Evaluating Treatment Outcomes in Women with Node-Negative T1 Breast Cancers

Background: With greater awareness and increased screening, cancers are increasingly being diagnosed at stage I. Women with these small node-negative tumours have excellent survival prospects after surgery, but many women, especially those with triple-negative and human epidermal growth factor receptor (HER)-2-positive tumours, still receive adjuvant systemic treatments to reduce the recurrence risk.

Aims: We review the outcomes of women diagnosed with stage I (T1N0M0) tumours in our unit and examine the effect of systemic chemotherapy with/without targeted therapy on recurrence patterns and survival outcomes.

Results: We reviewed 643 women diagnosed with T1N0M0 disease over a 10-year period. Five-year recurrence-free survival (RFS) was 96.6% and the 10-year RFS was 95.5%. Recurrence occurred in 4.7% of the women and was limited to locoregional sites in two-thirds of the instances. Systemic recurrences developed in 12 women, all of whom had ER-positive/HER2-negative disease. The mode of surgery emerged as the only independent predictor of recurrence. Recurrence was highest in women treated with wide local excision (WLE) alone (p < 0.05), but not in those who had received breast radiation after WLE (p = 0.112). Systemic chemotherapy, with or without anti-HER2 therapy, was discussed with 334 women, of whom 50.6% received the treatment; these women were more often younger and had triple-negative or HER2-positive tumours (p < 0.001). Women who received chemotherapy showed a non-significant tendency to develop locoregional recurrence (p = 0.104), but the number of systemic recurrences were similar to those documented in women who had not received chemotherapy. Chemotherapy and/or targeted treatment was not observed to have a significant effect on 5-year recurrence-free survival (p = 0.444).

Conclusions: Stage I cancers have excellent survival outcomes. An optimal local surgical treatment is important and we did not find chemotherapy and/or targeted therapy to produce any significant differences in survival.