Early Response to Neo-adjuvant Chemotherapy in Carcinoma of the Breast Predicts Both Successful Breast-Conserving Surgery and Decreased Risk of Ipsilateral Breast Tumor Recurrence

Abstract: Neo-adjuvant chemotherapy enables us to increase the possibility of breast-conserving surgery for large, bulky tumors. However, several studies have reported that ipsilateral breast tumor recurrences (IBTRs) occur more frequently after neo-adjuvant chemotherapy than originally envisaged. Recently, it was demonstrated that clinical early response after neo-adjuvant chemotherapy predicts pathological complete response. In this study, we assessed the association of clinical early response after neo-adjuvant chemotherapy with successful breast-conserving surgery and IBTR risk. Between 1995 and 2002, 114 patients with T 3.1–6 cm, N 0 or 1, M 0 breast cancer who were candidates for mastectomy but desired breast-conserving surgery were treated with neo-adjuvant chemotherapy. After two cycles of anthracycline-based neo-adjuvant chemotherapy and before surgery, breast tumors were measured by palpation or ultrasound. Clinical response after two cycles of chemotherapy was defined as positive when the largest tumor dimension was reduced by 30% or greater. Median follow-up time was 72 months. After two cycles of neo-adjuvant chemotherapy, 54 (47.4%) of 114 patients achieved an early response. Patients with the early response underwent breast-conserving surgery significantly more frequently than those without the early response (78% versus 58%, p = 0.03). In addition, the early response was significantly correlated with selection of breast-conserving surgery (odds ratio 3.8, p = 0.01) after adjustments for various clinicopathological factors. Patients without the early response showed significantly lower 6-year IBTR-free survival than patients with the early response (75% versus 97%, p = 0.02). In addition, patients with the early response showed significantly higher 6-year disease-free survival rates than those with the early response (p = 0.02). Multivariate analysis showed that the early response was a predictive factor of IBTR-free survival, being independent of other clinicopathological factors. In conclusion, the early response to neo-adjuvant chemotherapy may be a useful predictor of both selection of surgical method and IBTR risk.