For patients with HER2+ breast cancer, the achievement of pCR after neoadjuvant chemotherapy is regarded as a surrogate end point of prognosis, however, which is not clear among HER2 + HR+ patients.Methods
We retrospectively investigated 163 HER2+ patients who received neoadjuvant chemotherapy in Hyogo Cancer Center between 2003 and 2010. HR+ was defined as estrogen or progesterone receptor positive, and pCR was no evidence of invasive carcinoma in the breast and axillary lymph nodes at surgery. Logistic regression analysis and logrank test were carried out to identify predictive factors of pCR and its prognostic significance on recurrence-free survival.Results
The median age was 55 years (range, 25–84) and the median follow-up was 59 months (range 12–104). Stages I, IIA, IIB, and III were 4, 57, 56, 46 patients, HER2 + HR+ and HER2 + HR− were 89 and 74 patients, respectively. The rates of patients receiving anthracycline, taxane and trastuzumab (T) were 66, 82 and 51%, respectively. After surgery, 98% of HER2 + HR+ patients received hormonal therapy. Multivariate analysis revealed that HER2 + HR+ (OR, 0.46; P = .047) and inclusion of T (OR, 2.87; P = .01) were significant predictors of pCR. Although 5 years recurrence-free survival rate was significantly higher in HER2 + HR− patients with pCR compared with non-pCR (88% versus 64%; P = .03), which was not in HER2 + HR+ patients (94% versus 84%; P = .49).Conclusions
HER2 + HR+ breast cancer patients had significantly lower achievement rate of pCR, which was less prognostic compared with that in HER2 + HR− patients. On the other hand, HER2 + HR+ patients had better prognosis; therefore, the reduction in side-effects by replacing cytotoxic drugs with anti-HER2 agents and hormonal therapy might be be more beneficial than the improvement of pCR in neoadjuvant settings. The predictive factors of response to achieve the replacement would be needed.