Results of 23,810 cases of ductal carcinoma-in-situ

Background: Screening mammography has increased the number of patients diagnosed with ductal carcinoma-in-situ (DCIS) in the past 20 years. The Florida Cancer Data System is the largest single source incident cancer registry in the United States. We analyzed this registry to determine the changing incidence and treatment patterns for DCIS. Methods: Patients with DCIS from 1981 to 2001 were identified. Age-adjusted rate, descriptive statistics, and incidence of future DCIS and invasive breast cancer were calculated. Results: A total of 23,810 DCIS patients were identified. The age-adjusted rate of DCIS has risen from 2.4 to 27.7 per 100,000 women between 1981 and 2001. Median age was 64 years; 85% of patients were white, 6.6% African American, and 7.5% Hispanic. Median tumor size was .9 cm. Forty-seven percent of patients had breast-conserving therapy (BCT). Half of the 53% of patients undergoing mastectomy underwent a modified radical mastectomy. Eight percent received no surgical treatment. Sentinel lymph node biopsy was used in 2.7% of patients who underwent a mastectomy. After BCT, 37.5% received adjuvant radiotherapy, and only 13% were treated with hormonal therapy. Conclusions: The incidence of DCIS has risen dramatically with the advent of screening mammography. Increasing numbers of these patients are treated with BCT, although a large proportion are still treated with mastectomy, in some cases combined with axillary dissection. Sentinel lymph node biopsy and tamoxifen are important components of therapy, the use of which is slowly increasing in the treatment of DCIS.