Bone Metastases

What Are Bone Metastases?

Bone metastases originate from tumors in other organs, e.g., breast cancer or prostate cancer. In some cases, such cells no longer adhere to natural tissue boundaries and can grow into neighboring organs or tissue. If such mutated cells reach lymphatic vessels or blood vessels, they can be carried on via the lymphatic fluid or blood and invade tissue elsewhere "downstream," where they form metastases.

Tumors can form such metastases in various tissues so that such metastases can occur in the immediate neighborhood of the original tumor and nearby lymph nodes and distant areas of the body. Tumors spread to different tissues, and other types of tumors have their preferred regions. Therefore, bone metastases occur more frequently with certain types of tumors.

Which Tumors Cause Bone Metastases?

In general, almost all tumors can metastasize to bone. In women, bone metastases are most often caused by breast cancer, in men by prostate cancer. Besides, lung cancer, thyroid cancer, renal cell cancer, and malignant melanoma often cause bone metastases.

How Are Bone Metastases Noticed?

The tumor cells in the bone produce messenger substances and growth factors that affect the bone cells. Either the bone-building or the bone-degrading cells can be stimulated. Metastases lead to bone destruction or excessive new bone formation. In the case of bone destruction, this can cause bones to fracture with little or no external exposure, which can also happen with newly formed bone tissue, as it is not as stable as healthy bone tissue.

The most common symptoms of bone metastases include pain in the affected bones. Metastases can also cause narrowing of the spinal canal, which manifests as sensory disturbances and paralysis. The breakdown of bone produces calcium, which can be verified by elevation in the blood count, affecting numerous metabolic processes and even expressing symptoms such as nausea, cardiac arrhythmias, and unconsciousness.

How Are Bone Metastases Treated?

There are several ways to treat bone metastases. It is essential to keep the objective in mind, i.e., consider whether a cure or a reduction in symptoms is the primary goal. The therapy is decided based on the type of tumor, the tumor stage, and the patient's state of health. The following treatments are available and can also be combined:

• Radiation
• Hormone therapy
• Chemotherapy
• Bisphosphonate therapy
• Surgical removal
• Antibody therapy

Radiation therapy can be used effectively to treat single, spatially defined bone metastases locally. The pain caused by metastases and the fracture risk can be reduced. To achieve this, the tumor tissue is targeted while the neighboring tissue is spared. Radiation therapy can take place as a single session (Cyberknife) or be performed in multiple sessions in outpatient settings. If bone metastases are found in several different parts of the body, drug therapy or radionuclide therapy is more likely to be used.

Chances of Cure and Prognosis

Bone metastases usually occur in the late stages of cancer and are an indication of advanced cancer. Therefore, in many cases, a cure is no longer possible. However, the symptoms caused by bone metastases can be alleviated by the therapies mentioned above. Further progression of the disease can also be slowed down. Overall, quality of life and lifetime must be weighed in every treatment decision.

Which Doctors and Clinics are Specialized in the Diagnosis and Treatment of Bone Metastases?

Bone metastases are primarily treated by physicians who are specialists in the primary tumor. For example, gynecologists are responsible for bone metastases that originate from breast cancer. For the best possible individual therapy, patients are presented to an interdisciplinary tumor board. Physicians from radiation therapy, oncology, and surgery cooperate and develop a treatment plan together.

Sources:

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