In this episode of Kentucky Health, host Dr. Wayne Tuckson speaks with Dr. Shawn Price, an orthopedic surgeon with Fortis Orthopaedic and Sarcoma Group, about diagnosing and treating primary and metastatic bone cancer.
A Rare but Serious Form of Cancer
Primary cancer of the bone is rare – about 3,600 cases per year in the U.S. – and occurs most often in children. Known as sarcomas, Price says these cancers can involve bone, cartilage, muscle, smooth muscle, fat, or fibrous and connective tissues.
“When we look at the most common malignancy of bone, that being an osteosarcoma, they tend to happen in kids that are around their growth spurt, and there may be some connection to that,” says Price. “But overwhelmingly, we don’t have an answer as to why certain kids develop them and certain kids don’t.”
So far, medical research has not found any direct link between environmental or behavioral risk factors to developing sarcomas, Price says. The same goes for traumatic injuries. Studies have found a connection between certain genetic mutations and a higher risk for osteosarcoma, but those mutations are rare.
Most cancer found in the bones actually begins in another organ and metastasizes or spreads to the bones. These cancers usually cover a larger area than primary bone cancer. Price says the most common organs that develop cancer which then spreads to the bones are breast, prostate, lung, kidney, and thyroid.
“But in my practice, I’ve seen patients with GI (gastrointestinal) cancers that metastasize to the bone, so I always tell patients that if they have a malignancy, the bone is fair game, because the cancer doesn’t obey what the textbook teaches us,” he says.
Patients who eventually are diagnosed with bone cancer usually have pain as their first symptom, Price says. Other signs include swelling and warmth in soft tissue around the affected area, possibly causing a lump.
“As far as osteosarcoma, those tend to happen at the ends of bones, so by that, it’s typically around the joints,” he explains. “You will tend to get night pain as well – patients often wake up from sleep with pain. That’s a very common phenomenon.”
Additional symptoms include fever, sweats, chills, and weight loss. Price tells parents to pay close attention to any pain their children feel in their bones or joints, especially if the child is an athlete. If pain persists, it may not be from competition. He says a simple X-ray, which can identify changes in bone density, is usually sufficient to discover if there is any underlying cancer causing the pain.
“An X-ray picture can significantly change (a patient’s) treatment outcome and their surgical plan,” he says. “Someone who has an osteosarcoma does not have a normal plain radiograph – very rarely is that something that’s found. Often times, the radiograph will be the first index of suspicion that something’s going on and that we need to order more advanced imaging and tests.”
Although primary bone cancer is rare, roughly two-thirds of people who are diagnosed with it die from it, Price says. Part of the high mortality rate is due to delayed diagnosis.
The standard treatment for primary bone cancer is chemotherapy. Price says those regimens can help some patients, but he adds there has been little improvement in their overall efficacy due to the lack of research investment by drugmakers.
“The rare things in medicine don’t get attention – and by that I mean they don’t get the attention of the pharmaceutical companies,” he says. “So there are no significant improvements in the treatment for these sarcomas.”
In his initial diagnosis, Price will determine the stage of primary bone cancer (whether it is localized or has spread to other areas in the body). After giving chemotherapy for a determined time, he will check the cancer’s spread again and re-stage it. He says the most common organ for bone cancer to spread to is the lungs.
Surgical options depend on the stage of the disease and the area affected. Price describes most orthopedic surgical oncologists as “limb-salvage surgeons” who will try to save a patient’s arm or leg if at all possible. Even so, he concedes that most surgical operations require removing part of a patient’s bone and muscular tissue in order to completely excise the cancerous tumor.
If surgery requires substantial bone removal to eradicate the tumor, Price will reconstruct the bone using either a prosthesis or a bone graft. If he chooses a graft, Price will take a bone from a cadaver or from another part of the patient’s body. Most patients will receive another round of chemotherapy after surgery.
For patients – especially young patients – who have osteosarcoma in the knee area, a Van Nes rotationplasty is an option. This complex surgery involves removing the affected bone, such as the tibia, as well as the knee joint. Price then rotates the ankle joint so the foot is pointing backward and affixes it to the thigh, and reroutes the muscle tissue connections as well. Once the patient heals from this initial step, a prosthesis is affixed to the reverse ankle joint, which takes the place of the knee joint and provides for a fuller range of movement.
“It’s a lot better for patients from the standpoint of activity, things of that sort, as opposed to a megaprosthesis or endoprosthesis,” Price says. “The endoprosthesis is oftentimes secured with a bone cement and it has plastic in it, and often times with kids who want to engage themselves in those types of activities it will predispose them towards wearing out those components which will prompt them to have to have a revision.”
Patients who have had bone cancer removed may also be treated with radiation after surgery. If they do, Price will have them undergo physical therapy as part of their long-term recovery but also to mitigate the effects of radiation on the joint, which can cause stiffness.
Price’s treatment approach for patients who have developed bone cancer metastases that originated elsewhere in the body is quite different. His primary objective for these patients is not to cure the cancer but to stabilize the bone and maintain its function as best as possible as the patient receives chemotherapy and/or radiation.