Breast biopsy rate and positivity in Rhode Island.

Breast biopsy is a common procedure for which few age-specific, population-based data are available. We identified all women who underwent breast biopsy in Rhode Island in 1989 by reviewing the specimen logs at each of 13 pathology laboratories. Among 425,000 women aged 15-97 years, 2685 underwent breast biopsy, for an overall rate of 6/1000. The rate increased with age, peaking among 45- to 54-year-olds and then declining in women over 75. Among those biopsied, 726 were diagnosed with breast cancer, for an overall biopsy positivity of 27%. In contrast to rate, positivity increased steadily with age. These results are within the range of estimates produced by smaller group studies.