The significance of autochthonous lymphocyte interactions with human breast cancer cells in primary tissue cultures

Short‐term primary tissue cultures of 16 human breast cancers were employed to study cancer cell interactions with autochthonous lymphocytes. Attention was given to 4 lymphocyte interactions, 1 random and 3 special forms, i.e., clustering, congregation, and emperipolesis. Stained tissue culture preparations were used to count the total number of cancer cells and the frequencies of the different lymphocyte interactions with the cancer cells. Comparisons were made of interactions of 2 groups of autochthonous lymphocytes—those already present in the explant of cancer tissue and those of homolateral axillary lymph node origin which were added to the nutrient media. Where lymphocytes were not added, only 29% of the cases had one or more preparations positive for interactions, whereas the corresponding figure for the group with added lymphocytes was 65%. In addition, the frequency of the interactions within each of the positive preparations was increased fourfold. Furthermore, in those preparations where an increased frequency was noted, the yield of viable cancer cells was significantly less than that found in the corresponding cultures without added lymphocytes. Conversely, an increase in cancer yield occurred in those cultures where the addition of lymphocytes failed to increase the frequency of interactions. These and other findings dealing with distinctive lymphocyte responses of an individual to his own cancer provide insight into host defense mechanisms not otherwise available.