No strong association between HER-2/neu protein overexpression and gene amplification in high-grade invasive urothelial carcinomas

Disitamab vedotin plus toripalimab in patients with locally advanced or metastatic urothelial carcinoma (RC48-C014): a phase Ib/II dose-escalation and dose-expansion study

BACKGROUND

Human epidermal growth factor receptor 2 (HER2)-targeted antibody-drug conjugates (ADCs) such as disitamab vedotin (DV) and trastuzumab deruxtecan (T-DXd) have emerged as effective treatment options and received regulatory approvals for HER2-expressing locally advanced or metastatic urothelial carcinoma (la/mUC). In addition, ADCs in combination with immunotherapy have demonstrated antitumor activity. The current study aimed to evaluate the combination of DV and toripalimab in patients with la/mUC.

PATIENTS AND METHODS

This open-label phase Ib/II study enrolled patients with untreated or chemo-refractory la/mUC. During the dose-escalation phase, DV was administered at escalating doses of 1.5 and 2.0 mg/kg in combination with toripalimab 3.0 mg/kg once every 2 weeks. Primary endpoints were safety and the recommended phase II dose (RP2D). Secondary endpoints included objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).

RESULTS

From August 2020 to December 2021, a total of 41 patients were enrolled, including 6 in the dose-escalation phase and 35 in the dose-expansion phase. Sixty-one percent of patients were treatment naive. No dose-limiting toxicity was observed. The RP2D was determined as DV (2.0 mg/kg) plus toripalimab (3.0 mg/kg). By the data cut-off date of 1 March 2024, the confirmed ORR was 73.2%. The median PFS was 9.3 months, and the median OS was 33.1 months. The most common treatment-related adverse events (TRAEs) were aspartate aminotransferase increased (65.9%), alanine aminotransferase increased (63.4%), and peripheral sensory neuropathy (63.4%). Grade 3 or higher TRAEs occurred in 51.2% of patients, with the most common being γ-glutamyltransferase increased (12.2%), asthenia (9.8%), and alanine aminotransferase increased (7.3%). One treatment-related death (due to pneumonitis) was reported.

CONCLUSIONS

The combination of DV and toripalimab demonstrated promising response rate and OS results with a manageable safety profile in HER2-unselected la/mUC patients. This combination represents a promising first-line option for la/mUC. Randomized phase III study is currently ongoing.

Effects of trastuzumab emtansine on canine urothelial carcinoma cells in vitro and in vivo

Urothelial carcinoma (UC) is the most common malignancy of the urinary tract in dogs and has aggressive behaviour. Although human epidermal growth factor receptor 2 (HER2) is a known therapeutic target with evidence in canine UC, the efficacy of anti-HER2 antibody drugs remains unknown. This study aimed to investigate the effects of anti-HER2 antibody drugs including trastuzumab and trastuzumab emtansine (T-DM1) on canine UC cell lines in vitro and in vivo. Four canine UC cell lines (Nene, TCCUB, Love, and Sora) were used. In western blotting, HER2 protein expression was observed in all the cell lines. Although both trastuzumab and T-DM1 showed dose-dependent growth inhibitory activity in the cell lines, T-DM1 showed much stronger activity than that of trastuzumab. In flow cytometry analyses with the canine UC cell line (Sora), T-DM1 but not trastuzumab significantly increased the percentages of early and late apoptotic cells in annexin V apoptotic assays and the sub-G1 phase fraction in cell cycle analyses. For the in vivo experiment, the canine UC cells (Sora) were subcutaneously injected into nude mice. Four days after inoculation, trastuzumab, T-DM1, or vehicle was administered intraperitoneally once a week for three times. Tumour volumes were significantly smaller in the T-DM1 group compared to the trastuzumab and vehicle control groups. These findings indicate that T-DM1 exerts a stronger antitumour effect than that of trastuzumab on canine UC cells in vitro and in vivo, possibly by inducing apoptosis due to DM1.

Predictive and Prognostic Biomarkers and Tumor Antigens for Targeted Therapy in Urothelial Carcinoma

Urothelial carcinoma (UC) is the fourth most prevalent cancer amongst males worldwide. While patients with non-muscle-invasive disease have a favorable prognosis, 25% of UC patients present with locally advanced disease which is associated with a 10-15% 5-year survival rate and poor overall prognosis. Muscle-invasive bladder cancer (MIBC) is associated with about 50% 5 year survival when treated by radical cystectomy or trimodality therapy; stage IV disease is associated with 10-15% 5 year survival. Current therapeutic modalities for MIBC include neoadjuvant chemotherapy, surgery and/or chemoradiation, although patients with relapsed or refractory disease have a poor prognosis. However, the rapid success of immuno-oncology in various hematologic and solid malignancies offers new targets with tremendous therapeutic potential in UC. Historically, there were no predictive biomarkers to guide the clinical management and treatment of UC, and biomarker development was an unmet need. However, recent and ongoing clinical trials have identified several promising tumor biomarkers that have the potential to serve as predictive or prognostic tools in UC. This review provides a comprehensive summary of emerging biomarkers and molecular tumor targets including programmed death ligand 1 (PD-L1), epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), fibroblast growth factor receptor (FGFR), DNA damage response and repair (DDR) mutations, poly (ADP-ribose) polymerase (PARP) expression and circulating tumor DNA (ctDNA), as well as their clinical utility in UC. We also evaluate recent advancements in precision oncology in UC, while illustrating limiting factors and challenges related to the clinical application of these biomarkers in clinical practice.

HER2 Expression Associated with Clinical Characteristics and Prognosis of Urothelial Carcinoma in a Chinese Population

BACKGROUND

The frequency of HER2 overexpression in bladder cancer is reported as 9%-61%. HER2 alteration correlates with aggressive disease in bladder cancer. Traditional anti-HER2 targeted therapy has failed to show clinical benefits in patients with advanced urothelial carcinoma .

METHODS

The information on pathologically proven patients with urothelial carcinoma with detected HER2 status was collected from the database of Peking University Cancer Hospital. The HER2 expression, as well as its association with clinical characteristics and prognosis, was analyzed.

RESULTS

A total of 284 consecutive patients with urothelial carcinoma were enrolled. HER2 was positive (IHC 2+/3+) in 44% of urothelial carcinoma. HER2 positivity was found more frequent in UCB than in UTUC (51% vs. 38%). Stage, radical surgery, and histological variant were associated with survival (P < .05). For metastatic patients, multivariate analysis shows that 3 indicators, including liver metastasis, the number of involved organs, and anemia, are independent risk factors of prognosis. Receiving immunotherapy or disitamab vedotin (DV) treatment is an independent protecting factor. The survival of patients with low HER2 expression was also significantly improved by the treatment of DV (P < .001). HER2 expression (IHC 1+, 2+, 3+) was associated with a better prognosis in this population.

CONCLUSION

DV has improved the survival of patients with urothelial carcinoma in the real world. With the new-generation anti-HER2 ADC treatment, HER2 expression is no longer a poor prognostic factor.

Expression of epidermal growth factor receptor and human epidermal growth factor receptor 2 in urothelial bladder carcinoma in an Egyptian cohort: Clinical implication and prognostic significance

BACKGROUND

Bladder cancer (BC) has a particular importance in Egyptian patients due to aggressive behavior and absence of prognostic markers.

OBJECTIVE

To evaluate the expression of gene and protein expression of HER2 and epidermal growth factor (EGFR) in Egyptian patients with BC and ultimately to investigate their clinical implication and prognostic significance.

MATERIAL AND METHODS

The study was carried out on 46 patients with urothelial bladder BC. Tissue were obtained from transurethral resection (N = 22) and radical cystectomy (N = 24) specimens. The original hematoxylin and eosin slides were re-evaluated and the formalin fixed, paraffin-embedded (FFPE) tissues which had sufficient tumor tissue (>75%) and minimal or absent tumor necrosis were selected for immunohistochemistry (IHC) and RNA extraction. Furthermore, five control biopsies were obtained from patients with cystitis. Follow-up data were retrieved from the medical records which included the treatment regimen, disease recurrence and/or progression, and survival.

RESULTS

EGFR and HER2 protein were overexpressed in 35% and 46% of patients respectively. EGFR was correlated with the tumor size, grade and pathological stage, with a similar trend for HER2. The recurrence rate was higher in patients with expression of any of the markers. Gene expression was significantly higher (10.6-folds) for EGFR and (21-folds) for HER2 in patients with BC in comparison to control patients. Survival analysis showed lower median disease-free survival in association with HER2 protein overexpression.

CONCLUSIONS

Our data highlighted the prognostic significance of EGFR and HER in BC and proposed their possible use as predictive markers and potential therapeutic targets.

Evaluation of the Expression of HER2 and c-KIT Proteins as Prognostic Markers in Superficial Bladder Urothelial Carcinoma

Background

The roles of c-KIT and HER2 protein expression in bladder cancer are still debated, and the prognostic value of these proteins as markers of tumor progression is inconclusive.

Objective

To assess the impact of HER2 and c-KIT protein expressions in the progression of non-muscle-invasive bladder cancer.

Methods

All patients undergoing transurethral resection of bladder tumors for non-muscle-invasive urothelial carcinoma, with standard regimen of BCG, between January 2017 and November 2019, were evaluated pathologically and immunohistochemically for HER1 and c-KIT proteins in urothelial carcinoma cells. Follow-up cystoscopy was performed for 100 patients every 3 months for the first 2-years and any recurred tumors were excised and examined pathologically, as well as stained for HER2 and c-KIT protein expression.

Results

HER2 and c-KIT positive expressions were detected in 49% and 38% of cases, respectively. After a mean follow-up of 26.4±7.2 months, the overall recurrence and progression rates were significantly correlated with overexpression of HER2 and c-KIT. In high-grade non-invasive muscle neoplasms, tumor cells showed weak expression for both HER2 and c-KIT proteins, but with progression to muscle-invasion, tumor cells strongly expressed HER2 and lost expression to c-KIT. In the multivariate model, overexpression of HER2 rather than c-KIT protein significantly predicted increased progression.

Conclusion

Recurrence and progression of non-muscle-invasive bladder cancer correlate with overexpression of HER2 and c-KIT proteins in tumor cells.

Human epidermal growth factor receptor 2 (HER2) gene amplification in non-muscle invasive urothelial bladder cancers: Identification of patients for targeted therapy

OBJECTIVES

To evaluate human epidermal growth factor receptor 2 (HER2) protein overexpression by immunohistochemistry (IHC) and gene amplification by fluorescent in situ hybridisation (FISH) in urothelial non-muscle-invasive bladder carcinoma (NMIBC), as HER2 is a potential therapeutic target in muscle-invasive bladder carcinoma (MIBC) and HER2 expression and gene amplification in low/high-grade and pTa/pT1 NMIBC is not clear.

PATIENTS AND METHODS

The study included 93 bladder cancers; 25 MIBC and 68 NMIBC (37 low- and 31 high-grade). All HER2 positive (3+) and equivocal (2+) cases were subjected to FISH using a HER2/CEN 17 dual-colour probe kit. IHC and FISH were scored as per the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) 2013 Guidelines for breast cancers. Based on the number of signals/nuclei, amplification was categorised as low (≥6-10) and high-level (≥10).

RESULTS

HER2 2-3+ expression was seen in 29% of NMIBCs (10.8% low- and 51.6% high-grade). HER2 3+ expression was seen in high-grade NMIBC (nine of 31; 29%) and MIBC (nine of 25; 36%). In all, 87% of high-grade NMIBCs were lamina invasive (pT1). Gene amplification was found in 45% (eight of 18) of 3+ tumours. None of the HER2 2+ tumours showed gene amplification. IHC and FISH results were in closest agreement when ≥50% of tumour cells showed 3+ expressions. High-level amplification correlated with increased gene expression on reverse transcriptase-polymerase chain reaction. On multivariate analysis, lower  stage, grade, and HER2 expression significantly correlated with progression-free survival. HER2 3+ expression in NMIBC correlated significantly with time to recurrence and progression.

CONCLUSION

Our present results show that HER2 FISH should not be performed for HER2 2 + and low-grade NMIBC. This contrasts with breast cancers where it is recommended for equivocal 2+ tumours. About 50% of HER2 3+ MIBC and high-grade NMIBC show HER2 gene amplification and can be potential candidates for HER2-targeted therapy.

ABBREVIATIONS

ASCO/CAP: American Society of Clinical Oncology/College of American Pathologists; DAB: 3,3'-diaminobenzidine; FISH: fluorescent in situ hybridisation; HER2: human epidermal growth factor receptor 2; IHC: immunohistochemistry;(N)MIBC: (non-) muscle-invasive bladder carcinoma; MPUC: micropapillary variant of urothelial bladder cancer; PFS: progression-free survival; TURBT: transurethral resection of bladder tumour.

ErbB2 Copy Number Aberration in Canine Urothelial Carcinoma Detected by a Digital Polymerase Chain Reaction Assay

Urothelial carcinoma (UC) is the most common tumor affecting the urinary bladder of dogs. Protein overexpression of ErbB2 (the canine homolog of HER2) has been observed in dogs with UC. However, no study regarding ErbB2 copy number aberration (CNA) is reported in dogs with UC. In this study, a digital PCR assay for detecting CNA of canine ErbB2 was developed. DNA samples were isolated from 83 formalin-fixed, paraffin-embedded urinary bladder tissues (36 UC, 8 polypoid cystitis, and 39 normal) and 94 urinary sediments (54 UC, 30 nonneoplastic, and 10 normal). The copy number of canine chromosome 8 (CFA8) was used as a control. In the urinary bladder tissues, ErbB2 CNA was detected in 12 of 36 (33%) UC, 2 of 8 (25%) polypoid cystitis, and 0 of 39 (0%) normal controls. In the urinary sediments, ErbB2 CNA was also detected in 19 of 54 (35%) UC; however, no ErbB2 CNA was detected in nonneoplastic diseases or normal controls. The sensitivity and specificity of ErbB2 CNA in urinary sediment for the detection of UC were 35% and 100%, respectively. There was a positive correlation between the copy number ratios of ErbB2 to CFA8 in the urinary bladder tissues and urinary sediments. Our findings indicate that the digital PCR assay of urinary sediments may be a useful, noninvasive method for detecting ErbB2 CNA in dogs with UC.

Prognostic and therapeutic role of HER2 expression in micropapillary carcinoma of the bladder

Micropapillary carcinoma of the bladder (MPBC) is a variant type of infiltrating urothelial carcinoma, which portends a poor biological behavior in terms of disease stage at first diagnosis and clinical outcome; its peculiar morphology raises issues concerning the ability of tumor detection by imaging techniques and proper biopsy procedure, and the appropriate treatment for non-muscle infiltrating and muscle-infiltrating MPBC remains a matter of debate. On the basis of its established prognostic and therapeutic role in breast and gastro-esophageal cancer in the first instance, the human epidermal growth factor receptor-2 (HER2) has been investigated in selected case series of MPBC over the last 10 years. The aim of the present review was to summarize the existing evidence on HER2 status in MPBC, and to discuss its present and future utility in risk assessment and treatment choice of this uncommon, yet aggressive, disease.

Overexpression of Epidermal Growth Factor Receptor (EGFR) and HER-2 in Bladder Carcinoma and Its Association with Patients' Clinical Features

BACKGROUND The aim of this study was to determine the expression of EGFR/HER-2 and investigate their association with patients' clinical features in bladder transitional cell carcinoma (BTCC). MATERIAL AND METHODS Immunohistochemistry was utilized in our study to explore the expression of EGFR/HER-2 of 56 human bladder cancer samples and 10 normal bladder samples. RESULTS EGFR and HER-2 expressions were both significantly higher in bladder transitional cell carcinoma (BTCC) than that in non-cancer bladder samples; the EGFR positivity rate was 55.4% among BTCC samples and 37.5% for HER-2a. A statistically significant correlation was also present between the increasing EGFR or HER-2 expression levels and the clinical stages, pathologic grades, and tumor recurrence. The expression level of EGFR increased along with higher clinical stages and pathologic grades of BTCC, and the obviously increased expression of HER-2 was statistically associated with clinical stages and tumor recurrence. In addition, the expression level of HER-2 increased along with the higher clinical stage of BTCC. EGFR expression and HER-2 levels were positively associated in BTCC samples. CONCLUSIONS Our findings demonstrate that high EGFR and HER-2 expressions are dramatically increased in the BTCC tissues and are closely related to the clinical stages, pathologic grades, and tumor recurrence. Therefore, the evaluation of EGFR and HER-2 expression in BTCC may contribute to identifying patients who are at increased risk of disease progression and recurrence.

Reappraisal of HER2 status in the spectrum of advanced urothelial carcinoma: a need of guidelines for treatment eligibility

Although human epidermal growth factor receptor 2 (HER2) may represent a therapeutic target, its evaluation in urothelial carcinoma of the bladder does not rely on a standardized scoring system by immunohistochemistry or fluorescent in situ hybridization (FISH), as reflected by various methodology in the literature and clinical trials. Our aim was to improve and standardize HER2 amplification detection in bladder cancer. We assessed immunohistochemical criteria derived from 2013 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAPs) guidelines for breast cancer and investigated intratumoral heterogeneity in a retrospective multicentric cohort of 188 patients with locally advanced urothelial carcinoma of the bladder. Immunohistochemistry was performed on 178 primary tumors and 126 lymph node metastases, eligible cases (moderate/strong, complete/incomplete membrane staining) were assessed by FISH. HER2 overexpression was more frequent with 2013 ASCO/CAP than 2007 ASCO/CAP guidelines (p < 0.0001). The rate of positive HER2 FISH was similar between primary tumor and lymph node metastases (8%). Among positive FISH cases, 48% were associated with moderate/strong incomplete membrane staining that were not scored eligible for FISH by 2007 ASCO/CAP criteria. Among 3+ immunohistochemistry score cases, 67% were associated with HER2-positive FISH. Concordance between primary tumors and matched lymph node metastases was moderate for immunohistochemistry (κ = 0.54 (CI 95%, 0.41-0.67)) and FISH (κ = 0.50 (CI 95%, 0.20-0.79)). HER2-positive FISH was more frequent in micropapillary carcinomas (12%) and carcinoma with squamous differentiation (11%) than in pure conventional carcinoma (6%). Intratumoral heterogeneity for HER2 immunohistochemistry was observed in 7% primary tumor and 6% lymph node metastases; 24% positive HER2 FISH presented intratumoral heterogeneity. Our study suggests that HER2 evaluation should include an immunohistochemistry screening step with eligibility for FISH including incomplete/complete and moderate/strong membrane staining. Spatial or temporal intratumoral heterogeneity prompts to perform evaluation on both tumor and lymph node, and for each histological variant observed.

HER2 and EGFR amplification and expression in urothelial carcinoma occurs in distinct biological and molecular contexts

We analyzed a cohort of 599 cases of urothelial carcinoma for EGFR, ERBB2, and ERBB3 gene expression and genomic alterations. The cohort consisted of a reference set (n = 292) comprising all stages and grades and one set (n = 307) of advanced tumors. All cases were previously classified into urothelial carcinoma molecular subtypes. Genomic amplifications were established by array-CGH or in-situ hybridization, and gene expression both at mRNA and protein levels. Clinical HER2 status was independently evaluated using standard clinical procedures. EGFR amplifications were observed in 14% and ERBB2 amplifications in 23% of the reference cohort. EGFR gains were enriched in the Basal/SCC-like and ERBB2 gains in the Genomically Unstable subtypes. The expression data suggests that the Genomically Unstable show high ERBB2/ERBB3 but low EGFR expression and that Basal/SCC-like tumors show high EGFR but low ERBB2/ERBB3 expression. Whereas the frequency of ERBB2 genomic amplification were similar for cases of the Genomically Unstable subtype in the two cohorts, the Urothelial-like subtype acquires ERBB2 amplifications and expression during progression. Even though a good correlation between gene amplification and ERBB2 gene expression was observed in the Urothelial-like and Genomically Unstable subtypes less than half of the Basal/SCC-like cases with ERBB2 amplification showed concomitant ERBB2 mRNA and protein expression. We conclude that clinical trials using ERBB2 (HER2) or EGFR as targets have not fully appreciated the molecular heterogeneity in which activated ERBB2 and EGFR systems operate. Proper tumor classification is likely to be critical for arriving at thorough conclusions regarding new HER2 and EGFR based treatment regimes.

Afatinib Activity in Platinum-Refractory Metastatic Urothelial Carcinoma in Patients With ERBB Alterations

PURPOSE

Somatic mutations and copy number variation in the ERBB family are frequent in urothelial carcinoma (UC) and may represent viable therapeutic targets. We studied whether afatinib (an oral, irreversible inhibitor of the ErbB family) has activity in UC and if specific ERBB molecular alterations are associated with clinical response.

PATIENTS AND METHODS

In this phase II trial, patients with metastatic platinum-refractory UC received afatinib 40 mg/day continuously until progression or intolerance. The primary end point was 3-month progression-free survival (PFS3). Prespecified tumor analysis for alterations in EGFR, HER2, ERBB3, and ERBB4 was conducted.

RESULTS

The first-stage enrollment goal of 23 patients was met. Patient demographic data included: 78% male, median age 67 years (range, 36 to 82 years), hemoglobin < 10 g/dL in 17%, liver metastases in 30%, median time from prior chemotherapy of 3.6 months, and Eastern Cooperative Oncology Group performance status ≤ 1 in 100%. No unexpected toxicities were observed; two patients required dose reduction for grade 3 fatigue and rash. Overall, five of 23 patients (21.7%) met PFS3 (two partial response, three stable disease). Notably, among the 21 tumors analyzed, five of six patients (83.3%) with HER2 and/or ERBB3 alterations achieved PFS3 (PFS = 10.3, 7.0, 6.9, 6.3, and 5.0 months, respectively) versus none of 15 patients without alterations (P < .001). Three of four patients with HER2 amplification and three of three patients with ERBB3 somatic mutations (G284R, V104M, and R103G) met PFS3. One patient with both HER2 amplification and ERBB3 mutation never progressed on therapy, but treatment was discontinued after 10.3 months as a result of depressed ejection fraction. The median time to progression/discontinuation was 6.6 months in patients with HER2/ERBB3 alterations versus 1.4 months in patients without alterations (P < .001).

CONCLUSION

Afatinib demonstrated significant activity in patients with platinum-refractory UC with HER2 or ERBB3 alterations. The potential contribution of ERBB3 to afatinib sensitivity is novel. Afatinib deserves further investigation in molecularly selected UC.

HER2 Protein Overexpression and Gene Amplification in Plasmacytoid Urothelial Carcinoma of the Urinary Bladder

Aim. HER2 overexpression has been reported in a minority of urothelial carcinomas, but little is known about HER2 protein expression and gene alterations in plasmacytoid urothelial carcinoma, a rare and aggressive variant. The aim of this study was to clarify the HER2 status in plasmacytoid urothelial carcinomas. Methods. Six cases of plasmacytoid urothelial carcinoma were included, in which we evaluated HER2 protein expression by immunohistochemistry (IHC) and HER2 gene amplification by fluorescence in situ hybridization (FISH). Results. The patients' ages ranged from 57 to 83 years (mean age, 71 years). Five patients were male and one was female. The ratio of the plasmacytoid component ranged from 30% to 100% (mean, 77%). HER2 expression score was 3+ in 4 cases, 2+ in one case, and negative in one case. HER2 gene amplification was positive in 3 cases, of which 2 cases showed a 3+ HER2 IHC score but one case was negative for HER2 IHC. Another 2 cases showed equivocal HER2 FISH results, and one remaining case was negative for HER2 FISH. Conclusion. Our observation that plasmacytoid urothelial carcinomas frequently demonstrated HER2 protein overexpression provides supporting evidence that HER2 may be a potential therapeutic target for plasmacytoid urothelial carcinoma.

Inhibition of proliferation and induction of apoptosis in RB116 retinoblastoma cells by afatinib treatment

The present study investigates the effect of afatinib on the growth, induction of apoptosis in RB116 cells, and reduction of carcinoma growth in the mice transplanted with RB116 cells. The results from MTT assay revealed that afatinib inhibited the growth of RB116 cells in a dose-dependent manner. Proliferation of RB116 cells was reduced to 64 % on treatment with 200 μM concentration of afatinib after 48 h. Afatinib treatment of RB116 cells at 200 μM concentration induced apoptosis and necrosis in 49.7 and 9.4 %, respectively, after 48 h. In the RB116-transplanted mice, treatment with afatinib at 10-mg/kg doses for 45 days caused a significant (p < 0.005) reduction in the tumor volume compared to the control group. The tissue lysates of the mice containing RB116 transplant showed a significant decrease in the expressions of Ki67 and p53 in the afatinib treatment group after 45 days. However, the expression of caspase-3 was increased and of Bcl-2 remained unaltered on treatment with afatinib. Measurement of the body weight of afatinib-treated animals showed no reduction during the study. Thus, afatinib can be of therapeutic value for the treatment of retinoblastoma.

Afatinib-based combination regimens for the treatment of solid tumors: rationale, emerging strategies and recent progress

In oncology, there is a clinical need for novel combination therapy regimens that maximize efficacy and delay resistance to individual treatment modalities. Given the role of aberrant ErbB receptor signaling in the pathogenesis of many human cancers, there is rationale for incorporating afatinib, an irreversible pan-ErbB tyrosine kinase inhibitor, into such combinations. This review focuses on: pharmacological properties of afatinib that facilitate its use in combination; preclinical rationale for the combination of afatinib with other agents; and recently completed, and ongoing, clinical trials of afatinib-based combinations across tumor types. Based on these data, we emphasize a number of areas of high unmet medical need that could benefit from afatinib-based combinations, including patients with relapsed/refractory non-small-cell lung cancer.

Clinical Significance of Substaging and HER2 Expression in Papillary Nonmuscle Invasive Urothelial Cancers of the Urinary Bladder

The study aimed to verify the prognostic utility, therapeutic application and clinical benefits of tumor substaging and HER2 status in papillary non-muscle invasive bladder cancer (NMIBC). Select NMIBC transurethral resection specimens from 141 patients were used to construct tissue microarrays for assessing the substaging, HER2 protein expression by immunohistochemistry (HER2-IHC) and gene amplification by dual-color silver in situ hybridization (HER2-SISH). Substages were identified by the differing depth of tumor invasion (pTa / pT1a / pT1b / pT1c). HER2 protein expression was semiquantitatively analyzed and grouped into negative (score 0, 1+) and positive (score 2+, 3+). Other clinicopathological variables were also investigated. For NMIBC, HER2-IHC and HER2-SISH showed positive results in 6/141 (4.3%) and 4/141 (2.8%) respectively, which correlated well with tumor substaging. In multivariate analysis, substaging, HER2-IHC, and HER2-SISH were found to be independent predictors of progression-free survival (P < 0.001, P < 0.001, P = 0.031). HER2-IHC was the sole independent predictor of recurrent free survival in NMIBC (P = 0.017). It is suggested that tumor substaging and HER2 status are independent predictive markers for tumor progression or recurrence, and thus could be included in diagnostic and therapeutic management for NMIBC.

Tracing the footprints of the breast cancer oncogene BRK - Past till present

Twenty years have passed since the non-receptor tyrosine kinase, Breast tumor kinase (BRK) was cloned. While BRK is evolutionarily related to the Src family kinases it forms its own distinct sub-family referred here to as the BRK family kinases. The detection of BRK in over 60% of breast carcinomas two decades ago and more remarkably, its absence in the normal mammary gland attributed to its recognition as a mammary gland-specific potent oncogene and led BRK researchers on a wild chase to characterize the role of the enzyme in breast cancer. Where has this chase led us? An increasing number of studies have been focused on understanding the cellular roles of BRK in breast carcinoma and normal tissues. A majority of such studies have proposed an oncogenic function of BRK in breast cancers. Thus far, the vast evidence gathered highlights a regulatory role of BRK in critical cellular processes driving tumor formation such as cell proliferation, migration and metastasis. Functional characterization of BRK has identified several signaling proteins that work in concert with the enzyme to sustain such a malignant phenotype. As such targeting the non-receptor tyrosine kinase has been proposed as an attractive approach towards therapeutic intervention. Yet much remains to be explored about (a) the discrepant expression levels of BRK in cancer versus normal conditions, (b) the dependence on the enzymatic activity of BRK to promote oncogenesis and (c) an understanding of the normal physiological roles of the enzyme. This review outlines the advances made towards understanding the cellular and physiological roles of BRK, the mechanisms of action of the protein and its therapeutic significance, in the context of breast cancer.

Morphological and molecular characteristics of HER2 amplified urothelial bladder cancer

Several (pre-) clinical trials are currently investigating the benefit of HER2-targeted therapy in urothelial bladder cancer (UBC). Patients with HER2 amplified UBC could potentially profit from these therapies. However, little is known about histomorphology, HER2 protein expression patterns and occurrence of alterations in the HER2 gene in their tumors. Among 150 metastasizing primary UBC, 13 HER2 amplified tumors were identified. Their histopathological features were compared with 13 matched, non-amplified UBC. HER2 protein expression was determined by immunohistochemistry. The 26 tumors were screened for mutations in exons 19 and 20 of the HER2 gene. UBC with HER2 amplification presented with a broad variety of histological variants (median 2 vs. 1), frequently featured micropapillary tumor components (77 % vs. 8 %) and demonstrated a high amount of tumor associated inflammation. Immunohistochemically, 10 of 13 (77 %) HER2 amplified tumors were strongly HER2 protein positive. Three tumors (23 %) were scored as HER2 negative. One of the HER2 amplified tumors harbored a D769N mutation in exon 19 of the HER2 gene; all other tested tumors were wild type. In conclusion, HER2 amplified UBC feature specific morphological characteristics. They frequently express the HER2 protein diffusely and are, therefore, promising candidates for HER2 targeted therapies. The detection of mutations at the HER2 locus might add new aspects to molecular testing of UBC.

EGFR-expression in primary urinary bladder cancer and corresponding metastases and the relation to HER2-expression. On the possibility to target these receptors with radionuclides

Background

There is limited effect of tyrosine kinase inhibitors or “naked” antibodies binding EGFR or HER2 for therapy of metastasized urinary bladder cancer and these methods are therefore not routinely used. Targeting radio-nuclides to the extracellular domain of the receptors is potentially a better possibility.

Methods

EGFR- and HER2-expression was analyzed for primary tumors and corresponding metastases from 72 patients using immunohistochemistry and the internationally recommended HercepTest. Intracellular mutations were not analyzed since only the receptors were considered as targets and intracellular abnormalities should have minor effect on radiation dose.

Results

EGFR was positive in 71% of the primary tumors and 69% of corresponding metastases. Local and distant metastases were EGFR-positive in 75% and 66% of the cases, respectively. The expression frequency of HER2 in related lesions was slightly higher (data from previous study). The EGFR-positive tumors expressed EGFR in metastases in 86% of the cases. The co-expression of EGFR and HER2 was 57% for tumors and 53% for metastases. Only 3% and 10% of the lesions were negative for both receptors in tumors and metastases, respectively. Thus, targeting these receptors with radionuclides might be applied for most patients.

Conclusions

At least one of the EGFR- or HER2-receptors was present in most cases and co-expressed in more than half the cases. It is therefore interesting to deliver radionuclides for whole-body receptor-analysis, dosimetry and therapy. This can hopefully compensate for resistance to other therapies and more patients can hopefully be treated with curative instead of palliative intention.

HER2 expression status in diverse cancers: review of results from 37,992 patients

Human epidermal growth factor receptor 2 (HER2) amplification/overexpression is an effective therapeutic target in breast and gastric cancer. Although HER2 positivity has been reported in other malignancies, previous studies generally focused on one cancer type, making it challenging to compare HER2 positivity across studies/malignancies. Herein, we examined 37,992 patient samples for HER2 expression (+/- amplification) in a single laboratory. All 37,992 patients were tested by immunohistochemistry (IHC); 21,642 of them were also examined for HER2 amplification with either fluorescent in situ hybridization (FISH) (11,670 patients) or chromogenic in situ hybridization (CISH) (9,972 patients); 18,262 patients had tumors other than breast or gastric cancer. All tissues were analyzed in a Clinical Laboratory Improvement Amendments (CLIA) laboratory (Caris Life Sciences) at the request of referring physicians. HER2 protein overexpression was found in 2.7 % of samples. Over-expressed HER2 was detected predominantly in malignancies of epithelial origin; for cancers derived from mesenchyme, neuroendocrine tissue, central nervous system, and kidney, HER2 expression and amplification were remarkably rare or non-existent. Bladder carcinomas, gallbladder, extrahepatic cholangiocarcinomas, cervical, uterine, and testicular cancers showed HER2 positivity rates of 12.4, 9.8, 6.3, 3.9, 3.0, and 2.4 %, respectively. HER2 overexpression and/or amplification is frequently found across tumor types. These observations may have significant therapeutic implications in cancers not traditionally thought to benefit from anti-HER2 therapies.

HER2 as a target in invasive urothelial carcinoma

We evaluated primary tumors from two cohorts, Spain (N = 111) and Greece (N = 102), for patients who were treated with platinum-based chemotherapy. Patients were tested for HER2 status (IHC score of 3+ or FISH ratio of ≥ 2.2) by immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), DNA copy number, mRNA expression, and mutation status in patients with metastatic urothelial carcinoma (UC), and its impact on survival. ERBB2 mutation was determined by hotspot sequencing. mRNA expression was assessed using NanoString counting. Association of overall survival (OS) and HER2 status was assessed by a Cox regression model. NIH-3T3 cells containing HER2 V777L were assessed for growth, invasion, and HER2 kinase activation. In all, 22% of Spanish and 4% of Greek cohorts had 3+ HER2 staining by IHC. FISH amplification was identified in 20% of Spanish and 4% of Greek cohorts. Kappa coefficient between FISH and IHC was 0.47. HER2 status was not associated with OS in univariate (Spanish P = 0.34; Greek P = 0.11) or multivariate (Spanish P = 0.49; Greek P = 0.12) analysis. HER2-positive tumors expressed higher levels of HER2 mRNA than HER2-negative tumors (P < 0.001). HER2 mutations (V777L and L755S) were identified in two (2%) patients. In vitro analysis of V777L results in transformation of NIH-3T3 cells, leading to increased growth, invasion on soft agar, and HER2 kinase constitutive activation. In summary, HER2 overexpression or amplification in the primary tumor did not predict OS in patients with metastatic UC. HER2 positivity rates can differ between different populations. Further trials in genomically screened patients are needed to assess HER2-targeted therapies in UC.

Afatinib inhibits proliferation and invasion and promotes apoptosis of the T24 bladder cancer cell line

Afatinib is a highly selective, irreversible inhibitor of the epidermal growth factor receptor (EGFR) and human EGFR 2 (HER-2). Although preclinical and clinical studies have indicated that afatinib has antitumor activity and clinical efficacy in non-small cell lung carcinoma, head and neck squamous cell carcinoma and breast cancer, there are few studies investigating its inhibitory effect on human bladder carcinoma cells. In this study, the antitumor effect of afatinib was investigated on the T24 bladder cancer cell line. The T24 bladder cancer cell line was treated with afatinib at various concentrations (0, 1, 5, 10 and 20 µmol/l). MTT assay was used to estimate the proliferation of the T24 cells; flow cytometric analysis was used to estimate the effect of afatinib on T24 cell apoptosis; cell invasion ability was assessed by a Transwell invasion assay; and western blot analysis was used to detect the expression of Bcl-2, Bax, Akt, extracellular-signal-regulated kinase (ERK)1/2, matrix metalloproteinase (MMP)-2 and MMP-9. The MTT assay demonstrated that afatinib inhibited the proliferation of T24 cells in a dose- and time-dependent manner. Flow cytometric analysis revealed that the cell apoptosis rate increased as the concentration of afatinib increased. The cell invasion assay indicated that afatinib treatment significantly inhibited the invasive behavior of T24 cells in a dose-dependent manner. Western blot analysis showed that with increasing afatinib concentrations, Bcl-2, phosphorylated (p)-ERK1/2, p-Akt, MMP-2 and MMP-9 expression levels were significantly decreased, whereas total (t)-ERK1/2 and t-Akt expression levels remained basically unchanged, and Bax expression levels were greatly increased. The results indicate that afatinib inhibits the proliferation and invasion of T24 cells in vitro and induces the apoptosis of these cells by inhibiting the EGFR signaling network.

A pan-cancer proteomic perspective on The Cancer Genome Atlas

Protein levels and function are poorly predicted by genomic and transcriptomic analysis of patient tumours. Therefore, direct study of the functional proteome has the potential to provide a wealth of information that complements and extends genomic, epigenomic and transcriptomic analysis in The Cancer Genome Atlas (TCGA) projects. Here we use reverse-phase protein arrays to analyse 3,467 patient samples from 11 TCGA 'Pan-Cancer' diseases, using 181 high-quality antibodies that target 128 total proteins and 53 post-translationally modified proteins. The resultant proteomic data are integrated with genomic and transcriptomic analyses of the same samples to identify commonalities, differences, emergent pathways and network biology within and across tumour lineages. In addition, tissue-specific signals are reduced computationally to enhance biomarker and target discovery spanning multiple tumour lineages. This integrative analysis, with an emphasis on pathways and potentially actionable proteins, provides a framework for determining the prognostic, predictive and therapeutic relevance of the functional proteome.

Single-cell quantitative HER2 measurement identifies heterogeneity and distinct subgroups within traditionally defined HER2-positive patients

Human epidermal growth factor receptor 2 (HER2) is an important biomarker for breast and gastric cancer prognosis and patient treatment decisions. HER2 positivity, as defined by IHC or fluorescent in situ hybridization testing, remains an imprecise predictor of patient response to HER2-targeted therapies. Challenges to correct HER2 assessment and patient stratification include intratumoral heterogeneity, lack of quantitative and/or objective assays, and differences between measuring HER2 amplification at the protein versus gene level. We developed a novel immunofluorescence method for quantitation of HER2 protein expression at the single-cell level on FFPE patient samples. Our assay uses automated image analysis to identify and classify tumor versus non-tumor cells, as well as quantitate the HER2 staining for each tumor cell. The HER2 staining level is converted to HER2 protein expression using a standard cell pellet array stained in parallel with the tissue sample. This approach allows assessment of HER2 expression and heterogeneity within a tissue section at the single-cell level. By using this assay, we identified distinct subgroups of HER2 heterogeneity within traditional definitions of HER2 positivity in both breast and gastric cancers. Quantitative assessment of intratumoral HER2 heterogeneity may offer an opportunity to improve the identification of patients likely to respond to HER2-targeted therapies. The broad applicability of the assay was demonstrated by measuring HER2 expression profiles on multiple tumor types, and on normal and diseased heart tissues.

HER2 status in primary stage T1 urothelial cell carcinoma of the urinary bladder

OBJECTIVE

The HER2 receptor is involved in pathways essential for cell proliferation, and is an important predictive and prognostic factor in breast cancer. HER2 probably plays a critical role in many types of cancer, including urothelial carcinoma of the bladder (UCB). Stage T1 UCB exhibits heterogeneous clinical behaviour, and the frequency of HER2 expression in such disease has not been thoroughly examined. The aim of this study was to use an immunohistochemical technique to evaluate the frequency of HER2 expression in a defined population-based cohort of patients registered as having primary stage T1 UCB.

MATERIAL AND METHODS

The initial study population comprised 285 patients registered as having primary stage T1 UCB. The original histological specimens were re-evaluated with regard to T stage and World Health Organization grade. Hospital records provided information on tumour size, multiplicity, possible presence of histologically proven recurrence and progression. The patients were followed for at least 5 years or until death. In tumours still considered stage T1 after re-evaluation, HER2 was investigated by immunohistochemistry of paraffin-embedded material and scored according to the guidelines used in breast cancer.

RESULTS

After histopathological re-evaluation, 201 patients were still T1 UCB and could be investigated regarding HER2 expression. HER2 overexpression was observed in 25 of those patients (12.4%). HER2 status was not significantly associated with recurrence or progression.

CONCLUSIONS

HER2 was overexpressed in 12.4% of the present cohort of patients with primary stage T1 UCB. There was no significant association between tumour HER2 status and prognosis.

Epidermal growth factor receptor expression in urinary bladder cancer

Objective:

To evaluate the expression pattern of epidermal growth factor receptor (EGFR) in urinary bladder cancer and its association with human epidermal growth factor receptor 2 (HER2), epidermal growth factor (EGF), interleukin-6 (IL-6), and high risk human papilloma virus (HPV) types 16 and 18.

Materials and Methods:

Thirty cases of urothelial carcinoma were analyzed. EGFR, HER2, EGF, and IL-6 expressions in the tissue were evaluated by immunohistochemical staining. For HPV, DNA from tissue samples was extracted and detection of HPV was done by PCR technique. Furthermore, evaluation of different intracellular molecules associated with EGFR signaling pathways was performed by the western blot method using lysates from various cells and tissues.

Results:

In this study, the frequencies of immunopositivity for EGFR, HER2, EGF, and IL-6 were 23%, 60%, 47%, and 80%, respectively. No cases were positive for HPV-18, whereas HPV-16 was detected in 10% cases. Overall, expression of EGFR did not show any statistically significant association with the studied parameters. However, among male patients, a significant association was found only between EGFR and HER2.

Conclusions:

Overexpression of EGFR and/or HER2, two important members of the same family of growth factor receptors, was observed in a considerable proportion of cases. Precise knowledge in this subject would be helpful to formulate a rational treatment strategy in patients with urinary bladder cancer.

Discussion on the influence of HER2 status on the clinical outcome of bladder cancer continues

Evaluation of: Bolenz C, Shariat SF, Karakiewicz PI et al. Human epidermal growth factor receptor 2 expression status provides independent prognostic information in patients with urothelial carcinoma of the urinary bladder. BJUI 106, 1216-1222 (2010). The article under evaluation by Bolenz et al. reports on an association between human EGF receptor 2 (HER2) overexpression and aggressive urothelial carcinoma of the urinary bladder: more lymphovascular invasion, higher risk of recurrence and higher disease-specific mortality. These results add to the controversy regarding HER2 status and clinical outcome that is currently known. First, a consensus for the best technique and cut-off is needed. Only then can the relationship between HER2 overexpression and clinical outcome be investigated without current limitations. Although there are already trials ongoing on targeted therapy in bladder cancer, this should be viewed with caution, as patient selection is based on inconsistent definitions of HER2 overexpression. Selection of patients who might benefit from targeted therapy can only be carried out after consensus has been reached.

HER2 gene amplification occurs frequently in the micropapillary variant of urothelial carcinoma: analysis by dual-color in situ hybridization

Human epidermal growth factor receptor-2 (HER2) is a well-recognized growth-promoting factor in cancer, although its application to urothelial carcinoma has been limited because of a low frequency of gene amplification. We evaluated HER2 protein expression and gene amplification in micropapillary carcinoma, a rare but highly aggressive variant of urothelial carcinoma by dual-color in situ hybridization. Gene amplification was defined by a HER2:CHR17 ratio of ≥2.2; low and high levels of amplification were further defined as <2.5 and ≥2.5, respectively. Immunohistochemistry was used to determine HER2 protein expression using the American Society of Clinical Oncology/College of American Pathologists Guidelines of HER2 staining. Protein expression, gene amplification, and chromosome 17 aneusomy were compared by Jonchkeere-Terpstra and Cochran-Armitage trend tests. In all, 19 of the 20 micropapillary carcinoma samples yielded usable dual-color in situ hybridization and immunohistochemistry results for evaluation. Overall, 68% (n=13) demonstrated HER2 protein expression of 2+ to 3+ staining. Gene amplification was present in 42% of samples (n=8), with 100% correlation with 2+ and 3+ protein expression. Gene amplification and protein expression were significantly associated (P=0.01). Overall, 53% of samples (n=10) had aneusomy of chromosome 17. Chromosome 17 aneusomy was present in approximately half of the samples evaluated, suggesting inherent genomic instability in this variant of urothelial carcinoma. However, increased HER2:CHR17 ratios demonstrate increased HER2 expression due to amplification in the majority of micropapillary carcinomas. These results suggest that HER2-targeted therapy may be successful on the genomic level in patients with this disease.

Novel targeted agents for the treatment of bladder cancer: translating laboratory advances into clinical application

Bladder cancer is a common and frequently lethal cancer. Natural history studies indicate two distinct clinical and molecular entities corresponding to invasive and non-muscle invasive disease. The high frequency of recurrence of noninvasive bladder cancer and poor survival rate of invasive bladder cancer emphasizes the need for novel therapeutic approaches. These mechanisms of tumor development and promotion in bladder cancer are strongly associated with several growth factor pathways including the fibroblast, epidermal, and the vascular endothelial growth factor pathways. In this review, efforts to translate the growing body of basic science research of novel treatments into clinical applications will be explored.

Role of anti-Her-2 therapy in bladder carcinoma

Bladder cancer, in its advanced stage, has very few therapeutic strategies with proven efficacy. Platinum-combination chemotherapy can be considered a standard for first-line therapy, but after progression there is no standard therapy, and the prognosis is very poor. The development of targeted therapies in the last few years has significantly changed the prognosis of a wide variety of tumors. In bladder cancer, there is no targeted therapy currently approved for its use in advanced disease. There is evidence that Her-2 amplification and/or overexpression is seen in bladder cancer, and may influence prognosis. Anti-Her-2 drugs, such as trastuzumab or lapatinib, are under investigation in urothelial neoplasms, but there is no phase III trial that has evaluated their use in bladder cancer. We review the published evidence about Her-2 determination, its influence on bladder carcinoma prognosis, the clinical development of anti-Her-2-targeted therapies, and the possible future research directions involving this pathway in bladder cancer.

'Image and treat': an individualized approach to urological tumors

PURPOSE OF REVIEW

The current treatment options for advanced urologic cancers demonstrate limited efficacy. To obtain optimal clinical results, there is a need for new, individualized, therapeutic strategies, which have only recently been applied to these malignancies. Nuclear medicine plays an important role in establishing imaging biomarkers necessary for personalized medicine. This review focuses on the current status of the 'image and treat' approach combining molecular imaging with targeted radionuclide therapy of urological malignancies

RECENT FINDINGS

Tumor-specific targets in uro-oncology are showing promising results for development of personalized therapy using positron emission tomography/computed tomography (PET/CT) molecular imaging and radioimmunotherapy. The antibody cG250, which binds to carbonic anhydrase IX, is being evaluated as a radiolabeled imaging and therapeutic agent in clear-cell renal cell carcinoma. I-cG250 PET/CT has demonstrated excellent targeting of clear-cell renal cell carcinoma. Prostate-specific membrane antigen is a promising target for both PET/CT and radioimmunotherapy of prostate cancer. HER2 may be another potential target in bladder and prostate cancer.

SUMMARY

Tumor-specific targets and biomarkers are being studied for PET/CT and radioimmunotherapy. This may lead to development of new therapeutic strategies. However, considerable investment in new research will be required for personalized medicine to be routinely used in uro-oncology.

Assessing HER2 gene amplification as a potential target for therapy in invasive urothelial bladder cancer with a standardized methodology: results in 1005 patients

Background: This study assessed the human epidermal growth factor receptor-2 (HER2) protein expression and its relationship with gene amplification in invasive bladder carcinoma, using the same criteria than for breast cancer.

Patients and methods: In 1005 patients, paraffin-embedded tissues of transurethral resection or cystectomy were evaluated by immunohistochemistry (IHC), using antibodies against HER2. All samples with a 2+ or 3+ HER2 overexpression were evaluated by FISH.

Results: HER2 overexpression was observed in 93 (9.2%) tumors (2+: 42 tumors and 3+: 51 tumors). Using FISH, all HER2 3+ tumors had a gene amplification, whereas no amplification was found in 2+ tumors. Intratumoral heterogeneity was observed in 35% of cases. These tumors showed the same heterogeneous pattern, with adjacent 3+ positive and negative areas by both IHC and FISH.

Conclusions: This study showed that 5.1% of invasive bladder carcinomas had a HER2 gene amplification. These findings may have clinical implications for the management of patients with HER2-positive locally advanced or metastatic bladder cancer, as they could be potential candidates for targeted therapy.

Biomarkers in bladder cancer

Detailed molecular insights into bladder cancer biology might allow more detailed prognostication and optimization of treatment with the objective of improving patient outcome and quality of life. However, in bladder cancer research the search for biomarkers has been called into question and has even obtained notoriety. It is unlikely that any single marker will be able to improve prognostication for patients with bladder cancer above and beyond grade and stage, but a combination of multiple independent markers might more precisely predict the outcome. From a previous review, we identified seven biomarkers to study within the setting of the Bladder Cancer Prognosis Programme (BCPP), a 5-year multicentre programme of research based at the University of Birmingham and funded by Cancer Research UK, investigating their effectiveness in predicting recurrence and progression. As part of the ongoing quality-assurance process for BCPP we present an updated review of our selected biomarkers, as well as highlighting other recent important developments in bladder cancer research.

Overexpression of PTK6 (breast tumor kinase) protein--a prognostic factor for long-term breast cancer survival--is not due to gene amplification

In a previous retrospective study, we demonstrated the prognostic value of protein tyrosine kinase 6 (PTK6) protein expression in breast carcinomas. Here, we analyzed PTK6 gene amplification using fluorescence in situ hybridization technique in a cohort of 426 invasive breast carcinomas and compared it with PTK6 expression level as well as with the clinical outcome of patients. Forty-five percent of tumors show increased PTK6 gene copy numbers when compared to normal tissue. Most of these, however, were related to chromosome 20 polysomy (30%), while gene amplification accounted for only 15%. Only "low level" amplification of the PTK6 gene, with up to eight signals per nucleus, was found. The PTK6 cytogenetic status (normal, gene amplification, polysomy 20) was not associated with histopathological parameters or with the protein expression of HER receptors. No statistical association was identified between PTK6 gene status and expression level. Further, the PTK6 gene status does not influence the disease-free survival of patients at > or = 240 months. Based on these results, we state that the PTK6 overexpression is not essentially attributed to gene amplification, and the PTK6 protein expression-but not gene status-is of prognostic value in breast carcinomas. PTK6 protein overexpression may result from polysomy 20 in a minority of the tumors. In a marked proportion of tumors, however, the overexpression is likely to be caused by posttranscriptional regulation mechanisms.

Role of Polysomy 17 in Transitional Cell Carcinoma of the Bladder: Immunohistochemical Study of HER2/neu Expression and FISH Analysis of c-erbB-2 Gene and Chromosome 17

This study investigates the potential clinical significance of c-erbB-2 gene and chromosome 17 alterations by fluorescence in situ hybridization (FISH) analysis and HER2/neu overexpression by immunohistochemical staining in transitional cell carcinoma (TCC) of urinary bladder correlating the results with tumor stage and grade categories and with clinical behavior. Sixty-three cases of TCC retrieved from the files of 2 institutions were analyzed for chromosome 17 aberrations and c-erbB-2 amplification by FISH analysis and evaluated immunohistochemically for HER2/neu overexpression. Five tumors were G1, 29 intermediate grade (G2), and 29 tumors high grade (G3); 32 tumors had stage Ta, 18 tumors T1, and 13 tumors T2. We found polysomy of chromosome 17 in 58.7% of TCC with average chromosome copy number >2.26; increased number of HER2/neu gene copy was observed in 66.7% of tumors. C-erbB-2 amplification occurred in 6.3% of tumors. Immunohistochemically, 60.3% of TCC overexpressed HER2/neu and 39.7% of tumors were negative. All tumors with polysomy showed simultaneously increase of HER2/neu gene copy number of which 34/37 with protein overexpression. A statistically significant correlation between polysomy of chromosome 17 and tumor stage ( P = .0003) and tumor grade ( P < .0001) was found; polysomy was not seen in G1 tumors; however, 8/29 G2 tumors and 29/29 G3 tumors revealed polysomy of chromosome 17; in 8/32 Ta tumors, 14/18 T1 and 13/13 of deeply invasive tumors (T2) polysomy 17 was observed. Moreover, it was found that 7 superficial tumors (1 Ta and 6 T1) showed high polysomy with average of chromosome 17 copy number ≥3.76 as observed in all invasive tumors. The data suggest that although HER2/neu amplification, found in high grade and invasive tumors, is a rare event in TCC, polysomy of chromosome 17 is an important factor correlated with tumor stage and grade categories and could be considered a molecular marker of tumor progression with interesting diagnostic implications.