MAMMOGRAPHIC FEATURES OF LOCAL RECURRENCE IN WOMEN WHO HAVE UNDERGONEBREAST-CONSERVING THERAPY FOR DUCTAL CARCINOMA IN-SITU

OBJECTIVE. This study was undertaken to evaluate the mammographic feat ures of local recurrence in women who have undergone breast-conserving therapy for ductal carcinoma in situ (DCIS). MATERIALS AND METHODS. R etrospective review revealed 162 women with DCIS treated with breast-c onserving therapy from 1978 to 1990 for whom follow-up data were avail able. Subsequent to therapy, 33 (20%) patients had a pathologically pr oven car; cinema in the treated breast. Mammograms at the time of loca l recurrence were available for 20 patients. We reviewed mammograms, c linical charts, and histopathologic findings in these 20 patients. For 14 of 20 patients, we also reviewed mammograms obtained at the time o f the original DCIS. RESULTS. The median interval from diagnosis of th e original DCIS to local recurrence was 26 months (range, 6-168 months ). Recurrences were detected solely by mammography in 17 (85%) of 20 p atients, by mammography and physical examination in two (10%), and sol ely by physical examination in one (5%), Eighteen (90%) local recurren ces contained calcifications and eighteen (90%) involved the tumorecto my quadrant. When we compared available mammographic findings of the o riginal DCIS and the local recurrence, we found the mammographic patte rn and calcification morphology to be the same in 11 (79%) of 14 DCIS and nine (82%) of 11 DCIS, respectively, Histopathologic analysis of r ecurrences found DCIS in 13 (65%) of 20 patients and DCIS and infiltra ting carcinoma in the remaining seven (35%) patients. Of 13 pure DCIS recurrences, 12 (92%) were detected solely by mammography. CONCLUSION. In our study, local recurrence after breast-conserving therapy for DC IS invariably contained DCIS; 35% of recurrences also contained invasi ve carcinoma, The most common mammographic pattern of local recurrence was calcifications in the tumorectomy quadrant that were morphologica lly similar to the original DCIS. These findings suggest that many of these local recurrences reflect failure to eradicate the primary DCIS. Mammography achieved high sensitivity in revealing these lesions: 85% of local recurrences and 92% of recurrences that were pure DCIS were detected solely by mammography.