Our 14-year-old daughter was diagnosed with osteosarcoma of the femur — just at the end of the bone where it meets the lower leg to form the knee joint. We are trying to be optimistic but we’d really like to know what to expect in the coming months to years. Will she even have that long?

Osteosarcoma (bone cancer) is a rare form of cancer with only about new 560 cases diagnosed each year. Children and teens are affected most often because of how fast they are growing. Rapid turnover of bone cells goes haywire when tumor-suppressor genes that normally regulate the bone cell cycle get turned off or get side tracked. It doesn’t look like osteosarcoma is an inherited condition, but there are some genetics involved with chromosomal abnormalities and of course, mutation of the tumor-suppressor gene.

Osteosarcoma has a difficult prognosis. If the diagnosis is delayed, the tumor has often spread. Experts estimate that this is the case in 20 per cent of all patients. There is also the chance that micrometastases (invisible or undetectable) are present at the time of diagnosis.

Early treatment can help prevent the growth and spread of tumors. Osteosarcoma spreads through the blood, first to the lungs and then to other bones. Treatment is aimed at removing the primary (main) tumor and killing off any tumor cells that can’t be seen before they have time to grow.

The results of a multidisciplinary approach to osteosarcoma with improved treatments have really improved survival and quality of life over the last 10 to 20 years. Survival rates have increased from 10 to 20 per cent back in the 1960s to almost 80 per cent today. That optimistic figure of 80 per cent applies to patients who don’t have any sign of metastases. The presence of mets changes the prognosis downward toward a shorter lifespan and increased risk of cancer recurrence.

Pre- and postoperative chemotherapy has helped improve results. It is hoped that with continued research, new and better drugs to target the cancer cells will be available in the near future. Before a specific treatment plan can be devised, the tumor must be staged. The physician relies on imaging studies (X-rays, MRIs, PET scans, bone scans) to stage the tumor from Grade I (low) to Grade IIB (high) and Grade III (low to high but with metastases already present). The prognosis is often linked with the stage of the cancer. This is where your oncologist can help you map out a course of treatment and expected outcomes.