Photodynamic therapy using NPe6 for bronchogenic carcinomas in central airways more than 1.0 cm in diameter.

Abstract

7081 Background: Photodynamic therapy (PDT) is recommended as a treatment option for centrally located early lung cancers (CLELCs), meaning roentgenographically occult squamous cell carcinomas that are located no more distally than segmental bronchi and, histologically, are either carcinoma in situ or carcinoma associated with only limited invasion. Since CLELC patients who are heavy smokers are at fairly high risk of developing a second primary lung cancer, they require treatment that will preserve their cardiopulmonary function. Most centrally located early lung cancers (CLELCs) less than 1.0 cm in diameter do not invade beyond the bronchial cartilage, and photodynamic therapy (PDT) with Photofrin is currently recommended as a treatment option for such lesions. NPe6 is a second-generation photosensitizer, and since it has a longer absorption band (664 nm) than Photofrin (630 nm), we hypothesized that NPe6-PDT would exert a strong antitumor effect against cancer lesions greater than > 1.0 cm in diameter, which are assumed to involve extracartilaginous invasion and to be unsuitable for treatment with Photofrin-PDT. Methods: Between June 2004 and December 2008, 75 patients (91 lesions) with CLELC underwent NPe6-PDT after the extent of their tumors had been assessed by fluorescence bronchoscopy for photodynamic diagnosis (PDD) and tumor depth had been assessed by optical coherence tomography (OCT). Results: Seventy-four cancer lesions Å…1.0 cm in diameter and 21 lesions >1.0 cm in diameter were identified, and the CR rate was 94.0% (66/70) and 90.4% (19/21), respectively. After the mass of large tumors and deeply invasive tumors, had been reduced by electrocautery, NPe6-PDT was capable of destroying the residual cancer lesions. Conclusions: NPe6-PDT has a strong antitumor effect against CLELCs >1.0 cm in diameter that have invaded beyond the bronchial cartilage, thereby enabling the destruction of residual cancer lesions after mass reduction of large nodular or polypoid type-lung cancers by electrocautery. The PDT guidelines for lung cancers should therefore be revised, because use of NPe6-PDT will enable expansion of the clinical indications for PDT. No significant financial relationships to disclose.