Tracy W. Hilton

Evaluation of B7-H3 Expression as a Biomarker of Biochemical Recurrence After Salvage Radiation Therapy for Recurrent Prostate Cancer

PURPOSE The ability to predict which men will experience biochemical recurrence (BCR) after salvage radiation therapy (SRT) for recurrent prostate cancer (PCa) remains less than optimal. Related to this, novel targets for adjuvant therapies are also lacking. Here, we evaluate the association of B7-H3 expression in primary PCa tumors and BCR after SRT. METHODS AND MATERIALS We identified 148 patients who received SRT between July 1987 and July 2003. Expression of B7-H3 in primary PCa tumors was detected using a monoclonal antibody. The staining levels were quantified via visual assessment and categorized as weak, moderate, or marked. Relative risks (RRs) and 95% confidence intervals (CIs) from Cox proportional hazards models were used to examine the association between B7-H3 staining and BCR. RESULTS With a median follow-up of 6.2 years (minimum, 0.6; maximum, 14.7), 78 patients (53%) experienced BCR. In single-variable analysis, there was evidence of an increased risk of BCR for patients with moderate (RR, 2.25; 95% CI, 1.24-4.09, p = 0.008) and marked (RR, 4.40, 95% CI, 2.29-8.43, p < 0.001) B7-H3 staining compared with weak staining. This evidence remained, albeit weaker, after adjustment for additional clinicopathologic covariates (RR, 1.82, p = 0.068 [moderate vs. weak]; RR, 2.87, p = 0.003 [marked vs. weak]). CONCLUSION This is the first report that higher tumor B7-H3 staining in primary PCa tumors is associated with increased risk of BCR after SRT. Future studies involving larger numbers of patients are required to validate these results and also to explore possible means of targeting B7-H3 in an adjuvant setting.

Higher expression of topoisomerase II alpha is an independent marker of increased risk of cancer-specific death in patients with clear cell renal cell carcinoma.

BACKGROUND Tumor-based biomarkers of outcome for patients with clear cell renal cell carcinoma (ccRCC) remain limited, especially for those with low-risk disease. Type IIa topoisomerase (TOPOIIa) is a well-known biomarker of DNA replication and a target for antineoplastic agents, but it has not been evaluated as a biomarker of ccRCC outcome. OBJECTIVE To evaluate the association of TOPOIIa expression in ccRCC and risk of cancer-specific death following surgery. DESIGN, SETTING, AND PARTICIPANTS Two independent cohort studies were studied in tertiary referral urology practices in the United States. We identified cohorts of 1378 (analytic) and 279 (validation) patients who underwent nephrectomy for clinically localized ccRCC and had paraffin tumor tissue available. TOPOIIa expression was assessed using immunohistochemistry and scored as the number of positive cells per square millimeter. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Our primary end point was cancer-specific survival (CSS). We evaluated TOPOIIa expression as a continuous variable and dichotomized as low versus high. For associations with CSS, we used Kaplan-Meier curves and Cox regression models. RESULTS AND LIMITATIONS In both cohorts, patients who had high TOPOIIa expression were approximately three times more likely to experience ccRCC death than those with low expression (hazard ratio [HR]: 2.75; 95% confidence interval [CI], 2.12-3.56; p=1.79E-14 and HR: 3.45; 95% CI, 1.34-8.88; p=0.0104, respectively). Multivariable adjustment for pathologic features of aggressiveness did not explain these associations, and stratified analysis suggests that the association is more pronounced among patients with low-risk disease as defined by the Mayo Clinic SSIGN (stage, size, grade, and necrosis) score. CONCLUSIONS Higher TOPOIIa expression is independently associated with increased risk of cancer death among patients undergoing surgery for ccRCC, and the prognostic value is pronounced among patients with low-risk disease. Evaluation of TOPOIIa in ccRCC provides the opportunity to help guide postsurgical surveillance for ccRCC patients as well as inform the design of more targeted clinical trials and novel treatment strategies.

Evaluation of Ki-67 Staining Levels as an Independent Biomarker of Biochemical Recurrence After Salvage Radiation Therapy for Prostate Cancer

PURPOSE We recently published a scoring algorithm to predict biochemical recurrence (BCR) after salvage radiation therapy (SRT) for prostate cancer. Currently, this algorithm is based on clinicopathologic features and does not incorporate information from tumor-based biomarkers. Herein, we evaluate the ability of Ki-67 staining in primary prostate cancer to independently aid in the prediction of BCR among men undergoing SRT. METHODS AND MATERIALS We identified 147 patients who were treated with SRT between July 1987 and July 2003 at Mayo Clinic (Rochester, MN; Jacksonville, FL; Scottsdale, AZ). Staining levels of Ki-67 in primary tumor samples were detected by use of a monoclonal antibody and quantified by use of a computer-assisted method. We used Cox proportional hazards models to examine the association of Ki-67 staining and BCR in single-variable models and after multivariable adjustment. RESULTS The risk of BCR for men with tumors in the highest tertile of Ki-67 staining is approximately two times that for men with tumors in the lower two tertiles (relative risk, 2.02; 95% confidence interval, 1.23-3.32; p = 0.005) after adjustment for the features in our original scoring algorithm. Further adjustment for additional covariates did not attenuate this association. Evidence from concordance index values supports that Ki-67 staining adds to the predictive ability of our existing scoring algorithm. CONCLUSIONS Our data suggest that higher levels of Ki-67 staining are associated with increased risk of BCR after SRT, independent of existing clinicopathologic covariates. Future studies involving larger numbers of patients are required to validate these results and also explore possible means of combining this biomarker with existing prognostic tools.

Clear Cell Type A and B Molecular Subtypes in Metastatic Clear Cell Renal Cell Carcinoma: Tumor Heterogeneity and Aggressiveness

BACKGROUND Intratumor molecular heterogeneity has been reported for primary clear cell renal cell carcinoma (ccRCC) tumors; however, heterogeneity in metastatic ccRCC tumors has not been explored. OBJECTIVE To evaluate intra- and intertumor molecular heterogeneity in resected metastatic ccRCC tumors. DESIGN, SETTING, AND PARTICIPANTS We identified 111 patients who had tissue available from their primary tumor and at least one metastasis. ClearCode34 genes were analyzed for all tumors. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Primary and metastatic tumors were classified as clear cell type A (ccA) or B (ccB) subtypes. Logistic and Cox regression were used to evaluate associations with pathologic features and survival. RESULTS AND LIMITATIONS Intratumor heterogeneity of ccA/ccB subtypes was observed in 22% (95% confidence interval [CI] 3-60%) of metastatic tumors. Subtype differed across longitudinal metastatic tumors from the same patient in 23% (95% CI 10-42%) of patients and across patient-matched primary and metastatic tumors in 43% (95% CI 32-55%) of patients. Association of subtype with survival was validated in primary ccRCC tumors. The ccA/ccB subtype in metastatic tumors was significantly associated with metastatic tumor location, metastatic tumor grade, and presence of tumor necrosis. A limitation of this study is that we only analyzed patients who had both a nephrectomy and metastasectomy. CONCLUSIONS Approximately one quarter of metastatic tumors displayed intratumor heterogeneity; a similar rate of heterogeneity was observed across longitudinal metastatic tumors. Thus, for biomarker studies it is likely adequate to analyze a single sample per metastatic tumor provided that pathologic review is incorporated into the study design. Subtypes across patient-matched primary and metastatic tumors differed 43% of the time, suggesting that the primary tumor is not a good surrogate for the metastatic tumor. PATIENT SUMMARY Primary and secondary/metastatic cancers of the kidney differed in nearly one half of ccRCC patients. The pattern of this relationship may affect tumor growth and the most suitable treatment.

Evaluation of MDM2, p16, and p53 staining levels as biomarkers of biochemical recurrence following salvage radiation therapy for recurrent prostate cancer.

The selection of appropriate candidates for salvage radiation therapy (SRT) to address a rising PSA following radical prostatectomy remains challenging. Herein, we provide the first evaluation of the ability of staining levels of the tumor based biomarkers MDM2, p16, and p53 to aid in prediction of biochemical recurrence (BCR) among men undergoing SRT for recurrent prostate cancer.

Differential gene expression profiling of matched primary renal cell carcinoma and metastases reveals upregulation of extracellular matrix genes.

Background The majority of renal cell carcinoma (RCC) studies analyze primary tumors, and the corresponding results are extrapolated to metastatic RCC tumors. However, it is unknown if gene expression profiles from primary RCC tumors differs from patient-matched metastatic tumors. Thus, we sought to identify differentially expressed genes between patient-matched primary and metastatic RCC tumors in order to understand the molecular mechanisms underlying the development of RCC metastases. Patients and methods We compared gene expression profiles between patient-matched primary and metastatic RCC tumors using a two-stage design. First, we used Affymetrix microarrays on 15 pairs of primary RCC [14 clear cell RCC (ccRCC), 1 papillary] tumors and patient-matched pulmonary metastases. Second, we used a custom NanoString panel to validate seven candidate genes in an independent cohort of 114 ccRCC patients. Differential gene expression was evaluated using a mixed effect linear model; a random effect denoting patient was included to account for the paired data. Third, The Cancer Genome Atlas (TCGA) data were used to evaluate associations with metastasis-free and overall survival in primary ccRCC tumors. Results We identified and validated up regulation of seven genes functionally involved in the formation of the extracellular matrix (ECM): DCN, SLIT2, LUM, LAMA2, ADAMTS12, CEACAM6 and LMO3. In primary ccRCC, CEACAM6 and LUM were significantly associated with metastasis-free and overall survival (P < 0.01). Conclusions We evaluated gene expression profiles using the largest set to date, to our knowledge, of patient-matched primary and metastatic ccRCC tumors and identified up regulation of ECM genes in metastases. Our study implicates up regulation of ECM genes as a critical molecular event leading to visceral, bone and soft tissue metastases in ccRCC.

An Examination of the Association between FOXA1 Staining Level and Biochemical Recurrence following Salvage Radiation Therapy for Recurrent Prostate Cancer.

Background Standardly collected clinical and pathological patient information has demonstrated only moderate ability to predict risk of biochemical recurrence (BCR) of prostate cancer in men undergoing salvage radiation therapy (SRT) for a rising PSA after radical prostatectomy (RP). Although elevated FOXA1 staining has been associated with poor patient outcomes following RP, it has not been studied in the specific setting of SRT after RP. The aim of this study was to evaluate the association between FOXA1 staining level and BCR after SRT for recurrent prostate cancer. Methods A total of 141 men who underwent SRT at our institution were included. FOXA1 staining levels in primary tumor samples were detected using immunohistochemistry. FOXA1 staining percentage and intensity were measured and multiplied together to obtain a FOXA1 H-score (range 0–12) which was our primary staining measure. P-values ≤ 0.0056 were considered as statistically significant after applying a Bonferroni correction for multiple comparisons. Results There was not a significant association between FOXA1 H-score and risk of BCR when considering H-score as an ordinal variable or as a categorical variable (all P≥0.090). Similarly, no significant associations with BCR were observed for FOXA1 staining percentage or staining intensity (all P≥0.14). Conclusions FOXA1 staining level does not appear to have a major impact on risk of BCR after SRT.

Association of topoisomerase II expression and cancer-specific death in patients with surgically resected clear cell renal cell carcinoma.

446 Background: Despite the development of prognostic algorithms based on clinico-pathologic features, the ability to identify aggressive forms of clear cell renal cell carcinoma (ccRCC) remains suboptimal. Topoisomerase IIA (TOP2a) is a biomarker of DNA replication and a target for antineoplastic agents. Herein, we evaluate the association of TOP2a expression in ccRCC tumors with pathologic features of aggressiveness and risk of cancer-specific death. METHODS We identified 947 patients who underwent nephrectomy to treat clinically localized ccRCC between January 16, 1990, and September 27, 2006. TOP2a expression was assessed using IHC and scored as number of positive cells per mm2. We evaluated TOP2a expression using a continuous variable and tertile categories. For associations with pathologic features, we employed Kruskal-Wallis tests and for associations with cancer-specific survival, we generated Cox proportional hazard regression models. RESULTS HigherTOP2a expression is associated with later stage, higher grade and higher Mayo SSIGN score (all p < 0.001). The risk of death from RCC increases with increasing TOP2a expression (p trend < 0.0001). Compared to patients in the lowest tertile, those patients with tumors in the highest tertile of TOP2a expression were at increased risk of RCC death (HR=2.31 95% CI 1.64-3.25; p < 0.0001). Interestingly, among those patients with low risk disease (SSIGN score 0-3; ~95% 10 year survival), those with high TOP2a were at increased risk of RCC death (HR=3.09 95% CI 1.29-7.40; p = 0.01). CONCLUSIONS Higher TOP2a expression is associated with more aggressive pathologic features and increased risk of cancer-specific death among patients undergoing surgery for localized ccRCC. If confirmed, these data support further inquiry for TOP2a as a prognostic and predictive biomarker for ccRCC patients.

LOSS OF EXPRESSION OF THE VITAMIN D RECEPTOR IN CLEAR CELL RENAL CELL CARCINOMA

biopsy yielding 91 specimens. Three patients had 2 masses and three more patients underwent rebiopsy. A definitive diagnosis was established in 76 patients (89%). Of the 91 specimens 22 (24%) were benign including 11 oncocytomas, 7 lipid poor angiomyolipomas, 2 abscess/ pyelitis, 1 metanephric adenoma, and 1 benign spindle cell neoplasm. 20 patients (24%) had minor complications including 14 small perinephric hematomas (none required transfusion or admission to the inpatient ward), 2 difficulty voiding, 1 small pneumothorax, 1 rash, 1 shoulder pain, and 1 generalized musculoskeletal pain. The biopsy changed management in 22 patients (26%) with benign lesions or metastatic disease from another primary. Of the remaining 63 patients 24 underwent partial or radical nephrectomy. In all these patients the final pathology of these tumors confirmed the malignant diagnosis derived from biopsy. The remainder of the patients elected needle ablation or observation. CONCLUSIONS: CT guided biopsy of a small solid renal mass is a safe procedure that provides diagnostic information about 90% of the time. Biopsy provides clinically useful information by identification of benign lesions and confirmation of type and grade of malignancy if either resection of needle ablative therapy is a consideration.

GATA2 expression and biochemical recurrence following salvage radiation therapy for relapsing prostate cancer

OBJECTIVE High GATA2 expression has been associated with an increased risk of poor clinical outcomes after radical prostatectomy; however, this has not been studied in relation to risk of biochemical recurrence (BCR) after salvage radiation therapy (SRT) for recurrent prostate cancer after radical prostatectomy. Our aim was to evaluate the association between protein expression levels of GATA2 in primary prostate cancer tumour samples and the risk of BCR after SRT. METHODS 109 males who were treated with SRT were included. The percentage of cells with nuclear staining and GATA2 staining intensity were both measured. These two measures were multiplied together to obtain a GATA2 H-score (range 0-12) which was our primary GATA2 staining measure. RESULTS In unadjusted analysis, the risk of BCR was higher for patients with a GATA2 H-score >4 (hazard ratio = 2.04, p = 0.033). In multivariable analysis adjusting for SRT dose, pre-SRT PSA, pathological tumour stage and Gleason score, this association weakened substantially (hazard ratio = 1.45, p = 0.31). This lack of an independent association with BCR appears to be the result of correlations between GATA2 H-score >4 and higher pre-SRT PSA (p = 0.021), higher Gleason score (p = 0.044) and more severe pathological tumour stage (p = 0.068). CONCLUSION Higher levels of GATA2 expression appear to be a marker of prostate cancer severity; however, these do not provide independent prognostic information regarding BCR beyond that of validated clinicopathological risk factors. Advances in knowledge: A higher GATA2 expression level appears to be correlated with known measures of prostate cancer severity and therefore is likely not an independent marker of outcome after SRT.