Taxanes as primary chemotherapy for early breast cancer. Meta-analysis of randomized trials

BACKGROUND. In patients with locally advanced and operable breast cancer, neoadjuvant chemotherapy has been demonstrated to increase the chance of breast-conserving surgery (BCS) when compared with adjuvant treatment; moreover, patients who achieve a pathologic complete response (pCR) have a better outcome. A literature-based meta-analysis of randomized clinical trials (RCTs) to 'weigh' how much taxanes add to anthracyclines as primary treatment over standard chemotherapy was conducted. METHODS. Event-based relative risk ratios (RR) with 95% confidence intervals (95% CI) were derived through both a fixed-effect and a random-effect model; a heterogeneity test was applied as well. Absolute differences (AD) and the number (of patients) needed to treat (NNT) were calculated. Primary endpoints were: 1) pCR rate and 2) BCS rate. A sensitivity analysis of 3 subgroups according to taxane strategies was conducted. RESULTS. Data for primary endpoints were available for 7 RCTs (2455 patients). The rate of BCS was significantly higher for patients receiving taxanes, with an AD of 3.4% (P = .012), which translates into 29 patients NNT, without significant heterogeneity. The rate of pCR was higher for patients receiving taxanes, although not statistically significant. In the sensitivity analysis, patients receiving taxanes as a sequential schedule had a significant higher probability to achieve pCR, with an AD of 2.4% (P = .013), which translates into 41 patients NNT, without significant heterogeneity. Patients receiving taxanes as a concomitant schedule had a significantly higher probability to achieve BCS, with an AD of 5.3% (P = .027), which translates into 19 patients NNT, without significant heterogeneity. The complete response rate was significantly higher in the taxane arms, regardless of the adopted strategy, with an AD ranging from 6.7% to 15.5%. CONCLUSIONS. The combination of taxanes and anthracyclines as neoadjuvant chemotherapy for early breast cancer improves the chance of achieving both higher BCS and pCR rates.