Trastuzumab combined to neoadjuvant chemotherapy in patients with HER2-positive breast cancer: a systematic review and meta-analysis.

PURPOSE

To perform a meta-analysis in order to quantify the actual cumulative randomized evidence for the benefit and toxicity of trastuzumab combined with neoadjuvant chemotherapy in HER2-positive breast cancer.

METHODS

Potentially eligible trials were located through PubMed and Cochrane Library searches and abstracts of major international conferences. The endpoints that we assessed were pathologic complete response (pCR) rate, breast-conserving surgery (BCS) rate and toxicity.

RESULTS

Five trials were identified with 515 eligible patients. The probability to achieve pCR was higher for the trastuzumab plus chemotherapy arm (RR 1.85, 95% CI: 1.39-2.46; p-value < 0.001). No significant difference in terms of breast-conserving surgery between the two treatment arms was observed (OR: 0.98, 95% CI: 0.80-1.19, p-value = 0.82). Regarding toxicity, the addition of trastuzumab did not increase the incidence of neutropenia, neutropenic fever, and cardiac adverse events.

CONCLUSION

The addition of trastuzumab in HER2-positive breast cancer in the neoadjuvant setting improves the probability of achieving higher pCR with no additional toxicity. Based on the available evidence, the use of trastuzumab combined with neoadjuvant chemothetherapy in patients with HER2-positive breast cancer seems to offer substantial benefit in terms of pCR.