Stage and pattern of metastases in patients with breast cancer

This study compares the pattern of metastases in 228 patients with initial stage I and 635 patients with initial stage II breast cancer. All these patients had recurrence within a median time of follow-up of 4.9 years (range 2.0-7.0 years). All patients were initially mastectomized, and staging was based on histopathological evaluation of mastectomy specimens. Patients with stage II disease received postoperative radiotherapy; 67% also received systemic adjuvant therapy. Locoregional recurrences were the most common sites of recurrence in stage I, whereas distant metastases occurred more often in stage II patients. Stage II patients had a significantly higher number of metastatic sites than stage I patients. Among patients with a single site of recurrence the frequency of local or regional recurrence was 62% in stage I patients compared to 16% in stage II patients. When correcting for this difference, which was ascribed to the effect of radiotherapy, the number and the distribution of metastatic sites were almost equal in stage I and II patients. The anatomical distribution of metastatic sites in different periods after mastectomy was almost the same in stage I and stage II patients; extraregional lymph node metastases, however, occurred earlier in stage II than in stage I patients. The recurrence-free interval, the survival after recurrence (SAR), and the overall survival were all significantly shorter for stage II than for stage I patients. The reduced SAR for patients with stage II disease hints that tumours of higher stages have a higher rate of progression. The progression time, however, was of the same duration in patients with initial stage I and II breast cancer. The prognostic significance of the classification of patients with breast cancer according to stage does not seem to discriminate tumours with different biological properties with regard to the rate as well as the pattern of dissemination. Postmastectomy follow-up of patients with stage I and II disease should therefore, follow the same guide-lines. Since the anatomical distribution of metastases was the same in different periods after mastectomy, the screening for recurrent disease should not be directed towards any specific sites in certain periods after initial diagnosis.