Antitumor activity of Corynebacterium parvum and retinyl palmitate used in combination on the Lewis lung carcinoma.
The effects of Corynebacterium parvum and retinyl palmitate given at various levels, schedules, and routes of administration on primary Lewis lung carcinoma and its metastases have been evaluated in C57BL/6J mice given s.c. inoculations of 5 X 10(5) tumor cells. Single i.v., but not i.p., s.c., or i.m., administration of C. parvum (0.35 mg/mouse given on Days 0, 1, or 3) reduced growth of tumor and prolonged survival time. Retinyl palmitate (3000 IU/mouse/day) given alone i.p. either before, after, or both before and after tumor inoculation showed no effect on tumor growth, survival of mice, or lung metastases. The combination of retinyl palmitate i.p. (6 daily injections of 1500 IU/mouse after tumor implantation) and C. parvum (0.175 mg/mouse) given i.v. resulted in an increase in life span over control of 146% and appeared to be therapeutically synergistic. This combination produced 90-day cures in about 20% of the treated animals, all of which were found to be tumor free. Two nonparametric statistical procedures, the Kruskal-Wallis and the Dunn test, were used to assess the effects of treatments on survival time and tumor growth and may be generally applicable to animal tumor studies. They provide multiple comparisons of different treatments and allow the inclusion of long-term survivors into the analysis.
D000818:Animals; D001428:Bacterial Vaccines / Q000627:therapeutic use; D002277:Carcinoma / Q000628:therapy; D005260:Female; D007167:Immunotherapy; D008175:Lung Neoplasms / Q000628:therapy; D051379:Mice; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000473:pathology / Q000628:therapy*; D011425:Propionibacterium acnes / Q000276:immunology*; D014801:Vitamin A / Q000627:therapeutic use*
D001428:Bacterial Vaccines; D014801:Vitamin A