Comparison of immunohistochemistry with PCR for assessment of ER, PR, and Ki-67 and prediction of pathological complete response in breast cancer

Abstract

BackgroundProliferation may predict response to neoadjuvant therapy of breast cancer and is commonly assessed by manual scoring of slides stained by immunohistochemistry (IHC) for Ki-67 similar to ER and PgR. This method carries significant intra- and inter-observer variability. Automatic scoring of Ki-67 with digital image analysis (qIHC) or assessment of MKI67 gene expression with RT-qPCR may improve diagnostic accuracy.MethodsKi-67 IHC visual assessment was compared to the IHC nuclear tool (AperioTM) on core biopsies from a randomized neoadjuvant clinical trial. Expression of ESR1, PGR and MKI67 by RT-qPCR was performed on RNA extracted from the same formalin-fixed paraffin-embedded tissue. Concordance between the three methods (vIHC, qIHC and RT-qPCR) was assessed for all 3 markers. The potential of Ki-67 IHC and RT-qPCR to predict pathological complete response (pCR) was evaluated using ROC analysis and non-parametric Mann-Whitney Test.ResultsCorrelation between methods (qIHC versus RT-qPCR) was high for ER and PgR (spearman´s r = 0.82, p < 0.0001 and r = 0.86, p < 0.0001, respectively) resulting in high levels of concordance using predefined cut-offs. When comparing qIHC of ER and PgR with RT-qPCR of ESR1 and PGR the overall agreement was 96.6 and 91.4%, respectively, while overall agreement of visual IHC with RT-qPCR was slightly lower for ER/ESR1 and PR/PGR (91.2 and 92.9%, respectively). In contrast, only a moderate correlation was observed between qIHC and RT-qPCR continuous data for Ki-67/MKI67 (Spearman’s r = 0.50, p = 0.0001). Up to now no predictive cut-off for Ki-67 assessment by IHC has been established to predict response to neoadjuvant chemotherapy. Setting the desired sensitivity at 100%, specificity for the prediction of pCR (ypT0ypN0) was significantly higher for mRNA than for protein (68.9% vs. 22.2%). Moreover, the proliferation levels in patients achieving a pCR versus not differed significantly using MKI67 RNA expression (Mann-Whitney p = 0.002), but not with qIHC of Ki-67 (Mann-Whitney p = 0.097) or vIHC of Ki-67 (p = 0.131).ConclusionDigital image analysis can successfully be implemented for assessing ER, PR and Ki-67. IHC for ER and PR reveals high concordance with RT-qPCR. However, RT-qPCR displays a broader dynamic range and higher sensitivity than IHC. Moreover, correlation between Ki-67 qIHC and RT-qPCR is only moderate and RT-qPCR with MammaTyper® outperforms qIHC in predicting pCR. Both methods yield improvements to error-prone manual scoring of Ki-67. However, RT-qPCR was significantly more specific.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-017-3111-1) contains supplementary material, which is available to authorized users.

Phase-I trial of survivin inhibition with EZN-3042 in dogs with spontaneous lymphoma

“…Surprisingly, there was no correlation between changes in survivin mRNA as assessed by qRT-PCR and changes in protein expression as assessed immunohistochemically. However, the semi-quantitative assessment of survivin expression by IHC may be less sensitive than qRT-PCR, as appears to be the case for several other measured targets in human cancer [60][61][62]. Despite our previous observations of significant reductions in proliferation and induction of apoptosis in canine lymphoma cells treated with EZN-3042 in vitro, [49] we observed no correlation between alterations in proliferation/apoptosis assessed immunohistochemically and changes in survivin mRNA expression.…”

Puberty is a critical window for the impact of diet on mammary gland development in the rabbit

“…However, the Ki67 reduced staining in the OD group, suggested that the lower representation of alveolar epithelium was due to a reduced proliferation of epithelial cells. Such discrepancy between transcript and protein expressions was already reported with Ki67 in breast cancer . We also investigated Itgb1 expression because of its implication in mammary proliferation .…”

“…Such discrepancy between transcript and protein expressions was already reported with Ki67 in breast cancer. 49 We also investigated Itgb1 expression because of its implication in mammary proliferation. 50 In the OD group, epithelial Itgb1 expression did not differ from that seen in CD animals.…”

Effect of IDH3a on glucose uptake in lung adenocarcinoma: A pilot study based on [18F]FDG

“…The bioinformatics analysis results, other than verified the correlation between IDH3a with GLUT1, also found the mild correlation between IDH3a with HK2, which was not consistent with immunohistochemistry study results. Previous studies also found the RNA expression did not always correlate with protein expression …”

“…Previous studies also found the RNA expression did not always correlate with protein expression. [30][31][32] Our study further explored the cellular mechanisms involved in IDH3a affecting glucose uptake. We identified key factors affecting glucose uptake in lung cancer cell, including GLUT1, HK2, and p-AKT.…”