Mammographic features after conservation therapy for malignant breast disease: serial findings standardized by regression analysis

The purpose of this study was to determine the incidence and natural history of mammographic changes in patients within 5 years of conservation therapy for malignant breast disease. We reviewed the records of 164 consecutive patients with a history of conservation therapy for malignant disease. We recorded mammographic changes related to treatment for each year after surgery. Linear regression analysis was applied to determine trends for progression, regression, or stability of findings. We evaluated 158 patients with 162 lesions for which initial mammographic evaluation had occurred within 5 years of surgery. Of these 158 patients, 121 (77%) underwent serial studies. A total of 152 patients (96%) showed changes on mammograms that represented scarring, usually in multiple locations. Findings at initial evaluation included architectural distortion (n = 110; 82%), increased regional density or scarring (n = 106; 79%), skin thickening (n = 73; 54%), masses (n = 16; 12%), and calcifications (n = 4; 3%). All findings except calcifications showed partial resolution over time, with architectural distortion showing the most significant resolution (p = .05). Mammographic features after conservation therapy for breast cancer are common at 1 year after treatment. With the exception of calcifications, we found that all changes showed decreased prominence during the next 5 years. Recognition of such trends during routine surveillance should facilitate the early identification of changes that represent recurrence or do novo malignancy.