RATIONALE: Radiation therapy uses high-energy x-rays to kill tumor cells. Drugs used in chemotherapy, such as docetaxel, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Celecoxib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving celecoxib after radiation therapy and chemotherapy may kill any tumor cells that remain after radiation therapy and chemotherapy. Sometimes, after radiation therapy and chemotherapy, the tumor may not need additional treatment until it progresses. In this case, observation may be sufficient.