Malignant bone tumors

The most commonly encountered of the malignant or aggressive primary bone tumors are the osteosarcoma, giant cell tumor (not technically malignant), chondrosarcoma, and Ewing's sarcoma. The survival data is capture by the SIngapore cancer registry and available for academic scrutiny. The data shown below is the survival data of the last 40 years since the late 1960s (Figure 1). While the curves shown span up to 40 years it should be understood that after 5 years or 60 months, the patient is considered disease-free and death after this time may be unrelated to the primary tumor.

Figure 1. Data from the Singapore Cancer registry accessed in 2008 for bone tumors managed in Singapore since the late nineteen sixties. Data shown here is for both metastatic and non-metastatic disease and is therefore less impressive than normally depicted for non-metastatic disease.

The first two curves from the top represent the survival curves of the giant cell tumor. The gold curve is for the malignant variant and the green the benign variant. Two points should be clear. Firstly, these two seem to have the same survival rate. This underscores the difficult in grading these tumors and so this practice of grading giant cell tumors is not uniformly practiced by all pathologists. Secondly, while giant cell tumors are supposed to be benign they do have about a 5% mortality rate underscoring that in a small percentage these tumors can be malignant.

The third blue curve is that of the chondrosarcoma. This exists in three grades with the poorer grades being responsible for the 30% fatalities seen above.

The next red curve is that of the Ewing's sarcoma which used to be considered uniformly fatal but with better chemotherapy and radiation has improved to being as good as osteosarcoma.

The bottom turquoise curve is that for osteosarcoma which is the archetype for management of all tumors in musculoskeletal oncology. Survival in the localised disease category is typically 70% at 5 years.