Photodynamic therapy for anal cancer

Summary 

Invasive anal cancers are generally successfully treated by combined chemotherapy with radiation therapy (XRT). For those patients who locally fail this intervention many are salvaged by surgery which generally results in permanent colostomy. We examined the treatment and outcome of Photofrin^® based photodynamic therapy (PDT) in a cohort of patients with anal cancer who failed locally despite chemo-radiation (N=6) and two patients with positive margins of resection after excision of small T₁ squamous cell anal cancers who refused further surgery or chemo-radiation. PDT consisted of outpatient infusion of Photofrin^® at 1.2mg/kg followed 48h later by outpatient illumination. Red light (630nm) illumination was delivered by a 5cm diffusing fiber, treating transphincterally at 300J/cm followed by microlens illumination at 200J/cm² to the perianal tumor bed with 2cm margin. All patients completed PDT without incident and all have maintained local control of disease in the anal region for the length of follow up (18–48 months). PDT may serve as a new means to salvage local failures and perhaps could be employed as a primary treatment modality in select patients with early stage of disease.

Keywords: Anal cancer, Photodynamic therapy, Photofrin^®