Regional lymphadenectomy and tumor curability in C3H/He mice transplanted with MH 134

In order to elucidate the effect of surgical removal of the regional nodes on the immunological defence of the host against the tumor, as well as on the cure rate of C3H/He mice transplanted with MH 134, three separate experiments were carried out, and the following results were obtained: 1) The cure rates of mice treated by removal of the primary tumor with regional lymph nodes were significantly lower than that of mice treated by simple amputation without regional lymphadenectomy. 2) It was demonstrated by a bioassay of the regional node that viable tumor cells presented in the nodes prior to the operation disappeared after removal of the primary tumor, whereas in 60-Co irradiated mice prior to the tumor inoculation, such phenomena were not observed. 3) Observation utilizing in vivo neutralization revealed that regional lymph node cells were capable of interfering with growth of tumor cells. These findings suggest that removal of the regional nodes impairs the restraint to the growth of residual tumor after the removal of the primary tumor, and this is probably due to a derangment of the immunologic response of the host.