Bone Cancer - Symptoms, Diagnosis, Treatment | Find the Right Doctor

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 sarcoma (in the bone marrow): Affects boys and girls equally and is most common between the ages of 10 and 15.
• chondrosarcoma (in the cartilage): Typically affects adults between the ages of 30 and 50.

Osteosarcoma of the femur © rob3000 | AdobeStock

Primary bone cancer—that is, cancer that originates directly in the bone tissue—is relatively rare. In Germany, only about 700 new cases are diagnosed each year. This accounts for about one percent of all malignant cancers.

However, bone metastases—which result from other cancerous lesions in the body (secondary bone cancer)—are significantly more common. Tumors of the lung, breast, prostate, kidneys, and thyroid, in particular, spread to the bones. In the case of aggressively growing tumors, metastases can already be detected before the primary disease itself becomes symptomatic. Tumors generally take several years to develop. Secondary bone cancer therefore occurs primarily in the second half of life.

Bone Metastases in the Femur

Doctors do not classify benign cellular changes in the bones as cancer, but rather as benign bone tumors. Benign bone tumors include, among others,

• the osteoma,
• osteoid osteoma, and
• osteoblastoma.

The specific causes of bone cancer are not yet known. However, since 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,
• Paget’s disease of the bone 
• previous radiation therapy or chemotherapy for another condition

Patients with retinoblastoma (a tumor of the retina) also have an increased risk of developing bone tumors.

The symptoms of bone cancer are generally rather nonspecific. They may include, for example,

• pain at the affected site,
• swelling of the skin, and
• associated pain during movement

. However, the specific signs that appear ultimately depend on the type, size, and location of the bone tumor.

Bone cancer typically manifests with nonspecific symptoms such as pain at the affected site © 9nong | AdobeStock

Osteosarcoma most commonly occurs in the long bones of the upper arms or thighs. It typically affects the area of the bone where the shaft transitions into the rounded end. Patients notice painful swelling that increasingly impairs the mobility of the affected limbs. The malignant tumor causes the bone to lose strength. As a result, even normal stress can lead to a bone fracture. Such spontaneous fractures without significant external force are always cause for concern.

The symptoms of Ewing sarcoma are similar to those of other bone tumors. Pain and swelling in the affected area indicate the presence of the disease. However, this is accompanied by a severe feeling of illness with fever. The signs resemble those of osteomyelitis, which is why the two conditions are often confused. Ewing sarcoma occurs particularly frequently in the shaft of the long bones of the leg or in the pelvic bone.

Chondrosarcoma, on the other hand, causes very little pain. It occurs most frequently in the pelvic region, the thigh, or the shoulder area.

If symptoms suggest bone cancer, a detailed medical history is taken first, followed, as a rule, by an X-ray examination. Radiologists are specialists in imaging examinations. If the suspicion of a malignant bone tumor is confirmed, the following tests are performed:

• an MRI (magnetic resonance imaging) and/or
• a CT (computed tomography) scan.

X-ray of the knee showing a malignant bone tumor on the femur © Richman Photo | AdobeStock

To detect 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 levels of certain enzymes are elevated, this strengthens the suspicion of osteosarcoma or Ewing’s sarcoma, for example.

However, only a biopsy can provide a definitive diagnosis of whether a bone tumor is benign or malignant. During the procedure, the doctor uses a needle to remove a tissue sample from the bone. A pathologist then examines this sample in the laboratory.

Taking a tissue sample from the bone to confirm a 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 typically recommend combination therapy. The following options are available:

• Surgery
• Chemotherapy
• Radiation therapy

During surgical removal of the tumor, the surgeon removes entire sections of bone and, in some cases, surrounding tissue as well. In particularly severe cases, surgeons are sometimes even forced to perform an amputation. If the surgeon removes only small portions of the bone, implanted foreign materials are used to stabilize the area. These include screws and plates. In some cases, an external fixation device is also used. For very large defects, a bone graft using the patient’s own bone tissue (often from the iliac crest) may be necessary.

For osteosarcoma, which occurs more frequently in the long 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 destroy micrometastases. This is followed by surgery, during which the surgeon attempts to remove the remaining bone tumor as completely as possible. Afterward, chemotherapy is administered again. In addition, medications can help stimulate the immune system so that the body can fight the cancer more effectively. Radiation therapy is usually not an option, as osteosarcoma hardly responds to ionizing radiation.

Chemotherapy for bone cancer © Tyler Olson | AdobeStock

The same treatment regimen is used for Ewing sarcoma. However, this type of bone cancer does respond well to radiation, which is why radiation therapy is an important part of the treatment plan.

Chondrosarcomas are unfortunately particularly difficult to treat, as these bone tumors are highly resistant to radiation. However, since there are currently no alternatives, chemoradiotherapy in combination with surgery is still used to treat chondrosarcoma. Despite the extremely high doses of chemotherapy, some chondrosarcomas do not respond to the treatment at all. In such cases, doctors can only provide palliative care for the patients.

Surgeons usually remove benign bone tumors surgically as well. In the case of slow-growing tumors that do not cause any symptoms, treating physicians often adopt a “wait-and-see” approach. With osteochondroma, however, prompt surgery is very likely. This bone tumor, which is benign in itself, can degenerate and develop into bone cancer.

The prognosis for bone cancer depends

• on the type of tumor,
• its size and extent, as well as
• the stage of the tumor

. Furthermore, even after successful treatment, the possibility of the tumor returning—known as a recurrence—cannot be ruled out.

In the case of osteosarcoma, the prognosis is particularly favorable if the disease is detected early. If no metastases have yet formed, the five-year survival rate after diagnosis is over 60 percent. The prognosis is far less favorable if secondary tumors (metastases) have already formed.

The same applies to Ewing’s sarcoma, although the mortality rate within the first five years after diagnosis is actually slightly lower.

Patients with chondrosarcoma have a particularly poor prognosis. For this severe form of cancer affecting the cartilage, doctors report a bone cancer survival rate of less than 50 percent five years after diagnosis.