[The potential and actual growth rate of breast cancer]

Potential and actual rates of tumor growth were assayed in 13 patients with primary breast cancer. Potential growth rate was calculated according to proliferative activity as assessed by histoautoradiography whereas actual growth--on the basis of changes in tumor size observed on mammograms obtained through the course of the disease. Actual tumor doubling time proved 22.8 times longer (which means that tumors grew slower) than that suggested by proliferative activity. Cell loss at the average rate of 95.5% proved the main reason accounting for the difference. The proliferative activity in regional lymph node metastases measured in 3 patients simultaneously with the primary tumor assay was 3.9 times higher.