Effect of tuftsin on in vivo development of 3-methylcholanthrene-induced primary fibrosarcoma and Lewis lung carcinoma in mice.

The effect of tuftsin therapy on tumor development was examined in a murine primary fibrosarcoma and the Lewis lung carcinoma systems. Following im injection of 3-methylcholanthrene (CAS: 56-49-5) on day 0, C57BL/10ScSn mice were treated weekly with 3 ip tuftsin injections beginning on day 1 or day 60. Similar patterns of tumor development were observed regardless of whether tuftsin therapy was immediate or delayed. Only modest differences in experimental and control tumor incidences were found upon termination of studies; however, treated animals developed significantly fewer tumors than controls early during the observation periods. Thus mean tumor latent periods varied significantly when therapy began on day 1 (103.6 days in controls vs. 119.1 in treated mice; P = .02) or 2 months later (104.6 days in controls vs. 115.3 in treated mice; P = .01). One day subsequent to intra-footpad implantation of 10(5) Lewis lung carcinoma cells, C57BL/6 mice received at least 10 iv injections of tuftsin and were compared with controls for variations in survival or lung tumor development. The mean survival time in treated mice, 41.2 days, differed sharply from that (30.1 days) in controls (P = .00001). Similar groups of mice varied significantly in mean metastatic lung colony counts when examined on day 30; there were 15.1 colonies in controls and 8.0 in experimental animals (P = .03).