Effects of intralesional versus ip administration of cisplatin on squamous cell carcinoma of mice.
The effects of intralesional versus ip administration of cisplatin (total, 24 mg/kg) given on different schedules were studied using transplantable squamous cell carcinoma of mice. The size of the tumor in the control group increased approximately 60 times at the end of the experiments, whereas it decreased to 0.04 of the initial volume following a single intralesional injection of cisplatin. The ratio of treated/control mice was 0%. The comparable values in the groups with intralesional cisplatin at 3- and 1-week intervals were 7% and 20%, respectively. The responses of the tumor to cisplatin in the ip groups were lower than those of the intralesional groups and were not dependent on the schedule of administration. Toxic deaths were less frequently encountered in the intralesional groups of animals. Platinum concentration in tumors of the intralesional group was two to five times higher than that of the ip group 15 minutes to 96 hours after injection of 12 mg/kg of cisplatin, whereas the concentration in sera of the intralesional group remained lower than that of the ip group until 48 hours after the injection. The results indicate that the intralesional route produces a good response of tumor to cisplatin by maintaining high levels of the non-protein-bound form of the agent in the tumor tissue that cannot be provided by other routes of administration.