Meta-Analysis: ¹⁸F-FDG PET or PET/CT for the Evaluation of Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer

Abstract

Purpose: To evaluate the accuracy and the predictive value of 18 F-FDG PET or PET/CT in the assessment of neoadjuvant chemotherapy (NAC) in locally advanced breast cancer by meta-analysis. Materials and Methods: Relevant studies were identified by systematic searches of PUBMED and COCHRANE databases, published in English. To ensure homogeneity of all included studies, selection criteria were established and all the studies were scored according to Quality Assessment of Diagnostic Accuracy Studies (QUADAS) criteria. Meta-analysis was done on the diagnostic performance data from eligible studies. Draw funnel plots to explore the publication bias. Draw forest plots to exclude abnormal data(s). Use Spearman correlation coefficients p , likelihood ratio x 2 test and I 2 index in order to indicate heterogeneity. Estimate and compare the weighted summary sensitivities ( SE s), specificities ( SP s), diagnostic odds ratios ( DOR s), and summary receiver operating characteristic (SROC) curves of PET and other examinations (measuring the size of tumor). Subgroup analyses were performed to identify heterogeneity potential sources. Do Z test to find significant difference between each results. Results: 27 groups of data in 19 eligible studies were included with a total of 1164 subjects evaluated by 18 F-FDG PET or PET/CT and 291 ones evaluated by other examinations. Funnel plots showed the existence of publication bias. Spearman correlation coefficients p , likelihood ratio x 2 test and I 2 index explored the heterogeneity. The Results of the Weighted Summary: SE PET was significantly higher than SE D [83.7% (329/393) vs. 59.0% (98/166), p < 0.001], SP PET was significantly higher than SP D [66.8% (512/766) vs. 40.8% (51/125), p < 0.001], DOR PET was significantly higher than DOR D (14.02 vs. 1.29, p < 0.05). The results show that FDG-PET was more accurate in assessment NAC efficiency. Draw SROC curves with Metadisc 14.0 and caculate results showed AUC PET and Q * PET were both significantly higher than AUC D and Q * D ( AUC s 0.8838 vs. 0.6046; Q *s 0.8143 vs. 0.5788, p < 0.001), which confirmed the advantage of FDG-PET. Subgroup analysis showed that performing FDG-PET after the 1 st or 2 nd cycle of NAC was a litter better than later with higher SE ( p = 0.083). Standardized uptake value (SUV) reduction rate between 40% and 45% as FDG-PET response threshold value was used for its highest SP (p = 0.01), while no significant difference was found comparing SE s and DOR s ( p > 0.05). Trend of higher SE and lower SP were found at ER negative breast cancers than ER positive ones ( SE s 93.94% vs. 83.33%; SP s 35.76% vs. 62.24%), though Z test did not find significant difference ( p > 0.05). Conclusion: This meta-analysis showed that FDG-PET or PET/CT does have a higher global accuracy in assessing the response for NAC in breast cancer. Comparing with clinical response, metabolic response plays a potential role in directing therapy for breast cancer. Factors which affected the accuracy of FDG-PET assessment included PET timing point, SUV reduction rate as threshold value and ER expression.