Metastatic Bone Cancer: What is Bone Metastasis? Causes, Symptoms, Diagnosis, treatment

Mohd Sufyan   by Mohd Sufyan, BSME, MBA    Last updated on May 1, 2019,

What is bone metastasis?

Bone metastasis or bone mets or bone metastases occurs when cancer cells from the primary tumor spread to the bone. Common cancers that are likely to spread to bones are prostate cancer, breast cancer, kidney cancer, thyroid cancer, and lung cancers. The bone is a common site for metastasis of other types of cancers.

Bone metastases do not begin from the bones. It starts in some other organ and then move to the bone from the primary tumor site. On the other hand, primary bone cancers are those cancers that begin in the bone. Primary bone cancers are rare. It should be understood that bone cancer and bone metastases are not the same.

Read about primary bone cancer.

Symptoms of metastatic bone cancer

Bone metastasis may not always cause signs and symptoms in the beginning. If it does show any signs and symptoms, these may include:

  • Bone fractures, fragile bones
  • Pain in bones
  • Urinary incontinence
  • Bowel incontinence
  • High levels of calcium in the blood which can cause nausea, vomiting, constipation, confusion, and other such problems
  • Weakness in the legs or arms
  • Low blood cell count and anemia due to the loss of bone marrow

What causes bone metastases?

Bone metastases aren’t same as bone cancer. Bone metastases occur from cancerous cells that begin somewhere else in the body. For example, bone metastases could be a cancerous breast tissue, or a lung tissue or another type of tissue in the body that has grown into the bone tissue.

Cancer is identified as a disease in which cells start dividing abnormally. Some cells can break off from another cancerous tissue and move around in the body. Most of these moving cells die eventually, but some may stay on in new tissue and create a metastatic tumors.

It’s not exactly known why certain tumors become metastatic and others don’t. Some types of cancers, such as advanced breast cancer and advanced prostate cancer have a very high chance of converting into metastatic bone cancer.

Common locations for bone metastasis

  • Pelvis
  • Hips
  • Bones of the leg
  • Arms
  • Skull
  • Ribs
  • Spine

Diagnosis of metastatic bone cancer

For diagnosing the disease, your doctor will review the complete medical history and perform a detailed physical exam. He or she will try to understand any past incidences of cancer of bone or any other location.

He or she will order certain tests to confirm the initial understanding if a metastatic bone cancer is suspected. These tests may include:

  • bone scans
  • CT scans
  • MRI
  • X-rays of the affected bone
  • blood tests

The doctor may also recommend a biopsy of bone tissue to determine whether the affected bone is a primary bone cancer or affected due to metastasis. In a biopsy, a small portion of the tumor is taken and examined in a pathology lab.

Treatment of bone metastases (Metastatic bone cancer treatment)

The best treatment for bone metastasis is the treatment of your primary cancer. Your doctor may use a combination of therapies such as chemotherapy, hormone therapy, radiation therapy, immunotherapy, etc.

He or she may recommend narcotics and other pain medications, such as non-steroidal anti-inflammatory agents for relieving the pain. Sometimes, physical therapy can be helpful. Surgery is considered particularly if there occurs a fracture in the bone.

Bone-building medications: Medicines that are recommended to people with osteoporosis or with weak bones may also be prescribed to people with bone metastasis. These medications help strengthen bones, which reduces the pain caused by bone cancer. This reduces the need for strong pain medications.

Steroids can help relieve pain associated with bone metastases by decreasing inflammation around the location of the cancer.

Certain cancers may respond better with targeted therapies. Your doctor may combine this with other treatment options for the metastatic cancer.

Surgical procedures can be employed to stabilize a bone that is at high risk of fractures. Following approaches may be used:

  • Surgeons can stabilize your bone using metal plates, screws etc through orthopedic fixation.
  • Cementing of the bone may be done if the fixation with plates and nails is not possible.
  • If the metastatic cancer has broken a bone, your surgeon will try to repair the broken bone using fixation techniques and metal fasteners.