Estrogen, progesterone, and androgen-binding sites in renal cell carcinoma. Observations obtained in Phase II trial of flutamide

PAQR5 Expression Is Suppressed by TGFβ1 and Associated With a Poor Survival Outcome in Renal Clear Cell Carcinoma

Background

Renal cell carcinoma (RCC) was sex-hormone responsive, and clinical trials using progesterone significantly reduced the incidence of distal metastasis after radical nephrectomy. Recently membrane-bound progesterone receptors (mPRs) were discovered to mediate the non-genomic effect of progesterone. Aberrant expressions of these mPRs were reported in human breast, ovarian, urinary bladder, brain, uterine, and prostate cancers. However, their expression profiles in RCC are yet to be assessed.

Methods

Multiple datasets from RNA sequencing (RNA-seq), cDNA microarray, and proteomic analysis were used to compare gene expression between cancerous and normal kidney tissues. Immunohistochemistry was conducted to examine protein expression in kidney tissues. Promoter methylation levels were assessed for correlation analysis with gene expression.

Results

Of the seven membrane-bound progesterone receptor genes, the progestin and adipoQ receptor-5 (PAQR5) gene is predominantly expressed in normal kidney tissue but was significantly downregulated in RCC tissues. PAQR5 downregulation correlated with tumor stage, cancer grade, lymph node invasion, and distal metastasis only in clear cell RCC (ccRCC) tissues. PAQR5 downregulation was associated with an increased promoter DNA methylation and a poor survival outcome in ccRCC patients. In addition, PAQR5 expression inversely correlated with transforming growth factor beta-1 (TGFB1) expression, and TGFβ1 treatment significantly reduced PAQR5 gene expression.

Conclusion

PAQR5 is a novel prognostic biomarker in ccRCC and is negatively regulated by the TGFβ1 pathway.

Sex and Gender Differences in Kidney Cancer: Clinical and Experimental Evidence

Simple Summary

Kidney cancer is a frequent malignant tumor that accounts for approximately 5% of all cancer incidences. It affects both males and females, but males are twice as likely to develop kidney cancer than females. Evidence shows that this discrepancy takes root in individual differences, such as genetics or pathologies that affect the patient. It is then reflected in the clinical characteristics of the tumors, as males have larger and more aggressive tumors. Understanding the sex- and gender-based differences in kidney cancer is essential to be able to offer patients individualized medicine that would better cover their needs in terms of prevention, diagnosis and treatment.

Abstract

Sex and gender disparities have been reported for different types of non-reproductive cancers. Males are two times more likely to develop kidney cancer than females and have a higher death rate. These differences can be explained by looking at genetics and genomics, as well as other risk factors such as hypertension and obesity, lifestyle, and female sex hormones. Examination of the hormonal signaling pathways bring further insights into sex-related differences. Sex and gender-based disparities can be observed at the diagnostic, histological and treatment levels, leading to significant outcome difference. This review summarizes the current knowledge about sex and gender-related differences in the clinical presentation of patients with kidney cancer and the possible biological mechanisms that could explain these observations. Underlying sex-based differences may contribute to the development of sex-specific prognostic and diagnostic tools and the improvement of personalized therapies.

The pVHL neglected functions, a tale of hypoxia-dependent and -independent regulations in cancer

The von Hippel–Lindau protein (pVHL) is a tumour suppressor mainly known for its role as master regulator of hypoxia-inducible factor (HIF) activity. Functional inactivation of pVHL is causative of the von Hippel–Lindau disease, an inherited predisposition to develop different cancers. Due to its impact on human health, pVHL has been widely studied in the last few decades. However, investigations mostly focus on its role in degrading HIFs, whereas alternative pVHL protein–protein interactions and functions are insistently surfacing in the literature. In this review, we analyse these almost neglected functions by dissecting specific conditions in which pVHL is proposed to have differential roles in promoting cancer. We reviewed its role in regulating phosphorylation as a number of works suggest pVHL to act as an inhibitor by either degrading or promoting downregulation of specific kinases. Further, we summarize hypoxia-dependent and -independent pVHL interactions with multiple protein partners and discuss their implications in tumorigenesis.

Prognostic relevance of androgen receptor expression in renal cell carcinomas

Background

Despite rapid discoveries in molecular biology of renal cell carcinoma (RCC) and advances in systemic targeted therapies, development of new diagnostic and therapeutic strategies is urgently needed. The androgen receptor (AR) has been shown to hold prognostic and predicitve value in several malignancies. Here, we studied a possible association between AR expression and prognosis in patients with RCCs.

Results

Low AR expression levels were associated with occurrence of distant metastasis and higher tumor stage in papillary and clear-cell RCCs. Importantly, multivariate Cox regression analyses revealed that AR is an independent prognostic factor for cancer-specific survival.

Materials and Methods

The expression of AR was measured by immunohistochemistry and assessed by digital image analysis using a tissue microarray containing tumor tissue of a large and well-documented series of RCC patients with long-term follow-up information. Chi-squared tests, Kaplan-Meier curves and Cox regression models were used to investigate the possible relationship between AR expression and clinico-pathological characteristics and patient survival.

Conclusions

Patients affected by AR-positive tumors exhibit a favorable prognosis by multiple Cox regression, while loss of AR expression is related to aggressive disease. Therefore, assessing AR expression offers valuable prognostic information that could improve treatment selection for metastatic disease. Moreover, our findings highlight a potential therapeutic use of AR pharmaceuticals in patients with RCCs.

Increased Expression of Androgen Receptor mRNA in Human Renal Cell Carcinoma Cells is Associated with Poor Prognosis in Patients with Localized Renal Cell Carcinoma

PURPOSE

The role of androgen receptor in renal cell carcinoma is not well understood. In this study the correlation between androgen receptor mRNA expression and clinicopathological features in patients with localized renal cell carcinoma was investigated. Additionally, human renal cell carcinoma cell lines were examined for the presence and effect of androgen receptor.

MATERIALS AND METHODS

Androgen receptor mRNA expression was evaluated by quantitative real-time polymerase chain reaction in 115 tumor samples from patients with primary pathological stage T1 or T2 (pT1/pT2) renal cell carcinoma and 57 specimens of corresponding normal kidney tissue. Reverse transcriptase-polymerase chain reaction and Western blot were done to examine the expression of androgen receptor in human renal cell carcinoma cell lines. Effects on cellular proliferation were investigated after activating and blocking androgen signaling in tissue culture.

RESULTS

Androgen receptor mRNA expression levels were significantly higher in patients with pT2 tumors than in those with pT1 tumors (p = 0.011). Kaplan-Meier estimates revealed significant differences in time to progression and cancer specific survival between low and high androgen receptor mRNA expression groups regardless of gender. Multivariate Cox regression analysis demonstrated that the level of androgen receptor expression was an independent predictor of cancer specific survival (HR 15.546, 95% CI 1.320-183.131, p = 0.029). In tissue culture treatment with dihydrotestosterone caused proliferation in androgen receptor positive cell lines while enzalutamide resulted in reduced cell viability in a dose dependent manner.

CONCLUSIONS

In patients with localized renal cell carcinoma the androgen receptor mRNA expression level is associated with prognosis. In addition, cell culture data suggest that enzalutamide may have an effect in limiting the growth of androgen receptor positive renal cell carcinoma.

Stage migration and increasing proportion of favorable-prognosis metastatic renal cell carcinoma patients: implications for clinical trial design and interpretation

BACKGROUND

The Memorial Sloan-Kettering Cancer Center risk model classifies patients with metastatic renal cell carcinoma (RCC) by 5 pretreatment features as favorable, intermediate, and poor risk. The number of Memorial Sloan-Kettering Cancer Center patients in each risk group was examined by year of treatment to analyze stage migration.

METHODS

The distribution of risk groups was examined retrospectively in 789 Memorial Sloan-Kettering Cancer Center patients with metastatic RCC treated in a first-line therapy clinical trial from 1975 to 2007. Date of treatment onset was divided into 6 cohorts between 1975 and 2007 (1975-1980, 1981-1985, 1986-1990, 1991-1995, 1996-2001, and 2001-2007).

RESULTS

The median age of the first-line metastatic RCC clinical trial patients was 59 years (range, 20-82 years). Most patients received cytokine therapy (55%), 37% received chemotherapy/other, and 8% received vascular endothelial growth factor-targeted therapies. Overall survival increased with each consecutive cohort year group (P < .001). Median survival was 0.43 years (95% confidence interval [CI], 0.27-0.68) in the 1973-1980 cohort and 1.5 years in the 2001-2007 cohort (95% CI, 1.15-2.11). Memorial Sloan-Kettering Cancer Center risk-group distribution shifted between 1975 and 2007 (P < .0001). The poor-risk group proportion became smaller (from 44% in 1975-1980 to 13% in 2001-2007), whereas the favorable-risk group increased (from 0% in 1975-1980 to 49% in 2001-2007). The intermediate-risk group remained stable at 50%. After adjusting for type of therapy, the shifts continue to be significant (P < .0001).

CONCLUSIONS

The risk-group distribution for metastatic RCC patients in clinical trials shifted from 1975 to 2007. These shifts have direct implications for data analysis, interpretation of metastatic RCC trends, and drug development.

Prognostic factors for survival in previously treated patients with metastatic renal cell carcinoma

PURPOSE

To describe survival in previously treated patients with metastatic renal cell carcinoma (RCC) who are candidates for clinical trials of new agents as second-line therapy.

PATIENTS AND METHODS

The relationship between pretreatment clinical features and survival was studied in 251 patients with advanced RCC treated during 29 consecutive clinical trials between 1975 and 2002. Clinical features were first examined in univariate analyses, and then a stepwise modeling approach based on Cox regression was used to form a multivariate model.

RESULTS

Median survival for the 251 patients was 10.2 months and differed according to year of treatment, with patients treated after 1990 showing longer survival. In this group, the median overall survival time was 12.7 months. Because the purpose of this analysis was to establish prognostic factors for present-day clinical trial design, prognostic factor analysis was performed on these patients. Pretreatment features associated with a shorter survival in the multivariate analysis were low Karnofsky performance status, low hemoglobin level, and high corrected serum calcium. These were used as risk factors to categorize patients into three different groups. The median time to death in patients with zero risk factors was 22 months. The median survival in patients with one of these prognostic factors was 11.9 months. Patients with two or three risk factors had a median survival of 5.4 months.

CONCLUSION

Treatment with novel agents during a clinical trial is indicated for patients with metastatic RCC after progression to cytokine treatment. Three prognostic factors for predicting survival were used to categorize patients into risk groups. These risk categories can be used in clinical trial design and interpretation.

Biomarkers of renal cell carcinoma. Past and future considerations

Renal cancer includes several distinct entities with a range of biologic and clinical behaviors from relatively indolent to extremely aggressive tumors. Although conventional prognostic factors such as stage and grade are quite useful, other clinical, laboratory, and pathologic findings are now believed to have additional predictive values. This article reviews the literature on the potential utility of biomarkers in renal cell carcinoma. To date, only a few biomarkers, such as Ki-67, appeared to be potentially useful for monitoring renal cancer patients. New biomarkers including MN/CA9 and circulating cell detection require further and extensive studies to assess their potential clinical utility.

Effect of cytokine therapy on survival for patients with advanced renal cell carcinoma

PURPOSE

To evaluate the relationship between treatment with cytokine therapy and survival, investigate the effect of nephrectomy on survival, and identify long-term survivors among a cohort of 670 patients with advanced renal cell carcinoma (RCC).

PATIENTS AND METHODS

A total of 670 patients with advanced RCC treated on 24 clinical trials of systemic chemotherapy or cytokine therapy were the subjects of this retrospective analysis. Treatment was categorized as cytokine (containing interferon alfa and/or interleukin-2) in 396 patients (59%) and as chemotherapy (cytotoxic or hormonal therapy) in 274 (41%). Among the 670 patients, those with survival times of greater than 5 years were identified as long-term survivors.

RESULTS

Patients treated with cytokine therapy had a longer survival time than did those treated with chemotherapy, regardless of the year of treatment or risk category based on pretreatment features. The median survival times for favorable-, intermediate-, and poor-risk patients were 27, 12, and 6 months for those treated with cytokines and 15, 7, and 3 months for those treated with chemotherapy, respectively. The magnitude of difference in median survival was greater in the favorable- and intermediate-risk groups. The median survival time was less than 6 months in the poor-risk group for both treatment programs. Median survival time was 14 months among patients with prior nephrectomy plus time from diagnosis to treatment greater than 1 year versus 8 months among those with time from diagnosis to treatment less than 1 year, regardless of pretreatment nephrectomy status. Thirty patients (4.5%) among the 670 patients were identified as long-term survivors; 12 were free of disease after nephrectomy and treatment with interferon alfa, interleukin-2, or surgical resection of metastasis.

CONCLUSION

The low proportion of patients with advanced RCC who achieve long-term survival emphasizes the need for clinical investigation to identify more effective therapy.

Survival and prognostic stratification of 670 patients with advanced renal cell carcinoma

PURPOSE

To identify prognostic factors and a model predictive for survival in patients with metastatic renal-cell carcinoma (RCC).

PATIENTS AND METHODS

The relationship between pretreatment clinical features and survival was studied in 670 patients with advanced RCC treated in 24 Memorial Sloan-Kettering Cancer Center clinical trials between 1975 and 1996. Clinical features were first examined univariately. A stepwise modeling approach based on Cox proportional hazards regression was then used to form a multivariate model. The predictive performance of the model was internally validated through a two-step nonparametric bootstrapping process.

RESULTS

The median survival time was 10 months (95% confidence interval [CI], 9 to 11 months). Fifty-seven of 670 patients remain alive, and the median follow-up time for survivors was 33 months. Pretreatment features associated with a shorter survival in the multivariate analysis were low Karnofsky performance status (<80%), high serum lactate dehydrogenase (> 1.5 times upper limit of normal), low hemoglobin (< lower limit of normal), high "corrected" serum calcium (> 10 mg/dL), and absence of prior nephrectomy. These were used as risk factors to categorize patients into three different groups. The median time to death in the 25% of patients with zero risk factors (favorable-risk) was 20 months. Fifty-three percent of the patients had one or two risk factors (intermediate-risk), and the median survival time in this group was 10 months. Patients with three or more risk factors (poor-risk), who comprised 22% of the patients, had a median survival time of 4 months.

CONCLUSIONS

Five prognostic factors for predicting survival were identified and used to categorize patients with metastatic RCC into three risk groups, for which the median survival times were separated by 6 months or more. These risk categories can be used in clinical trial design and interpretation and in patient management. The low long-term survival rate emphasizes the priority of clinical investigation to identify more effective therapy.

Estrogen and progesterone binding sites in renal cell carcinoma

Twenty-five renal cell carcinomas were assayed for estrogen and progesterone receptor levels. Estrogen specific binding was present in only 4 patients (16%) and progesterone specific binding in 7 patients (28%). In all cases these receptors were present in very low titers, less than 10 fm/mg. We believe that earlier reports citing significant estrogen and progesterone binding activity may reflect high levels of nonspecific protein binding.

Hormone receptors in renal cancer: an overview

The current literature concerning hormone receptors in renal cell cancer is reviewed. Our own results of histochemical determination of estrogen receptors by means of monoclonal antibodies are presented. Based on the studies that have been reviewed and the differing results of the receptor assays, we conclude that there is a very limited basis to apply hormone therapy in renal cell cancer. However, the new immunohisto-chemical methods should be used to resolve the question about the hormone dependency of renal carcinoma.