context: Osteosarcoma, sometimes called osteogenic sarcoma, is the most common kind of bone cancer in children and teens. It can affect adults, too, but teenage boys are most likely to get it. It happens when the cells that grow new bone form a cancerous tumor. The treatment for osteosarcoma -- chemotherapy and surgery to remove the tumor -- is usually successful when the disease is diagnosed early on, before it can spread. In children and teens, osteosarcoma often happens at the ends of long bones, where bone grows quickest. Most tumors develop around the knee, either in the lower part of the thighbone or the upper part of the shinbone. They also may grow in the upper arm bone close to the shoulder. But osteosarcoma can develop in any bone in your body, especially in older adults. The condition stems from an error in your child's DNA, or genetic code. Bone-growing cells make osteosarcoma tumors by mistake. Teenagers who are having a âgrowth spurtâ are most likely to get it, and taller kids may be more at risk. There may also be a link between the speed of the growth spurt and tumor development, but scientists are still studying this. Treatments like radiation therapy for other types of cancer, or cancer medicines called alkylating agents, can also make this disease more likely. Certain illnesses, like Paget's disease of the bone or a type of eye cancer called hereditary retinoblastoma, may also raise the risk. Warning signs include: Swelling or lumps around bones or the ends of bones. Bone or joint pain or soreness. This pain may come and go for months. Broken bones that don't seem to be caused by normal events like a fall. Your child may have pain at night or after he plays or exercises. He might get a limp if osteosarcoma affects his legs. Tell your doctor about these symptoms right away. Your child may need to be tested to see if cancer is causing the pain, swelling, or breaks. The doctor will ask you about your child's medical history and your family health background. He'll check your child's body for unusual lumps around bones, or to figure out what's causing the pain. He may do imaging tests like X-rays, CT scans, MRIs, or bone scans. These can show unusual changes in bones that may be signs of osteosarcoma. They can also show areas where the tumor may have spread. If your doctor sees signs of the disease on imaging tests, your child may need a biopsy. A surgeon will take a small sample of bone or tissue from a painful or swollen area. This test may show cancer cells in the bone, or if cancer cells have spread to muscles or other areas around the bone. Your medical team will work closely to make sure that the biopsy is done in a way that doesn't interfere with possible surgical treatments. There are different kinds of treatment for osteosarcoma. It depends on several things, such as where the tumor is, how fast it's growing, and whether it has spread. Age and overall health are also factored in. Most people with osteosarcoma need both surgery and chemotherapy. Some also get radiation therapy. The goal of surgery is to remove all the cancer. If even a small number of cancer cells are left behind, they can grow into a new tumor. For tumors in the arms and legs: In most cases, your surgeon will be able to remove the tumor and some of the tissue around it and save your child's limb. A special medical device, or prosthesis, will fill in part or all of the gap left in the bone. Your doctor may also consider a bone graft, which uses a piece of bone from another part of the body or from a donor. If the tumor is large and has gotten into nerves or blood vessels, the surgeon may have to amputate or remove all or part of your child's leg or arm. Depending on how much needs to be amputated, your child may need to get fitted for an artificial limb, or prosthetic. Each of these surgeries can have short-term side effects and cause long-term social and emotional issues. Talk to your doctor about your child's best options and what to expect after surgery. For tumors in other areas: Osteosarcoma that forms in the pelvis, jaw bone, spine, or skull may be harder to remove completely with surgery. For this kind of cancer, some people also need radiation therapy. If the cancer spreads to the lungs or elsewhere, those tumors also need to be surgically removed. â Chemoâ uses powerful medications to kill cancer cells or stop them from growing. You usually get them through an IV tube. Doctors treat most osteosarcomas with chemo. Your child's doctor will talk with you about the timing of the chemo and surgery. Chemo may shrink the tumor, which makes surgery easier. It also gets rid of small clusters of cancer cells in the body that doctors may not be able to see on medical scans. Children tend to have less severe side effects from chemo than adults. Because of this, your child's cancer doctor may use higher doses of chemo to try to kill the tumor. Some side effects may include nausea and vomiting, not feeling hungry, and diarrhea. Usually, doctors don't use radiation to treat osteosarcoma. But the doctor may talk with you about this option in certain circumstances. Doctors can use high-energy X-rays to kill cancer cells. It doesn't work as well on osteosarcoma cells as it may with the cells of other cancers. But your doctor might consider what's called external beam radiation therapy if surgery can't remove all the cancer. That often happens when the tumor is in the hip or jaw bone. This type of therapy focuses high-energy beams on the tumor from a machine outside the body to kill the remaining cancer cells. Scientists are studying the best combination of chemo medications to treat osteosarcoma and testing newer types of drugs. Researchers are also working to develop more targeted and more powerful radiation therapies. You may want to ask your doctor about clinical trials. These are how experts test potential new treatments before they're made widely available. Your doctor can help you find one that might be a good match and help you understand what's involved. A cancer diagnosis can be hard to handle, especially when it affects your child. You may want to consider joining a support group. Counseling is also a good option if the emotions that you and your family are going through take a toll. Let your family and friends know how they can support you as you go through this. Chances are they'll want to help but may not know how. Treatment works best when it's started before the cancer spreads beyond the bones to other tissues or organs. Most tumors are found early because kids speak up about pain or parents notice swelling or a limp. So let the doctor know about warning signs like these as soon as possible.