Recurrent cancer after breast-conserving surgery with radiation therapy for ductal carcinoma in situ: Mammographic features, method of detection, and stage of recurrence

OBJECTIVE. The purpose of our study was to determine the mammographic appearance, detection method, and stage of ipsilateral breast tumor recurrence in women treated with breast-conserving surgery and whole-breast radiation therapy for ductal carcinoma in situ ( DCIS). MATERIALS AND METHODS. Following institutional review board approval, records of women treated with breast-conserving surgery and radiation therapy for DCIS who developed an ipsilateral breast tumor recurrence from 1981 to 2003 were reviewed retrospectively. Multiinstitutional database records showed 513 women were treated, of whom 42 (8.2%) developed local recurrence. Study criteria were fulfilled and complete records were available for 32 women. Mean age at initial diagnosis was 49 years ( range, 26 - 73 years). RESULTS. Of the 32 patients included in our study, 31 (97%) recurrences were mammographically apparent. Twenty-nine (91%) of 32 were diagnosed exclusively by mammography. Mammographic findings at recurrence were calcifications in 24 (75%) of 32, mass in six (19%) of 32, and distortion in one (3%) of 32. The mean time to recurrence was 4.5 years. Twelve ( 40%) of 30 had the recurrence in a remote quadrant from the original cancer. Recurrences were DCIS in 17 (53%) of 32, DCIS with microinvasion in six ( 19%) of 32, invasive ductal cancer in three ( 9%) of 32, invasive lobular cancer in two (6%) of 32, and mixed DCIS and invasive cancer in four (13%) of 32. Six (67%) of nine patients with invasive cancer ( excluding microinvasion) had tumors smaller than 1 cm. Ninety-one percent of recurrences were minimal cancers. All recurrences were stage 0 or 1. CONCLUSION. Mammography successfully detected ipsilateral breast tumor recurrence, predominantly as calcifications or masses, after breast-conserving surgery with radiation therapy for DCIS in 97% of cases. The recurrences were located at variable distances from the lumpectomy site. Ninety-one percent of recurrences were minimal cancers and all were early stage, connoting excellent prognosis.