Irinotecan Plus Gemcitabine in Treating Patients With Unresectable or Metastatic Solid Tumors

RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining more than one drug may kill more tumor cells. PURPOSE: Phase I trial to study the effectiveness of combining irinotecan and gemcitabine in treating patients who have unresectable or metastatic solid tumors.