The most common types of malignant bone cancer are
- osteosarcoma (in the bone): Primarily affects male adolescents between the ages of 10 and 20.
- Ewing's sarcoma (in the bone marrow): Affects boys and girls equally and occurs more frequently between the ages of 10 and 15.
- Chondrosarcoma (in the cartilage): Usually affects adults between the ages of 30 and 50.
Osteosarcoma of the femur © rob3000 | AdobeStock
Primary bone cancer, i.e. cancer that develops by itself directly in the bone tissue, is comparatively rare. In Germany, only around 700 new cases occur each year. This corresponds to around one percent of all malignant cancers.
However, bone metastases resulting from other cancer sites in the body(secondary bone cancer) are much more common. Tumors of the lung, breast, prostate, kidneys and thyroid gland in particular spread to the bones. Metastases can already be detected in aggressively growing tumors before the original disease itself becomes symptomatic. Tumor diseases usually take several years to develop. Secondary bone cancer therefore mainly occurs in the second half of life.
Bone metastases in the femur
Benign cell changes in the bones are not referred to by doctors as cancer, but as benign bone tumors. Benign bone tumors include, among others
- the osteoma,
- osteoid osteoma and
- osteoblastoma.
The causes of bone cancer are not yet known in detail. However, as malignant tumors in the bones often occur during childhood or puberty, doctors suspect that growth-related and hormonal factors play a role. Other risk factors for the development of bone cancer include
- a genetic predisposition,
- the bone disease Paget's disease
- previous radiotherapy or chemotherapy due to another disease
Patients suffering from retinoblastoma (retinal tumor) also have an increased risk of bone tumors.
The symptoms of bone cancer are generally rather unspecific. They can include
- Pain in the affected area,
- swelling of the skin and
- associated pain on movement
may occur. However, the signs that occur ultimately depend on the type, size and location of the bone tumor.
Bone cancer manifests itself rather unspecifically through pain in the affected area © 9nong | AdobeStock
Osteosarcoma occurs more frequently in the long bones of the upper arms or thighs. It usually affects the area of the bone where the bone shaft merges into the spherical end of the bone. Patients experience painful swelling, which increasingly impairs the mobility of the affected limbs. The malignant tumor causes the bone to lose strength. Therefore, even normal stress can lead to a fracture. Such spontaneous fractures without major external force are always suspicious.
The symptoms of Ewing's sarcoma are similar to those of other bone tumors. Pain and swelling in the affected area indicate a disease. However, there is also a strong feeling of illness with fever. The signs are similar to those of bone marrow inflammation, which is why there is often confusion. Ewing's sarcoma occurs particularly frequently in the shaft of the long bone in the leg or in the pelvic bone.
Chondrosarcoma, on the other hand, causes hardly any pain . It occurs particularly frequently in the pelvic area and on the thigh or in the shoulder region.
If symptoms suggest bone cancer, a detailed medical history is taken first, followed by an X-ray examination as a rule. Radiologists are specialists in imaging examinations. If the suspicion of a malignant bone tumor is confirmed, this is followed by
X-ray of the knee shows a malignant bone tumor on the femur © Richman Photo | AdobeStock
In order to find any bone metastases, a scintigraphy may also be necessary. This is a nuclear medicine imaging procedure that makes the tumor cells directly visible.
A blood test provides further information. If certain enzymes are elevated, this confirms the suspicion of an osteosarcoma or Ewing's sarcoma, for example.
However, only a biopsy can provide the final diagnosis of a benign or malignant bone tumor. The doctor uses a needle to take a tissue sample from the bone. A pathologist then examines this sample in the laboratory.
Taking a tissue sample from the bone to confirm the diagnosis of "bone cancer" © Алексей Доненко | AdobeStock
The treatment of bone cancer depends on the type of tumor and how far it has spread. Oncologists usually advocate a combination therapy. These are available:
- Surgery
- chemotherapy
- Radiotherapy
During surgical removal of the tumor, the surgeon removes entire sections of bone and, in some cases, surrounding tissue. In particularly severe cases, surgeons are sometimes even forced to perform an amputation. If the surgeon only removes small parts of the bone, foreign materials are incorporated to stabilize it. These are screws and plates. In some cases, a connecting frame located outside the body is also used. In the case of very large defects, it may be necessary to transfer the patient's own bone tissue (often from the iliac crest).
In the case of osteosarcoma, which occurs more frequently in the long tubular bones, a combination of chemotherapy and surgery is used in most cases. The first step is chemotherapy, which is intended to shrink the bone tumor and kill the micrometastases. This is followed by surgery, in which the surgeon attempts to remove the remaining bone tumor as completely as possible. Chemotherapy is then used again. In addition, medication can help to stimulate the immune system so that the body can fight the cancer more efficiently. Radiotherapy is usually not an option, as osteosarcoma hardly reacts to ionizing radiation.
Chemotherapy for bone cancer © Tyler Olson | AdobeStock
The same treatment procedure is used for Ewing's sarcoma. However, this type of bone cancer does respond to radiation, which is why radiotherapy is an important part of the treatment plan.
Unfortunately,chondrosarcomas are particularly difficult to treat, as these bone tumors are very resistant to radiation. However, as there are currently no alternatives, radiochemotherapy in combination with surgery is still used to treat chondrosarcoma. Despite the extremely high dosage of chemotherapy, some chondrosarcomas do not respond to the therapy at all. Doctors can then only provide palliative care for the patient.
Benign bone tumors are usually also removed surgically by surgeons. In the case of slow-growing tumors that do not cause any symptoms, the treating physicians often even wait and see. In the case of osteochondromas, however, a quick operation is very likely. This is because the benign bone tumor can degenerate and become bone cancer.
The prognosis for bone cancer depends
- the type of tumor,
- the size and spread and
- the stage of the tumor
tumor stage. Furthermore, even after successful treatment, the possibility of tumor recurrence cannot be ruled out.
In the case of osteosarcoma, the chances are particularly good if the disease is detected early. If no metastases have yet formed, the chance of survival five years after diagnosis is over 60 percent. The prognosis is far less favorable if metastases have already formed.
The same applies to Ewing's sarcoma, although the death rate within the first five years after diagnosis is even slightly lower.
Chondrosarcoma patients have a particularly poor prognosis. Doctors speak of a bone cancer survival rate of less than 50 percent up to five years after diagnosis for this serious disease in the cartilage.