The vast majority of cancers, especially breast and prostate, can spread to the bones and form bone metastases. Are there any warning symptoms? A pain ? What are the chances of survival?
When a cancer breaks away from its original tissue to spread and colonize the bones, it is called bone metastases. These metastases usually occur in progression of breast or prostate cancer. Can we predict the formation of bone metastases? Are there any warning symptoms ? Of the pains evocative? What treatment to get rid of it ? What are the potential complications ? Answers with Dr. Mahasti Saghatchian, oncologist and practitioner specializing in breast cancer at the American Hospital of Paris and Gustave Roussy.
A cancer is a tumor caused by the proliferation of cancer cells. If they are not destroyed, these cancer cells can detach themselves from their tissue of origin and via the blood or lymphatic vessels, colonize neighboring organs or other parts of the body to form secondary cancers. We then speak of metastases. “And when cancerous cells nest in one or more bones, it is bone metastases“, explains our expert from the outset.
“In the event of bone metastases, the cancerous cells nibble the bone, which weakens it”, says our expert. We can then feel:
- Sharp pains in the bones (intermittent or continuous), whichintensify overnight.
- vertebral compression
- Dare fractures
- Back pain, sometimes neuralgia (sciatica or pain in the chest), when metastases form in the spine, tumor cells can exert a pressure on the spinal cord and compress it: this is called spinal cord compression.
- Difficulty walking that can even go as far as paralysis.
It is common to find metastases in the vertebrae, ribs, long bones of the arms or legs
“We cannot predict whether a person is at risk of developing metastases or not.. However, the appearance of bone metastases is more frequent in patients suffering from a homo-sensitive canceri.e. when hormones play a role in the proliferation of cancer cells, emphasizes Dr. Saghatchian. It is in particular the case of breast cancer and of prostate“.”For hormone-sensitive breast cancer (75% of breast cancers)it has been estimated that bone metastases appear on average between 5 and 6 years after the onset of the disease“Hormone-responsive cancers have better prognoses with less risk of relapse than non-hormone-responsive cancers.”All bones can be the site of metastases, but it is more common to find metastases at the level bones of the spine (vertebrae), ribs, long bones of the arms or legs (femur or radius for example)”, explains Dr. Mahasti Saghatchian. Metastases on the bones of the extremities of the limbs (phalanges, metatarsals…) are rather rare. Finally, it is possible that bone metastases appear in several bones at the same time.
Bone is not a fixed tissue and is therefore in perpetual renewal. Thus, it is constantly being destroyed by osteoclasts (cells that destroy aging bone tissue), then reformed by osteoblasts (cells that synthesize/build bone). In a normal situation, the bone remodels itself, remains strong and healthy thanks to the activity of these two types of cells. On the other hand, when a cancer from another part of the body spreads to the bones, bone metastases disrupt this process by destroying the balance maintained by the osteoblasts and osteoclasts. We distinguish two types of bone metastases:
► THE osteolytic metastases which develop when the activity of osteoclasts (cells responsible for bone destruction) dominates. Thus, the bones are very fragile and can even be perforated. It is these metastases that form when cancer cells from breast cancer spread to the bones. Note that osteolytic metastases are more common than osteoblastic metastases.
► THE osteoblastic metastases which develop when the activity of osteoblasts (cells responsible for bone formation) dominates. Thus, the bones are very dense or ossified. It is these metastases that often form when cancerous cells from prostate cancer spread to the bones.
No matter where it is located, cancer is always defined by its tissue of origin (in other words, its starting point). Thus, breast cancer that has sent metastases to the bones does not develop into bone cancer. Bone cancer (or primary bone cancer) is a tumor that develops directly in the bones, from bone, cartilage or fibrous tissue. Moreover, bone metastases are much more frequent than primary bone cancer.
The doctor will first do a review of symptoms, patient medical history and risk factors and a physical examination during which he will look for the presence of metastases in the regions where pain is felt. “Complementary radiological examinations will then be made as a bone scan, which is used to look for metastases in the bones, or a PET Scan which makes it possible to track metastases or very small tumors, not always visible during conventional radiological examinations“, explains Dr. Saghatchian. More targeted examinations such as MRI or CT scan can better describe the injury, the risk of fracture or compression.
“At present, it is very difficult to completely eliminate bone metastases of the organism. However, effective treatments can slow their growth and prevent their proliferation. Also, treatments can treat or prevent complications related to bone metastases“, reassures Dr. Saghatchian. “THE anti-hormonal treatments contain molecules that prevent cancer cells from spreading. Prescribed for hormone-sensitive cancers, these inhibitors administered orally are very effective and are generally combined with new oral molecules that act in a targeted manner on tumor cells. Targeted radiotherapy can also be combined, particularly on bone lesions that are painful or at risk of compression.
Thank you to Dr. Mahasti Saghatchian, oncologist and practitioner specializing in breast cancer at the American Hospital of Paris and Gustave Roussy.