Bone metastasis occurs when cancer cells spread from their original site to a bone. It can occur in any bone but is most common in the spine, pelvis and thigh. Bone metastasis may be the first sign that an individual has cancer or it may occur years after cancer treatment. It can cause pain and broken bones and with rare exceptions, cancer that has spread to the bones cannot be cured.

Symptoms 

At times, bone metastasis provides no signs or symptoms or being present, however, when they do occur, these symptoms include:

  • Pain in the bone
  • Broken bones
  • Loss of bladder control
  • Inability to control bowel movements
  • Weakness in the arms or legs
  • High levels of calcium in the blood (hypercalcemia), which can cause nausea, vomiting, constipation and confusion

Causes 

Bone metastasis occurs when cancer cells break away from the original tumor and spread to the bones, where they begin to multiply.Doctors are not sure of what it is that causes some cancers to spread and it is not clear why cancers travel to the bones rather than to other common sites for metastasis, such as the liver.

Risk Factors

Although any type of cancer can spread to the bones, the most common risk factors for bone metastasis are the cancers it is most likely to cause individuals. These types of cancers include: 

  • Breast cancer
  • Kidney cancer
  • Lung cancer
  • Prostate cancer
  • Thyroid cancer
  • Lymphoma
  • Multiple myeloma