Prognostic factors and selection for clinical studies of patients with kidney cancer

Genome-wide profiling of chromosomal alterations in renal cell carcinoma using high-density single nucleotide polymorphism arrays

The identification of genetic aberrations may help understand the mechanisms of tumorigenesis and has important implications in diagnosis, prognosis and treatment. We applied Illumina's 317K high-density single nucleotide polymorphism (SNP) arrays to profile chromosomal aberrations in clear cell renal cell carcinoma (ccRCC) from 80 patients and analyzed the association of LOH/amplification events with clinicopathological characteristics and telomere length. The most common loss of heterozygosity (LOH) were 3p (69 cases) including 38 whole 3p arm losses, 30 large fragment LOH (spanning 3p21-36), and 1 interstitial LOH (spanning 3p12-14, 3p21-22, 3p24.1-24.2 and 3p24.3), followed by chromosome losses at 8p12-pter, 6q23.3-27, 14q24.1-qter, 9q32-qter, 10q22.3-qter, 9p13.3-pter, 4q28.3-qter and 13q12.1-21.1. We also found several smallest overlapping regions of LOH that contained tumor suppressor genes. One smallest LOH in 8p12 had a size of 0.29 Mb and only contained one gene (NRG1). The most frequent chromosome gains were at 5q (32 cases), including 10 whole 5q amplification, 21 large amplifications encompassing 5q32-ter and 1 focal amplification in 5q35.3 (0.42 Mb). The other common chromosome gains were 1q25.1-qter, 7q21.13-qter, 8q24.12-qter and whole 7p arm. Significant associations of LOH at 9p, 9q, 14q and 18q were observed with higher nuclear grade. Significant associations with tumor stage were observed for LOH at 14q, 18p and 21q. Finally, we found that tumors with LOH at 2q, 6p, 6q, 9p, 9q and 17p had significantly shorter telomere length than those without LOH. This is the first study to use Illumina's SNP-CGH array that provides a close estimate of the size and frequency of chromosome LOH and amplifications of ccRCC. The identified regions and genes may become diagnostic and prognostic biomarkers as well as potential targets of therapy.

Expression and cytoplasmic localization of SAM68 is a significant and independent prognostic marker for renal cell carcinoma

PURPOSE

This retrospective study aimed to examine the expression and localization of SAM68 (Src-associated in mitosis, 68 kDa) in a larger cohort of surgical specimens of renal cell carcinoma and their correlation with the progression of human renal cell carcinoma.

EXPERIMENTAL DESIGN

The protein and mRNA expression levels of SAM68 in normal renal tubular epithelial cells, renal cell carcinoma cell lines, as well as nine pairs of renal cell carcinoma and matched tumor-adjacent renal tissues were examined using reverse transcription-PCR and Western blot. Moreover, SAM68 protein expression and localization in 241 clinicopathologically characterized renal cell carcinoma samples were examined by immunohistochemistry. Prognostic and diagnostic associations were examined by statistical analyses.

RESULTS

SAM68 was markedly overexpressed in renal cell carcinoma cell lines and renal cell carcinoma tissues at both the transcriptional and translational levels. Immunohistochemical analysis revealed high SAM68 protein expression in 129 of the 241 (53.5%) paraffin-embedded archival renal cell carcinoma specimens. Moreover, there was a significant correlation between SAM68 expression and pathologic stage (P < 0.001), T classification (P = 0.003), N classification (P = 0.001), M classification (P = 0.006), and Fuhrman grade (P < 0.001). Patients with higher SAM68 expression had shorter overall survival time than patients with lower SAM68 expression, and the cytoplasmic localization of SAM68 significantly correlated with clinicopathologic grade and outcome. Multivariate analysis indicated that SAM68 protein overexpression and cytoplasmic localization were independent predictors for poor survival of renal cell carcinoma patients.

CONCLUSIONS

Our results suggest that SAM68 could represent a novel and useful prognostic marker for renal cell carcinoma. High SAM68 expression and cytoplasmic localization are associated with poor overall survival in renal cell carcinoma patients.

Presence of intratumoral neutrophils is an independent prognostic factor in localized renal cell carcinoma

PURPOSE

We have previously demonstrated a significant negative impact of intratumoral neutrophils in metastatic renal cell carcinoma. This study assessed intratumoral neutrophils in localized clear cell renal cell carcinoma (RCC).

PATIENTS AND METHODS

The study comprised 121 consecutive patients who had a nephrectomy for localized RCC. Biomarkers (intratumoral CD8+, CD57+ immune cells, CD66b+ neutrophils, and carbonic anhydrase IX [CA IX]) were assessed by immunohistochemistry, and the relationship with clinical and histopathologic features and patient outcome was evaluated.

RESULTS

The intratumoral neutrophils ranged from zero to 289 cells/mm(2) tumor tissue. The presence of intratumoral neutrophils was statistically significantly associated with increasing tumor size, low hemoglobin, high creatinine, and CA IX < or = 85%. In multivariate analysis, the presence of intratumoral neutrophils (hazard ratio [HR], 3.0; 95% CI, 1.7 to 5.4; P < .0001), pT stage T3b/T4 (HR, 2.1; 95% CI, 1.2 to 3.6; P = .007), and low hemoglobin (HR, 1.8; 95% CI, 1.0 to 3.1; P = .03) were independent prognostic factors significantly associated with short recurrence-free survival. The presence of intratumoral neutrophils was also an independent prognostic factor for cancer-specific survival (HR, 3.5; 95% CI, 1.9 to 6.4; P < .0001) and overall survival (HR, 3.1; 95% CI, 1.9 to 5.0; P < .0001). Applying the prognostic value of intratumoral neutrophils to the Leibovich low-/intermediate-risk group (n = 78) showed a 5-year recurrence-free survival of 53% (95% CI, 34.6% to 71.8%; presence of intratumoral neutrophils) versus 87% (95% CI, 77.8% to 96.8%; absence of intratumoral neutrophils). The estimated concordance index was 0.74 using the Leibovich risk score and 0.80 when intratumoral neutrophils were added.

CONCLUSION

The presence of intratumoral neutrophils is a new, strong, independent prognostic factor for short recurrence-free, cancer-specific, and overall survival in localized clear cell RCC.

Tissue biomarkers in renal cell carcinoma: issues and solutions

Renal cell carcinoma (RCC) is an aggressive malignancy that is associated with a high rate of metastasis. Although several promising therapeutic strategies are now available for the treatment of patients with metastatic kidney cancer, the prognosis of these patients remains poor. Research is ongoing to identify RCC-specific biomarkers that can improve early diagnosis, surveillance of tumor progression, and prediction of patient prognosis. The identification of biomarkers that may predict response to specific therapies also will be useful in stratifying patients with RCC for treatment selection. Unfortunately, biomarker detection and measurement in kidney tumor tissues can be biased significantly by the lack of standardization in tissue sample acquisition, storage, and analysis. Consequently, the establishment of standardized operating procedures is necessary to maximize the accuracy of tissue-based biomarker assays. Herein, the authors discuss current issues in tissue-based translational research aimed at identifying clinically useful biomarkers for kidney cancer.

Predicting disease progression after nephrectomy for localized renal cell carcinoma: the utility of prognostic models and molecular biomarkers

Disease progression after nephrectomy for pathologically localized renal cell carcinoma (RCC) is associated with a significant mortality rate, given the limited efficacy of available treatment regimens for metastatic disease. As such, several adjuvant trials have been designed to treat patients at particularly high risk for postsurgical RCC progression. Several different prognostic models designed to identify patients at high risk of disease progression are available. Although these available predictive models provide a reasonable assessment of patients' risks of disease progression, the accuracy of these models may further be improved via the incorporation of molecular prognostic biomarkers. Although numerous candidate molecules have been described, few have been specifically assessed for the association with disease progression after nephrectomy. IMP-3, CXCR3, p53, Survivin, cIAP1, B7-H1, and B7-H4 have all been associated with disease progression after nephrectomy. The incorporation of 1 or several of these biomarkers may increase the accuracy of currently available prognostic models and thereby facilitate the appropriate use of adjuvant therapies aimed at preventing future disease progression. As such, the authors review the current prognostic tools for predicting disease progression for localized RCC, and detail studies to date that have evaluated various biomarkers in this setting.

The medical treatment of metastatic renal cell cancer in the elderly: position paper of a SIOG Taskforce

Treatments currently recommended for metastatic renal cell cancer (mRCC) have not been evaluated specifically in elderly patients. Here we consider what may be learned by analysing according to age the efficacy and toxicity data from key phase III trials of the targeted agents sorafenib (Nexavar), sunitinib (Sutent), temsirolimus (Torisel), and bevacizumab (Avastin), and from a study of expanded access to sunitinib and sorafenib. This paper represents the first systematic review of the role of targeted agents specifically in the elderly population. Retrospective subgroup analyses of clinical trial data cannot be considered definitive. However, they suggest in general that the progression-free and overall survival benefits seen in mRCC patients aged 65 years and over are similar to those in the younger age group. The frequency of major toxicities in elderly patients treated with targeted agents is no greater than in younger patients, although such toxicities may have greater impact on the quality of life. That said, no meaningful data are available for patients over 85 years. To confirm and extend these conclusions, prospective studies should be undertaken in the elderly to determine whether recommendations made for the wider mRCC population apply equally to this group of patients in whom comorbidities, comedication and the greater impact of low-grade toxicity may influence the efficacy and tolerability of treatment. Such studies are increasingly needed, given the growing number of elderly people and their rising life expectancy. Meanwhile, when considering the most appropriate drug to use in a particular patient, the toxicity profiles of the individual targeted agents--and any implications for specific comorbid conditions--should be taken into account.