Photodynamic Therapy Using Porfimer Sodium in Treating Patients With Recurrent Mouth or Throat Dysplasia or Recurrent In Situ Cancer or Stage I Cancer of the Mouth or Throat

RATIONALE: Photodynamic therapy uses a drug that becomes active when it is exposed to a certain kind of light. When the drug is active, tumor cells are killed. Photodynamic therapy using porfimer sodium may be effective against mouth or throat dysplasia and cancer of the mouth and throat. PURPOSE: This phase I trial is studying how well photodynamic therapy using porfimer sodium works in treating patients with recurrent mouth or throat dysplasia, recurrent in situ cancer of the mouth or throat, or stage I cancer of the mouth or throat.