[Breast cancer-specific immunity evaluated by a new in vitro method--IL-2 enhanced MLTR]

Peripheral blood lymphocytes from 81 patients with breast cancer were stimulated in vitro with solubilized sonicated autologous tumor extract as an antigen source . The significance of tumor-stimulation (mixed lymphocyte tumor reaction; MLTR) was evaluated with or without the addition of interleukin-2 (IL-2,90 U/ml). As a result, MLTR with the addition of IL-2 (IL-2 enhanced MLTR) showed a higher significance even at a stimulation index (S.I.) of 1.5 than MLTR without IL-2. The values of S. I. in IL-2 enhanced MLTR in preoperative cancer patients were the highest in the patients without lymph node metastasis (n0). The patients with advanced lymph node metastasis (n2) showed a lower response preoperatively but their response was similar to that of the n0-patients 1 to 2 was after operation. These difference were not observed in the blastogenic response to IL-2. These results suggest that IL-2 enhanced MLTR is a useful method to assess the tumor-specific immunological status of the cancer patients.