Meta-analysis of neoadjuvant therapy and its impact in facilitating breast conservation in operable breast cancer.

BACKGROUND: Neoadjuvant therapy (NAT) for operable breast cancer may facilitate more breast-conserving surgery (BCS). It seems, however, that this benefit is not being realized fully.

METHODS: A systematic review of the literature was performed. RCTs were included. The criteria for inclusion were: documentation of surgical assessment before and after NAT, surgery performed (BCS or mastectomy), and clinical and pathological responses.

RESULTS: A total of 1452 patients from seven RCTs met the inclusion criteria. After NAT, the feasibility of BCS increased from 43·3 to 60·4 per cent (P < 0·001), but BCS was performed in only 51·8 per cent (P = 0·04). Only 31 per cent of patients who became eligible for BCS (assessed on clinical response) underwent BCS (pooled rate ratio 0·31, 95 per cent c.i. 0·22 to 0·44; P < 0·001). Of the mastectomy candidates who achieved a pathological complete response after NAT, only 41 per cent underwent BCS (pooled rate ratio 0·41, 0·23 to 0·74; P = 0·003). The main factors that influenced the decision not to shift to BCS, even though it was feasible, were clinical assessment before NAT, multicentricity and tumour size at presentation.

CONCLUSION: Breast surgery performed after NAT does not reflect tumour response, resulting in potentially unnecessary radical surgery, especially mastectomy. The barriers to maximizing the surgical benefits of NAT need to be better understood and explored.