Nova Scotia Breast Screening Program experience: Use of needle core biopsy in the diagnosis of screening-detected abnormalities

PURPOSE: To evaluate a mammography screening program that uses a multidisciplinary team approach and needle core biopsy. MATERIALS AND METHODS: A total of 10,000 asymptomatic women (aged 40-74 years) underwent screening in the Nova Scotia Breast Screening Program between June 1991 and April 1994. Women aged 50-69 years were the target group. All mammograms were read by one of four radiologists. Patients with abnormal screening findings underwent work-up, which included needle core biopsy, at one of two diagnostic centers. RESULTS: Of 10,000 women, 2,794 were aged 40-49 years; 4,097, 50-59 years; 2,941, 60-69 years; and 168, 70-74 years, with 3.9, 6.4, 12.2, and 23.8 cancers detected per 1,000 patients, respectively. The overall rate was 7.7 cancers detected per 1,000 patients. Abnormalities were detected at screening in 838 patients (8.4%), 181 of whom underwent open surgery, with malignancy diagnosed in 77 (42%). Sixty-one (79%) of 77 patients had stage 0 or I cancer. In 43 (72%) of 60 patients in whom node status was assessed, findings were negative. CONCLUSION: A screening program with needle core biopsy and a multidisciplinary team approach to diagnosis is effective.