Thalidomide in Treating Patients Who Have Undergone Surgery and Chemotherapy for Cancer That Has Spread Throughout the Abdomen Due to Colorectal Cancer or Appendix Cancer

RATIONALE: Thalidomide may stop the growth of tumor cells by blocking blood flow to the tumor. Giving thalidomide after surgery and chemotherapy may kill any remaining tumor cells. PURPOSE: This phase II trial is studying how well thalidomide works in treating patients who have undergone surgery and received chemotherapy directly into the abdomen by hyperthermic perfusion for cancer that has spread throughout the abdomen due to colorectal cancer or appendix cancer .