Validation of tissue microarray technology in endometrioid cancer of the endometrium

Differential impact of clinicopathological risk factors within the 2 largest ProMisE molecular subgroups of endometrial carcinoma

OBJECTIVE

To assess whether the prognostic impact of conventional risk factors and ancillary biomarkers differs across the 2 largest ProMisE molecular subgroups of endometrial carcinoma (EC).

METHODS

Direct sequencing of POLE exonuclease domain hot spots and immunohistochemistry for MLH1, PMS2, MSH2, MSH6 and p53 were performed on 745 unselected endometrioid ECs to identify mismatch repair deficient (MMR-D, n = 264) and no specific molecular profile (NSMP, n = 206) ECs. Molecular group-specific survival analyses and interaction analyses were performed to determine the prognostic relevance of clinicopathological factors and various biomarkers (L1 cell adhesion molecule, estrogen and progesterone receptor, beta-catenin, p16, E-cadherin, KRAS) within the subgroups.

RESULTS

Molecular subgroup did not have an independent effect on disease-specific survival after adjustment for conventional risk factors (P = 0.101). High grade (G3) and p16 hyperexpression remained significant predictors of survival in NSMP. Stage II-IV, ≥50% myometrial invasion, lymphovascular space invasion and loss of E-cadherin were independent predictors in the MMR-D group. In the interaction analysis, molecular subclass significantly modified the prognostic effect of high grade and p16 hyperexpression, which showed a stronger negative effect on survival in NSMP as compared to MMR-D (P for interaction = 0.016 for grade and 0.033 for p16).

CONCLUSIONS

Grade of differentiation and p16 hyperexpression appear to have a stronger prognostic impact in NSMP as compared to MMR-D EC. While these results need to be confirmed in a larger study population, they indicate that differential impact of risk factors needs to be taken into account when developing new molecular class-integrated risk stratification algorithms for EC.

Epithelial-mesenchymal transition and cancer stem cell interactions in breast phyllodes tumours: immunohistochemical evaluation of EZH2, EZR, HMGA2, CD24 and CD44 in correlation with outcome analysis

AIM

Phyllodes tumours (PTs) categorised as benign, borderline and malignant, account for 1% of all breast tumours. Histological assessment does not always predict tumour behaviour, hindering determination of the clinical course and management.Epithelial-mesenchymal transition (EMT) is an important process during embryogenesis. Dysregulation of EMT causes loss of cell polarity, decreased intercellular adhesion, increased motility and invasiveness, promoting tumour progression. Similarly, cancer stem cells (CSCs) promote tumour growth, resistance and recurrence. The aim of this study is to evaluate expression of CSC markers; enhancer of zeste homolog 2 (EZH2), CD24 and CD44 and EMT associated proteins; ezrin (EZR) and high-mobility group AT-hook 2 (HMGA2) in PTs.

METHOD

Uing tissue microarray sections, immunohistochemistry was performed on 360 PTs. Epithelial and stromal expressions of EZH2, EZR, HMGA2, CD24 and CD44 were evaluated to assess their impact on disease progression and behaviour in correlation with clinicopathological parameters.

RESULTS

Stromal expression of EZH2, EZR and HMGA2 was observed in 73 (20.3%), 53 (14.7%) and 28 (7.8%) of tumours, epithelial expression in 121 (35.9%), 3 (0.8%) and 351 (97.5%) tumours, respectively. CD24 and CD44 staining was absent in both components.

CONCLUSION

Expression of biomarkers correlated significantly with aggressive tumour traits such as stromal hypercellularity, atypia, mitoses and permeative tumour borders.Stromal expression of EZH2 and EZR shortened disease-free survival and overall survival; HMGA2 expression did not alter patient survival. EZH2 and EZR may thus be useful in predicting PT behaviour.

Mismatch repair protein and MLH1 methylation status as predictors of response to adjuvant therapy in endometrial cancer

BACKGROUND

Mismatch repair (MMR) system has been implicated in the response of mammalian cells to ionizing radiation and DNA damaging agents. We investigated the value of the MMR system in predicting response to adjuvant therapy in endometrial cancer.

METHODS

This was a single institution retrospective study. MMR protein status of endometrial carcinomas was assessed by immunohistochemistry. MMR deficient (MMR-D) tumors were identified as MLH1 methylated or nonmethylated by methylation-specific multiplex ligation-dependent probe amplification. Tumors with abnormal p53 staining or polymerase ϵ exonuclease domain mutation were excluded from the MMR proficient subgroup, which was termed as "no specific molecular profile" (NSMP). Disease-specific survival analyses were adjusted for age, stage, histology and grade, depth of myometrial invasion, and lymphovascular space invasion.

RESULTS

A total of 505 patients were included in the study. Median follow-up time was 81 months (range 1-136). Whole pelvic radiotherapy (adjusted hazard ratio [HR] 0.092 vs. no adjuvant therapy) and chemotherapy combined with radiotherapy (adjusted HR 0.18) were associated with improved disease-specific survival in the NSMP subgroup (n = 218). In contrast, adjuvant therapies showed no effect on disease-specific survival in the full MMR-D cohort (n = 287) or in MLH1 methylated tumors (n = 154). Whole pelvic radiotherapy (adjusted HR 25 vs. no adjuvant therapy/vaginal brachytherapy) and chemotherapy combined with whole pelvic radiotherapy (adjusted HR 32) were associated with poor disease-specific survival in MMR-D nonmethylated tumors (n = 70).

CONCLUSION

MMR protein and MLH1 methylation status predict the response to adjuvant therapy in endometrial cancer. The MMR system could be utilized for selection of patients who most likely benefit from adjuvant therapy.

Clinicopathological significance of deficient DNA mismatch repair and MLH1 promoter methylation in endometrioid endometrial carcinoma

The pathogenesis of DNA mismatch repair (MMR)-deficient endometrial carcinoma (EC) is driven by inactivating methylation or less frequently mutation of an MMR gene (MLH1, PMS2, MSH2, or MSH6). This study evaluated the prognostic and clinicopathologic differences between methylation-linked and nonmethylated MMR-deficient endometrioid ECs. We performed MMR immunohistochemistry and methylation-specific multiplex ligation-dependent probe amplification, and classified 682 unselected endometrioid ECs as MMR proficient (MMRp, n = 438) and MMR deficient (MMRd, n = 244), with the latter subcategorized as methylated (MMRd Met) and nonmethylated tumors. Loss of MMR protein expression was detected in 35.8% of the tumors as follows: MLH1 + PMS2 in 29.8%, PMS2 in 0.9%, MSH2 + MSH6 in 1.3%, MSH6 in 2.8%, and multiple abnormalities in 0.9%. Of the 244 MMRd cases, 76% were methylation-linked. MMR deficiency was associated with older age, high grade of differentiation (G3), advanced stage (II-IV), larger tumor size, abundant tumor-infiltrating lymphocytes, PD-L1 positivity in immune cells and combined positive score, wild-type p53, negative L1CAM, ARID1A loss, and type of adjuvant therapy. MMRd-Met phenotype correlated with older age and larger tumor size, and predicted diminished disease-specific survival in the whole cohort. In the MMRd subgroup, univariate analysis demonstrated an association between disease-specific survival and disease stage II-IV, high grade (G3), deep myometrial invasion, lymphovascular invasion, ER negativity, and L1CAM positivity. In conclusion, MMR methylation profile correlates with clinicopathologic characteristics of endometrioid EC, and MMRd-Met phenotype predicts lower disease-specific survival. MMR deficiency, but not MLH1 methylation status, correlates with T-cell inflammation and PD-L1 expression.

Immunohistochemical expression of hormone receptors, Ki-67, endoglin (CD105), claudins 3 and 4, MMP-2 and -9 in endometrial polyps and endometrial cancer type I

Objective

The aim of this study was to investigate the malignant potential of endometrial polyps (EP) by assessing the immunoexpressions of both estrogen receptor (ER) and progesterone receptor (PR), Ki-67 cell proliferation index, neovascularization network (endoglin – CD105), cellular adhesion molecules (claudins 3 and 4), and extracellular matrix proteins (MMP-2 and -9) in both EP and endometrioid adenocarcinoma (type I) in comparison with the normal endometrium.

Study design

This is a cross-sectional comparative study. Patients were identified from the database of Botucatu Medical School, São Paulo State University (BMS-UNESP) Clinical Pathology Laboratory.

Setting

The study was conducted using a convenience sample of patients attending the Sectors of Gynecologic Endoscopy and Family Planning and Gynecologic Oncology of the Department of Gynecology and Obstetrics of BMS-UNESP, Brazil.

Patients

A total of 90 women were allocated into the following three groups: EP without atypia (EP, n=30), endometrioid endometrial cancer (EC, n=30), and normal endometrium (control, n=30).

Methods

Epidemiological and clinical data were obtained by reviewing medical records. Adenocarcinoma and control cases were assessed using the tissue microarray technique. The immunoexpressions of ER, PR, Ki-67, CD105, claudins 3 and 4, and MMP-2 and -9 were assessed in paraffin blocks containing sections of the largest polyploid lesion fragment and tissue microarray recipient blocks.

Major results

Compared to the control group, significant differences in the expression of ER (P<0.001), PR (P<0.05), Ki-67 (P<0.001), CD105 (P<0.001), and claudin 3 (P<0.001) were observed in EP and EC. No significant differences were found between EP and EC (P≥0.05). MMP-2 and -9 expression were nearly absent in all groups.

Conclusion

The malignant potential of EP could not be determined through the immunohistochemical parameters used in this study. No MMP-2 or -9 expression was observed in any endometrial tissue sample. Further studies are necessary for a better understanding of the biomolecular mechanisms underlying endometrial carcinogenesis.

Tissue microarray is suitable for scientific biomarkers studies in endometrial cancer

The aim of this study was to define the concordance between tissue microarrays (TMAs) of different sizes and whole slide for 15 different antibodies in endometrial cancer and study the use of TMAs in preoperative endometrial samples. Cores of preoperative and hysterectomy specimens of 14 endometrial cancer and three atypical hyperplasia cases were collected in TMA blocks. Two 0.6-mm and two 2.0-mm cores were used from each sample. Different antibodies were tested in TMAs and compared with results of whole slides of hysterectomy. Tested antibodies were as follows: ER, PR, p53, Ki-67, MLH1, PMS2, MSH2, MSH6, ARID1A, stathmin, IMP3, L1CAM, PTEN, β-catenin, and p16. Seventeen cases with four cores per paraffin block (both 0.6 and 2.0 mm in duplicate) and 15 different antibodies resulted in a total of 1020 cores for both preoperative and hysterectomy specimen. Overall, 2.0-mm cores were more assessable for evaluation than 0.6-mm cores (96.0 versus 79.5%, p < 0.01). For most antibodies, a substantial to good agreement between hysterectomy TMA and whole slide was present, with lowest agreement for p16 and stathmin and perfect agreement for mismatch repair proteins. Preoperative TMAs showed for most antibodies moderate to perfect agreement with hysterectomy TMAs. In conclusion, 2.0-mm cores are the preferred size for immunohistochemical studies in endometrial cancer. For all tested antibodies, TMAs are a good alternative for whole slide analysis in scientific studies with large patient cohorts, even in preoperative endometrial samples. However, caution is required for interpretation of TMA results of p16 and stathmin.

Proteomic profiling of endometrioid endometrial cancer reveals differential expression of hormone receptors and MAPK signaling proteins in obese versus non-obese patients

Endometrial cancer development is strongly linked to obesity, but knowledge regarding the influence of excess weight on endometrial tumor signaling pathways remains scarce. We therefore analyzed reverse phase protein array (RPPA) data for obesity-related protein expression patterns, using one training (n=272) and two test cohorts (n=68; n=178) of well-annotated samples from women treated for endometrioid endometrial cancer. Gene expression profiling and immunohistochemistry were used for cross-platform validation. Body mass index (BMI) was significantly correlated with progesterone receptor (PR) expression and a hormone receptor protein signature, across all cohorts. In two of the cohorts, BMI was negatively correlated with RTK- and MAPK-pathway activation, particularly phosphorylated MAPK T202 Y204 (p-MAPK) level. Using stepwise selection modelling, a BMI-associated protein signature, including phosphorylated estrogen receptor α S118 (p-ERα) and p-MAPK, was identified. In the subset of FIGO stage 1, grade 1-2 tumors, obese patients (BMI≥30) had better survival compared to non-obese patients in the two cohorts with longest follow-up time (p=0.042, p=0.058). Non-obese patients had higher p-MAPK levels, whereas obese patients had higher p-ERα levels and enrichment of gene signatures related to estrogen signaling, inflammation, immune signaling and hypoxia. In subgroup analysis of non-obese patients with FIGO stage 1 tumors, low PI3K-activation was associated with reduced survival (p=0.002, training cohort). In conclusion, increasing BMI is associated with increased PR and p-ERα levels and reduced MAPK signaling, both in all patients and in subsets with predicted excellent prognosis. The MAPK-pathway represents a potential therapeutic target in non-obese patients with low stage and low grade tumors.

Expression of L1CAM in curettage or high L1CAM level in preoperative blood samples predicts lymph node metastases and poor outcome in endometrial cancer patients

BACKGROUND

Several studies have identified L1 cell adhesion molecule (L1CAM) as a strong prognostic marker in endometrial cancer. To further underline the clinical usefulness of this biomarker, we investigated L1CAM as a predictive marker for lymph node metastases and its prognostic impact in curettage specimens and preoperative plasma samples. In addition, we aimed to validate the prognostic value of L1CAM in hysterectomy specimen.

METHODS

Immunohistochemical staining of L1CAM was performed for 795 hysterectomy and 1134 curettage specimen from endometrial cancer patients. The L1CAM level in preoperative blood samples from 372 patients was determined using ELISA.

RESULTS

Expression of L1CAM in curettage specimen was significantly correlated to L1CAM level in corresponding hysterectomy specimen (P<0.001). Both in curettage and preoperative plasma samples L1CAM upregulation was significantly associated with features of aggressive disease and poor outcome (P<0.001). The L1CAM was an independent predictor of lymph node metastases, after correction for curettage histology, both in curettage specimen (P=0.002) and plasma samples (P=0.048). In the hysterectomy samples L1CAM was significantly associated with poor outcome (P<0.001).

CONCLUSIONS

We demonstrate that preoperative evaluation of L1CAM levels, both in curettage or plasma samples, predicts lymph node metastases and adds valuable information on patient prognosis.

L1 Cell Adhesion Molecule as a Predictor of Disease-Specific Survival and Patterns of Relapse in Endometrial Cancer

Objective

The aim was to study the association of L1 cell adhesion molecule (L1CAM) expression with the outcome of patients with endometrial cancer, especially with regard to conventional risk variables, and to compare the patterns of relapse in L1CAM-positive and -negative cancers.

Methods

This was a retrospective study of 805 women. The Kaplan–Meier method and univariate and multivariate Cox regression models were applied for survival analyses. Missing data were replaced using multiple imputation. The median follow-up time was 51 months (range, 1–98).

Results

One hundred twenty-one (15.0%) cases were L1CAM positive. L1CAM positivity was associated with high stage (I vs II–IV) (odds ratio [OR], 2.3), lymph node involvement (OR, 2.9), poor differentiation (OR, 6.1), non-endometrioid histology (OR, 9.9), lymphovascular space invasion (OR, 2.8), cervical stromal invasion (OR, 1.8), positive peritoneal cytology (OR, 4.1), and age older than 65 years (OR, 2.8). The frequencies of deep myometrial invasion (50% or deeper), tumor size 2 cm or greater, and body mass index 30 kg/m2 or greater were not significantly different between L1CAM-positive and -negative cases. L1CAM predicted poor disease-specific survival in endometrioid (P < 0.0001) but not in non-endometrioid carcinomas (P = 0.934). The negative impact of L1CAM on outcome was confirmed in a Cox multivariate disease-specific survival analysis. Univariate survival analyses in the different ESMO–ESGO–ESTRO endometrial cancer risk groups showed an association between L1CAM positivity and poor outcome in intermediate (hazard ratio, 12) and high-risk advanced metastatic (hazard ratio, 2.0) groups. Extra-abdominal relapses were more frequent in L1CAM-positive (13.2%) than L1CAM-negative (1.9%) stage I endometrioid carcinomas (P < 0.0001), whereas other site-specific relapses in local cancers were L1CAM independent.

Conclusions

L1CAM is associated with the occurrence of poor prognostic variables and predicts advanced disease in endometrial cancer. L1CAM predicts extra-abdominal relapses and poor survival in endometrioid endometrial cancer, but seems not to be a prognostic factor in non-endometrioid carcinomas.

Clinicopathological characteristics of oestrogen receptor negative, progesterone receptor positive breast cancers: re-evaluating subsets within this group

Aims

The presence of oestrogen and progesterone receptors (ER, PR) in breast carcinoma is an important prognostic indicator as well as a predictor of likely response to hormonal treatment. Current ambiguity surrounds ER-negative (–)/PR-positive (+) breast cancer (BC) as to whether this phenotype exists as a distinct entity. The independent predictive value of PR for treatment considerations is also in question, as some investigators believe ER status to be the single most important therapeutic predictive factor in BC. We undertook this study to determine the existence of ER(–)/PR(+) BC and the prognostic effect, if any, of this phenotype.

Methods

We investigated 267 archival documented ER(–)/PR(+) BCs diagnosed between January 1994 and July 2009. Histological slides were retrieved and reviewed. Tissue microarrays were constructed by selecting two 1 mm cores of tumour per case. Repeat immunohistochemistry was performed for confirmation of the ER(–)/PR(+) status. Clinicopathological parameters including age, ethnicity, tumour size, histological grade, histological subtype, associated ductal carcinoma in situ, lymphovascular invasion and lymph node status were evaluated.

Results

On repeat immunohistochemistry, 92 tumours were confirmed as ER(–)/PR(+) BCs. This phenotype accounted for 1.1% of all BC phenotypes and exhibited different clinicopathological features and survival outcome when compared with other phenotypes. ER(–)/PR(+) tumours showed a trend for an early recurrence and poorer overall survival as compared with the patients with ER(+)/PR(+) tumours and similar to ER(–)/PR(–) tumours.

Conclusions

Our findings suggest that ER(–)/PR(+) BCs exist, although rare, with distinct pathological and clinical characteristics from patients with ER(+)/PR(+) BCs.

Principles of Analytic Validation of Clinical Immunohistochemistry Assays

All assays performed in anatomic and clinical pathology laboratories must be validated before they are placed into clinical service. This review summarizes strategies for validation of clinical immunohistochemistry assays, and is chiefly based on the recently released guideline released by The College of American Pathologists.

Prediction model for regional or distant recurrence in endometrial cancer based on classical pathological and immunological parameters

BACKGROUND

Adjuvant therapy increases disease-free survival in endometrial cancer (EC), but has no impact on overall survival and negatively influences the quality of life. We investigated the discriminatory power of classical and immunological predictors of recurrence in a cohort of EC patients and confirmed the findings in an independent validation cohort.

METHODS

We reanalysed the data from 355 EC patients and tested our findings in an independent validation cohort of 72 patients with EC. Predictors were selected and Harrell's C-index for concordance was used to determine discriminatory power for disease-free survival in the total group and stratified for histological subtype.

RESULTS

Predictors for recurrence were FIGO stage, lymphovascular space invasion and numbers of cytotoxic and memory T-cells. For high risk cancer, cytotoxic or memory T-cells predicted recurrence as well as a combination of FIGO stage and lymphovascular space invasion (C-index 0.67 and 0.71 vs 0.70). Recurrence was best predicted when FIGO stage, lymphovascular space invasion and numbers of cytotoxic cells were used in combination (C-index 0.82). Findings were confirmed in the validation cohort.

CONCLUSIONS

In high-risk EC, clinicopathological or immunological variables can predict regional or distant recurrence with equal accuracy, but the use of these variables in combination is more powerful.

Loss of ASRGL1 expression is an independent biomarker for disease-specific survival in endometrioid endometrial carcinoma

OBJECTIVE

For endometrial carcinoma, prognostic stratification methods do not satisfactorily identify patients with adverse outcome. Currently, histology, tumor grade and stage are used to tailoring surgical treatment and to determine the need for adjuvant treatment. Low-risk patients are not considered to require adjuvant therapy or staging lymphadenectomy. For patients with intermediate or high risk, some guidelines recommend tailoring adjuvant treatment according to additional negative prognostic factors. Our objective was to evaluate the biomarker potential of the ASRGL1 protein in endometrial carcinoma.

METHODS

Using The Human Protein Atlas (www.proteinatlas.org), the l-asparaginase (ASRGL1) protein was identified as an endometrial carcinoma biomarker candidate. ASRGL1 expression was immunohistochemically evaluated with an extensively validated antibody on two independent endometrial carcinoma cohorts (n=229 and n=286) arranged as tissue microarrays. Staining results were correlated with clinical features.

RESULTS

Reduced expression of ASRGL1, defined as <75% positively stained tumor cells, was significantly associated with poor prognosis and reduced disease-specific survival in endometrioid endometrial adenocarcinoma (EEA). In multivariate analysis the hazard ratios for disease-specific survival were 3.55 (95% CI=1.10-11.43; p=0.003) and 3.23 (95% CI=1.53-6.81; p=0.002) in the two cohorts, respectively. Of the 48 cases with Grade 3 Stage I tumor all disease-related deaths were associated with low ASRGL1 expression.

CONCLUSIONS

Loss of ASRGL1 in EEA is a powerful biomarker for poor prognosis and retained ASRGL1 has a positive impact on survival. ASRGL1 immunohistochemistry has potential to become an additional tool for prognostication in cases where tailoring adjuvant treatment according to additional prognostic factors besides grade and stage is recommended.

Principles of analytic validation of immunohistochemical assays: Guideline from the College of American Pathologists Pathology and Laboratory Quality Center

CONTEXT

Laboratories must validate all assays before they can be used to test patient specimens, but currently there are no evidence-based guidelines regarding validation of immunohistochemical assays.

OBJECTIVE

To develop recommendations for initial analytic validation and revalidation of immunohistochemical assays.

DESIGN

The College of American Pathologists Pathology and Laboratory Quality Center convened a panel of pathologists and histotechnologists with expertise in immunohistochemistry to develop validation recommendations. A systematic evidence review was conducted to address key questions. Electronic searches identified 1463 publications, of which 126 met inclusion criteria and were extracted. Individual publications were graded for quality, and the key question findings for strength of evidence. Recommendations were derived from strength of evidence, open comment feedback, and expert panel consensus.

RESULTS

Fourteen guideline statements were established to help pathology laboratories comply with validation and revalidation requirements for immunohistochemical assays.

CONCLUSIONS

Laboratories must document successful analytic validation of all immunohistochemical tests before applying to patient specimens. The parameters for cases included in validation sets, including number, expression levels, fixative and processing methods, should take into account intended use and should be sufficient to ensure that the test accurately measures the analyte of interest in specimens tested in that laboratory. Recommendations are also provided for confirming assay performance when there are changes in test methods, reagents, or equipment.

Tissue microarray is a reliable method for immunohistochemical analysis of pleomorphic adenoma

OBJECTIVE

To determine the most adequate number and size of tissue microarray (TMA) cores for pleomorphic adenoma immunohistochemical studies.

STUDY DESIGN

Eighty-two pleomorphic adenoma cases were distributed in 3 TMA blocks assembled in triplicate containing 1.0-, 2.0-, and 3.0-mm cores. Immunohistochemical analysis against cytokeratin 7, Ki67, p63, and CD34 were performed and subsequently evaluated with PixelCount, nuclear, and microvessel software applications.

RESULTS

The 1.0-mm TMA presented lower results than 2.0- and 3.0-mm TMAs versus conventional whole section slides. Possibly because of an increased amount of stromal tissue, 3.0-mm cores presented a higher microvessel density. Comparing the results obtained with one, two, and three 2.0-mm cores, there was no difference between triplicate or duplicate TMAs and a single-core TMA.

CONCLUSIONS

Considering the possible loss of cylinders during immunohistochemical reactions, 2.0-mm TMAs in duplicate are a more reliable approach for pleomorphic adenoma immunohistochemical study.

Immunohistochemical expression of estrogen and progesterone receptors in endometrial polyps: A comparison between benign and malignant polyps in postmenopausal patients

The aim of the present study was to evaluate estrogen receptor (ER) and progesterone receptor (PR) expression in the glandular epithelium and stroma of benign and malignant endometrial polyps of postmenopausal patients. A total of 1,050 females underwent surgical hysteroscopy at the Professor Dr José Aristodemo Pinotti Women’s Hospital, Center for Integral Attention to Women’s Health of the State University of Campinas, between January 1998 and December 2008. Of the total number, 390 postmenopausal females with endometrial polyps were included in the study. Polypoid lesions were histologically classified as benign lesions (endometrial polyps and polyps with non-atypical simple hyperplasia or non-atypical complex hyperplasia) and premalignant and malignant lesions (polyps with atypical simple hyperplasia or atypical complex hyperplasia and carcinomatous polyps). ER and PR expression was evaluated by immunohistochemistry according to cell staining, intensity of nuclear staining and final score. The final score for receptor expression was compared between the benign and premalignant/malignant polyps. The prevalence of malignancy in endometrial polyps was 7.1% and was associated with postmenopausal bleeding. Only the final score for ER expression in the stroma of endometrial polyps was higher in the benign group than in the premalignant/malignant group, and this difference was significant. However, no difference was identified in PR expression. In addition, the risk of malignancy in endometrial polyps was significantly higher when the expression of ER and PR was negative in the stromal component of the polyp (P<0.01). The malignancy of endometrial polyps was also associated with a low expression of stromal ER, however, PR expression did not show any association with the risk of malignancy.

Differences in estrogen and progesterone receptor expression in endometrial polyps and atrophic endometrium of postmenopausal women with and without exposure to tamoxifen

Postmenopausal women who use tamoxifen present with an increased incidence of endometrial alterations, such as polyps and hyperplasia, in addition to a higher risk of malignant endometrial neoplasms. Among these endometrial changes, polyps are the most common, with a pathogenesis associated with hormonal influence. The objective of this study was to compare the expression of estrogen receptors (ERs) and progesterone receptors (PRs) in endometrial polyps from tamoxifen users with that in endometrial polyps and the atrophic endometrium of postmenopausal tamoxifen non-users. Among women undergoing surgical hysteroscopy, 84 tamoxifen users with benign endometrial polyps were selected. This group was compared to 84 samples of atrophic endometrium and to 252 benign polyps from postmenopausal women who were not treated with tamoxifen. The expression of ER/PR was assessed by immunohistochemical analysis, according to the percentage of stained cells, intensity of nuclear staining and final score. The polyps from tamoxifen users exhibited a higher expression of ER and PR in the glandular epithelium and stroma compared to the atrophic endometrium (P<0.0001). Compared to the polyps from women not treated with tamoxifen, tamoxifen users exhibited a higher PR expression in the epithelium (P=0.0014) and stroma (P=0.0056), with no difference in the expression of ER. In conclusion, endometrial polyps frequently exhibit an increase in ER expression, regardless of tamoxifen use. High levels of PR expression appear to be consistent with the estrogen agonist effects of tamoxifen.

Further evidence that E-cadherin is not a tumour suppressor gene in invasive ductal carcinoma of the breast: an immunohistochemical study

AIMS

E-cadherin is a cell adhesion molecule expressed in normal breast tissue; it is used generally as a phenotypical marker in breast cancer, with the absence of its expression observed frequently in lobular tumours. We have reported E-cadherin expression previously in 1516 ductal breast carcinoma using tissue microarray (TMA), where 7% of cases showed a complete absence of membrane staining. In this study, we investigated further the existence of E-cadherin-negative ductal carcinoma and evaluated the status of the E-cadherin-catenin complex in this subgroup.

MATERIAL AND METHODS

Full-face sections from excision specimens of 72 ductal breast carcinomas reported previously as E-cadherin-negative were assessed morphologically using haematoxylin and eosin staining, and immunohistochemically using two E-cadherin antibodies (HECD-1 and CDH1/4A2C7) and antibodies recognizing β-catenin and p120 proteins. Only membrane expression was considered.

RESULTS

Forty-seven ductal carcinomas were assessed after the exclusion of inappropriate cases; 34 of these showed positive E-cadherin (HECD-1) membrane expression which was focal and weak and seen mainly in invasion fronts. Ten cases showed E-cadherin (4A2C7) staining. Staining for p120 and β-catenin showed membrane staining in all cases for both antibodies, which was variable in both intensity and the proportion of positive cells.

CONCLUSION

These results demonstrate that E-cadherin-negative ductal carcinoma is rare, and in these cases p120 and β-catenin maintained their membranous localization, suggesting a functional E-cadherin-membrane complex.

Tissue microarray construction for salivary gland tumors study

OBJECTIVE

To describe and discuss the design, building and usefulness of tissue microarray (TMA) blocks for the study of salivary gland tumors (SGTs).

STUDY DESIGN

Two hundred thirty-eight formalin-fixed, paraffin-embedded SGTs were arranged in blocks of TMA using a manual tissue arrayer. Three representative cores of 1.0, 2.0 or 3.0mm were taken from each original block and their characteristics were analyzed and described.

RESULTS

It was created 12 TMA blocks that presented highly representative neoplastic cylinders. However, those neoplasias rich in cystic spaces such as mucoepidermoid carcinoma and Warthin tumor presented more difficulties to be sampled, as the neoplastic tissue available was scarce. Tissue damage and loss during TMA construction was estimated as 3.7%.

CONCLUSION

Representative areas of SGTs, with relatively small loss of tissue, can be obtained with the construction of TMA blocks for molecular studies. However, tumors rich in cystic spaces present more difficulties to be adequately sampled.

Serum carbonic anhydrase IX and its prognostic relevance in vulvar cancer

INTRODUCTION

Therapeutic options in advanced or recurrent vulvar cancer are limited. The identification of new prognostic factors and markers for therapy stratification is therefore highly desirable. Carbonic anhydrase IX (CAIX) is up-regulated in various solid tumors and a promising new target. We therefore determined CAIX serum concentration and its prognostic relevance in correlation to intratumoral CAIX expression in patients with primary vulvar cancer.

METHODS

Thirty-one serum samples of patients with primary vulvar cancer were prospectively collected before surgery and analyzed for CAIX by enzyme-linked immunosorbent assay. In addition, intratumoral CAIX expression was determined by immunohistochemistry and correlation with serum CAIX and clinicopathological factors, and outcome was analyzed.

RESULTS

Preoperative serum concentration of CAIX ranged between 56 and 879 pg/mL (median, 147 pg/mL; mean, 237.29) and was significantly higher in patients with high intratumoral expression (median, 269 pg/mL vs 126 pg/mL, P = 0.03). High serum CAIX was not associated with any of the analyzed clinicopathological parameters. However, disease-free survival was shorter in patients with high preoperative serum CAIX (above median; P = 0.012). By immunohistochemistry, 26% of the tumors showed a moderate or strong expression of CAIX, whereas 74% showed weak or no expression. High intratumoral expression of CAIX was also associated with unfavorable disease-free survival (P = 0.043).

CONCLUSIONS

Carbonic anhydrase IX serum concentration is higher in patients with high intratumoral expression, and elevated preoperative serum values are associated with unfavorable prognosis. Serum CAIX might therefore be an easily assessable marker to stratify patients for adjuvant therapy and potentially monitor response. Carbonic anhydrase IX is differentially expressed in vulvar cancer and potentially associated with negative outcome.

Genomic profile of endometrial tumors depends on morphological subtype, not on tamoxifen exposure

Tamoxifen has been a very effective treatment for breast cancer for several decades, however, at the same time increases the risk of endometrial cancer, especially after prolonged exposure. In addition, tamoxifen has been associated with a higher proportion of unfavorable uterine tumor subtypes (carcinosarcomas and serous adenocarcinomas) with worse survival. We investigated whether endometrial tumors, which developed after prolonged tamoxifen treatment for breast cancer, are genetically different from endometrial tumors without preceding tamoxifen exposure. Array CGH was used on archival formalin-fixed paraffin embedded endometrial tumors to determine genomic aberrations. We compared the genomic profiles of 52 endometrial tumors from breast cancer patients after long-term (>or=2 years) tamoxifen use (endometrioid adenocarcinomas, n = 26; carcinosarcomas, n = 14; and serous adenocarcinomas, n = 12) with endometrial tumors from unexposed breast cancer patients (n = 45). Genomic profiles were correlated with tamoxifen exposure, tumor subtypes, and histopathological characteristics of the endometrial tumors. The common uterine corpus cancers of the endometrioid subtype show few genomic aberrations. Tumors with many genomic aberrations were in general ER-negative. In contrast, carcinosarcomas and serous adenocarcinomas showed many aberrations; however, they were indistinguishable from each other. Tumors that developed after prolonged tamoxifen use did not show more or different aberrations than unexposed tumors. This was true for all tumor subtypes. Thus, endometrial carcinomas that develop after prolonged tamoxifen use cannot be distinguished from nonusers on basis of their tumor genomic profile.

Limitations of tissue microarrays compared with whole tissue sections in survival analysis

Tissue microarray (TMA) is a promising technique in the evaluation of immunohistochemical markers in tumors and may be used as an alternative for whole sections. However, only a few studies have correlated a clinical outcome with both TMA and results obtained from whole sections. This study compared immunostaining for Ki-67 and p16 in TMA (3 cores from each specimen) and whole sections of 171 cases of stage III epithelial ovarian cancer with clinical data. A high expression of Ki-67 was identified in 85.0, 85.5, 85.8, 90.5 and 84% of cores 1, 2 and 3, TMAs and whole tissue sections, respectively. A high p16 expression was found in 36.5, 31.4, 30.3, 46.3 and 31.0% of cores 1, 2 and 3, TMAs and whole tissue sections, respectively. The high expression of Ki-67 and p16 in whole tissue sections significantly correlated with that of Ki-67 and p16 in core 1 (P<0.0001 and P<0.0001, respectively), core 2 (P<0.0001 and P<0.0001, respectively), core 3 (P<0.0001 and P<0.0001, respectively), and TMAs (P<0.0001 and P<0.0001, respectively). In univariate analysis, a high expression of Ki-67 and p16 in two of the cores; TMA and the whole tissue sections were significantly correlated to disease-related survival (Ki-67: P=0.008, 0.012, 0.012 and 0.0001, respectively, and p16: P=0.0007, 0.0005, 0.0008 and 0.005, respectively). However, in the multivariate analysis only Ki-67 on whole tissue sections retained an independent prognostic significance (P=0.025). We concluded that more studies, with a higher number of cores, are necessary to determine the efficacy of TMA in reflecting the prognostic value of different antibodies. Morever, evaluation of this method is crucial for each type of tumor and each separate antigen. It is also essential to confirm the clinical correlations on the whole sections before investigating the same parameters on TMA.

Mucins and CD56 as markers of tumour invasion and prognosis in periampullary cancer

BACKGROUND

This study investigated the association of mucins and cluster of differentiation (CD) 56 with vascular and perineural invasion and survival in patients with periampullary cancer.

METHODS

Immunohistochemical staining was performed on formalin-fixed pancreatic tissue microarrays (cancer, chronic pancreatitis and normal pancreatic tissue) constructed from 126 pancreatic resections (cancer, 104; chronic pancreatitis, 22). Mucin (MUC) 1, MUC4 and MUC5AC expression was quantified using the immunohistochemical score (range 0-300), MUC3 expression was described as membranous or cytoplasmic, and expression of CD56, MUC2 and MUC6 as present or absent.

RESULTS

In cancers, vascular invasion correlated with overexpression (immunohistochemical score of 100 or more) of MUC1 (P = 0.003) and presence of MUC6 (P = 0.024), and perineural invasion correlated with overexpression of MUC5AC (P = 0.015). Reduced survival was observed with overexpression of MUC4 (P = 0.032) and MUC5AC (P = 0.048), membranous expression of MUC3 (P = 0.048), and presence of CD56 (P = 0.041). Perineural invasion also correlated with CD56 expression (P = 0.001). Overexpression of MUC4 and MUC5AC correlated with tumour recurrence (P = 0.001 and P = 0.034 respectively). Multivariable analysis identified membranous expression of MUC3 (P = 0.023), lymphatic invasion (P = 0.015) and perineural invasion (P = 0.004) as independent predictors of poor survival.

CONCLUSION

Mucins and CD56 may be markers of prognosis in patients with periampullary cancer.

Tissue microarrays: one size does not fit all

BACKGROUND

Although tissue microarrays (TMAs) are commonly employed in clinical and basic-science research, there are no guidelines for evaluating the appropriateness of a TMA for a given biomarker and tumor type. Furthermore, TMA performance across multiple biomarkers has not been systematically explored.

METHODS

A simulated TMA with between 1 and 10 cores was designed to study tumor expression of 6 biomarkers with varied expression patterns (B7-H1, B7-H3, survivin, Ki-67, CAIX, and IMP3) using 100 patients with clear cell renal cell carcinoma (RCC). We evaluated agreement between whole tissue section and TMA immunohistochemical biomarker quantification to assess how many TMA cores are necessary to adequately represent RCC whole tissue section expression. Additionally, we evaluated associations of whole tissue section and TMA expression with RCC-specific death.

RESULTS

The number of simulated TMA cores necessary to adequately represent whole tissue section quantification is biomarker specific. Although 2-3 cores appeared adequate for B7-H3, Ki-67, CAIX, and IMP3, even as many as 10 cores resulted in poor agreement for B7-H1 and survivin compared to RCC whole tissue sections. While whole tissue section B7-H1 was significantly associated with RCC-specific death, no significant associations were detected using as many as 10 TMA cores, suggesting that TMAs can result in false-negative findings if the TMA is not optimally designed.

CONCLUSIONS

Prior to TMA analysis, the number of TMA cores necessary to accurately represent biomarker expression on whole tissue sections should be established as there is not a one-size-fits-all TMA. We illustrate the use of a simulated TMA as a cost-effective tool for this purpose.

Overexpression of carbonic anhydrase IX (CAIX) in vulvar cancer is associated with tumor progression and development of locoregional lymph node metastases

Carbonic anhydrase IX (CAIX) is a strictly membranous expressed metalloenzyme involved in cell adhesion, pH homeostasis, and cancer progression. The protein is specifically overexpressed in a wide variety of malignant tumors. This study was designed to assess the role of CAIX in primary vulvar cancer. One hundred forty-two well-characterized primary vulvar carcinomas were analyzed on a tissue microarray (TMA). Three tissue cores were sampled from each tumor. CAIX expression was determined by immunohistochemistry, using a four-step scoring system. To determine CAIX expression in benign vulvar tissue, we constructed a TMA with 120 samples of normal mucosa and non-neoplastic diseases. CAIX expression was found in 77/135 (57%) of all assessable vulvar cancer specimens and 48 (35.5%) exhibited a moderate or strong expression. CAIX expression in vulvar carcinomas was significantly stronger compared to non-neoplastic vulvar tissue (p < 0.001). High levels of CAIX expression were related to pT stage (p < 0.01), tumor size (p < 0.01), depth of invasion (p < 0.05), as well as inguinal lymph node metastases (p < 0.05). There was also a trend towards shorter recurrence-free patient survival in CAIX-positive compared to CAIX-negative vulvar cancers. CAIX staining results in different tissue cores from the same tumor were homogeneous, raising the possibility of a hypoxia-independent expression. In conclusion, CAIX is overexpressed in the majority of vulvar carcinomas with relationships to advanced tumor stages and development of lymph node metastases. Our data support the potential therapeutic benefit of newly developed targeting antibodies in advanced vulvar cancer.

The prognostic role of classical and nonclassical MHC class I expression in endometrial cancer

The aim of this study was to investigate classical MHC class I and nonclassical MHC (human leukocyte antigen-G [HLA-G]) expression in a large cohort of patients with endometrial cancer, to determine the prognostic value of these cell surface markers and their relation with clinicopathological variables. Tissue microarrays containing epithelial endometrial carcinoma tissue from 554 patients were stained for classical and nonclassical MHC class I using the following monoclonal antibodies: 4H84 (anti-HLA-G), beta2-m (anti-beta-2-microglobulin) and HC-10 (MHC class I antigen heavy chain). Expression data were linked to known clinicopathological characteristics and survival. HLA-G upregulation and MHC class I downregulation in neoplastic cells was observed in 40% and 48%, respectively. Nonendometrioid tumor type, advanced stage disease (FIGO stage > or = II) and poorly or undifferentiated tumors were associated with MHC class I downregulation. Absence of HLA-G expression was independently associated with MHC class I downregulation. In univariate analysis, MHC class I downregulation was a predictor of worse disease-specific survival. Prognostic unfavorable tumor characteristics were correlated with downregulation of MHC class I expression in endometrial cancer cells. Furthermore, downregulated MHC class I has a negative impact on disease-specific survival, observed in a large cohort of patients with endometrial cancer. As there seems to be a relation between classical and nonclassical MHC class I molecules (HLA-G), further research is warranted to unravel this regulatory mechanism.

EGFR and Ki-67 expression in oral squamous cell carcinoma using tissue microarray technology

OBJECTIVE

Our aim was to validate the use of tissue microarrays (TMA) in oral squamous cell carcinomas (OSCC) to analyse epidermal growth factor receptor (EGFR) and Ki-67 expression. We also analysed the relationship that the expression of these markers may have with clinical, pathological and survival variables.

PATIENTS AND METHODS

The study sample comprised 39 unselected patients diagnosed and treated for OSCC. We analysed Ki-67 and EGFR expression by immunohistochemistry on formalin-fixed, paraffin-embedded surgical specimens. Whole sections (WS) were compared with double 1.5 mm core-tissue microarrays.

RESULTS

High EGFR expression was observed both on TMA (in 98% of the cases) and WS (in 100% of the cases) with substantial agreement kappa value (0.720). EGFR expression was not significantly associated with clinical, pathological and survival variables on TMA and WS. Ki-67 analysis showed a Spearman correlation of 0.741 with a Ki-67 mean labelling index of 45% in TMA and 56.8% in WS. We found a significant relationship between gender and Ki-67 labelling index on WS (P = 0.022) and TMA (P = 0.002). Clinical stage was the only parameter in multivariate analysis that had a significant predictive value.

CONCLUSION

We demonstrate that dual 1.5 mm core TMA is a valid, rapid, economical and tissue-saving way to study OSCC biopsies and that it presents strong correlation with the WS. EGFR overexpression in OSCC suggests that these tumours may be a candidate for therapy investigation directed to EGFR.

Complete absence of M2-pyruvate kinase expression in benign pancreatic ductal epithelium and pancreaticobiliary and duodenal neoplasia

Background

Elevated serum concentrations of M2-pyruvate kinase (M2-PK) correlate with poor prognosis in patients with pancreaticobiliary and duodenal cancer, but the expression of M2-PK in formalin-fixed pancreatic tissue is unknown. We aimed to characterise the immunohistochemical expression of M2-PK in archived specimens of pancreaticobiliary and duodenal cancers, premalignant lesions, chronic pancreatitis, and normal pancreas.

Methods

Immunohistochemical staining was performed with mouse anti-M2-PK monoclonal antibody (clone DF-4) at an optimal dilution of 1:25 on tissue microarrays constructed from formalin-fixed paraffin-embedded pancreatic tissue of 126 consecutive patients undergoing pancreatic resections between June 2001 and June 2006. 104 underwent resection for cancer and 22 for chronic pancreatitis. 78 specimens of chronic pancreatitis tissue were obtained adjacent to areas of cancer. Normal pancreatic tissue was obtained from the resection specimens in a total of 30 patients. Metastatic tumours in 61 regional lymph nodes from 61 patients were also studied. A further 11 premalignant pancreaticobiliary and duodenal lesions were studied. M2-PK expression was quantified with the immunohistochemical score (IHS; Range 0-12).

Results

Benign non-ductal tissue in chronic pancreatitis and normal pancreas showed variable expression of M2-PK (IHS = 1 in 25%, IHS = 2-3 in 40%, IHS>3 in 40%). Benign pancreatic ductal epithelium, all primary pancreaticobiliary and duodenal premalignant lesions and cancers (and lymph node metastasis) showed complete lack of expression (IHS = 0).

Conclusion

Complete lack of M2-PK expression was observed in benign pancreatic ducts, premalignant lesions and cancer. M2-PK is present only in benign non-ductal epithelium in normal pancreas and peri-tumoural tissue.

Differential expression of KAI1 metastasis suppressor protein in renal cell tumor histological subtypes

PURPOSE

The similar appearance of renal tumor histological subtypes can complicate differential diagnoses. This problem is most notable for the chromophobe subtype of renal cell carcinoma, which can be histologically indistinguishable from oncocytoma with investigational molecular markers failing to provide reliable differentiation. KAI1 is a metastasis suppressor gene whose expression correlates inversely with the metastatic potential of most solid tumor cancer types. We tested the hypothesis that KAI1 is differentially expressed among renal tumor histological subtypes.

MATERIALS AND METHODS

Immunohistochemical staining for KAI1 protein was performed in 152 nephrectomy specimens, including 48 clear cell, 35 papillary and 31 chromophobe renal cell carcinoma samples, 28 oncocytomas and 10 tumor-free kidneys. Staining was scored as none/minimal, low, moderate or high. KAI1 mRNA levels were compared by quantitative reverse transcriptase-polymerase chain reaction in an additional 22 chromophobe renal cell carcinoma and oncocytoma samples.

RESULTS

In all 10 tumor-free kidneys KAI1 protein was detected exclusively in distal tubule cell membranes. Of the tumor specimens KAI1 protein was absent in all papillary renal cell carcinoma specimens. It was present in only 1 of 48 clear cell renal cell carcinomas (2%) and 2 of 28 oncocytomas (7%) but only at low levels. In contrast, 27 of 31 chromophobe renal cell carcinoma specimens (87%) expressed KAI1 protein, most at moderate or high levels. The diagnostic accuracy of KAI1 immunostaining for discerning chromophobe renal cell carcinoma from oncocytoma was 90% with similar results observed at the RNA level.

CONCLUSIONS

KAI1 is an accurate biomarker for chromophobe renal cell carcinoma that may aid in the diagnostic differentiation of chromophobe renal cell carcinoma from oncocytoma. It remains to be determined whether KAI1 expression contributes to the low metastatic potential of chromophobe renal cell carcinoma.

Quality aspects of the tissue microarray technique in a population-based cohort with ductal carcinoma in situ of the breast

AIMS

Tissue microarray (TMA) is an efficient technique for analysis of molecular markers. Prospectively collected samples have been reported to give excellent concordance between TMA data and corresponding whole-sections. The aim was to evaluate the usefulness of TMA in a population-based cohort of 213 women with ductal carcinoma in situ of the breast (DCIS).

METHODS AND RESULTS

We studied immunohistochemical HER2, oestrogen (ER) and progesterone (PR) receptor status. The prognostic impact was similar for all markers comparing whole sections and TMAs. The proportion of positive tumours was similar regarding HER2 and ER, whereas PR tumours were more frequently positive in the TMAs (P = 0.007). The concordance was 80% (kappa value 0.63) between original sections and TMAs. The proportion of successfully analysed tumours was 70%. Smaller tumours had a lower ratio (P < 0.0001) and a larger proportion of mismatched results (P = 0.05).

CONCLUSIONS

Retrospective analyses of tumours from cohorts with long-term follow-up are indispensable. We have shown that the TMA technique is a useful tool for high-throughput analysis of DCIS. However, our study has pinpointed some technical hazards within a population-based cohort, including many small lesions and the poor condition of some donor blocks. Mismatched results may be due to tumour heterogeneity.

Validation of tissue microarray technology in squamous cell carcinoma of the esophagus

Tissue microarray (TMA) technology has been developed to facilitate high-throughput immunohistochemical and in situ hybridization analysis of tissues by inserting small tissue biopsy cores into a single paraffin block. Several studies have revealed novel prognostic biomarkers in esophageal squamous cell carcinoma (ESCC) by means of TMA technology, although this technique has not yet been validated for these tumors. Because representativeness of the donor tissue cores may be a disadvantage compared to full sections, the aim of this study was to assess if TMA technology provides representative immunohistochemical results in ESCC. A TMA was constructed containing triplicate cores of 108 formalin-fixed, paraffin-embedded squamous cell carcinomas of the esophagus. The agreement in the differentiation grade and immunohistochemical staining scores of CK5/6, CK14, E-cadherin, Ki-67, and p53 between TMA cores and a subset of 64 randomly selected donor paraffin blocks was determined using kappa statistics. The concurrence between TMA cores and donor blocks was moderate for Ki-67 (κ = 0.42) and E-cadherin (κ = 0.47), substantial for differentiation grade (κ = 0.65) and CK14 (κ = 0.71), and almost perfect for p53 (κ = 0.86) and CK5/6 (κ = 0.93). TMA technology appears to be a valid method for immunohistochemical analysis of molecular markers in ESCC provided that the staining pattern in the tumor is homogeneous.