Immunohistochemistry profiles of breast ductal carcinoma: factor analysis of digital image analysis data

Abstract

BackgroundMolecular studies of breast cancer revealed biological heterogeneity of the disease and opened new perspectives for personalized therapy. While multiple gene expression-based systems have been developed, current clinical practice is largely based upon conventional clinical and pathologic criteria. This gap may be filled by development of combined multi-IHC indices to characterize biological and clinical behaviour of the tumours. Digital image analysis (DA) with multivariate statistics of the data opens new opportunities in this field.MethodsTissue microarrays of 109 patients with breast ductal carcinoma were stained for a set of 10 IHC markers (ER, PR, HER2, Ki67, AR, BCL2, HIF-1α, SATB1, p53, and p16). Aperio imaging platform with the Genie, Nuclear and Membrane algorithms were used for the DA. Factor analysis of the DA data was performed in the whole group and hormone receptor (HR) positive subgroup of the patients (n = 85).ResultsMajor factor potentially reflecting aggressive disease behaviour (i-Grade) was extracted, characterized by opposite loadings of ER/PR/AR/BCL2 and Ki67/HIF-1α. The i-Grade factor scores revealed bimodal distribution and were strongly associated with higher Nottingham histological grade (G) and more aggressive intrinsic subtypes. In HR-positive tumours, the aggressiveness of the tumour was best defined by positive Ki67 and negative ER loadings. High Ki67/ER factor scores were strongly associated with the higher G and Luminal B types, but also were detected in a set of G1 and Luminal A cases, potentially indicating high risk patients in these categories. Inverse relation between HER2 and PR expression was found in the HR-positive tumours pointing at differential information conveyed by the ER and PR expression. SATB1 along with HIF-1α reflected the second major factor of variation in our patients; in the HR-positive group they were inversely associated with the HR and BCL2 expression and represented the major factor of variation. Finally, we confirmed high expression levels of p16 in Triple-negative tumours.ConclusionFactor analysis of multiple IHC biomarkers measured by automated DA is an efficient exploratory tool clarifying complex interdependencies in the breast ductal carcinoma IHC profiles and informative value of single IHC markers. Integrated IHC indices may provide additional risk stratifications for the currently used grading systems and prove to be useful in clinical outcome studies.Virtual SlidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1512077125668949

Expression of SATB1 protein in the ductal breast carcinoma tissue microarrays — preliminary study

“…Similar results were shown by Patani et al who found that high SATB1 expression levels occurred more often in ERnegative cancers [29]. Towards to this observations, the use of SATB1 as target or prognostic marker for breast cancer should be viewed with caution and a possible confounding effect of the estrogen receptor status of the tumor should be taken into account when analyzing the diagnostic and prognostic value of SATB1 [30,37].…”

“…The authors focused on clinical application of results, so they analyzed expression of markers according to the status of hormone. They implied that SATB1 and HIF-1a may be important markers of the disease associated with ER-positive cancers, whereas their biological and clinical significance remains to be elucidated [30]. Their findings seem to be contrary to our data since we found moderate correlation between expression of SATB1 and Ki-67 in ER-negative tumors.…”

“…E.g. Laurinavicius et al [30] carried out IHC studies on tissue microarrays of 109 patients with ductal breast carcinoma and stained a set of 10 IHC markers -ER, PR, HER2, Ki67, AR, BCL2, HIF-1a, SATB1, p53, and p16. They did not observe any significant associations between SATB1 and other tested markers, except HIF-1a.…”

“…The majority of studies on SATB1 expression in breast cancer have been based on mRNA testing [29], while the use of immunohistochemical method has been rather limited [30]. Moreover, it seems that the immunohistochemistry performed on tissue microarrays (TMA-IHC method) should be abundantly implemented to laboratory studies, because of all its advantages (reaction environment standardization, reagents, time and money savings etc.)…”

The Immunohistochemical Expression of the Oestrogen Receptor (ER), HER-2/NEU and Cytokeratin 8/18 and 5/6 in Invasive Breast Carcinoma

“…As compared to the luminal A tumours, they may have a higher proliferation rate, they may express genes that seem to be shared with the basal-like and the Her-2 subtypes and they are associated with a less favourable outcome [8,9]. The high Ki67/ER factor scores were strongly associated with the higher grade and the luminal B type of tumours, but they were also detected in a set of grade1and luminal A cases , thus potentially indicating the high risk patients in these categories [10].…”