle to extract a tissue cylinder from the suspicious area. These procedures are often performed with imaging guidance, such as CT or X-ray fluoroscopy, to ensure the needle accurately reaches the target.
An incisional biopsy involves a surgeon making a small cut to remove a portion of the suspicious mass. This method provides a larger tissue sample compared to needle biopsies. The choice between needle and incisional biopsy depends on the tumor’s location, size, and other clinical factors.
In some cases, an open surgical biopsy removes a larger piece of tissue or the entire tumor during surgery. This method is often chosen when the tumor is easily accessible or previous needle biopsies were insufficient. The surgeon carefully plans the biopsy to avoid compromising future limb-sparing surgery.
The tissue sample is sent to a pathology laboratory. A pathologist examines the cells and tissue under a microscope, looking for characteristics unique to cancer cells, such as abnormal growth patterns and irregular nuclei. The report confirms the diagnosis, classifies the bone cancer type (e.g., osteosarcoma, Ewing sarcoma), and assigns a grade, which helps predict its behavior.
Assessing the Extent of Cancer
After bone cancer diagnosis is confirmed, doctors assess the disease’s extent. This process, known as staging, describes the tumor’s size and whether it has spread from its original location. Staging provides a standardized way to classify the cancer, important for guiding treatment decisions and predicting outcomes.
Staging typically uses imaging tests similar to initial diagnosis, but focused on detecting spread. CT scans of the chest routinely check for lung metastases, as the lungs are a common site for bone cancer to spread. PET-CT scans can also identify cancer cells that may have traveled to other bones or organs, even if very small.
Bone scans are valuable in staging, revealing if cancer has spread to other bones. By highlighting areas of increased metabolic activity, these scans help identify additional disease sites not apparent on other imaging studies. Magnetic resonance imaging (MRI) of the primary tumor site helps define the cancer’s local extent and its relationship to surrounding structures.
Information from these tests assigns a cancer stage. Staging systems categorize bone cancer based on factors like tumor size, spread to nearby lymph nodes, and distant metastasis. Understanding the cancer’s stage directly influences treatment planning and provides important prognostic information.