Positive EGFR Expression Research Articles

Prognostic and predictive value of p-Akt, EGFR, and p-mTOR in early breast cancer

There are scarce data available on the prognostic/predictive value of p-Akt and p-mTOR protein expression in patients with high-risk early breast cancer. Formalin-fixed paraffin-embedded (FFPE) tumor tissue samples from 997 patients participating in two adjuvant phase III trials were assessed for EGFR, PTEN, p-Akt, p-mTOR protein expression, and PIK3CA mutational status. These markers were evaluated for associations with each other and with selected patient and tumor characteristics, immunohistochemical subtypes, disease-free survival (DFS), and overall survival (OS). p-mTOR protein expression was negatively associated with EGFR and positively associated with PTEN, with p-Akt473, and with the presence of PIK3CA mutations. EGFR expression was positively associated with p-Akt473, p-Akt308, and PIK3CA wild-type tumors. Finally, p-Akt308 was positively associated with p-Akt473 expression. In univariate analysis, EGFR (p = 0.016) and the coexpression of EGFR and p-mTOR (p = 0.015) were associated with poor OS. Among patients with p-Akt308-negative or low-expressing tumors, those treated with hormonal therapy were associated with decreased risk for both relapse and death (p = 0.013 and p < 0.001, respectively). In the subgroup of patients with locoregional relapse, positive EGFR and mTOR protein expression was found to be associated with increased (p = 0.034) and decreased (p < 0.001) risk for earlier relapse, respectively. In multivariate analysis, low levels of p-Akt308 and the coexpression of EGFR and p-mTOR retained their prognostic value. Low protein expression of p-Akt308 was associated with improved DFS and OS among patients treated with hormonal therapy following adjuvant chemotherapy. Coexpression of EGFR and p-mTOR was associated with worse OS.

Abstract P2-06-05: Association of promoter methylation status of the FHIT gene and Fhit expression with HER2/neu status in breast cancer

Abstract Purpose: Aberrant DNA methylation has been recognized to contribute to breast carcinogenesis, and promoter hypermethylation of many tumor suppressor genes has been correlated with decreased gene expression. The fragile histidine triad (FHIT) gene is a putative tumor suppressor gene in breast and other cancers, and loss of Fhit expression has been observed in breast cancers. The aim of this study was to evaluate the association between methylation of the FHIT gene and its expression in breast cancer, and to investigate whether methylation and expression of the FHIT gene would correlate with clinicopathological characteristics in relation to human epidermal growth factor receptor 2 (HER2) status. Methods: Pyrosequencing of bisulfite treated DNA was performed to study the methylation status of the FHIT gene in 60 breast cancer samples from Korean women obtained at Daegu Catholic University Hospital. We examined the expression of FHIT using tissue microarrays by immunohistochemical staining. Association between the methylation status of the FHIT gene and its expression was analyzed, and the relationship between the FHIT expression and the clinicopathological characteristics of the patients was evaluated. Results: FHIT methylation was detected in 96.7% and positive expression rate of Fhit was 87.3% of the patients. The mean methylation level of the FHIT gene was associated with intratumoral inflammation. Methylation level of the FHIT gene had no significant differences according to molecular subtypes. Loss of Fhit expression was associated with large tumor size, basal-like subtype and positive expression of EGFR. In HER2-negative breast cancers, loss of Fhit expression was significantly associated with tumor size, estrogen receptor status and Ki-67 proliferation index. There was no significant correlation between methylation of the FHIT gene and its expression in this study. Conslusion: Our study revealed that loss of Fhit expression in breast cancer is associated with poor prognostic features, although there is no significance association between the FHIT gene methylation and Fhit expression. We found that in HER2-negatvie breast cancers, loss of Fhit expression was associated with poor prognostic features. These results support the possibility of potential complementation between HER2 and the Fhit pathway. The clinical significance of our findings needs to be further evaluated in larger cohorts with longer follow-up. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-06-05.

Lymphocytic infiltrate is associated with favorable biomarkers profile in HER2-overexpressing breast cancers and adverse biomarker profile in ER-positive breast cancers

The value for lymphocytic infiltration (LI) has been increasingly recognized for tumor assessment. In breast cancer, however, the overall significance of LI remains poorly defined, probably due to its heterogeneity. A large cohort of breast cancer was evaluated for the degree of LI and its association with traditional pathologic factors, biomarker expression, and cancer subtypes. The number of CD8 cytotoxic effector and FoxP3 regulatory T cell (Treg) was evaluated in those cases with high LI. High LI was associated with negative ER and PR but positive HER2 and EGFR expression (p<0.001 for all). In ER-positive cancers, high LI was associated with poor prognostic features including higher grade, the presence of necrosis, and lymphovascular invasion (LVI) (p=0.007 for LVI and <0.001 for the others). Conversely, LI correlated with smaller tumor size, a good prognostic feature (p=0.046) in HER2+ ER-cancers. These observations suggested LI may show opposite prognostic values in different breast cancer subgroups. Interestingly, when the phenotype of LI in these subgroups was evaluated, a strong positive association with intratumoral accumulation of Treg was found in ER-positive cancers (p=0.003, Rs=0.319), while the opposite was observed in HER2+ ER-cancers (p<0.001, Rs=-0.427). Also, in ER-positive cancers, positive associations between peri- and intra-tumoral distribution were found with both CD8 and Tregs (CD8: p<0.001, Rs=0.547; Treg: p=0.001, Rs=0.460). Nonetheless, in HER2+ ER-cancers, such strong association was found with CD8 (p<0.001, Rs=0.766) but not Tregs. The results may implicate a differential intratumoral migration of LI in different subtypes of breast cancer. In summary, the clinical value of LI in breast cancers could be subtype-dependent. In ER-positive cancers, high LI correlated with biologic parameters associated with poor prognosis, whereas in HER2 positive cancers, LI correlated with biologic parameters of favorable prognosis.

Promoter methylation status of the FHIT gene and Fhit expression: Association with HER2/neu status in breast cancer patients

Aberrant DNA methylation has been recognized to contribute to breast carcinogenesis, and promoter hypermethylation of several tumor suppressor genes has been correlated with decreased gene expression. The fragile histidine triad (FHIT) gene is a putative tumor suppressor gene in breast and other types of cancer, and loss of Fhit expression has been observed in breast cancer. The aim of the present study was to evaluate the association between methylation of the FHIT gene and its expression in breast cancer, and to investigate whether methylation and expression of the FHIT gene correlates with clinicopathological characteristics in relation to human epidermal growth factor receptor 2 (HER2) status. Pyrosequencing of bisulfite-treated DNA was performed to study the methylation status of the FHIT gene in 60 breast cancer samples. We examined the expression of Fhit using tissue microarrays by immunohistochemical staining. FHIT methylation was detected in 96.7% and the positive expression rate of Fhit was 87.3% of the patients. The mean methylation level of the FHIT gene was associated with intratumoral inflammation. Methylation level of the FHIT gene had no significant differences according to molecular subtypes. Loss of Fhit expression was associated with large tumor size, basal-like subtype and positive expression of EGFR. In HER2-negative breast cancer, loss of Fhit expression was significantly associated with tumor size, estrogen receptor status and Ki-67 proliferation index. No significant correlation between methylation of the FHIT gene and its expression was observed in the present study. Our results suggest that loss of Fhit expression in breast cancer is associated with poor prognostic features, and it is also relevant to the results in HER2-negative breast cancer. Further studies with larger sample sizes and longer follow-up are required to clarify the predictive and prognostic value of Fhit expression and the FHIT gene methylation status in breast cancer.

A diagnostic algorithm using EGFR mutation-specific antibodies for rapid response EGFR-TKI treatment in patients with non-small cell lung cancer

BackgroundWe previously reported that EGFR mutation-specific antibodies performed well in immunohisto/cytochemical analysis. Assessment of EGFR mutation status for EGFR-TKIs (tyrosin kinase inhibitors) treatment of non-small cell lung cancer (NSCLC) patients can be performed by DNA-based assay. To establish a testing algorithm for EGFR mutation status in NSCLC patients, we utilized the peptide nucleic acid-locked nucleic acid (PNA-LNA) PCR clamp assay to determine the EGFR mutation, and immunostaining to detect the delE746-A750 and L858R mutation protein. Patients and methodsOne hundred thirty-three patients with NSCLC were examined by immunostaining with EGFR mutation-specific antibodies, and by the PNA-LNA PCR clamp assay, using histological or cytological samples. The expression levels of immunostaining were classified as positive (score 2+), negative (score 0) or equivocal (score 1+), indicating questionable, negative or weak expression. Of these patients, 42 NSCLC patients received EGFR-TKIs treatment and we analyzed whether expression of mutant EGFR proteins was correlated with progression-free survival in patients with NSCLC treated with EGFR-TKIs. ResultsIn the 133 samples, positive, negative and equivocal results for EGFR mutation-specific antibodies were observed in 37 patients (27.8%), 85 patients (63.9%) and 11 patients (8.3%), respectively. Thirty-seven patients showed positive EGFR expression by immunostaining, and 35 (94.6%) of these also tested positive in the DNA-based assay. Of 85 EGFR-negative patients by immunostaining, 77 (90.6%) also tested negative in the DNA-based assay. Of the 11 patients with equivocal immunostaining results, DNA-based assay detected EGFR mutation in 8 (72.7%) patients. Immunostaining for the EGFR mutation-specific antibodies showed a sensitivity of 81.4%, specificity of 97.5%, positive predictive value of 94.6% and negative predictive value of 90.6%, excluding the 11 patients with equivocal results. In NSCLC patients treated with EGFR-TKIs, the progression-free survival after the start of EGFR-TKIs treatment was significantly longer in patients with EGFR positive expression than in those with equivocal and negative expression (P=0.002). ConclusionsOur results suggest that patients testing positive for EGFR mutations by immunostaining are good candidates for rapid response EGFR-TKI therapy. Immunostaining for EGFR mutation-specific antibodies is a new test for EGFR-TKI inhibition and could be a useful indicator with regard to patient management.

Development of an assay based on SOMAmer affinity reagents that detects drug-unbound serum EGFR in the presence of cetuximab and panitumumab.

2587 Background: EGFR is an oncogene product whose extracellular domain (ECD) can be either up-regulated or down-regulated in serum of patients with various cancers. In colon cancer patients with positive tissue EGFR expression, 2 EGFR ECD-targeting monoclonal antibody drugs, cetuximab (Erbitux) and panitumumab (Vectibix), are widely used chemotherapeutic agents. Patient responses to these drugs vary, and the mechanism of this variability remains unelucidated. Methods: A Slow Off-Rate Modified Aptamer (SOMAmer) targeting the EGFR ECD was selected via Systematic Evolution of Ligands by Exponential Enrichment (SELEX). Using this SOMAmer as a capturing reagent and based on published studies ( Gold et al. PLoS ONE; Dec 7, 2010:10.1371/journal.pone.0015004), we developed a quantitative serum EGFR assay to reliably quantify EGFR in serum. Results: Recovery tests using various amounts of purified EGFR spiked into serum demonstrated a full level of EGFR. Intra and inter assay variability were tested and showed minimum variability. The detection range is 0.95 ng/ml to 600 ng/ml. Interestingly, when serum samples from patients taking cetuximab or panitumumab at the time of blood collection were tested, we observed markedly lower levels of EGFR-captured SOMAmer. ELISA assays from 2 different vendors showed normal to high levels of EGFR in these samples. We further showed that pretreatment of normal serum with either cetuximab or panitumumab can dose-dependently reduce the EGFR SOMAmer signal. The data suggest that our EGFR SOMAmer assay detects serum EGFR molecules that are unbound by cetuximab or panitumumab. Some treated patient samples had more drastic reductions in circulating serum EGFR than others. Conclusions: Various assay development parameters such as accuracy, detection range, and intra and inter assay variability showed that a SOMAmer-based assay detecting serum EGFR can be used in a clinical setting. Our data suggest that this assay can accurately measure drug-unbound EGFR in patients, which may serve as a surrogate drug efficacy indicator, and this may help physicians to adjust the drug dosage. Further studies will be necessary to investigate this possibility.

Progranulin expression in breast cancer with different intrinsic subtypes

Progranulin is a newly discovered 88-kDa glycoprotein originally purified from the highly tumorigenic mouse teratoma-derived cell line PC. We found that high progranulin expression was associated with higher breast carcinoma angiogenesis, reflected by increased vascular endothelial growth factor expression and higher microvessel density. However, no immunohistochemical evidence currently exists to correlate progranulin expression with clinicopathological features in different intrinsic subtypes of breast carcinoma biopsies. The aim of this study was to investigate the progranulin expression profiles in the intrinsic subtypes of breast carcinomas and their relevance to histopathological and clinicopathological features.Tissue blocks containing 264 cases of breast carcinomas from 2006 to 2009 were classified as different intrinsic subtypes. Tissues of four intrinsic subtypes were immunostained for progranulin, vascular endothelial growth factor and CD105. Their relevance to histopathological and clinicopathological features was also analyzed. Twenty tissue samples from breast fibroadenomas were included in this study.Progranulin expression showed no significant differences in different intrinsic subtypes, although an increasing tendency could be found in the triple-negative breast cancer (TNBC) subgroup (χ2=5.00, df=3, p=0.17). However, differences were significant when pathologically node metastasis-positive (pN+) TNBC were excluded (χ2=17.84, df=3, p<0.01). Some clinicopathological parameters, including CK5/6 (χ2=0.08, df=3, p=0.78), E-cadherin (χ2=0.71, df=3, p=0.40) and P53 (χ2=0.05, df=3, p=0.83), displayed no correlation with activity of progranulin in pathologically node metastasis-negative (pN−) TNBC. It was noted that the EGFR expression level of the pN− TNBC subtype was significantly higher in cases with strong progranulin expression than in cases with weak progranulin expression (χ2=11.26, df=1, p<0.01).A significantly higher expression level of progranulin in pN− TNBC suggests that progranulin is a promising new target for pN− TNBC treatment. Strong expression of progranulin correlates with positive EGFR expression in the pN− TNBC subtype. The close relationship between EGFR and progranulin/VEGF/CD105 expression may partly play a role in high angiogenesis levels in the pN− TNBC subtype.

Abstract 2272: Survivin and acetylated Survivin predict outcome in breast cancer and correlate separately with a basal-like and luminal-type expression profile

Abstract Background: Basal-like breast cancer is a highly aggressive breast tumor subtype associated with an adverse prognosis for which biologic therapies are not available. These tumors have a distinct molecular profile characterized by an absence of estrogen receptor expression, absence of HER2 amplification, and positive expression of EGFR and/or cytokeratin (CK) 5/6. The object of this study was to evaluate the expression of the anti-apoptotic protein Survivin in basal-like breast cancer and compare it with other molecular subtypes. Our laboratory recently identified that post-translational modification of Survivin by acetylation (Ac) at Lys-129 regulates its export from the nucleus and therefore its anti-apoptotic function. In an effort to understand the expression profile of Survivin and Ac-Survivin in breast tumors, we developed an antibody to the Ac Lys-129 residue. Methods: 4 μM sections of 238 consecutive grade 3 invasive ductal carcinoma cases, arranged on 15 tissue microarrays were stratified into 67 luminal (ER+), 66 HER2 positive (HER2+), 93 basal-like (ER-, HER2-, CK5/6+ and/or EGFR+), and 12 ER-/HER2-/CK5/6-/EGFR- carcinomas. TMAs were immunostained with a rabbit polyclonal Survivin antibody generated to the Lys-129 acetylated residue, a full-length (FL) rabbit polyclonal Survivin antibody (NB-500-201), or normal rabbit serum control. Tumors were scored semiquantitatively and compared with recurrence-free (RF) and overall survival (OS) and with expression of ER, PR, HER2, CK 5/6, and EGFR. Results: In all breast carcinomas examined, FL-Survivin and Ac-Survivin had a predominantly nuclear localization pattern. Ac-Survivin was also expressed in the nucleus of normal breast epithelium. RF (70%) and OS (90%) for FL-Survivin low tumors was significantly better than for tumors with strong FL-Survivin expression (40% and 70%, respectively) at 10 yrs, p = 0.02. By contrast, strong expression of Ac-Survivin was associated with improved RF (70% vs. 40%) and OS (85% vs. 75%), p = 0.03. Molecular subset analyses showed that FL-Survivin expression was associated with a basal-like expression profile, while Ac-Survivin expression was associated with a luminal-type profile, p &amp;lt;0.001. Conclusions: This is the first study to comprehensively demonstrate Survivin and Ac-Survivin expression in different molecular subtypes of breast cancer. High levels of the FL-Survivin protein are predictive of poor outcome in patients with grade 3 invasive ductal carcinoma and correlate directly with a basal-like phenotype. By contrast, high expression of Ac-Survivin is associated with favorable outcome and preferentially correlates with luminal-type tumors. These data suggest that Survivin has different functions in different types of breast cancer and may be useful as a prognostic marker for these distinct tumor subtypes. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2272. doi:10.1158/1538-7445.AM2011-2272

Analysis of KRAS, BRAF, PTEN, IGF1R, EGFR intron 1 CA status in both primary tumors and paired metastases in determining benefit from cetuximab therapy in colon cancer

The aim of this study was to determine the expression of molecular markers in metastatic colorectal cancer (mCRC) and the concordance between primary tumor and metastasis. We also aimed to determine the relationship between molecular markers and clinical outcomes of cetuximab-containing chemotherapy. Seventy-five mCRC patients who received cetuximab-containing chemotherapy between 2000 and 2008 were consecutively enrolled. EGFR, p-EGFR, PTEN, and IGF-1R expression by immunohistochemistry, DNA sequencing for EGFR, KRAS, BRAF, and PI3 KCA, and EGFR amplification by FISH were done. The positive expression of EGFR, p-EGFR, PTEN, and IGF-1R was determined in 45 (64.3%), 9 (14.8%), 35 (50.7%), and 10 patients (16.1%), respectively. EGFR gene amplification or high polysomy was detected in 10 patients (17.6%). KRAS mutation and BRAF mutation were detected in 19 patients (27.5%) and five patients (7.0%), respectively. Among tested biomarkers, only the EGFR intron 1 CA repeat polymorphism and BRAF mutation showed concordance (kappa=0.600, P=0.003; and kappa=0.692, P=0.001, respectively) between primary tumor and paired metastasis. Skin rash was a strong predictive marker for response rate, PFS, and OS. In KRAS mutant tumors, PTEN expression was associated with a longer PFS. BRAF mutation was related to poor outcome in KRAS wild-type tumors. BRAF mutations and EGFR intron 1 CA repeat polymorphisms were concordant between primary tumors and paired metastases. In KRAS mutant tumors, PTEN expression was a predictive marker for favorable outcomes. In KRAS wild type, BRAF mutation was strong predictive markers for poor outcomes.

Prognostic value of expression of EGFR and nm23 for locoregionally advanced nasopharyngeal carcinoma

The purpose of this study was to evaluate the prognostic value of expression of EGFR and nm23 in patients with advanced-stage nasopharyngeal carcinoma (NPC). The study population comprised 127 patients with stage III-IVa NPC with sufficient pretreatment tumor biopsy specimens from 2003 to 2004 and clinical follow-up data. The expression of EGFR and nm23 was detected by immunohistochemistry. Survival analysis was performed using Kaplan-Meier method. The correlation between pretreatment expression of EGFR and nm23, and the effectiveness of chemoradiotherapy was analyzed. The EGFR expression was correlated with primary lesion stage and clinical stage (P = 0.001, 0.002, respectively). There was a statistically significant association between nm23 expression and local lymph node stage (P = 0.000). The positive EGFR expression had a higher recurrent rate than the negative (P = 0.015). The positive nm23 expression had a lower distant metastasis rate than the negative (P = 0.021). Negative expression of EGFR had a significantly better 5-year OS and DFS than positive expression (P = 0.015, 0.013, respectively). Positive expression of nm23 had a significantly higher 5-year OS and DFS than negative expression (P = 0.001, 0.006, respectively). Multivariate analysis indicated that both pretreatment EGFR and nm23 expression were strong independent factors for the overall survival of patients with NPC (P = 0.000, 0.000, respectively). Our data suggested that EGFR and nm23 can serve as reliable biomarkers for prognosis prediction in patients with NPC who may benefit from alternate treatment strategy and targeted treatment.

Expression of EGFR and HER2/neu and absence of activating mutations in patients with castration-resistant prostate cancer.

4652 Background: Immunohistochemical expression (IHC) and activating mutations of EGFR and HER2 have been used as predictive markers for response to targeted therapies in various cancer types. The aim of our study was to analyze the expression of EGFR and HER2 and presence of activating mutations in castration-resistant prostate cancer (CRPC) tumor tissue for the use as predictive markers. Methods: IHC of EGFR and HER2 using paraffin-embedded samples of tumor tissue from 51 patients with CRPC was analyzed according to the percentage of positively stained tumor cells and the intensity of staining. Genomic DNA was extracted from 18 tissue samples containing ≥60% tumor tissue. Nested PCR using specific primers for exons 18, 19 and 21 of EGFR and exons 18-24 of the HER2 followed by direct DNA sequencing was performed. Internet based BLAST-search was used to identify mutations of the amplified exons and neighbouring introns. Results: According to the different cut-off values of 10%, 30%, 50% or 70% for the percentage of positively stained cells, expression rates ranged from 30.6%-61.2% for EGFR and 9.6%-28.8% for HER2. Defining positive expression as ≥30% positively stained tumor cells, with an intensity of staining of ≥2+, resulted in positive expression of EGFR in 38.8% and HER2 in 13.5% of the patients. None of the 180 examined exons and neighbouring introns of EGFR and HER2 contained activating mutations that are known to influence response to targeted therapies. Conclusions: Our results demonstrate different rates of expression according to the definition of positive expression for EGFR and HER2 which may have a major impact on the results of clinical targeted trials. In our series no activating mutations of EGFR and HER2 were found. Since activating mutations for EGFR have only been found in about 10% of patients with non-small cell lung cancer, the number of analyzed samples seems to be too small to detect a relevant number of mutations in CRPC. Nevertheless, our series adds information to already published data about mutations of EGFR and HER2 in 33 patients with CRPC and 89 patients with hormone-sensitive prostate cancer that revealed activating mutations in 8/122 (6.6%) altogether. No significant financial relationships to disclose.

HIF-1α and EGFR as progonostic factors for therapy response and 1-year locoregional recurrence not for distant metastasis and 2-year OS in unresectable stage IIIA NSCLC treated with combined chemoradiotherapy.

10640 Background: The purpose is to evaluated the effect of prognosis of HIF-1α and EGFR in unresectable stage IIIA NSCLC treated with chemoradiotherapy. Methods: A retrospective review of 44 patients with unresectable stage IIIA NSCLC treated with chemoradiotherapy (CRT) in 2007 was performed. Stage diagnosis data including PET/CT and CT guided primary tumor biopsy tissue could be obtained. HIF-1α and EGFR expression were inspected by IHC method. Definitive combined CRT schemes were vinorelbine or gemcita plus cisplatin and irradiation with a total dose of 60 to 65 Gy. 36 patients were underwent follow-up (median time 31 ± 2.7 months, range 25-36 months). Results: HIF-1α expression was diffused in cytoplasma and nuclear, EGFR expresssion in cell membrane. Of 44 patients, the cut-off value for HIF-1α positive expression was 72%, 60% for EGFR. HIF-1α and EGFR expression were only correlated with histological type (70% and 33.% for SCC and ADC). HIF-1α, EGFR expression and SUVmax value were significantly correlated. HIF-1α and EGFR were significant predictors for 79.5% effective treatment response (CR+PR) evaluated by RECIST. Of 36 followed-up patients, patients with positive HIF-1α and EGFR expression (cut-off value 78%, 60%) had statistically superior 1-year loco-regional recurrence rate (p = 0.000, 0.004) and shorten mean time to first locoregional recurrence (9.08 ± 1.37 months vs. 10.3 ± 1.37 months) compared with negative expression. However, there is no significance for HIF-1α and EGFR in the 1-year distant-metastasis recurrence (DMR) rate, 2-year overall survival (OS) (p = 0.105, 0.077) by univariate analysis. HIF-1α expression was significant for 1-year loco-regional recurrence (HR 27.11, p = 0.009, 95%CI 2.31-318.73), and both not for 1-year DMR and 2-year OS analysised by COX ratio hazard regression. Conclusions: HIF-1α and EGFR expression were two good prognostic factors for therapy response and HIF-1α for 1-year loco-regional recurrence in stage IIIA NSCLC treated by combined CRT. The results suggest the need for an elaborate examination of HIF-1α protein expression to get its prognostic value. No significant financial relationships to disclose.

Improving the efficacy of targeted trials by multiple-marker analysis in castration-resistant prostate cancer

Objectives In order to improve the efficacy of targeted therapy trials, the expression profiles of several molecular markers that are potential candidates for targeted therapy were analyzed in patients with progressive castration-resistant prostate cancer. Methods and materials Paraffin-embedded samples of tumor tissue from 51 patients obtained from biopsies of metastases or remaining prostates were analyzed immunohistochemically for the expression of EGFR, PDGFRβ, Her-2/neu, c-Kit, and VEGF. Staining was analyzed according to the percentage of positively stained tumor cells and the intensity of staining. Results According to the different cut-off values of 10%, 30%, 50%, or 70% for the percentage of positively stained cells, different rates of expression were found. Expression rates ranged from 30.6% to 61.2% for EGFR, from 34.7% to 57.1% for PDGFRβ, from 9.6% to 28.8% for Her-2/neu, from 12.5% to 22.4% for c-Kit, and from 51.1% to 74.5% for VEGF. Defining positive expression as ≥30% positively stained tumor cells, with an intensity of staining of ≥2+, resulted in positive expression of EGFR in 38.8%, PDGFRβ in 24.5%, Her-2/neu in 13.5%, c-Kit in 6.4%, and VEGF in 44.7% of the patients. Conclusions Our results demonstrate simultaneous expression of several markers in castration-resistant prostate cancer tissue. Translation of the results into modern, multi-arm clinical trial designs will improve the efficacy of recruiting and obtaining results, compared with multiple double-arm trials.

The Potential Value of EGFR and P53 Immunostaining in Tumors of the Urinary Bladder

The expression of EGFR and p53 has not been adequately studied as a prognostic tool in urinary bladder tumors. We analyzed 74 bladder cancer samples from Egypt for EGFR and p53 expression using immunohistochemistry. The tumors were of different histological types, grades and clinical stages, and with established lymph node status. Almost 61% of the tumors showed positive membranous EGFR expression and 74.3% had positive nuclear staining of p53. Analysis of correlation of the IHC staining with clinical variables showed a significant correlation only between EGFR expression and histological type (p=0.002, ANOVA), in that the expression was higher in squamous cell carcinomas than in other histological types. There were no significant correlations between p53 or EGFR with the other clinicopathological variables, including age, sex, staging, grading, and lymph node status. Further studies are needed to determine if EGFR and p53 might be used as prognostic tools in bladder cancer.

Expression of BRCA1 protein in breast cancer and its prognostic significance

BRCA1 is a tumor suppressor gene which, when mutated, is associated with the development of hereditary breast cancers. In sporadic tumors, although inherent gene mutations are rare, loss of BRCA1, resulting from reduced expression or incorrect subcellular localization, is postulated to be important. The purpose of the current study was to examine the expression and localization of BRCA1 protein and to assess its prognostic value, in a well-characterized series of unselected breast carcinomas. We have examined BRCA1 in a series of invasive breast carcinoma (1940 cases) using tissue microarray and immunohistochemistry, to evaluate its expression pattern and to correlate this with clinicopathologic variables and patient outcome. In breast cancer, complete loss of nuclear expression was observed in 223 cases (15%) and cytoplasmic expression was found in 541 breast cancers (36.6%). Absent or reduced nuclear BRCA1 expression was observed more frequently in ductal carcinoma of no special type and medullary-like carcinoma and less frequently in lobular and tubular mixed carcinomas. It was also associated with high-grade, advanced lymph node stage, larger size, vascular invasion, negative estrogen receptor, progesterone receptor and androgen receptor expression, and positive p53 and P-cadherin expression, and with the basal-like class of breast cancer. Altered BRCA1 was associated with shorter disease-free interval. Cytoplasmic expression was also associated with development of recurrence and positive EGFR and HER2 expression. It showed an inverse association with survival particularly in low-grade, small-size, and estrogen receptor-positive subgroups. In the grade 1 subgroup, multivariate analysis with adjustment for other prognostic factors showed that cytoplasmic expression of BRCA1 was an independent predictor of disease-free interval. BRCA1 alteration may play a significant role in the development and progression of breast cancer. Immunohistochemical assessment of BRCA1 expression could provide additional clinically relevant information in routine classification of breast cancer.

The Potential Value of EGFR and P53 Immunostaining in Tumors of the Urinary Bladder

The expression of EGFR and p53 has not been adequately studied as a prognostic tool in urinary bladder tumors. We analyzed 74 bladder cancer samples from Egypt for EGFR and p53 expression using immunohistochemistry. The tumors were of different histological types, grades and clinical stages, and with established lymph node status. Almost 61% of the tumors showed positive membranous EGFR expression and 74.3% had positive nuclear staining of p53. Analysis of correlation of the IHC staining with clinical variables showed a significant correlation only between EGFR expression and histological type (p=0.002, ANOVA), in that the expression was higher in squamous cell carcinomas than in other histological types. There were no significant correlations between p53 or EGFR with the other clinicopathological variables, including age, sex, staging, grading, and lymph node status. Further studies are needed to determine if EGFR and p53 might be used as prognostic tools in bladder cancer.

Morphological and immunophenotypic analysis of breast carcinomas with basal and myoepithelial differentiation

The aim of this study was to assess the morphological characteristics and immunohistochemical profile of breast carcinomas with basal and myoepithelial phenotypes to obtain a better understanding of their biological behaviour and nature. One thousand nine hundred and forty-four invasive breast carcinomas were examined, using tissue microarray (TMA) technology and immunohistochemistry, to identify those tumours that showed basal and myoepithelial phenotypes, and their immunophenotype profile was characterized using a variety of markers. In addition, haematoxylin and eosin-stained sections of these tumours were studied for several morphological parameters. The findings were correlated with patient and tumour characteristics and outcome data. Tumours were classified into two groups: (1) tumours with basal phenotype [expressing one or both basal markers (CK5/6 and/or CK14)] and (2) tumours with myoepithelial phenotype (expressing SMA and/or p63). Group 1 was further subdivided into two subgroups: (A) dominant basal pattern (more than 50% of cells positive) and (B) basal characteristics (10-50% of cells positive). Group 1 tumours constituted 18.6% (8.6% and 10% for groups 1A and 1B, respectively) and group 2 constituted 13.7% of the cases. In both groups, the most common histological types were ductal/no specific type, tubular mixed and medullary-like carcinomas; the majority of these tumours were grade 3. There were positive associations with adenoid cystic growth pattern, loss of tubule formation, marked cellular pleomorphism, poorer Nottingham prognostic index, and development of distant metastasis. In addition, associations were found with loss of expression of steroid hormone receptors and FHIT proteins and positive expression of p53 and EGFR. The most common characteristics in group 1 were larger size, high-grade comedo-type necrosis, development of tumour recurrence, and absence of lymph node disease. Group 2 tumours were more common in younger patients and were associated with central acellular zones, basaloid change, and positive E-cadherin protein expression. Group 1 characteristics were associated with both reduced overall survival (OS) [log rank (LR) = 22.5, p < 0.001] and reduced disease-free interval (DFI) (LR = 30.1, p < 0.001), while group 2 characteristics showed an association with OS (LR = 5, p = 0.02) but not with DFI. Multivariate analysis showed that basal, but not myoepithelial, phenotype has an independent value in predicting outcome. Breast cancers with basal and myoepithelial phenotypes are distinct groups of tumours that share some common morphological features and an association with poor prognosis. The basal rather than the myoepithelial phenotype has the strongest relationship with patient outcome.

Cell growth after withdrawal of gefitinib (‘Iressa’, ZD1839) in human lung cancer cells

Gefitinib ("Iressa", ZD1839) is a selective epidermal growth factor receptor-tyrosine kinase inhibitor, which blocks signal transduction pathways implicated in proliferation and survival of cancer cells. However, in vitro and in vivo studies concerning cell growth after withdrawal of gefitinib are limited. To determine whether cancer cells would resume proliferation upon removal of gefitinib, an in vitro study was undertaken using 4 human non-small cell lung cancer cell lines. With immunocytochemical staining and Western blot analysis, we confirmed positive expression of EGFR in these cell lines. We next evaluated growth inhibition before and after withdrawal of gefitinib. After incubation with 0-100 microM gefitinib for 24 h, medium containing gefitinib was removed, followed by addition of fresh growth medium to cell cultures. MTT assays were performed daily over a 6-day time course. Even at very low levels of gefitinib (<1 microM), these 4 TKB cells had 1-10% growth inhibition, respectively. With these levels of gefitinib, continued inhibitory effects after withdrawal of getitinib were observed in 3 of the 4 cell lines. Furthermore, none of the 4 cell lines, including the cell line which had abolished growth inhibition, showed accelerated re-growth rate after the withdrawal of gefitinib even in these exposure conditions. Based on our in vitro experiments, additional in vivo studies, which can compare the pre- and post-treatment growth rate, will be necessary to help better understand the mechanisms behind cell growth recovery after temporary gefitinib treatment.

喉頭癌のリンパ節転移に関する臨床病理学的ならびに免疫組織化学的研究

In 52 cases of T2-4 glottic carcinoma, factors that may be responsible for neck metastasis were investigated by clinicopathological and immunohistochemical techniques. These factors included clinicopathological factors such as T-staging, tissue differentiation and the ploidy pattern of nuclear DNA ; ploliferation factors such as the S-phase cell labelling index (SLI) and EGF-R; factors related to the basement membrane such as Type-4 collagen and matrix metalloproteinase 2(MMP-2); and cell adhesion factors including E-cadherin, catenin, cathepsin D and desmoglein. The correlation of each factor to neck metastasis was evaluated statistically.No significant difference was observed between T2 and T3-4, nor between any two groups of well, moderately and poorly differentiated carcinomas. No significant difference was seen between the diploid and aneuploid groups. On the other hand, cases with a positive expression of EGF-R showed a statistically higher incidence of neck metastasis than those with a nagative expression. Cases with an SLI higher than 30, especially those higher than 40, showed a greater incidence of neck metastasis than those with scores lower than 30. A significant difference was also found between the groups with positive and negative expressions of desmoglein. It was further observed that E-cadherin and catenin show the same pattern of expression, but cathepsin has an inverse correlation to them. As for the components of the basement membrane, Type-4 collagen had a close correlation with neck metastasis, and a much higher incidence of neck metastasis was found in cases with a fragmented or negative expressions. Cases with a higher tissue titer of MMP-2 that may degrade Type-4 collagen showed a higher incidence of neck metastasis. On the other hand, no significant difference was observed between the two groups with positive and negative expressions of p53 oncoprotein.