Growth dynamics of cultured myofibroblasts from human breast cancer and nonmalignant contracting tissues.

Myofibroblasts were successfully grown in tissue culture from the connective tissue stroma of three human breast adenocarcinomas. These cells had slower growth kinetics than fibroblasts from normal human dermis, as did myofibroblasts from two granulating wounds. Electron microscopy of breast cancer slices and tissue cultures of these specimens confirmed the presence of myofibroblasts in both. In early passages, the specificity of carcinoma-derived myofibroblast growth kinetics is preserved. The exact role of myofibroblasts in breast cancer, whether helping or hindering tumor growth, remains undetermined.