Yeditepe University Hospitals Orthopedics and Traumatology Specialist Assoc. Prof. Dr. Koray Başdelioğlu answered the questions of how bone metastasis occurs, whether bone metastasis gives any symptoms, and whether any cancer metastasizes to the bone.

What Is Bone Metastasis?

Bone metastasis is the formation of a cancerous mass settling in the bone through various complex mechanisms of cancer that occurs in any organ in the body.

Which Cancers Most Commonly Metastasize to Bone?

Every cancer has the potential to metastasize to the bone. But most commonly, breast and prostate cancers metastasize to the bone. Less frequently, lung cancer, thyroid cancer, bladder cancer, kidney cancer, and colorectal cancer are among the cancers that can metastasize to the bone.

Are Bone Metastases Common?

Bone metastasis is a very common problem. According to some studies, it is the most common site for metastases, while according to some studies, it is the third most common site for metastasis after lung and liver metastases. In autopsy studies, it was determined that 70% of breast and prostate cancer patients and 35-42% of lung, thyroid, and kidney cancer patients had bone metastases. In addition, the incidence of bone metastases is increasing as a result of the increase in survival with new treatments.

In Which Bones Do Bone Metastases Occur Most? Is There a Reason for This?

Although bone metastases can be seen in any bone, they are most common in the spine, pelvis, and thigh bone close to the hip. The main reason for the more frequent occurrence of bone metastases in these regions is that these are regions where the bone marrow is more active and the extensive venous networks around the spine.

How Does Bone Metastasis Occur?

There are quite complex mechanisms in the formation of bone metastases. The main factor is the microenvironment of the tumor. Cancer cells that come to the bone by leaving main cancer as a result of various mechanisms and signals try to adapt to this new microenvironment. Cancer cells that come to the bone plant the seeds of bone metastasis by premetastatic niche, a process called osteomimicry, in which they imitate bone cells. Interestingly, these cancer cells that settle in the bone may be in a low-proliferation or dormant state until a signal is received that triggers activation. When they start to proliferate, they first form micrometastases that cannot be detected, and then bone metastases that can be clinically revealed.

What Are the Symptoms of Bone Metastases?

It may not be noticed in cases where it does not cause clinical symptoms or routine follow-up is not made. It may present with conditions such as pain, pathological fracture, hypercalcemia, and spinal cord compression.

How is a Patient with Bone Metastases Treated?

The clinical condition of the patient, the number and location of metastases, and the life expectancy are the factors taken into consideration for treatment. In the treatment of bone metastasis, surgery, radiotherapy, various drugs, thermal ablation, electrochemotherapy, and MRI-guided high-intensity focused ultrasound can be used.