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BACKGROUND: Hereditary renal cell carcinoma (RCC) is a complex and rapidly evolving topic as there is a growing body of literature regarding inherited syndromes and mutations associated with an increased risk of RCC. OBJECTIVES: We sought to systematically review 13 hereditary syndromes associated with RCC; von Hippel-Lindau Disease associated RCC (VHLRCC), BAP-1 associated clear cell RCC (BAPccRCC), Familial non-von Hippel Lindau clear cell RCC (FccRCC), Tuberous Sclerosis Complex associated RCC (TSCRCC), Birt-Hogg-Dub e ´ Syndrome associated RCC (BHDRCC), PTEN Hamartoma Tumor Syndrome associated RCC (PHTSRCC), Microphthalmia-associated Transcription Family translocation RCC (MiTFtRCC), RCC with Chromosome 6p Amplification (TFEBRCC), Autosomal Dominant Polycystic Kidney Disease associated RCC (ADPKDRCC), Hereditary Leiomyomatosis associated RCC (HLRCC), Succinate Dehydrogenase RCC (SDHRCC), Hereditary Papillary RCC (HPRCC), and ALK-Rearrangement RCC (ALKRCC). RESULTS: Hereditary RCC is generally associated with an early age of onset, multifocal and/or bilateral lesions, and aggressive disease course. VHLRCC, BAPccRCC, FccRCC, and certain mutations resulting in SDHRCC are associated with clear cell RCC (ccRCC). HPRCC is associated with Type 1 papillary RCC. HLRCC is associated with type 2 papillary RCC. BHDRCC is associated with Chromophobe RCC. TSCRCC, PHTSRCC, MiTFtRCC, TFEBRCC, ADPKDRCC, certain SDHRCC and ALKRCC have variable histology. CONCLUSIONS: There has been tremendous advancement in our understanding of the pathophysiology of hereditary RCC. Ongoing research will refine our understanding of hereditary RCC and its therapeutic targets.

Tibia xenograft histology of lapatinib, and cetuximab+trastuzumab treated animals.

Activation of the EGF receptors EGFR (ErbB1) and HER2 (ErbB2) drives the progression of multiple cancer types through complex mechanisms that are still not fully understood. In this study, we report that HER2 expression is elevated in bone metastases of prostate cancer independently of gene amplification. An examination of HER2 and NF-κB receptor (RANK) coexpression revealed increased levels of both proteins in aggressive prostate tumors and metastatic deposits. Inhibiting HER2 expression in bone tumor xenografts reduced proliferation and RANK expression while maintaining EGFR expression. In examining the role of EGFR in tumor-initiating cells (TIC), we found that EGFR expression was required for primary and secondary sphere formation of prostate cancer cells. EGFR expression was also observed in circulating tumor cells (CTC) during prostate cancer metastasis. Dual inhibition of HER2 and EGFR resulted in significant inhibition of tumor xenograft growth, further supporting the significance of these receptors in prostate cancer progression. Overall, our results indicate that EGFR promotes survival of prostate TIC and CTC that metastasize to bone, whereas HER2 supports the growth of prostate cancer cells once they are established at metastatic sites. Cancer Res; 77(1); 74–85. ©2016 AACR.

Supplemental materials, methods and figure legends.

PDF file - 491K, Supplementary Figure 3. Effect of trastazumab on stem cell marker expression. Supplementary Figure 2. Trastuzumab inhibits tertiary tumorsphere formation in luminal cell lines. Supplementary Figure 1. Representative FACS analysis demonstrating an overlap between HER2 expression and ALDH activity. Supplementary Figure 4. Trastuzumab treatment or HER2 gene knockdown reduces tumorsphere formation of MCF7 cells. Supplementary Figure 5. Rank mediated upreglation of HER2 expression in MCF7 cells. Supplementary Figure 6. Elevated HER2 expression in bone metastasis compared to matched primary luminal tumors is not due to HER2 gene amplification. Supplemental Figure 7. No significant differences in HER2 protein expression were found in matched primary tumors and bone metastasis in women with HER-positive breast cancer.

The COVID-19 pandemic has had a distinct spatiotemporal pattern in the United States. Patients with cancer are at higher risk of severe complications from COVID-19, but it is not well known whether COVID-19 outcomes in this patient population were associated with geography.To quantify spatiotemporal variation in COVID-19 outcomes among patients with cancer.This registry-based retrospective cohort study included patients with a historical diagnosis of invasive malignant neoplasm and laboratory-confirmed SARS-CoV-2 infection between March and November 2020. Data were collected from cancer care delivery centers in the United States.Patient residence was categorized into 9 US census divisions. Cancer center characteristics included academic or community classification, rural-urban continuum code (RUCC), and social vulnerability index.The primary outcome was 30-day all-cause mortality. The secondary composite outcome consisted of receipt of mechanical ventilation, intensive care unit admission, and all-cause death. Multilevel mixed-effects models estimated associations of center-level and census division-level exposures with outcomes after adjustment for patient-level risk factors and quantified variation in adjusted outcomes across centers, census divisions, and calendar time.Data for 4749 patients (median [IQR] age, 66 [56-76] years; 2439 [51.4%] female individuals, 1079 [22.7%] non-Hispanic Black individuals, and 690 [14.5%] Hispanic individuals) were reported from 83 centers in the Northeast (1564 patients [32.9%]), Midwest (1638 [34.5%]), South (894 [18.8%]), and West (653 [13.8%]). After adjustment for patient characteristics, including month of COVID-19 diagnosis, estimated 30-day mortality rates ranged from 5.2% to 26.6% across centers. Patients from centers located in metropolitan areas with population less than 250 000 (RUCC 3) had lower odds of 30-day mortality compared with patients from centers in metropolitan areas with population at least 1 million (RUCC 1) (adjusted odds ratio [aOR], 0.31; 95% CI, 0.11-0.84). The type of center was not significantly associated with primary or secondary outcomes. There were no statistically significant differences in outcome rates across the 9 census divisions, but adjusted mortality rates significantly improved over time (eg, September to November vs March to May: aOR, 0.32; 95% CI, 0.17-0.58).In this registry-based cohort study, significant differences in COVID-19 outcomes across US census divisions were not observed. However, substantial heterogeneity in COVID-19 outcomes across cancer care delivery centers was found. Attention to implementing standardized guidelines for the care of patients with cancer and COVID-19 could improve outcomes for these vulnerable patients.

Key Points Question Given the higher COVID-19–related mortality rate observed among men than among women, is androgen deprivation therapy associated with decreased rate of 30-day mortality from COVID-19 among patients with prostate cancer? Findings In this cohort study of 1106 patients, no statistically significant difference was found in the rates of all cause 30-day mortality following COVID-19 infection among men with prostate cancer receiving androgen deprivation therapy (15%) vs those not receiving androgen deprivation therapy (14%). Meaning The findings of this cohort study do not support an association between androgen deprivation therapy and 30-day mortality among patients with COVID-19 infection., Importance Androgen deprivation therapy (ADT) has been theorized to decrease the severity of SARS-CoV-2 infection in patients with prostate cancer owing to a potential decrease in the tissue-based expression of the SARS-CoV-2 coreceptor transmembrane protease, serine 2 (TMPRSS2). Objective To examine whether ADT is associated with a decreased rate of 30-day mortality from SARS-CoV-2 infection among patients with prostate cancer. Design, Setting, and Participants This cohort study analyzed patient data recorded in the COVID-19 and Cancer Consortium registry between March 17, 2020, and February 11, 2021. The consortium maintains a centralized multi-institution registry of patients with a current or past diagnosis of cancer who developed COVID-19. Data were collected and managed using REDCap software hosted at Vanderbilt University Medical Center in Nashville, Tennessee. Initially, 1228 patients aged 18 years or older with prostate cancer listed as their primary malignant neoplasm were included; 122 patients with a second malignant neoplasm, insufficient follow-up, or low-quality data were excluded. Propensity matching was performed using the nearest-neighbor method with a 1:3 ratio of treated units to control units, adjusted for age, body mass index, race and ethnicity, Eastern Cooperative Oncology Group performance status score, smoking status, comorbidities (cardiovascular, pulmonary, kidney disease, and diabetes), cancer status, baseline steroid use, COVID-19 treatment, and presence of metastatic disease. Exposures Androgen deprivation therapy use was defined as prior bilateral orchiectomy or pharmacologic ADT administered within the prior 3 months of presentation with COVID-19. Main Outcomes and Measures The primary outcome was the rate of all-cause 30-day mortality after COVID-19 diagnosis for patients receiving ADT compared with patients not receiving ADT after propensity matching. Results After exclusions, 1106 patients with prostate cancer (before propensity score matching: median age, 73 years [IQR, 65-79 years]; 561 (51%) self-identified as non-Hispanic White) were included for analysis. Of these patients, 477 were included for propensity score matching (169 who received ADT and 308 who did not receive ADT). After propensity matching, there was no significant difference in the primary end point of the rate of all-cause 30-day mortality (OR, 0.77; 95% CI, 0.42-1.42). Conclusions and Relevance Findings from this cohort study suggest that ADT use was not associated with decreased mortality from SARS-CoV-2 infection. However, large ongoing clinical trials will provide further evidence on the role of ADT or other androgen-targeted therapies in reducing COVID-19 infection severity., This cohort study using data from the COVID-19 and Cancer Consortium registry examines whether androgen deprivation therapy is associated with decreased rates of mortality within 30 days of COVID-19 diagnosis among patients with prostate cancer.

When the COVID-19 pandemic began, formal frameworks to collect data about affected patients were lacking. The COVID-19 and Cancer Consortium (CCC19) was formed to collect granular data on patients with cancer and COVID-19 at scale and as rapidly as possible. CCC19 has grown from five initial institutions to 125 institutions with >400 collaborators. More than 5,000 cases with complete baseline data have been accrued. Future directions include increased electronic health record integration for direct data ingestion, expansion to additional domestic and international sites, more intentional patient involvement, and granular analyses of still-unanswered questions related to cancer subtypes and treatments.

Background: The impact of disease characteristics and androgen deprivation therapy (ADT) or other treatments for prostate cancer (PC) on severity of infection with Covid-19 has not been elucidated. We report results from our PC patients (pts) with Covid-19 in our registry of Covid-19 treated cancer patients at the Cleveland Clinic Foundation. Methods: We performed a retrospective analysis of PC pts who tested positive for Covid-19 between 3/16/2020 and 5/21/2020 at the Cleveland Clinic. Additional information including prostate specific antigen (PSA), Gleason score, disease extent, and current treatment were also obtained. Severe Covid-19 infection was defined as any pt requiring hospitalization, ICU care, and/or death. PSA values from prior to Covid-19 infection or first available after Covid-19 infected were collected. Analysis was carried out with Fisher’s exact test and Wilcoxon rank sum test, as applicable, and overall survival (OS) by log rank test. Results: A total of 54 pts with prostate cancer that tested positive for Covid-19 were identified, of which 4 were receiving active treatment (2 with metastatic disease and 2 with localized disease). Of the 2 pts with metastatic disease, 1 was on docetaxel with ADT and other on abiraterone/prednisone with ADT. Of the 2 pts with localized disease, 1 was on ADT and bicalutamide and other on ADT alone. A total of 40 patients had severe Covid-19 disease. There was no correlation with ADT and Covid-19 disease severity (p=0.67). There were 22 pts with Gleason 6, 20 pts with Gleason 7, 6 pts with Gleason 8, 4 pts with Gleason 9, 1 pt with Gleason 10, and 1 pt with Gleason unknown PC. There was no correlation between absolute (p=0.21) or divided (p=0.65) Gleason score with disease severity. There were 4 pts with metastatic disease and 46 with localized disease and no correlation was seen with extent of disease and Covid-19 severity (p>0.99). Fifty pts had PSA data available, and there was no correlation of PSA with Covid-19 disease severity (p=0.28). The mortality from Covid-19 was 26% (14 out of 54 pts) in our cohort. Out of the 14 pts who died, 2 were on active treatment that included ADT. There was no association between Gleason score (p=0.2649), extent of disease (p=0.9642), or treatment (p=0.5998) and OS. Conclusions: In our registry of Covid-19 treated cancer patients, we did not see any correlation between PC disease-risk factors and treatment with Covid-19 severity. While the results are limited by small patient population, they provide valuable information that PC treatment did not affect severity of Covid-19. Citation Format: Scott J. Dawsey, Nathan A. Pennell, Christopher Lemmon, Amanda Nizam, Wei Wei, Timothy D. Gilligan, Moshe C. Ornstein, Shilpa Gupta. Prostate cancer and COVID-19 outcomes: Results from the Cleveland Clinic registry of COVID-19 and cancer patients [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2021 Feb 3-5. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(6_Suppl):Abstract nr P25.

39 Background: The presence of progressing cancer, male sex and advanced age have been shown to increase the severity of coronavirus disease 2019 (COVID-19). Given that the androgen regulated gene TMPRSS2 has been implicated in SARS-CoV-2 viral entry, we hypothesized that ADT may improve COVID-19 outcomes. This analysis evaluated clinical outcomes of pts with PCa with concurrent SARS-CoV-2 infection and investigated the impact of ADT on occurrence of severe-COVID-19 and mortality. Methods: Data was obtained via the COVID-19 and Cancer Consortium (CCC19), a multicenter registry including >120 cancer centers with de-identified data from pts with COVID-19 and cancer. Men with confirmed SARS-CoV-2 infection and a primary diagnosis of prostate cancer were included: data cutoff of July 31, 2020. The primary endpoint was the development of severe-COVID-19 (death, ICU admission, or mechanical ventilation) among pts on ADT vs. those not on ADT at time of COVID-19 infection. Secondary endpoints included 30-day mortality based on ADT use. Mortality and development of severe-COVID-19 were assessed in Pts grouped by therapy: 1st generation androgen receptor inhibitor (ARI-1), 2nd generation ARI (darolutamide, enzalutamide, apalutamide, ARI-2), abiraterone/prednisone, and chemotherapy. Propensity score matching was utilized. Logistic regression was utilized to adjust for age, ECOG PS, comorbidities, and race. Results: 589 pts were included; median follow-up was 42 days (IQR 25-90) and 62% (363/589) were hospitalized. Severe-COVID-19 developed in 28% of pts and the all-cause 30-day mortality rate was 19%. There was no significant difference in the development of severe-COVID-19 or 30-day mortality between Pts on ADT vs not on ADT, whether using descriptive statistics with the entire population or using the propensity score matched population (Table). Among the descriptive population, the numerical rates of severe-COVID-19 and mortality were lowest in Pts receiving ARI-2, but sample size was low. Conclusions: The overall 30-day mortality rate and percentage developing severe-COVID-19 were high. There was no statistical difference in the development of severe-COVID-19 or mortality based on receipt of ADT; however, this analysis is limited by the retrospective nature and small N after propensity-matching. [Table: see text]

417 Background: There is emerging evidence that patients (pts) treated with immune-checkpoint inhibitors (ICIs) may have a poorer response in the setting of antibiotic use (ABx), possibly due to negative impact on gut microbiota. Our group previously demonstrated that Abx use 60 days before or 60 days in mUC pts after initiation of ICI therapy did not have a significant impact on overall survival (OS) in real-world setting. We now studied the effect of Abx use within 30 days of initiation of ICI on OS in the same cohort of mUC patients. Methods: We performed a retrospective analysis of adult pts with mUC treated at the Cleveland Clinic between 2015 and 2020. Pts included in the study received at least 2 cycles of ICI therapy with either atezolizumab or pembrolizumab. Statistical analysis included study of OS in weeks using the Kaplan Meier method and rank log test, Fischer’s exact test, and Kruskal-Wallis test. Results: A total of 115 pts that received ICI therapy were included. 57 pts received atezolizumab and 58 pts received pembrolizumab. 38 pts (33%) received antibiotics and 77pts (67%) did not. The most commonly used Abx used were Cephalosporins (27%), Penicillins/Carbapenems (25%), Flouroquinolones (23%), and Bactrim (11%). 18 pts received Abx within 30 days before initiation of ICI, 13 pts received Abx within 30 days after initiation of ICI, and 7 pts received Abx before and after initiation of ICI. There was no statistical difference in OS in the group of pts that received Abx 30 days prior to initiation of ICI with median OS of 5.95 months (95% CI 3.22-13.67, p=0.0695) compared to 12.39 months (95% CI 10.09 – 18.6) in those who did not receive Abx. Similarly, there was no statistical difference in OS in the group of pts that received Abx 30 days after initiation of ICI with median OS of 5.09 months (95% CI 2.53-22.57, p=0.2339) compared to 12.02 months (95% CI 8.6`-17.02 Table). Conclusions: In our single institution study of mUC patients receiving ICI treatment, the use of Abx did not affect the OS. Although there was a trend for better OS seen in pts who did not receive Abx, it was not statistically significant (Table). Due to the limitations of a retrospective analysis and small sample size, further studies are warranted taking into account other factors that may affect gut microbiota in mUC pts. [Table: see text]

493 Background: Factors affecting response to immune checkpoint inhibitor (ICI) are poorly understood in metastatic urothelial carcinoma (mUC). While tumor PD-L1 status is often used as a biomarker, it is not always predictive and ICI also benefits patients (pts) with PD-L1 negative tumors. Therefore, we sought to study the effect of some host and disease-related variables like gender, ethnicity, body mass index (BMI), platelet to lymphocyte ratio (PLR), and neutrophil to lymphocyte ration (NLR) on objective responses in pts with mUC treated with ICI. Methods: We performed a retrospective analysis of adult pts with mUC who received ≥2 cycles of ICI (pembrolizumab or atezolizumab) at the Cleveland Clinic from 2015 to 2020. Tumor and host-related factors evaluated are listed in the table below. We focused on meaningful treatment response, so only partial response (PR) and complete response (CR) were included as responders, while stable disease (SD) and progressive disease (PD) were counted as non-responders. Analysis was carried out with Fisher’s exact test and Wilcoxon rank sum test as applicable. Results: A total of 124 pts with mUC that received ICI were included. Gender did not correlate with response (p>0.99) or duration of response (p=0.37). Ethnicity did not correlation with response (p=0.78) or duration of response (p=0.24). Histology (UC, mixed variant histology or non UC) did not correlate with response (p=0.13) or duration of response (p=0.87). Location of primary malignancy (upper tract versus lower tract) did not correlate with response (p>0.99) or duration of response (p=0.36). BMI (p=0.23), PLR (p=0.9), and NLR (p=0.9) did not correlate with objective response. Conclusions: In our single center experience of pts with mUC treated with ICI, host factors (gender, ethnicity, histology, BMI, NLR, PLR) and location of primary tumor did not correlate with treatment response or duration of response. Although there were few African Americans represented in this study as commonly seen for minority representation, it is encouraging that no significant differences in responses were observed. The role of BMI and gender in response to ICI treatment in mUC was not observed. While there are limitations of a retrospective analysis, our study warrants investigation into predictive factors of response to ICI in mUC. Ongoing work integrating radiomics and pathomics will further our understanding and develop potential predictive biomarkers of response to ICI in mUC. [Table: see text]

BACKGROUND Epidermal growth factor receptor overexpression is associated with poor outcomes in urothelial carcinoma (UC). Cetuximab (CTX) exhibited an antitumor effect in in vivo UC models. The efficacy of gemcitabine/cisplatin (GC) with or without CTX in patients with advanced UC was evaluated. METHODS Patients with advanced UC, measurable disease, and adequate organ function were randomized 1:2 to cisplatin (70 mg/m2) on day 1 plus gemcitabine (1000 mg/m2) on days 1, 8, and 15 (arm A) or GC plus CTX (500 mg/m2) on days 1 and 15 (arm B). The primary endpoint was the overall response rate. The secondary endpoints were the response duration, safety, progression-free survival, overall survival, determination of whether or not CTX sensitized nonresponders to GC, and exploratory biomarker analysis. The accrual targets were 27 and 54 patients for the 2 arms, respectively. The overall response rate was reported by arm with binomial confidence intervals (CIs). Kaplan-Meier methods were used for time-to-event endpoints. RESULTS Eighty-eight eligible patients were randomized; 87 were toxicity-evaluable, and 85 were response-evaluable. The overall response rates were 57.1% for arm A (95% CI = 37%-76%) and 61.4% for arm B (95% CI = 48%-74%). The median progression-free survival times were 8.5 months for arm A (95% CI = 5.7-10.4 months) and 7.6 months for arm B (95% CI = 6.1-8.7 months). The median overall survival times were 17.4 months for arm A (95% CI = 12.8 months to unreached) and 14.3 months for arm B (95% CI = 11.6-22.2 months). The most common grade 3/grade 4 adverse events in both arms were myelosuppression and nausea. Thromboembolism, acneiform rash, fatigue, pain, hypersensitivity reactions, elevated transaminases, hyponatremia, and hypomagnesemia were more common in arm B; 3 grade 5 adverse events occurred in arm B. The presence of primary disease significantly correlated with thromboembolism. An increased soluble E-cadherin level after cycle 2 correlated with a higher risk of death. CONCLUSIONS GC plus CTX was feasible but was associated with more adverse events and no improvements in outcomes. Cancer 2014;120:2684–2693. © 2014 American Cancer Society.

Although current breast cancer treatment guidelines limit the use of HER2-blocking agents to tumors with HER2 gene amplification, recent retrospective analyses suggest that a wider group of patients may benefit from this therapy. Using breast cancer cell lines, mouse xenograft models and matched human primary and metastatic tissues, we show that HER2 is selectively expressed in and regulates self-renewal of the cancer stem cell (CSC) population in estrogen receptor-positive (ER+), HER2− luminal breast cancers. Although trastuzumab had no effects on the growth of established luminal breast cancer mouse xenografts, administration after tumor inoculation blocked subsequent tumor growth. HER2 expression is increased in luminal tumors grown in mouse bone xenografts, as well as in bone metastases from patients with breast cancer as compared with matched primary tumors. Furthermore, this increase in HER2 protein expression was not due to gene amplification but rather was mediated by receptor activator of NF-κB (RANK)-ligand in the bone microenvironment. These studies suggest that the clinical efficacy of adjuvant trastuzumab may relate to the ability of this agent to target the CSC population in a process that does not require HER2 gene amplification. Furthermore, these studies support a CSC model in which maximal clinical benefit is achieved when CSC targeting agents are administered in the adjuvant setting. Cancer Res; 73(5); 1635–46. ©2012 AACR.

Activation of the EGF receptors EGFR (ErbB1) and HER2 (ErbB2) drives the progression of multiple cancer types through complex mechanisms that are still not fully understood. In this study, we report that HER2 expression is elevated in bone metastases of prostate cancer independently of gene amplification. An examination of HER2 and NF-κB receptor (RANK) coexpression revealed increased levels of both proteins in aggressive prostate tumors and metastatic deposits. Inhibiting HER2 expression in bone tumor xenografts reduced proliferation and RANK expression while maintaining EGFR expression. In examining the role of EGFR in tumor-initiating cells (TIC), we found that EGFR expression was required for primary and secondary sphere formation of prostate cancer cells. EGFR expression was also observed in circulating tumor cells (CTC) during prostate cancer metastasis. Dual inhibition of HER2 and EGFR resulted in significant inhibition of tumor xenograft growth, further supporting the significance of these receptors in prostate cancer progression. Overall, our results indicate that EGFR promotes survival of prostate TIC and CTC that metastasize to bone, whereas HER2 supports the growth of prostate cancer cells once they are established at metastatic sites. Cancer Res; 77(1); 74–85. ©2016 AACR.

A clinical appraisal and clinical application of Koch KL, Karafin MS, Simpson P, Field JJ. Intensive management of high-utilizing adults with sickle cell disease lowers admissions. Am J Hematol. 2015 Jan;90(3):215-219. doi:10.1002/ajh.23912

4506 Background: In UCpts EGFR over-expression correlates with high grade, stage, progression, short survival. Preclinical data show enhanced anti-tumor effect with CET + chemotherapy (CT). In several solid tumors CET added to CT improved survival. CET is hypothesized to improve UC response to CT. Methods: Pts with ECOG PS 0-2, adequate organ function, unresectable, locally recurrent or metastatic UC were stratified by disease state and randomized (1:2) to C 70mg/m2 d1, G 1000mg/m2 d1, d8, d15 (Arm A) or same CT + CET 500mg/m2 d1, d15 (Arm B) q28 days. Due to high thromboembolic events rate in Arm B, G dose was reduced to 800 mg/m2. 6 GC cycles were planned. Arm A pts progressing after 2 GC cycles had CET added. Arm B pts were to continue on CET monotherapy after 4-6 CT cycles. Imaging was q8 weeks. Primary endpoint: RECIST response rate (RR); secondary: safety, PFS, survival. Since E-cadherin impacts UC response to CET in vitro, serum level (sE-cad) was assessed at baseline, after 2 cycles, end of CT and at progression. With 1-stage design, assuming RR 50% (Arm A) and at least 65% (Arm B), planned sample size was 27/54 pts. RR improvement of 5% has 81% probability if true difference is 15%. Results: 88 pts were eligible and randomized, Arm A/B: median age 66/61 years; bladder primary 71.4%/77.2%; metastatic disease 92.9%/89.5%, median CT cycles number 6/5. 28 Arm B pts continued CET (median 3 cycles, range 1-29); 1 Arm A pt had CET added. Most common G3/4 adverse events (AEs) (Arm A, B): neutropenia (34.5%, 33.9%), anemia (10.3%, 5.1%), thrombocytopenia (27.6%, 22%), thromboembolism (6.9%, 18.6%), hyponatremia (3.5%, 10.2%); Arm B only: rash 28.8%, fatigue 11.9%, hypomagnesemia 11.9% and 2 deaths. 84 pts were response evaluable (see table below). sE-cad did not correlate with outcome. sE-cad increased in Arm A, but decreased in Arm B over time. Conclusions: GC/CET was feasible with no outcome improvement but higher AEs. sE-cad did not correlate with outcome. Decreased sE-cad in Arm B suggests potential EGFR-mediated E-cad proteolysis. [Table: see text]

HER-2 is a receptor tyrosine kinase that has been shown to be over expressed in 30% of human primary breast cancers (BrCa). Our animal model data and human bone met data, which we present here, indicates that HER-2 up-regulation is required for breast cancer cells to grow in and remodel bone. However, most bone metastases from BrCa will arise from a primary diagnosis of ER positive/HER-2 negative disease. We found that MCF-7 cells, an ER positive/HER-2 negative breast cancer model, formed tumors in bone that had up-regulated HER-2 protein expression. In order to directly test whether or not HER-2 expression has an affect on bone metastasis, we engineered a knock down of the HER-2 receptor in MCF-7 cells by utilizing a lentivirus plasmid containing the shRNA to the HER-2 receptor. Both the shRNA HER-2 knock-down and the vector-only control expressed the Green Fluorescence Protein (GFP) and puromycin resistance for plasmid selection. Our engineered MCF-7 control cells (shVector alone) or the HER-2 knock-down (shHER-2) were injected into the tibia of SCID mice. We found that both the vector-only and HER-2 knock-down cells grew tumors in mouse tibia. Anti-HER-2 immunohistochemical (IHC) analysis showed that the HER-2 protein was re-expressed in the knock down cells in tumors formed in tibiae. Additionally, we found that in eight patients with breast cancer bone metastasis, 100% of these cases contained a significant expression of HER-2 positive cells by IHC. As confirmation of our mouse studies, we found that all of the human bone biopsies obtained from ER positive/HER-2 negative disease were up-regulated for HER-2 in the bone microenvironment. Concomitant with our human data, MCF-7 cells required exogenous estrogen to form tumors in mammary fat pads and did not require exogenous estrogen to form tumors in bone. Therefore, we believe that BrCa cells can change, up-regulate protein expression of HER-2, and become estrogen independent in the bone microenvironment. It may be that these women could benefit from intervention with agents against HER-2. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 482.