What are bone metastases?
Bone metastases are tumors that occur when cancer cells break away from the
place where they started growing and move into bone tissue. Bone metastases are
considered a form of advanced cancer. These secondary cancers within the bone
are difficult to cure, but treatments are available to lessen the symptoms and
What are the symptoms of
Bone metastases are common in many people with cancer. Bone metastases can sometimes
result in severe pain and neurological impairment due to changes in your bone
structure. Other symptoms of bone metastases can include:
- fragile bones
- high levels of calcium in the blood, which may cause
nausea and confusion
- a loss of urinary or bowel control
- weakness in the legs
- a low blood cell count and anemia due to the loss of bone marrow
Metastatic cancer can severely damage your bones. Metastatic tumors can
destroy your surrounding bone tissue, causing osteolytic bone destruction.
Osteolytic damage occurs most often from tumors that originate in the:
Other damage can result when new bone is formed due to chemicals released by
the tumor. This new bone may be weak and deformed. When this occurs it’s known
as osteoblastic, or bone formation, damage. This occurs in cancers that begin
as prostate, bladder, or stomach cells. Some cancers, like breast cancer, can
create both osteolytic and osteoblastic damage.
Both osteoblastic and osteolytic damage can cause pathological bone
fractures. A pathological bone fracture is a fracture caused by a disease, as
opposed to a traumatic fracture caused by external damage to your bone. Bones
affected by this kind of damage break not from a fall or pressure, but during
everyday activities. Damage to the bones of the spine can also affect the
nerves of the spinal cord, causing neurological problems.
What causes bone metastases?
Bone metastases aren’t the same as bone cancer. Bone metastases are formed
from cancerous cells that start elsewhere in your body. So, bone metastases
could, for instance, be cancerous breast tissue, or another type of tissue somewhere
in your body, that has started growing inside the bone tissue.
Cancer is a disease in which abnormal cells start dividing without control.
Some tumors cells can break off and move around your body. Most of these shed
cells die off, but some live on in new tissue and create a metastatic tumor.
These metastases can remain hidden, even when the original tumor is gone and your
doctor determines that you’re free of cancer.
It’s unclear why certain tumors become metastatic, and others don’t. In
certain types of cancer, such as advanced breast cancer or advanced prostate
cancer, up to 70
percent of patients develop bone metastases.
The most common cancers that result in bone metastases include:
- breast cancer
- prostate cancer
- lung cancer
- kidney cancer
- thyroid cancer
The most common locations for bone metastases include the:
- long bones of the leg
- upper arms
are bone metastases diagnosed?
Your doctor will perform a full medical history and physical exam, including
a discussion of any past incidence of cancer. They can then order several tests,
- X-rays of the affected bone
- bone scans to see if other bones are affected
- CT scans
- MRI scans
- blood tests
If your doctor needs to determine whether the affected bone is the result of
a bone metastasis or a primary bone cancer, they may perform a biopsy. During a biopsy, they’ll
remove a small amount of the tumor and send it to a pathologist for a thorough
How are bone
Treatment of metastases often depends on the location and the source tumor
cells. Treatments can include radiation, medication, and surgery.
Radiation therapy is often used to slow the growth of a bone metastasis. The
types of radiation therapy include the following:
- Local field radiation
involves your doctor directing radiation at the tumor and nearby
tissue. It can completely relieve pain in 50-60 percent of cases.
- Hemi-body radiation
involves your doctor directing radiation at a large part of your body.
Your doctor can do this if you have multiple bone metastases.
- Radioisotope therapy involves your doctor
injecting radioactive medication through your vein.
Medications are a key part of therapy for treating bone metastases. They may
include one or more of the following:
medications, such as bisphosphonates, to help reduce bone damage
- chemotherapy to kill tumor cells and
reduce tumor size
- hormone therapy to slow certain hormones
for cancers like breast cancer and prostate cancer
- pain medications
Surgery may be necessary when your bones have fractured or will soon
fracture. Your docotor may remove tumors surgically. They may attach fixation devices
directly to surrounding bone. They can use bone cement for reinforcing your bone
Heating or freezing cancer cells with a probe, called radiofrequency
ablation or cryoablation, can also reduce tumor size.
All of these treatment methods have risks. You and your doctor will arrive at
a unique treatment for your specific cancer. You may work with a variety of
doctors to tailor your care.
What is the outlook
for people with bone metastases?
Bone metastases are a type of advanced cancer. It’s often not possible for
doctors to remove all cancer cells. A wide variety of treatments are available to
reduce the size of metastases and slow their growth. This can reduce pain and
other symptoms, and it can improve quality of life and longevity.