Impact of the mode of detection on outcome in breast cancer patients treated with breast-conserving therapy

The impact of the mode of detection on outcome in patients with early stage breast cancer treated with breast-conserving therapy (BCT) was reviewed. B etween January 1980 and December 1987, 400 cases of stage I and LI breast c ancer were created with BCT. All patients underwent an excisional biopsy, e xternal beam irradiation (RT) to the whole breast (45-50 Gy), and a boost t o 60 Gy to the tumor bed. One hundred twenty-four cases (31%) were mammogra phically detected, whereas 276 (69%) were clinically detected. Median follo w-up was 9.2 years. Patients whose cancers were detected by mammography mor e frequently had smaller tumors (90% T1 vs. 62%, p < 0.0001), lower overall disease stage (78% stage I vs. 47%, p < 0.0001), were older at diagnosis ( 78% >50 years vs. 54%,p < 0.001), less frequently received chemotherapy (8% vs. 21%, p = 0.001), and had an improved disease-free survival (DFS) (80% vs. 70%, p = 0.014), overall survival (OS) (82% vs. 70%, p = 0.005), and ca use-specific survival (CSS) (88% vs. 77%, p = 0.003) at 10 years. However, controlling for tumor size, nodal status, and age, no statistically signifi cant differences in the 5- and 10-year actuarial rates of local recurrence (LR), DFS, CSS, or OS were seen based on the mode of detection. Initial mod e of detection was the strongest predictor of outcome after a LR. The 3-yea r DFS rate after LR was significantly better in initially mammographically detected versus clinically detected cases (100% vs. 61%, p = 0.011). Patien ts with mammographically detected breast cancer generally have smaller tumo rs and lower overall disease stage at presentation. However, the mode of de tection;does not independently appear to affect the success of BCT in these patients.