Osteosarcoma is the most common malignant bone tumor in adolescents and young adults (100 to 150 new patients per year in France). The majority of these osteosarcomas (70%) occur in young people aged 10 to 25 years, and it affects boys more frequently (1 girl affected for every 1.4 boys). Localized osteosarcomas are limited to one bone, the site of original development. Half of these tumors occur on the femur and around the knee, but other bones can also be affected. In 10 to 20% of cases, metastases are present at the time of diagnosis. These metastases are located in 85 to 90% of cases in the lungs, and others subsequently occur on another bone.
The main symptoms
The most common symptoms of bone cancers are swelling of the affected area and pain. Sometimes these pains manifest following trauma (accident, sport), but there is no link between this incident and the occurrence of a bone tumor. Other symptoms depend on the organs near the tumor: motor problems, respiratory problems, compression of a vertebral tumor. At the slightest doubt, we recommend making an appointment with your general practitioner, who will prescribe the necessary diagnostic tests for the child.
Diagnosis
The diagnosis and decision for surgical intervention (and if necessary, the type of bone reconstruction) are made through multiple examinations (X-ray, CT scan, MRI (magnetic resonance imaging), angiography, and scintigraphy).
Treatments
Non-metastatic osteosarcoma
The initial treatment of osteosarcoma includes three phases, all of which are important to control the disease, achieve remission, minimize the risk of disease recurrence, and maximize the chances of cure with minimal sequelae. The choice of treatment should be discussed in a multidisciplinary consultation meeting (RCP) “sarcoma” for adult patients or “pediatric” for patients under 18 years old.
Initial “neoadjuvant” chemotherapy
It has many advantages:
- Stop the progression of the disease wherever it is located
- Early attack on metastases
- Eliminate pain and facilitate the surgical procedure The chemotherapy drugs used most often in France combine high-dose methotrexate, ifosfamide, and etoposide, less frequently doxorubicin and cisplatin. The duration of the treatment is 8 to 10 months. At the end of phase 1 of the treatment, the tumor’s response to treatment will be evaluated through examination of the tumor after surgery. This analysis determines the histological response, which is considered good if there are fewer than 10% of live tumor cells remaining.
Conservative surgery
The key element of local treatment is surgery, which aims to remove the entire portion of the initially affected bone. This is known as “conservative” surgery with resection and then reconstruction of the bone in the same operation. In less than 10% of cases, amputation may be necessary when local invasion is such that it is impossible to preserve healthy tissue around the lesion, when the tumor is infected, or when it invades the skin. Very rarely, when osteosarcomas are considered “inoperable,” radiotherapy can be used as local treatment, but the chances of disease control are lower.
Post-operative “adjuvant” chemotherapy
In France, this chemotherapy is adapted to the presence of risk factors for osteosarcoma recurrence (presence of metastases at diagnosis, inoperability of the tumor, and/or poor histological response to preoperative chemotherapy). The drugs used are the same as those used during initial chemotherapy if the response obtained is deemed satisfactory.
Metastatic osteosarcoma
Metastatic osteosarcomas are more severe. The treatment regimen is identical to the one described above, with the addition of surgical removal of the metastases if possible. If this is not possible, irradiation of the metastases may be considered.
RESEARCH AGAINST OSTEOSARCOMA WITH IMAGINE FOR MARGO
Since 2011, Imagine for Margo has made cancer research for children, adolescents and young adults its top priority. Faced with the current situation, the association is funding a number of research programs aimed at curing young people affected by cancer more effectively. These include the IMAGINE osteosarcoma program and Dr. Verechia’s project on the role of calcium conductance in the development of pediatric sarcoma.
The research currently being carried out on osteosarcoma in children should further improve the management of this disease, by increasing the efficacy of treatments and reducing their side-effects.
If you would like to help research and build a world with cancer-free children, please donate by clicking here. Every gesture is essential in our fight for life.
Together, we can beat childhood and adolescent cancer.
