The value of mammography within 1 year of conservative surgery for breast cancer

Guidelines for screening mammography have been established by numerous medical societies. Guidelines have not been established for follow-up mammography for patients who have been treated with breast-conserving surgery. Many radiologists recommend mammography of the treated breast 6 months after completion of treatment. The purpose of this study was to determine the value of interval mammography.

Patients were identified by searching the breast cancer database for the diagnoses of ductal carcinoma in situ, infiltrating ductal carcinoma and infiltrating lobular carcinoma. Postoperative mammogram dates and results were obtained. Patients with mammography within 8 months of surgery were included in the study.

Ductal carcinoma in situ, infiltrating ductal carcinoma, and infiltrating lobular carcinoma were found in 1,000 patients who underwent breast-conserving surgery, and 789 patients had complete mammographic follow-up data available. Postoperative interval mammography was performed in 169 patients (21 %), including 23 patients who had preradiation mammography. Ninety percent of the interval mammograms were BI-RADS 1 to 3 and 10 % were BI-RADS 4 or 5. Two cancers were found on interval mammography (1.2 % of 169) and 4 of 620 (0.6 %) patients who did not have interval mammography were found to have malignancy within 1 year of surgery (1.2 % vs. 0.6 %, P = 0.614). The use of interval mammography was not related to the mammographic findings at diagnosis. Interval mammography did not affect local and distant disease-free survival.

The likelihood of obtaining a significant finding on short interval follow-up mammography after conservative surgery for breast cancer is 1.2 %.