There are two types of bone cancers. Primary bone cancers (sarcomas) are the rarest type of human cancer and probably affect fewer than 100 Kentuckians per year. Metastatic cancer which spreads to the bone is much more common, and often originates in the prostate, breast, thyroid, kidney or lung.
Bones have a complex network of cellular types, so primary bone cancer can develop in cells designed to make bone itself (osteosarcoma), cartilage (chondrosarcoma), fibrous tissue (spindle cell sarcoma of bone), or the marrow elements (multiple myeloma). There are also other types of tumors which occur in bone which we haven't fully characterized, such as Ewing's sarcoma of bone.
How does bone cancer develop?
Any bone in the body can develop a cancer, but bones that grow the fastest (like the knee and the shoulder) have a higher risk for cancer. Additionally, specific types of bone cancer are common in certain areas. For example, Ewing's sarcoma of bone tends to occur in the flat bones of the pelvis, shoulder girdle, and spine, while osteosarcoma and chondrosarcoma typically occur in the limbs.
There are some genetic syndromes that predispose patients to develop certain types of bone cancer, but most cases are sporadic. There is no association between bone cancer and lifestyle or environmental factors. Most cases of bone cancer are just genetic bad luck.
How is bone cancer treated?
The two types of bone cancer are treated differently. For primary bone cancers that haven't metastasized, we have an opportunity to cure the patient with appropriate care.
Treatment for primary bone cancers typically involve a combination of chemotherapy and surgery. These are the rarest and most aggressive types of human cancer, and surgery to remove them is carefully planned.
Think of the cancer like the fruit of an orange — these cancers are so aggressive, they have to be removed with a "rind" of normal tissue completely surrounding the tumor so that the cancer doesn't see the light of day during surgical excision.
These surgeries are difficult due to the complex anatomy of the skeletal system — the location of the cancer can mean that you are only millimeters away from major blood vessels or nerves that serve other areas of the body.
Twenty years ago, bone cancer was treated with amputation more than 90 percent of the time.
Today, with advanced surgical techniques, limb-salvage surgery is the treatment of choice. After removing a section of bone from the body, we have developed internal prosthetic devices which can restore function for children, young adults and adults who have been afflicted with bone cancer. These truly "robotic" internal prostheses can restore leg length, gait, and can even grow with a growing child.
When a cancer spreads to the bone from another organ, however, the ability to "cure" that cancer decreases drastically. As such, treatment of metastatic cancer to bone typically involves improving the quality of life by decreasing pain and improving patient function.
Dr. Patrick O'Donnell is an orthopaedic oncologist for UK HealthCare.