RATIONALE: Drugs used in chemotherapy work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Radiation therapy uses high-energy x-rays to kill tumor cells. Giving combination chemotherapy before surgery may make the tumor smaller and reduce the amount of normal tissue that needs to be removed. Giving chemotherapy and radiation therapy after surgery may kill any tumor cells that remain after surgery. Sometimes, the tumor may not need any treatment until it progresses. In this case, observation may be sufficient.