Clinical Efficacy of Including Capecitabine in Neoadjuvant Chemotherapy for Breast Cancer: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

<div><h3>Background</h3><p>Capecitabine has proven effective as a chemotherapy for metastatic breast cancer. Though several Phase II/III studies of capecitabine as neoadjuvant chemotherapy have been conducted, the results still remain inconsistent. Therefore, we performed a meta-analysis to obtain more precise understanding of the role of capecitabine in neoadjuvant chemotherapy for breast cancer patients.</p> <h3>Methods</h3><p>The electronic database PubMed and online abstracts from ASCO and SABCS were searched to identify randomized clinical trials comparing neoadjuvant chemotherapy with or without capecitabine in early/operable breast cancer patients without distant metastasis. Risk ratios were used to estimate the association between capecitabine in neoadjuvant chemotherapy and various efficacy outcomes. Fixed- or random-effect models were adopted to pool data in RevMan 5.1.</p> <h3>Results</h3><p>Five studies were included in the meta-analysis. Neoadjuvant use of capecitabine with anthracycline and/or taxane based therapy was not associated with significant improvement in clinical outcomes including: pathologic complete response in breast (pCR; RR = 1.10, 95% CI 0.87–1.40, p = 0.43), pCR in breast tumor and nodes (tnpCR RR = 0.99, 95% CI 0.83–1.18, p = 0.90), overall response rate (ORR; RR = 1.00, 95% CI 0.94–1.07, p = 0.93), or breast-conserving surgery (BCS; RR = 0.98, 95% CI 0.93–1.04, p = 0.49).</p> <h3>Conclusions</h3><p>Neoadjuvant treatment of breast cancer involving capecitabine did not significantly improve pCR, tnpCR, BCS or ORR. Thus adding capecitabine to neoadjuvant chemotherapy regimes is unlikely to improve outcomes in breast cancer patients without distant metastasis. Further research is required to establish the condition that capecitabine may be useful in breast cancer neoadjuvant chemotherapy.</p> </div

Simulation model: (a) spherical cavity and (b) cylindrical cavity.

<p>Simulation model: (a) spherical cavity and (b) cylindrical cavity.</p

Spherical and cylindrical cavity expansion models based prediction of penetration depths of concrete targets

<div><p>The cavity expansion theory is most widely used to predict the depth of penetration of concrete targets. The main purpose of this work is to clarify the differences between the spherical and cylindrical cavity expansion models and their scope of application in predicting the penetration depths of concrete targets. The factors that influence the dynamic cavity expansion process of concrete materials were first examined. Based on numerical results, the relationship between expansion pressure and velocity was established. Then the parameters in the Forrestal’s formula were fitted to have a convenient and effective prediction of the penetration depth. Results showed that both the spherical and cylindrical cavity expansion models can accurately predict the depth of penetration when the initial velocity is lower than 800 m/s. However, the prediction accuracy decreases with the increasing of the initial velocity and diameters of the projectiles. Based on our results, it can be concluded that when the initial velocity is higher than the critical velocity, the cylindrical cavity expansion model performs better than the spherical cavity expansion model in predicting the penetration depth, while when the initial velocity is lower than the critical velocity the conclusion is quite the contrary. This work provides a basic principle for selecting the spherical or cylindrical cavity expansion model to predict the penetration depth of concrete targets.</p></div

Comparison of numerical and theoretical results of radial stress after expanded for 5 us under an expansion pressure of 1.5 GPa.

<p>Comparison of numerical and theoretical results of radial stress after expanded for 5 us under an expansion pressure of 1.5 GPa.</p

The expansion process of the spherical cavity under an expansion pressure of 1.5 GPa.

<p>The expansion process of the spherical cavity under an expansion pressure of 1.5 GPa.</p

Radial stress in spherical and cylindrical cavity models at t = 5 us.

<p>Radial stress in spherical and cylindrical cavity models at t = 5 us.</p

Expansion velocity of cavity wall with different pressures.

<p>Expansion velocity of cavity wall with different pressures.</p

Comparison of the expansion velocity between cylindrical and spherical cavity.

<p>Comparison of the expansion velocity between cylindrical and spherical cavity.</p

Comparison of penetration depths predicted by spherical cavity expansion model and test data.

<p>Comparison of penetration depths predicted by spherical cavity expansion model and test data.</p

Forest plot to meta-analyze pCR outcomes for neoadjuvant therapy with or without capecitabine.

<p>Forest plot to meta-analyze pCR outcomes for neoadjuvant therapy with or without capecitabine.</p