Osteosarcoma

Disease information

Overview
Causes
and Symptoms
Treatment

Overview

Osteosarcoma is a kind of cancer that starts in the cells that form bones. It usually happens during puberty when kids are growing quickly. In Korea, about 50 kids under 15 get diagnosed with osteosarcoma each year. Around 60% of osteosarcomas are diagnosed in children and teenagers, and about 10% happen in people in their 20s. This type of cancer most often affects the ends of the long bones in the body, especially around the knee. But it can also show up in the middle of the body, like the pelvic and vertebral bones, though this is less common.

Causes and Symptoms

We don't fully understand what causes osteosarcoma, but we know that genes play a role in some cases. For example, people with a kind of eye cancer called hereditary retinoblastoma are more likely to develop osteosarcoma than people in the general population. We've also seen osteosarcoma develop after radiation therapy in some instances.

The most common signs of osteosarcoma are pain and swelling. This type of cancer often shows up in teenagers, a time when they're very active, and the symptoms can sometimes look like injuries from playing sports. At first, the bone pain might happen only during physical activity and get better with rest, which can make a lot of people think it's just from exercise. But, if a teenager has ongoing bone pain, especially around the knee or in the long bones of the legs, and there's no clear reason why, it's important to get it checked out by a doctor. Swelling in the joint and tenderness when you press on it, along with warmth in the area, can also happen, and these symptoms can sometimes be mistaken for osteoarthritis.

Distinguishing between growing pains and other conditions

Distinguishing between growing pains and other conditions
Growing pains	Pain due to other diseases
Intermittent and mild pain Typically, the pain occurs in the late afternoon or before bedtime, particularly after an active day The pain is in the muscles, not the joints	Continuous pain in joints or other specific areas Limping or the presence of a lump Accompanied by symptoms such as fever, skin rash, or decreased appetite The area of pain is swollen, painful to touch, and shows signs of redness

Treatment

Chemotherapy

In the past, the survival rate for osteosarcoma patients who only had surgery was as low as 20%. But with the introduction of chemotherapy, we've seen that rate increase significantly to 80%. Today, the standard treatment for osteosarcoma in the arms or legs begins with two cycles of chemotherapy even before surgery. If the chemotherapy successfully reduces the tumor size, we then perform a surgery called a wide excision to remove the tumor. After surgery, we continue with several more cycles of chemotherapy. The main drugs we use in chemotherapy for osteosarcoma are methotrexate, cisplatin, and doxorubicin. These drugs have proven effective in significantly improving the prognosis for patients with this type of cancer.

Surgery

Surgery is a key part of treating osteosarcoma. The decision about whether to try to save the bone where the tumor is located is important, both for medical reasons and because of how it might affect a patient's appearance and feelings. In most cases, when osteosarcoma shows up in the bones of the arms or legs, we can take out the bone with the tumor without needing to amputate, or remove, the whole arm or leg. Instead, we can replace the removed bone with an artificial one, or prosthesis.

However, sometimes the tumor is pressing on or wrapped around important blood vessels or nerves. If we can't separate these from the tumor, we might need to amputate the affected arm or leg. During surgery, we look at how much the chemotherapy has destroyed the cancer cells. If most of the cells have been killed, that usually means a better outlook for the patient. Also, how completely the cancer is removed during surgery has a big impact on the patient's prognosis.

In the case of metastatic lesions in the lungs

If the osteosarcoma has spread to the lungs but the metastases are within a range that can be surgically removed, lung resection may be performed as part of the treatment. Even when the metastases are limited to an area that can be resected, we consider lung resection if we judge that the remaining lung function would be sufficient to support life. Osteosarcoma, in general, does not respond well to radiation therapy, so we typically do not use this method of treatment. The primary treatments for osteosarcoma remain surgery, possibly including amputation or limb-saving surgery, and chemotherapy.