Therapeutic in vivo and in vitro effects of argon dye laser and hematoporphyrin derivative in lung cancer.

In clinical and experimental study the therapeutic efficacy of argon dye laser irradiation with hematoporphyrin derivative (HpD) was evaluated in lung cancer. A total of 14 lung cancer cases including 12 squamous cell, 1 adeno- and 1 small cell carcinomas were irradiated superficially 48 hours or more after i.v. injection of 3 mg/kg of HpD (100-300 mW, 20-30 min.). Human adenocarcinoma cells implanted subcutaneously into nude mice were photoirradiated (200 mW, 20 min.) 48 h after i.p. injection of HpD. The in vitro effect of phototherapy was studied in the same cell line after incubation in medium containing HpD compared to untreated, only irradiated or only in HpD incubated cells. Among 3 early stage squamous cell carcinoma cases 2 complete and 1 partial remissions were obtained. Among 11 cases including 10 with advanced and 1 with recurrent disease 7 demonstrated partial remission. In vivo, two of 9 mice had a complete tumor remission. In the in vitro study, tumor cells incubated in 30 micrograms HpD/ml showed severe cytotoxic effects resulting in cell death 12 hours after photo irradiation, whereas cells incubated in 30 micrograms HpD/ml only regenerated after initial cytotoxic reaction. Laser irradiation only had no effects. HpD phototherapy demonstrated a considerable antitumor efficacy and must be considered as one of the promising endoscopic treatments in cases with early stage primary lung cancer.