2002 OITE Question 265

Question

Osteosarcoma is more common in patients with what other malignancy ?

1) Ewing’s sarcoma

2) Rhabdomyosarcoma

3) Wilm’s tumor

4) Neuroblastoma

5) Retinoblastoma

Figures

Answer (click for answer)

The correct answer is 5.

This relationship is based on a tumor suppressor gene that is found to be altered in both disease states. The retinoblastoma gene is responsible for creating a protein that is considered a tumor suppressor. This protein is important with respect to DNA synthesis. Its absence or alteration allows cells to advance through the cell cycle in an uncontrolled manner thus resulting in a higher chance of malignancy. This protein has been found to be missing or inactivated in retinoblastomas, sarcomas, and small cell carcinomas of the lung.

Reference: Buckwalter JA, Einhorn TA, Simon SR: Orthopaedic Basic Science: Biology and Biomechanics of the Musculoskeletal System ed. 2. Rosemont, IL, AAOS 2000 427-41