Photodynamic Therapy in Treating Patients With Precancerous Esophageal Conditions or Early Stage Esophageal Cancer

RATIONALE: Photodynamic therapy uses a drug, such as HPPH, that is absorbed by tumor cells. The drug becomes active when it is exposed to light, and kills tumor cells. HPPH may be effective in killing precancerous cells and tumor cells. PURPOSE: This randomized phase II trial is studying how well photodynamic therapy with HPPH works in treating patients with precancerous esophageal conditions or stage 0 or stage I esophageal cancer.