Membranous Insulin-like Growth Factor-1 Receptor Research Articles

Abstract 2690: Loss of E-cadherin induces IGF1R activation revealing a targetable pathway in invasive lobular breast carcinoma

Abstract Invasive Ductal Carcinoma (IDC) and Invasive Lobular Carcinoma (ILC) are two major subtypes of breast cancer with significant differences in their histological and molecular underpinnings. ILC has a unique loss of E-cadherin (CDH1) which we have previously demonstrated as a negative regulator of the Insulin-like Growth Factor 1 receptor (IGF1R) through a comprehensive analysis of cell line models and tumor samples. We propose that loss of E-cadherin in ILC sensitizes cells to growth factor signaling and thus alters their sensitivity to growth factor signaling inhibitors. To investigate this, we used CRISPR to generate CDH1 knockout (KO) IDC cell lines (MCF7, T47D, ZR75.1) to uncover the mechanism by which E-cadherin loss activates the IGF pathway while also assessing its targetability. CDH1 KO cells exhibited anchorage independent growth in suspension culture and altered p120 catenin localization as observed in ILC tumors. Through in vitro studies, we show increased signaling sensitivity to IGF/insulin ligands and enhanced signaling duration in CDH1 KO cells. In addition, we observed a higher migratory potential of CDH1 KO cells compared to wild type (WT) cells, which was further enhanced as a chemotactic response to IGF1 or serum. Further, this phenotype could be reversed with an IGF1R inhibitor, BMS-754807. We additionally identified an increase in Collagen I haptotaxis in the CDH1 KO cells, which was also translated into a novel invasive phenotype towards serum in the T47D CDH1 KO cells. Despite no significant differences in membranous IGF1R levels between WT and CDH1 KO cells, higher ligand-receptor interaction was observed with CDH1 KO cells, demonstrating an increased ligand-receptor complex formation upon stimulation. Our results suggest that loss of CDH1 results in an increase in IGF1 receptor availability for ligand binding which in turn allows for an enhanced downstream signaling activation. Interestingly, a physical repression of E-cadherin on IGF1R could not be demonstrated, suggesting spatial changes on the membrane following E-cadherin loss may control ligand binding. Critically, increased sensitivity to IGF1R, PI3K, AKT and MEK inhibitors was observed in CDH1 KO cells suggesting that these targets should be further explored in ILC and that CDH1 loss may be exploited as a biomarker of response, or for patient stratification to inhibitors targeting these pathways. Citation Format: Ashuvinee Elangovan, Laura Savariau, Megan E. Yates, Jagmohan Hooda, Alison M. Nagle, Steffi Oesterreich, Jennifer M. Atkinson, Adrian V. Lee. Loss of E-cadherin induces IGF1R activation revealing a targetable pathway in invasive lobular breast carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2690.

Correlation of Insulin-like Growth Factor 1 Receptor Expression With Different Molecular Subtypes of Breast Cancer in the UAE.

Insulin-like growth factor 1 receptor (IGF1R) activation triggers multiple signaling pathways involved in proliferation and anti-apoptosis in breast cancer (BC). Immunohistochemistry for IGF1R was performed on 50 BC cases; expression was assessed for staining intensity and localization pattern (mixed, membranous, and cytoplasmic) which was correlated to hormone receptor status. Of estrogen receptor-positive (ER+) cases, 97.2% were IGF1R+ (48.6% mixed, 43.2% membranous, and 5.4% cytoplasmic pattern) compared to ER- cases (38.5%, 7.7% and 30.8%, respectively) (p=0.003). In progesterone receptor-positive (PR+) cases, 97.2% were IGF1R+, (47.2%, 41.7% and 8.3%, respectively) compared to PR- ones (42.9%, 14.3% and 21.4%, respectively) (p=0.036). For human epidermal growth factor receptor 2-negative (HER2-) cases, 88.8% were IGF1R+ (44.4%, 8.3% and 36.1%, respectively). All HER2+ cases were IGF1R+ (71.4%, 7.1% and 21.4%, respectively) (p=0.015). In conclusion, hormone receptor-positive HER2- cases showed membranous and mixed IGF1R localization. However, hormone receptor-negative and HER2+ showed cytoplasmic or diminished IGF1R expression. These luminal subtypes may benefit from targeted IGFR therapy in the future.

Insulin-like growth factor-1 receptor expression in upper tract urothelial carcinoma.

Insulin-like growth factor-1 receptor (IGF1R) is a transmembrane tyrosine kinase receptor that plays a crucial role in cell proliferation, growth, differentiation, and apoptosis. IGF1R overexpression has been observed in several cancers, including invasive bladder carcinomas, as a potential prognostic factor. Given known biologic differences between upper and lower urinary tract urothelial carcinoma, we assessed the expression status and prognostic significance of IGF1R in upper tract urothelial carcinoma (UTUC). Two tissue microarrays (TMAs) were built from 99 Japanese patients with non-metastatic UTUC submitted to radical nephroureterectomy between 1997 and 2011. TMAs were constructed with triplicate tumor and paired benign urothelium. Membranous IGF1R staining was evaluated using immunohistochemistry. Two scoring methods were applied (Her2-score and H-score). The highest score was assigned to each tumor. IGF1R positivity was defined as Her2-score ≥ 1+. Association with clinicopathologic parameters and outcome was assessed using hazard ratios (HR) with 95% confidence intervals (CI) and adjusted P values. We found positive IGF1R expression in 70% of UTUC. Outcomes were as follows: tumor recurrence, 33%; tumor progression, 59%; overall mortality, 33%; and cancer-specific mortality, 30%. IGF1R was not associated with any clinicopathologic features. In addition, IGF1R expression was not associated with tumor recurrence (HR = 0.54, CI = 0.25-1.1, P = 0.11), tumor progression (HR = 1.6, CI = 0.8-3.1, P = 0.19), overall mortality (HR = 1.5, CI = 0.68-3.4, P = 0.31), or cancer-specific mortality (HR = 1.6, CI = 0.68-3.8, P = 0.27). Positive IGF1R expression was found in more than two thirds of UTUC. This finding provides a rationale to investigate IGF1R as a potential therapeutic target in UTUC. In contrast to bladder cancer, IGF1R expression in UTUC did not correlate with outcome, further pointing to biologic differences between UTUC and bladder cancer.

Strong association of insulin-like growth factor 1 receptor expression with histologic grade, subtype, and HPV status in penile squamous cell carcinomas: a tissue microarray study of 112 cases.

Insulin-like growth factor-1 receptor (IGF1R) plays a key role in cell growth and transformation. It is overexpressed in several solid tumors. This study evaluates IGF1R immunoexpression in penile squamous cell carcinoma (SCC). Four tissue microarrays were built from formalin-fixed, paraffin-embedded blocks of 112 penile SCC from Paraguay. Membranous IGF1R expression was evaluated by immunohistochemistry using two different approaches. An H-score was calculated in each spot (stain intensity by extent), and a median score per tumor was obtained. The second approach consisted of a score similar to the scoring system that was used for evaluating HER2 immunoexpression. For each case, the highest category obtained at any spot was used for statistical analyses. IGF1R expression was compared by histologic subtype, grade, and human papillomavirus (HPV) status. Median H-score was 22.5. The distribution of IGF1R expression by HER2 approach was as follows: 0 in 33.0% cases, 1+ in 46.4%, 2+ in 14.3%, and 3+ in 6.2%. IGF1R H-scores were associated with basaloid and warty/basaloid subtypes (p=0.0026) and higher grade (p=0.00052). Although weaker when using the HER2 approach, the association of IGF1R expression with subtype (p=0.015) and grade (p=0.015) remained significant. Furthermore, there was an association between IGF1R expression by HER2 approach and HPV status (p=0.012). IGF1R was expressed in about two thirds of penile SCC cases, showing a strong positive association with histologic grade, subtype, and HPV status. Considering that grade is a predictor of outcome IGF1R expression may have prognostic relevance and could point to a potential role for IGF1R inhibitors in treating penile SCC.

Membranous Insulin-like Growth Factor-1 Receptor (IGF1R) Expression Is Predictive of Poor Prognosis in Patients with Epidermal Growth Factor Receptor (EGFR)-Mutant Lung Adenocarcinoma.

Background:Insulin-like growth factor-1 receptor (IGF1R) is a membrane receptor-type tyrosine kinase that has attracted considerable attention as a potential therapeutic target, although its clinical significance in non-small cell lung cancer (NSCLC) is controversial. This study aimed to clarify the clinical significance of IGF1R expression in human NSCLC.Methods:IGF1R protein expression was evaluated using immunohistochemistry in 372 patients with NSCLC who underwent curative surgical resection (146 squamous cell carcinomas [SqCCs] and 226 adenocarcinomas [ADCs]). We then analyzed correlations between expression of IGF1R and clinicopathological and molecular features and prognostic significance.Results:Membranous and cytoplasmic IGF1R expression were significantly higher in SqCCs than in ADCs. In patients with SqCC, membranous IGF1R expression was associated with absence of vascular, lymphatic, and perineural invasion; lower stage; and better progression-free survival (PFS) (hazard ratio [HR], 0.586; p = .040). In patients with ADC, IGF1R expression did not have a significant prognostic value; however, in the subgroup of epidermal growth factor receptor (EGFR)-mutant ADC, membranous IGF1R expression was associated with lymphatic and perineural invasion, solid predominant histology, and higher cancer stage and was significantly associated with worse PFS (HR, 2.582; p = .009).Conclusions:Lung ADC and SqCC showed distinct IGF1R expression profiles that demonstrated prognostic significance. High membranous IGF1R expression was predictive of poor PFS in EGFR-mutant lung ADC, while it was predictive of better PFS in SqCC. These findings will help improve study design for subsequent investigations and select patients for future anti-IGF1R therapy.

Upregulation of IGF-1R expression during neoadjuvant therapy predicts poor outcome in breast cancer patients.

IntroductionThe insulin-like growth factor 1 receptor (IGF-1R) may be involved in the development of resistance against conventional cancer treatment. The aim of this study was to assess whether IGF-1R expression of breast tumors changes during neoadjuvant therapy and to study whether these changes were associated with survival.MethodsParaffin embedded tumor tissue was collected from pretreatment biopsies and surgical resections of 62 breast cancer patients who were treated with neoadjuvant chemotherapy or endocrine therapy. IGF-1R expression was determined immunohistochemically and compared before and after treatment.ResultsHigh membranous IGF-1R expression at diagnosis correlated significantly with ER positivity, low tumor stage (stage I/II) and longer overall survival (p < 0.05). After neoadjuvant treatment, membranous IGF-1R expression remained the same in 41 (65%) tumors, was upregulated in 11 (18%) tumors and downregulated in 11 (18%) tumors. Changes in membranous IGF-1R expression were associated with overall survival (log-rank test: p = 0.013, multivariate cox-regression: p = 0.086). Mean overall survival time for upregulation, no change, and downregulation in IGF-1R expression was 3.0 ± 0.5 years, 7.3 ± 1.0 years and 15.0 ± 1.8 years, respectively. Changes in other parameters were not significantly associated with survival.ConclusionNeoadjuvant therapy can induce changes in IGF-1R expression. Upregulation of IGF-1R expression after neoadjuvant treatment is a poor prognostic factor in breast cancer patients, providing a rationale for incorporating anti-IGF-1R drugs in the management of these patients.

The impact of IGF-1R expression on the outcomes of patients with breast cancer: a meta-analysis.

PurposeThe value of insulin-like growth factor 1 receptor (IGF-1R) for predicting survival of patients with breast cancer remains controversial. The purpose of this study was to perform a meta-analysis of the published data to attempt to clarify the impact of IGF-1R.MethodsStudies published between January 1, 1990 and October 1, 2014 were identified using an electronic search to aggregate the available survival results. Studies were included if they reported detecting IGF-1R expression in the primary breast cancer and analyzed patient survival data according to IGF-1R status. The principal outcome measures were hazard ratios (HRs) for survival of IGF-1R-positive patients. Combined HRs and 95% confidence intervals (CIs) were estimated using fixed- or random-effects models according to between-study heterogeneity.ResultsTen studies, involving 5,406 patients, satisfied our inclusion criteria. Data from five studies provided the impact of IGF-1R on overall survival (OS), three studies the impact on breast cancer-specific survival (BCSS), and seven studies the impact on disease-free survival (DFS). The results of meta-analysis showed that for DFS, membranous IGF-1R positivity was not a significant predictor. The combined HR for OS/BCSS was 0.63 (95% CI: 0.42–0.95, P=0.03), indicating that membranous IGF-1R positivity was a significant predictor of better survival. IGF-1R cytoplasmic positivity was significantly associated with longer DFS and OS/BCSS (combined HR: 0.56, 95% CI: 0.35–0.89, P=0.01; combined HR: 0.55, 95% CI: 0.35–0.85, P=0.008, respectively). The results of subgroup analysis suggested that membranous IGF-1R positivity in hormone-receptor-positive breast cancer was correlated with favorable DFS (combined HR: 0.61, 95% CI: 0.41–0.92, P=0.02) and OS/BCSS (combined HR: 0.73, 95% CI: 0.57–0.93, P=0.01). Membranous IGF-1R positivity in triple-negative breast cancer predicted worse DFS (combined HR: 1.86, 95% CI: 1.03–3.34, P=0.04). Membranous IGF-1R positivity in Her-2-positive or ER (estrogen receptor)-negative breast cancer was not found to be a significant prognostic indicator.ConclusionThe results of this meta-analysis suggest that IGF-1R expression has different prognostic values for patients with breast cancers of different molecular subtypes. It was a favorable prognostic indicator in unselected breast cancers and hormone-receptor-positive cancers, but indicated poor survival in triple-negative breast cancers.

Insulin-like Growth Factor-1 Receptor Overexpression Is Associated With Outcome in Invasive Urothelial Carcinoma of Urinary Bladder: A Retrospective Study of Patients Treated Using Radical Cystectomy

To assess the insulin-like growth factor-1 receptor (IGF1R) expression in urothelial carcinoma (UC) and its prognostic role in relation to clinicopathologic parameters. A total of 100 cases of invasive UC were evaluated using tissue microarrays. Membranous IGF1R staining was evaluated using immunohistochemistry. A scoring method analogous to that of HER2 expression in breast carcinoma was used, and the highest score was assigned in each tumor. IGF1R was considered overexpressed in cases with score≥1. We found IGF1R overexpression in 62% of invasive UC. IGF1R overexpression was associated with race (P=.04) and pT category (P=.03). Median follow-up was 29 months (range, 0.5-212). Progression rate was 60%, and overall mortality and cancer-specific mortality rates were 69% and 51%, respectively. In invasive UC, IGF1R overexpression was significantly associated with overall mortality and cancer-specific mortality (Mantel Cox P=.0002 and P=.006, respectively). IGF1R overexpression was associated with increased hazard ratios (HRs) for overall mortality (HR=2.63, P=.001) and cancer-specific mortality (HR=2.45, P=.01), independently and after adjusting for clinicopathologic features and treatment modalities. We found IGF1R overexpression in 62% of bladder UC. More importantly, IGF1R overexpression was a significant predictor of overall mortality and cancer-specific mortality, suggesting its potential role as a prognosticator in UC of bladder.

Dynamics of IGF-1R Expression During Endocrine Breast Cancer Treatment

The aim was to assess changes in insulin-like growth factor 1 receptor (IGF-1R) expression with immunoSPECT/CT and to study the dynamics of IGF-1R expression of human breast tumors during endocrine treatment. Mice with MCF-7 xenografts were treated with estradiol or tamoxifen, and IGF-1R expression was measured by immunohistochemistry and immunoSPECT/CT using (111)In-R1507 (anti-IGF-1R antibody). Moreover, IGF-1R expression was analyzed immunohistochemically on 22 human breast tumors, treated preoperatively with endocrine therapy. Estradiol resulted in an increased expression of IGF-1R, as measured by immunohistochemistry and immunoSPECT/CT. In contrast, tamoxifen resulted in a downregulation of IGF-1R, whereas this could not be measured with immunoSPECT/CT. A downregulation was also detectable in 9 out of 22 (41 %) human breast tumors after endocrine therapy. Anti-estrogen treatment can cause a reduction in membranous IGF-1R expression. Based on these results, a combination of anti-IGF-1R antibodies with anti-estrogen therapy might not be a rational treatment strategy.

Insulin-like growth factor 1 pathway mutations and protein expression in resected non-small cell lung cancer.

The purpose of this study was to characterize the prevalence of insulin-like growth factor 1 receptor (IGF1R) mutations, single nucleotide polymorphisms (SNP), and protein overexpression in surgically resected non-small cell lung cancers in relation to patient characteristics and prognosis. This retrospective study was conducted on 304 patients with non-small cell lung cancers who underwent curative pulmonary resection (median follow-up for surviving patients, 3.6 years). IGF1R gene alterations (n = 304) and protein expression (n = 181) were evaluated by polymerase chain reaction-based assays and immunohistochemistry, respectively. Membranous and cytoplasmic staining were analyzed separately. In an exploratory analysis, 1 silent mutation in exon 16 and 3 mutations in introns of the IGF1R gene comprising the tyrosine kinase domain were detected. Moreover, evaluating selected IGF1R SNPs, patients with adenocarcinomas and homozygous for the rs8038415 T-allele had a significantly better survival (P = .025) but no different disease-free survival. Regarding expression, membranous but not cytoplasmic IGF1R staining was higher in squamous cell carcinomas versus other histologies (P < .0001) and showed a trend to longer survival (P = .08). No association between SNP variations and protein expression was found. Membranous IGF1R protein expression is higher in squamous cell versus other histologies but does not correlate with prognosis. SNPs and mutations can be detected and may harbor prognostic value. These alterations may be of interest when evaluating the IGF1R as potential therapeutic target and should receive further research.

Association of IGF1R overexpression (OE) with outcome in invasive urothelial carcinoma (UC) of urinary bladder.

4523 Background: Insulin-like growth factor-1 receptor (IGF1R) is a transmembrane tyrosine kinase receptor involved in cell proliferation and differentiation. IGF1R is overexpressed in several tumors including UC and is currently under investigation as a target of Rx. We here explore IGF1R expression in UC, its association with clinicopathologic parameters and prognostic role. Methods: Fivetissue microarrays (TMA) were constructed from 100 cystectomy specimens performed for invasive UC at our institution (1994 to 2007). Formalin-fixed paraffin-embedded paired tumor and benign samples were spotted 3-4 times each. Membranous IGF1R staining was evaluated using immunohistochemistry (G11, Ventana Medical Systems). A scoring method analogous to that of Her2 expression in breast cancer was used and the highest score was assigned to each tumor. IGF1R was considered overexpressed in cases with score 1. Endpoints of the study included overall survival (OS) and disease-specific survival (DSS). Patients were followed-up for a median of 33.5 months (range 1, 141 months). Results: IGF1R OE was found in 62% of UC. No differences were noted between normal urothelium and UC regarding IGF1R OE (74% vs. 60%; P=0.14). IGFR1 OE was more frequent in tumors from African-American patients compared to Caucasians (100% vs. 59%, P=0.04). Tumors at stage pT4 overexpressed IGF1R more frequently than tumors at stages pT1-pT3 (71% vs. 29%, P=0.005). No association with other analyzed clinicopathologic parameters such as patient's age or gender, muscularis propria invasion, or lymph node metastasis) was found. OS and disease-specific survival (DSS) rates were 58% and 69%, respectively. Patients with tumors overexpressing IGF1R had a lower OS and DSS compared to those without IGF1R OE (Mantel-Cox P=0.0007 and P=0.006, respectively). Using Cox proportional hazards regression, IGF1R OE remained a significant predictor of OS (HR=3.49, P=0.001) and DSS (HR=3.54, P=0.007) after adjusting for pathologic stage. Conclusions: OE of IGF1R was found in 62% of UC. High stage tumors overexpressed IGF1R more frequently than low stage tumors. Further, IGF1R OE was a significant independent predictor of OS and DSS in invasive UC.

Overexpression of IGF1R to predict outcome in invasive urothelial carcinoma of urinary bladder.

280 Background: Insulin-like growth factor-1 receptor (IGF1R) is a transmembrane tyrosine kinase receptor involved in cell proliferation and differentiation. IGF1R is overexpressed (OE) in several tumors including bladder cancer and is currently under investigation as a target of Rx. Here we explore IGF1R expression in urothelial carcinoma (UC), its association with clinicopathologic parameters and prognostic role. Methods: Fivetissue microarrays (TMA) were constructed from 100 cystectomy specimens performed for invasive UC at our institution (1994 to 2007). Formalin-fixed paraffin-embedded paired tumor and benign samples were spotted 3-4 times each. Membranous IGF1R staining was evaluated using immunohistochemistry (G11, Ventana Medical Systems). A scoring method analogous to that of Her2 expression in breast cancer was used and the highest score was assigned to each tumor. IGF1R was considered OE in cases with score 1. Endpoints of the study included overall survival and cancer-specific survival. Patients were followed-up for a median of 33.5 months (range 1, 141 months). Results: IGF1R was OE in 62% of UC. No differences were noted between normal urothelium and malignant counterparts (74% vs. 60%; P=0.14). IGFR1 was more frequently OE in tumors from African-American patients compared to Caucasians (100% vs. 59%, P=0.04). pT4 tumors OE IGF1R more frequently than pT1-pT3 tumors (71% vs. 29%, P=0.005). No association was found with other analyzed clinicopathologic parameters such as patient's age or gender, muscularis propria invasion, or lymph node metastasis). Overall survival (OS) and disease-specific survival (DSS) rates were 58% and 69%, respectively. Patients whose tumors OE IGF1R had a lower OS and DSS compared to those whose tumors did not OE IGF1R (Mantel-Cox P=0.0007 and P=0.006, respectively). Using Cox proportional hazards regression, IGF1R overexpression remained a significant predictor of OS (HR=3.49, P=0.001) and DSS (HR=3.54, P=0.007) after adjusting for pathologic stage. Conclusions: Overexpression of IGF1R was found in 62% of UC. High stage tumors OE IGF1R more frequently than low stage tumors. More importantly, IGF1R overexpression was a significant independent predictor of OS and DSS.

Abstract 5573: Nuclear IGF-1R expression as a prognostic factor in cervical cancer patients

Abstract Background: Insulin-like growth factor-1 receptor (IGF-1R) is an unusual transmembrane receptor in that both α and β subunits, regulated by IGF-1, translocate from the membrane to the nucleus and then bind to DNA, increasing gene transcription. Insulin receptor substrate-1 (IRS-1), a docking protein for IGF-1R, also traffics to the nucleus and then activates promoters of cell cycle progression genes. We studied the prognostic significance of nuclear and membranous IGF-1R and nuclear IRS-1 in cervical cancer, previously unreported. Methods: We retrospectively reviewed all patients (pts) with stage Ib2-IIb disease who received platinum-based neoadjuvant chemotherapy (NAC) at Hyogo Cancer Center between 2002 and 2009. Age, performance status, FIGO stage, histology, tumor size, pelvic lymph nodes on MRI, squamous cell carcinoma (SCC) antigen level, hemoglobin levels before NAC, chemotherapeutic agents and chemotherapy cycles were evaluated. Paraffin-embedded pretreatment tissue was stained immunohistochemically with an anti-IGF-1Rβ (Cell signaling, MA) or anti-IRS-1 (Millipore, MA) rabbit polyclonal antibody. IGF-1R and IRS-1 expressions were scored from 0 to 3 according to frequency and intensity. All slides were reviewed by a single pathologist. We analyzed prognostic factors associated with overall survival by a Cox proportional-hazards model. Results: A total of 128 pts (median age 57 years) were identified. The majority had stage II (61%) and SCC (69%). Median tumor size was 40 mm. Overall response rate to NAC was 59%, and median follow-up was 34 months. Nuclear and membranous IGF-1R and nuclear IRS-1 expressions were scored as 0/1-2/3 in 49/60/19 pts, 97/12/19 pts, and 65/41/22 pts, respectively. Multivariate analysis revealed that nuclear IGF-1R expression (HR, 2.6; P= .035 for score 1-3 vs. 0) and age &amp;lt;40 (HR, 2.6; P= .026) were independently associated with worse overall survival. Neither membranous IGF-1R nor IRS-1 expression had a prognostic impact on survival. Conclusions: Nuclear IGF-1R is commonly expressed in cervical cancer and is an independent prognostic factor, unlike membranous IGF-1R or nuclear IRS-1. Approaches that block the translocation of IGF-1R from the cell membrane to nucleus might hold promise for the treatment of cervical cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5573. doi:1538-7445.AM2012-5573

Predicting IGF-1R Therapy Response in Bone Sarcomas: Immuno-SPECT Imaging with Radiolabeled R1507

To investigate whether indium-111-labeled R1507 ((111)In-R1507) immuno-SPECT (single-photon emission computed tomography), a novel noninvasive, in vivo screening method to visualize membranous insulin-like growth factor 1 receptor (IGF-1R) expression and accessibility, can be used to predict IGF-1R treatment (R1507) response in bone sarcomas. BALB/c nude mice were subcutaneously implanted with IGF-1R-expressing human bone sarcoma xenografts (OS-1, EW-5, and EW-8) which showed high, modest, or no response, respectively, to R1507, a monoclonal antibody targeting the extracellular domain of IGF-1R. An IGF-1R-negative tumor (OS-33), unresponsive to IGF-1R inhibitors, was examined as well. Mice were injected with (111)In-R1507. Biodistribution and immuno-SPECT/computed tomography imaging studies were carried out 1, 3, and 7 days p.i. in mice with OS-1 and EW-5 xenografts and 3 days p.i. in mice with EW-8 and OS-33 xenografts. Biodistribution studies showed specific accumulation of (111)In-R1507 in OS-1 and EW-5 xenografts (27.5 ± 6.5%ID/g and 14.0 ± 2.8%ID/g, 3 days p.i., respectively). Most importantly, (111)In-R1507 uptake in IGF-1R positive, but unresponsive, EW-8 xenografts (6.5 ± 1.5%ID/g, 3 days p.i.) was similar to that of the IGF-1R-negative OS-33 tumor (5.5 ± 0.6%ID/g, 3 days p.i.). Uptake in normal tissues was low and nonspecific. Corresponding immuno-SPECT images clearly discriminated between high, modest, and nonresponding tumors by showing a homogeneous (OS-1), heterogeneous (EW-5), or nonspecific (EW-8 and OS-33) tumor uptake of (111)In-R1507. (111)In-R1507 immuno-SPECT is an excellent method to visualize membranous IGF-1R expression and target accessibility in vivo in human bone sarcoma xenografts and may serve as an independent marker to predict IGF-1R therapy (R1507) response in bone sarcoma patients.

Highlights of This Issue

Improving risk classification of children with neuroblastoma is an important challenge in pediatric oncology. Through one of the largest microRNA (miRNA) expression studies on cancer biopsies, De Preter and colleagues developed a 25-miRNA signature that identifies neuroblastoma patients with increased risk for adverse outcome. This classifier is independent of currently used risk factors and enables further patient stratification within the current highrisk subgroup. Importantly, the 25-miRNA signature performs equally well in archived formalin-fixed, paraffin-embedded material as it does in fresh frozen samples. Results were confirmed in 2 independent patient cohorts and indicate that use of the miRNA signature can substantially improve risk stratification of patients with neuroblastoma.The insulin-like growth factor 1 receptor (IGF-1R) is a potential new therapeutic target. Unfortunately, a suitable biomarker predictive for anti-IGF-1R therapy response is not available. Fleuren and colleagues investigated whether indium-111-labeled R1507 (111In-R1507) immuno-SPECT, a novel noninvasive, in vivo screening method to visualize membranous IGF-1R expression and accessibility, can be used to predict IGF-1R treatment response in Ewing sarcoma and osteosarcoma. This novel imaging technique could clearly distinguish among high, modest, and nonresponsive xenografts, whereas conventional techniques could not. This new technique may therefore enable the selection of patients susceptible to IGF-1R targeted therapy and monitor treatment response.Ever since its approval in 1976, dacarbazine has represented the standard of care for the treatment of patients with metastatic melanoma; however, only a minority of melanoma patients responds to dacarbazine treatment. This article presents clinical evidence that the combination of dacarbazine with the tumor-targeting immunocytokine L19-IL2 (a biopharmaceutical agent consisting of the human recombinant antibody L19, specific to the alternatively-spliced EDB domain of fibronectin, fused to human interleukin-2) is well tolerated in patients with metastatic melanoma and can induce long-lasting objective responses in a subset of patients.Examination of epidermal growth factor (EGFR) mutations is a diagnostic routine for treatment of lung cancer that involves the use of EGFR tyrosine kinase inhibitors. Because it is difficult to obtain primary lesions, especially in patients with progressive disease, a noninvasive procedure is desirable. Taniguchi and colleagues used BEAMing (beads, emulsion, amplification, and magnetics) to detect EGFR mutations in circulating tumor DNA. In addition to its high sensitivity, BEAMing can estimate the extent to which the activating mutation alleles have been converted into resistant alleles. Because BEAMing and next-generation sequencers are based on the same technologic principle, we can predict how next-generation sequencers will detect mutations in circulating tumor DNA based on the findings from this study.

Epidermal growth factor receptor and insulinlike growth factor 1 receptor expression predict poor survival in pancreatic ductal adenocarcinoma

The aim of this study was to evaluate the expression of epidermal growth factor receptor (EGFR) and insulinlike growth factor 1 receptor (IGF-1R) proteins and IGF-1R gene copy numbers in pancreatic ductal adenocarcinoma in relation to patients' characteristics and prognosis. Immunohistochemical staining was performed on formalin-fixed paraffin-embedded tissue derived from tumor specimens recovered during surgery. Slides were evaluated for membranous EGFR and IGF-1R staining using both the HercepTest and the semiquantitative H-score systems. Chromogenic in situ hybridization was performed to quantify IGF-1R gene copy number. The primary outcome was the association between EGFR expression, IGF-1R expression-in both neoplastic epithelial and stromal cells-or IGF-1R gene copy number and overall survival. Secondary outcomes included associations between EFGR and IGF-1R expression and pathologic variables. A total of 105 patients were included. EGFR expression was present in 30.4% of cases and was associated with lymph node metastasis (P = .038). IGF-1R was overexpressed in 53% of tumors and correlated with higher tumor grade (P = .033). High membranous expression of EGFR (P < .001) and/or IGF-1R (P = .004), the cytoplasmic detection of EGFR (P = .027), and high expression levels of IGF-1R in the tumoral stroma (P < .001) were all associated with shorter overall survival, being significantly better in patients who simultaneously do not express membranous EGFR or stromal IGF-1R. EGFR and IGF-1R expression, in neoplastic and stromal cells, seems to be an important prognostic factor.

Insulin-like growth factor-1 receptor expression in invasive ductal breast carcinoma is related to tumor characteristics and prognosis

10563 Background: The role of the insulin-like growth factor-1 receptor (IGF-1R) in the outcome of breast cancer is poorly understood. Therefore, we analyzed the prognostic value of IGF-1R expression in relation to clinically relevant tumor characteristics. Methods: Expression of IGF-1R, insulin receptor, estrogen receptor (ER), progesterone receptor (PR), HER2 receptor, epidermal growth factor receptor and phosphorylated Akt (pAkt) was determined on tissue microarrays comprising primary invasive ductal breast carcinoma samples of a consecutive series of 221 patients. Patients presented at the University Medical Center Groningen between 1996 and 2001. Patient records were reviewed for clinical and tumor parameters. Cytoplasmic and membranous IGF-1R staining were scored separately, as the relevance of IGF-1R cellular localization is yet unknown. Associations were tested by Chi-square, Log Rank test and Cox regression analysis. Results: Overall, IGF-1R expression was present in 79% of the tumors. Cytoplasmic staining was present in 69%, membranous in 52%, staining was combined cytoplasmic and membranous in 42% of the tumors. Cytoplasmic, but not membranous, IGF-1R staining was associated with expression of ER (p&lt;0.001), PR (p=0.001), pAkt (p=0.04), and increased relapse free and overall survival (RFS, p=0.01; OS, p=0.006). No correlations with other parameters were found. In ER/PR positive, HER2 negative tumors, but not in HER2 positive tumors, cytoplasmic IGF-1R expression correlated with increased RFS (p=0.002) and OS (p=0.001). In contrast, in triple negative tumors cytoplasmic and membranous expression of IGF-1R were both significantly associated with shorter RFS (p=0.02, p=0.04, resp.). In multivariate analysis, cytoplasmic IGF-1R expression was an independent prognostic factor for OS (HR 0.3, 95% CI 0.1–0.9, p=0.035). Conclusions: Cytoplasmic IGF-1R expression in invasive ductal breast carcinoma is associated with hormone receptor expression, phosphorylated Akt and good prognosis. Surprisingly, triple negative tumors expressing IGF-1R have a worse prognosis than those without. These results suggest that IGF-1R targeted therapy may have additional value in the treatment of triple negative tumors. No significant financial relationships to disclose.

Coexpression of IGF-1R and c-Src proteins in human pancreatic ductal adenocarcinoma.

Aberrant c-Src protein kinase activation has been identified as one of the molecular alterations involved in human pancreatic carcinogenesis. It has been postulated that c-Src may induce transformation by causing the overexpression of the insulinlike growth factor-1 receptor (IGF-1R) in pancreatic tumor cell lines. To further study the interaction between c-Src and IGF-1R proteins in human pancreatic cancer, we examined their coexpression in 47 human pancreatic ductal adenocarcinomas (PDA). Formalin-fixed, paraffin-embedded sections from 47 cases of PDA were stained using the immunohistochemical avidin-biotin-peroxidase method. We used an anti-human IGF-1R mouse monoclonal antibody (dilution 1:100 with antigen retrieval), and an anti-c-Src mouse monoclonal antibody (dilution 1:100 with antigen retrieval). The stains were semiquantitatively evaluated using the Allred score system, assessing intensity of stain and percentage of positive tumor cells. High cytoplasmic c-Src expression (Allred score 7-8) was seen in 33/47 (70%) tumors. In only 4 cases was c-Src either negative or low (Allred score 3). Strong and diffuse membranous IGF-1R stain (Allred score 7-8) was identified in 30/47 (64%) tumors. IGF-1R staining was low (Alled score 2-4) in 2 cases and negative in 1. Interestingly, in 40/47 (85%) cases c-Src and IGF-1R stains had similar scores. An inverse staining pattern was detected in only 6/47 (13%) tumors. Normal pancreatic ducts as well as areas of chronic pancreatitis were negative for IGF-1R. In conclusion, our data support the role of IGF-1R and c-Src in human pancreatic carcinogenesis; the coexpression of both these molecules may play an important role in transformation of pancreatic ductal cells.