Abstract: It is generally accepted that women with axillary node-negative minimally invasive breast cancers (≤1 cm) are not candidates for systemic therapy because of their low risk for distant metastases and excellent overall prognosis. However, recent studies have suggested that a subset of these patients may have a significant risk of failure. In this study, 188 women with axillary node-negative minimally invasive breast cancer (≤1 cm) were treated with conservative surgery and radiation. Their median age was 56 years. The median followup was 6.2 years. The following factors were analyzed for their ability to predict for freedom from distant metastases, distant disease-free survival, and cause-specific survival: patient age, method of detection of the primary, tumor size, estrogen and progesterone receptor status, and lymphatic invasion.
The ten year actuarial distant disease-free survival, cause-specific, and overall survival were 80%, 94%, 92% respectively. There were no significant prognostic factors for freedom from distant metastases or distant disease-free survival although young women and those with estrogen receptor negative tumors had a 20–25% risk of distant disease at ten years. The median interval to distant metastases was five years. Estrogen receptor negativity was a significant prognostic factor for cause-specific survival (ten year 81%).
We have identified a subgroup of patients with axillary node-negative minimally invasive breast cancer (≤ 1 cm) whose risk of distant failure at ten years is 20% or greater. These patients are characterized by young age and estrogen receptor negativity and may be candidates for adjuvant systemic therapy. We await confirmation of our results by others.