Pathological prognostic factors in stage I (T1N0M0) and stage II (T1N1M0) breast carcinoma: a study of 644 patients with median follow-up of 18 years.

Prognostic factors have been examined in 644 patients with tumor-node-metastasis (TNM) stage T1 breast carcinoma treated by mastectomy and followed for a median of 18.2 years. Overall, 148 patients (23%) died of recurrent breast carcinoma. Eighteen (3%) were alive with recurrent disease and 478 (74%) were alive or died of other causes without recurrence. Unfavorable clinicopathologic features were larger tumor size (1.1 to 2.0 cm v less than or equal to 1 cm), perimenopausal menstrual status, the number of axillary lymph node metastases, poorly differentiated grade, presence of lymphatic tumor emboli (LI) in breast tissue near the primary tumor, blood vessel invasion (BVI), and an intense lymphoplasmacytic reaction around the tumor. Median survival after recurrence for the entire series was 2 years. This was not significantly influenced by tumor size, the number of axillary nodal metastases, the type of treatment for recurrence, or the interval to recurrence. The proportions surviving 5 and 10 years after recurrence were 17% and 5%, respectively. Among T1N0M0 cases, the chance of a local recurrence was 2.8% within 20 years. Median survival of T1N0M0 cases after local recurrence (4.5 years) was significantly longer than after systemic recurrence (1.5 years). A similar trend (3.7 v 2.0 years), not statistically significant, was seen in T1N1M0 patients, who had a 6.5% chance of local recurrence within 20 years. Median survival following systemic recurrence detected 10 or more years after diagnosis in T1N0M0 and in T1N1M0 patients was significantly longer than the median survival for systemic recurrences found in the first decade of follow-up. This difference did not apply following local recurrence in either T1N0M0 or T1N1M0 cases. It is evident that patients with T1 breast carcinoma can be subdivided into differing prognostic groups and this must be taken into account when considering the role of adjuvant chemotherapy for stage I disease. Systemic adjuvant treatment may prove to be beneficial for patients with unfavorable prognostic factors, while women with an especially low risk for recurrence (eg, T1N0M0 tumor 1.0 cm or less) might be spared such treatment.