Shah R K, Valdez T A, Wang Z, Shapshay S M
Department of Otolaryngology-Head and Neck Surgery, Otolaryngology Research Center, Tufts-New England Medical Center, Boston, Massachusetts, USA.
Laryngoscope. 2001 Jul;111(7):1203-8. doi: 10.1097/00005537-200107000-00013.
OBJECTIVES/HYPOTHESIS: This study examined the role of the pulsed-dye laser (PDL) at 585 nm coupled with retinoic acid at therapeutic (5.0 mg/kg) and nontherapeutic (0.5 mg/kg) doses to delay the progression of cancer with a two-hit approach. The existing vasculature is selectively targeted by the laser, whereas retinoic acid inhibits future angiogenesis.
Randomized, prospective study in a murine model.
Twenty-five athymic nude mice were inoculated with oral squamous cell cancers on six flank sites and randomly divided into five groups: 1) control subjects, 2) treatment with 0.5 mg/kg retinoic acid (RA 0.5), 3) treatment with 5.0 mg/kg retinoic acid (RA 5.0), 4) treatment with RA 0.5 + PDL, and 5) treatment with RA 5.0 + PDL. The PDL groups received irradiation after inoculation. The retinoic acid was administered daily. The tumors were counted and measured for 14 days.
The control group developed visible tumors in 50% of the inoculation sites at 3 days compared with 3 days (RA 0.5) and 4 days (RA 5.0) for the retinoic acid groups and 9 days (RA 0.5 + PDL) and 10 days (RA 5.0 + PDL) for the laser treatment groups. There was no tumor growth until day 7 in the RA 5.0 + PDL group. The tumor volume was statistically different between the treatment groups.
This study demonstrated the superiority of a single treatment with the PDL coupled with retinoic acid to delay the progression of cancer when compared with treatment with retinoic acid alone, thus introducing a novel strategy in cancer control.
