Progress in early breast cancer detection.

Evidence indicates progress in the early detection of breast cancer. After 1982 there was a reported increase in the incidence of breast cancer, presumably as a result of increased screening for the disease. The increase was especially noted in early stage breast cancer. The incidence of in situ cases also increased. Since 1973 the San Francisco-Oakland Bay area has reported a statistically significant decrease in mortality for white women. The evidence supports continued efforts at early breast cancer detection.