Osteosarcoma, also known as osteogenic sarcoma or OGS, is the most common bone cancer in children and young adults. Older adults may be affected as well, however. The tumor tends to occur at the ends of the long bones near a joint, such as the femur (thigh bone), tibia (lower leg bone), and humerus (arm bone). X-rays and MRI can be suggestive of the diagnosis, but a biopsy is needed for final confirmation. On conventional X-rays, OGS appears as new bone formed by tumor cells within or next to normal bone. The tumor can weaken the patient's bone and actually cause a fracture with little or no trauma. Patients present to their doctor complaining of increasing bone pain and occasionally a fracture. Like other cancers, OGS is capable of spreading to other sites (metastasis) through the blood stream. The most common sites of metastasis are the lungs and other bones. Once the diagnosis is made, "staging" is done which is important to determine the extent of disease. Staging consists of a bone scan and chest xrays.

MRI of an osteosarcoma in the distal femur, near the knee

Since 1989, physicians at The Denver Clinic for Extremities at Risk have treated many patients of all ages with OGS. Several papers have been published by the Extremities at Risk team, reporting superior survival and outcomes in saving patient lives -- and limbs. Since 1989 a unique multi-specialty approach has utilized individualized chemotherapy and limb saving surgery.

Over 90% of patients with non-metastatic OGS of an extremity were cancer-free at 10 years after diagnosis. The treatment method ("protocol") involves tailoring the dose and duration of chemotherapy to the size of the tumor. It is in the treatment of OGS that the team concept has been perfected by The Denver Clinic.

From the time the diagnosis of OGS is suspected until treatment begins is ideally less than 24 hours. The highly experienced professionals include:

1. an orthopedic oncologist makes the presumptive diagnosis and performs the appropriate biopsy;
2. a pathologist confirms the diagnosis;
3. patient consults with an oncologist who will order staging studies and prescribe chemotherapy;
4. the skill of an interventional radiologist is required for a portion of the chemotherapywhich is injected directly into the tumor under sedation in the radiology department;
5. over the course of the next few months, the patient and his/her reponse to therapy is closely monitored by the oncologist;
6. as the tumor "dies," the patient is assessed as "responding" to chemotherapy, and the oncologist and orthopedic oncologist will determine a "window" of time for surgery to be scheduled;
7. an orthopedic oncologist and plastic surgeon take out the tumor and reconstruct the bone, joint and soft tissue area;
8. in the lab, the pathologist dissects the resected tumor specimen and reports on how much of the tumor has died.
9. In addition, other members of Denver Clinic who become involved with helping the patient and family are physical therapists, prosthetists, and social workers.

The Chemotherapy

Under sedation, an experienced interventional radiologist threads a small catheter into the main artery that directly "feeds" the tumor. High doses of chemotherapy are injected directly into the tumor through this "feeding" artery. The goal is to "kill" at least 90% of the tumor before surgery, making limb salvage possible. Before each cycle of chemotherapy pictures of the tumor and its blood supply are assessed and compared using X-ray techniques. In this way patients undergo enough chemotherapy cycles to maximize the effectiveness and kill the tumor. The average number of cycles is 4, but always at least 3 and not more than 6.

Arteriogram of osteosarcoma in the proximal tibia (near knee). The dark area is the tumor	Arteriogram of the tumor after 1 cycle of chemotherapy.	Arteriogram showing  the tumor after 2nd  cycle of chemotherapy	Arteriogram of the tumor after the 3rd cycle of chemotherapy. The tumor has shown a good response to chemo.

Once the tumor has been effectively weakened by chemotherapy, the second phase of treatment is surgery. This generally includes removal of the entire tumor and reconstruction of the resulting defect in the bone. Reconstructive options depend on the location and size of the tumor… as well as the age and functionality of the patient. We use the most modern techniques available to restore function and minimize pain after surgery.

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