Mammographic follow-up after conservation therapy for breast cancer

Objective: To recognize the mammographic changes after conservation therapy for breast carcinoma. Methods: A total of 139 follow-up mammographic examinations in 85 cases were studied during the period between 1999 and 2004. Mammography was performed at intervals of 6 months for the first 2 years, then annually. Attention was paid to mammographic change patterns of conservation therapy for breast carcinoma, including breast edema, skin thickening, architectural disturbance, asymmetric density, architectural distortion retraction, and calcifications. SPSS version 11.0 for windows was used to perform all statistical tests. Kruskal-Wallis H test was used for calculating the overall statistical differences between difference periods. Categorical data were expressed as percentages and analyzed by using the X2 test. The age of the patients ranged from 25 to 63 years (mediate, 44 years old). The time of follow-up observation ranged from 1 week to 72 months. Results: Two cases were normal on mammograms. High proportion of abnormal mammography was seen in the period of 12 month (40.3%, 56/139) and 24 month (21.6%, 30/139), respectively. Various findings appeared in various periods and the difference was statistically significant(X2=30.998, v=6, P=0.001). Mild edema appeared in the first 3 years. Moderately severe or marked breast edema may be present between 6 months to 12 months, then slowly resolved. The appearance and disappearance of skin thickening were similar to the process of breast edema. The changes of architectural disturbance did not correlate with time (X2=8.634, P>0.05), but on sequential mammograms for same patient, the extent of architectural disturbance relieved over time (17/19). Asymmetric density was found in only 5 patients, and disappeared in later period of follow-up in 3. Architectural distortion retraction got more and more obvious with time, and kept stable after certain period of time. Calcifications were shown in 2 patients, including 1 residual carcinoma at the excision site and 1 sutural calcification, respectively. Conclusion: Familiarity with normal mammographic sequelae after conservation therapy for malignant disease should assist radiologists in distinguishing the similar features that may represent recurrent breast cancer. (authors)