Sarcomatoid features, necrosis, and grade are prognostic factors in metastatic clear cell renal cell carcinoma with vascular endothelial growth factor-targeted therapy

Clinical impact of early response to first-line VEGFR-TKI in patients with metastatic renal cell carcinoma on survival: A multi-institutional retrospective study

It remains unknown whether the early response to vascular endothelial growth factor receptor tyrosine kinase inhibitor (VEGFR-TKI) management in malignancies links to long-term survival. The objective of this study was to investigate the survival rates and predictive factors of early response in patients with metastatic renal cell carcinoma (mRCC) managed by VEGFR-TKIs. From Jan. 2008 to Oct. 2018, 496 patients were treated with VEGFR-TKIs as first-line treatment at the eight Japanese hospitals (Michinoku RCC). Early cessation was defined as VEGFR-TKIs being given up within 3 months after their initiation. The number of patients in early cessation VEGFR-TKIs (Cohort I) was 173 (34.9%), and in long-term use (Cohort II) was 323 (65.1%). The cancer-specific survival (CSS) and overall survival (OS) were better in Cohort II. IMDC Poor-risk was at risk of early cessation of a first-line VEGFR-TKI. Axitinib was the most preferred drug for long-term treatment. On closer examination, both Cohort I and II were divided into two groups, the patients ceased VEGFR-TKI due to adverse events (Group A [67 from Cohort I] and Group C [51 from Cohort II]) and disease progression (Group B [106 from Cohort I] and Group D [272 from Cohort II]). Despite that the cessation was adverse events, CSS and OS in Group A were worse than both Group C and D. Axitinib was administered with the safer profile. IMDC Poor risk was the risk factor for the early disease progression. Managing early adverse events may contribute to a better prognosis in mRCC patients treated VEGFR-TKIs.

Involvement of the TNF-α Pathway in TKI Resistance and Suggestion of TNFR1 as a Predictive Biomarker for TKI Responsiveness in Clear Cell Renal Cell Carcinoma

BACKGROUND

Mechanism and predictive biomarkers for tyrosine kinase inhibitor (TKI) resistance of advanced clear cell renal cell carcinoma (ccRCC) have not been fully evaluated.

METHODS

We performed gene expression profiling on samples from an acquired TKI resistance cohort that consisted of 10 cases of TKI-treated ccRCC patients with matched tumor tissues harvested at pre-treatment and TKI-resistant post-treatment periods. In addition, a public microarray dataset from patient-derived xenograft model for TKI-treated ccRCC (GSE76068) was retrieved. Commonly altered pathways between the datasets were investigated by Ingenuity Pathway Analysis using commonly regulated differently expressed genes (DEGs). The significance of candidate DEG on intrinsic TKI resistance was assessed through immunohistochemistry in a separate cohort of 101 TKI-treated ccRCC cases.

RESULTS

TNFRSF1A gene expression and tumor necrosis factor (TNF)-α pathway were upregulated in ccRCCs with acquired TKI resistance in both microarray datasets. Also, high expression (> 10% of labeled tumor cells) of TNF receptor 1 (TNFR1), the protein product of TNFRSF1A gene, was correlated with sarcomatoid dedifferentiation and was an independent predictive factor of clinically unfavorable response and shorter survivals in separated TKI-treated ccRCC cohort.

CONCLUSION

TNF-α signaling may play a role in TKI resistance, and TNFR1 expression may serve as a predictive biomarker for clinically unfavorable TKI responses in ccRCC.

Epithelial-mesenchymal transition as a mechanism of resistance to tyrosine kinase inhibitors in clear cell renal cell carcinoma

Tyrosine kinase inhibitors (TKIs) are widely accepted as treatment for metastatic clear cell renal cell carcinoma (ccRCC). However, most patients eventually experience disease progression despite TKI treatment, even if the initial response is favorable. To define the underlying mechanism of TKI resistance, 10 TKI-treated metastatic ccRCC cases in which tumor samples were harvested before treatment and immediately after disease progression were examined. Gene expression profiles and copy number variations of matched pre- and post-treatment tumor samples were investigated. Altered biologic characteristics were confirmed in sunitinib-resistant ccRCC cell lines, which were generated by long-term treatment with sunitinib-containing media. Gene transcript levels related to the cell cycle and epithelial-mesenchymal transition (EMT) were significantly upregulated in the treated tumor samples compared with the pre-treatment samples. The mitotic count and sarcomatoid component were significantly increased in treated tumor samples. Alteration of EMT-related genes was also demonstrated in a sunitinib-resistant ccRCC cell line that showed enhanced migration and invasion compared to the parent cell line. siRNA-induced inhibition of EMT-related gene expression significantly suppressed the migration and invasion capacity of TKI-resistant cell lines. The present study shows that both ccRCC cases that progressed after TKI treatment and sunitinib-resistant ccRCC cell lines demonstrated alteration of EMT-related gene expression and enhancement of EMT-related behavior. These results suggest that EMT may explain the aggressive behavior of TKI-resistant ccRCC.

Percentage grade 4 tumour predicts outcome for clear cell renal cell carcinoma

Heterogeneity of tumour grading is common in clear cell renal cell carcinoma (ccRCC). WHO/ISUP grading specifies that RCC should be graded based on the highest grade present in at least one high power field. This does not take into account the proportion of high grade tumour present in a cancer, which may itself influence outcome. Cases of ccRCC accessioned by Aquesta Uropathology, Brisbane, Australia, between 2008 and 2015, were reviewed and grading assigned according to WHO/ISUP criteria. For tumours classified as grade 3 (G3) and 4 (G4), the percentage of tumour showing G3 and G4 morphology was assessed for each case. Survival analysis, with time to the development of metastases as the clinical outcome, was performed for six grading subclasses (G3 <10%, G3 10-50%, G3 >50%, G4 <10%, G4 10-50%, G4 >50%). Of the 681 cases of ccRCC in the series, there were 153 cases classified as G3 (91 cases) and G4 (62 cases) for which follow-up was available. During the follow-up period of <1-89 months, 19 (20.9%) patients with G3 and 30 (48.3%) patients with G4 cancers developed metastatic disease. The three subgroups of <10%, 10-50% and >50% G3 tumour were not significant in predicting outcome (p=0.47). Separating G3 into two groups of ≤50% vs >50% was also not significantly associated with outcome (p=0.22). For the three subgroups of G4 ccRCC (<10%, 10-50% and >50% G4) a higher percentage of G4 correlated with time to the development of metastases (p=0.01). Even though G4 tumours as a whole had a significantly worse outcome than G3 tumours (p=0.0004), the difference between G4 <10% and G3 tumours was not significant (p=0.27). On multivariate analysis, that included pT staging category and tumour size, there was a significant difference in survival between G4<10% and G4>50% tumours (p=0.018). The results of the study suggest that for ccRCC, WHO/ISUP G4 category should incorporate the percentage of G4 tumour present.

Grading of renal cell carcinoma

Grading of renal cell carcinoma (RCC) has been recognised as a prognostic factor for almost 100 years. Numerous grading systems have been proposed, initially focusing upon a constellation of cytological features and more recently on nuclear morphology. It has been recommended that grading of RCC should be based upon nucleolar prominence/eosinophilia for grades 1-3, while grade 4 requires nuclear anaplasia (including tumour giant cells, sarcomatoid differentiation and/or rhabdoid morphology). The grading system was adopted formally by the International Society of Urological Pathology (ISUP) and subsequently by the World Health Organisation (WHO), being designated the WHO/ISUP grading classification in the fourth edition of the WHO classification tumours of the urinary system and male genital organs (2016). This grading system has been validated for both clear cell and papillary RCC. Validation studies for chromophobe RCC failed to demonstrate a correlation between grade and outcome for both the superseded Fuhrman grading system and the WHO/ISUP grading classification, and it has been recommended that these tumours not be graded. The WHO/ISUP system has been incorporated into the structured reports of the International Cancer Collaboration on Cancer Reporting for both clear cell and papillary RCC. It is also noted that other types of RCC may be graded, but it must be emphasised in the report that this is for descriptive and diagnostic purposes, and not outcome prediction. More recent studies have shown the incorporation of the presence of tumour necrosis into RCC grading to improve outcome prediction, and this has been validated in several studies.

Prognostic value of performance status in metastatic renal cell carcinoma patients receiving tyrosine kinase inhibitors: a systematic review and meta-analysis

BACKGROUND

The association between performance status (PS) and the prognosis of metastatic renal cell carcinoma (mRCC) patients receiving tyrosine kinase inhibitors (TKIs) remains controversial. The aim of this study is to evaluate the prognostic value of PS in mRCC patients treated with TKIs.

METHODS

Electronic databases were searched to identify the studies that had assessed the association between pretreatment PS and prognosis in mRCC patients receiving TKIs. Hazard ratios (HRs) and 95% confidence interval (CI) for overall survival (OS) and progression-free survival (PFS) from eligible studies were used to calculate combined HRs. The heterogeneity across the included studies was assessed by Cochrane's Q test and I² statistic. The Begg's funnel plot and Egger's linear regression teats were used to evaluate the potential publication bias. The meta-analysis was performed with RevMan 5.3 and Stata SE12.0 according to the PRISMA guidelines.

RESULTS

A total of 6780 patients from 19 studies were included in this meta-analysis. The results showed that a poor PS was an effective prognostic factor of both OS (pooled HR: 2.08, 95% CI: 1.78-2.45) and PFS (pooled HR: 1.51, 95% CI: 1.20-1.91). Subgroup analysis revealed that poor PS significantly associated with poor OS and PFS in studies using Karnofsky PS scale (OS, pooled HR: 2.20, 95% CI: 1.65-2.94; PFS, pooled HR: 1.74, 95% CI: 1.19-2.56), conducted in Asia (OS, pooled HR: 2.25, 95% CI: 1.71-2.95; PFS, pooled HR: 1.73, 95% CI: 1.14-2.64) and Newcastle-Ottawa Scale score of 8 (OS, pooled HR: 2.61, 95% CI: 1.92-3.55; PFS, pooled HR: 2.43, 95% CI: 1.36-4.33).

CONCLUSIONS

This study suggests that a poor PS is significantly associated with poor prognosis in mRCC patients receiving TKIs.

WHO/ISUP classification, grading and pathological staging of renal cell carcinoma: standards and controversies

PURPOSE

Pathological parameters assessed on biopsies and resection specimens have a pivotal role in the diagnosis, prognosis and management of patients with renal cell carcinoma (RCC).

METHODS

A non-systematic literature search was performed, updated to January 2018, to identify key standards and controversies in the pathological classification, grading and staging of RCC.

RESULTS

Although most RCCs exhibit characteristic morphology that enables easy categorisation, RCCs show considerable morphological heterogeneity and it is not uncommon for there to be difficulty in assigning a tumour type, especially with rarer tumour subtypes. The differentiation between benign and malignant oncocytic tumours remains a particular challenge. The development of additional immunohistochemical and molecular tests is needed to facilitate tumour typing, because of the prognostic and therapeutic implications, and to enable more reliable identification of poorly differentiated metastatic tumours as being of renal origin. Any new tests need to be applicable to small biopsy samples, to overcome the heterogeneity of renal tumours. There is also a need to facilitate identification of tumour types that have genetic implications, to allow referral and management at specialist centres. Digital pathology has a potential role in such referral practice.

CONCLUSION

Much has been done to standardise pathological assessment of renal cell carcinomas in recent years, but there still remain areas of difficulty in classification and grading of these heterogeneous tumours.

Tumor necrosis as a prognostic variable for the clinical outcome in patients with renal cell carcinoma: a systematic review and meta-analysis

Background

Tumor necrosis (TN) correlates with adverse outcomes in numerous solid tumors. However, its prognostic value in renal cell carcinoma (RCC) remains unclear. In this study, we performed a meta-analysis to evaluate associations between TN and cancer-specific survival (CSS), overall survival (OS), recurrence-free survival (RFS) and progression-free-survival (PFS) in RCC.

Methods

Electronic searches in PubMed, EMBASE and Web of Science were conducted according to the PRISMA statement. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated to evaluate relationships between TN and RCC. A fixed- or random-effects model was used to calculate pooled HRs and 95%CIs according to heterogeneity.

Results

A total of 34 cohort studies met the eligibility criteria of this meta-analysis. The results showed that TN was significantly predictive of poorer CSS (HR = 1.37, 95% CI: 1.23–1.53, p < 0.001), OS (HR = 1.29, 95% CI: 1.20–1.40, p < 0.001), RFS (HR = 1.55, 95% CI: 1.39–1.72, p < 0.001) and PFS (HR = 1.31, 95% CI: 1.17–1.46, p < 0.001) in patients with RCC. All the findings were robust when stratified by geographical region, pathological type, staging system, number of patients, and median follow-up.

Conclusions

The present study suggests that TN is associated with CSS, OS, RFS and PFS clinical outcomes of RCC patients and may serve as a predictor of poor prognosis in these patients.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4773-z) contains supplementary material, which is available to authorized users.

Development of Response Classifier for Vascular Endothelial Growth Factor Receptor (VEGFR)-Tyrosine Kinase Inhibitor (TKI) in Metastatic Renal Cell Carcinoma

Vascular endothelial growth factor receptor (VEGFR)-targeted therapy improved the outcome of metastatic renal cell carcinoma (mRCC) patients. However, a prediction of the response to VEGFR-tyrosine kinase inhibitor (TKI) remains to be elucidated. We aimed to develop a classifier for VEGFR-TKI responsiveness in mRCC patients. Among 101 mRCC patients, ones with complete response, partial response, or ≥24 weeks stable disease in response to VEGFR-TKI treatment were defined as clinical benefit group, whereas patients with <24 weeks stable disease or progressive disease were classified as clinical non-benefit group. Clinicolaboratory-histopathological data, 41 gene mutations, 20 protein expression levels and 1733 miRNA expression levels were compared between clinical benefit and non-benefit groups. The classifier was built using support vector machine (SVM). Seventy-three patients were clinical benefit group, and 28 patients were clinical non-benefit group. Significantly different features between the groups were as follows: age, time from diagnosis to TKI initiation, thrombocytosis, tumor size, pT stage, ISUP grade, sarcomatoid change, necrosis, lymph node metastasis and expression of pAKT, PD-L1, PD-L2, FGFR2, pS6, PDGFRβ, HIF-1α, IL-8, CA9 and miR-421 (all, P < 0.05). A classifier including necrosis, sarcomatoid component and HIF-1α was built with 0.87 accuracy using SVM. When the classifier was checked against all patients, the apparent accuracy was 0.875 (95% CI, 0.782-0.938). The classifier can be presented as a simple decision tree for clinical use. We developed a VEGFR-TKI response classifier based on comprehensive inclusion of clinicolaboratory-histopathological, immunohistochemical, mutation and miRNA features that may help to guide appropriate treatment in mRCC patients.

Initial computed tomography imaging details during first-line systemic therapy is of significant prognostic value in patients with naïve, unresectable metastatic renal cell carcinoma

Purpose

We aimed to determine the prognostic significance of computed tomography imaging parameters of unresectable primary renal tumor lesions, obtained at baseline and at first follow-up, on overall survival in naïve, unresectable metastatic renal cell carcinoma patients during first-line systemic therapy.

Materials and methods

Clinicopathological parameters of 56 patients treated between 2007 and 2015, including imaging parameters (such as the longest tumor diameter, necrotic area diameter, and attenuation in primary renal tumor lesions on baseline vs. follow-up computed tomography), were retrospectively reviewed to derive predictive factors of overall survival. The best overall response was measured according to the RECIST v1.1.

Results

The median treatment period was 206.3 days and the median follow-up was 14.6 months. Forty-four (78.6%) patients progressed after a median 4.6 months of progression-free survival, and 6 (10.7%) patients survived with a median overall survival of 12.5 months. Multivariate analysis showed that the baseline tumor diameter (hazard ratio [HR] 0.903) and mean attenuation (HR 0.936), change of tumor diameter (HR 0.714) and necrosis diameter (HR 0.861), change in the percentage of tumor diameter (HR 1.483) and of necrosis diameter (HR 1.028) between baseline and follow-up computed tomography images; treatment duration (HR 0.986) and baseline serum hemoglobin (HR 1.790) and albumin level (HR 0.060) were significant factors for overall survival (p<0.05).

Conclusion

The study showed that baseline and first follow-up computed tomography findings of primary renal lesions during first-line systemic therapy are useful and significant predictors of OS in patients with naïve unresectable mRCC.

Pathological T3a Upstaging of Clinical T1 Renal Cell Carcinoma: Outcomes According to Surgical Technique and Predictors of Upstaging

Purpose

To evaluate the prognosis of pT3a upstaging from cT1 renal cell carcinoma, and to compare the outcomes of partial or radical nephrectomy in cases of pT3a upstaging.

Materials and Methods

We reviewed the records of patients who underwent partial or radical nephrectomy for cT1 at our center between January 2001 and October 2013. We compared the 2-year recurrence-free survivals for cases with pT1 or pT3a upstaging, and for partial or radical nephrectomy in cases with pT3a upstaging. Clinicopathological parameters were analyzed in univariate and multivariate analyses to evaluate their associations with upstaging.

Results

Among the 1,009 eligible patients, 987 patients were included in the analysis. The mean follow-up was 48.5 ± 27.8 months in whole patients. The 2-year recurrence-free survival was worse in the pT3a upstaging group, compared to the pT1 group (87.3% vs. 98.7%; p < 0.001). Partial nephrectomy and radical nephrectomy had no significant difference in 2-year recurrence-free survivals (91.9% vs. 83.7%; p = 0.251). The multivariate analysis revealed that upstaging was associated with old age, cT1b stage, clinical symptoms, and a high Fuhrman grade.

Conclusions

Pathological T3a upstaging of cT1 renal cell carcinoma was associated with a poorer prognosis, compared to pT1 disease. However, the surgical technique (radical or partial nephrectomy) did not affect the recurrence rate. Therefore, clinicians should select the treatment method based on the clinical stage, and consider the pathological stage during the follow-up.

Non-crossing weighted kernel quantile regression with right censored data

Regarding survival data analysis in regression modeling, multiple conditional quantiles are useful summary statistics to assess covariate effects on survival times. In this study, we consider an estimation problem of multiple nonlinear quantile functions with right censored survival data. To account for censoring in estimating a nonlinear quantile function, weighted kernel quantile regression (WKQR) has been developed by using the kernel trick and inverse-censoring-probability weights. However, the individually estimated quantile functions based on the WKQR often cross each other and consequently violate the basic properties of quantiles. To avoid this problem of quantile crossing, we propose the non-crossing weighted kernel quantile regression (NWKQR), which estimates multiple nonlinear conditional quantile functions simultaneously by enforcing the non-crossing constraints on kernel coefficients. The numerical results are presented to demonstrate the competitive performance of the proposed NWKQR over the WKQR.

The Association Between PD-L1 Expression and the Clinical Outcomes to Vascular Endothelial Growth Factor-Targeted Therapy in Patients With Metastatic Clear Cell Renal Cell Carcinoma

BACKGROUND

Vascular endothelial growth factor pathway (VEGF)-tyrosine kinase inhibitors (TKIs) are used as the first-line treatment for patients with metastatic clear cell renal cell carcinoma (mCCRCC). Recently, programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) blockade emerged as promising therapy for renal cell carcinoma. However, the expression pattern and prognostic implication of programmed death-ligands (PD-Ls) in mCCRCC patients receiving VEGF-TKI remain unclear.

PATIENTS AND METHODS

PD-L1 and PD-L2 expression in tumor cells and the quantities of PD-1+ tumor-infiltrating lymphocytes were immunohistochemically evaluated in 91 mCCRCC patients treated with VEGF-TKI, and their associations with VEGF-TKI responsiveness and clinical outcome were analyzed.

RESULTS

PD-L1 immunopositivity was observed in 17.6% and significantly associated with a high International Society of Urological Pathology grade (p = .031) and sarcomatoid features (p = .014). PD-L2 immunopositivity was observed in 39.6% and was not associated with any of the assessed clinicopathological variables. PD-L1-positive cases showed poor VEGF-TKI responsiveness (p = .012) compared with PD-L1-negative cases. In univariate survival analysis, PD-L1 immunopositivity was significantly associated with shorter overall survival (OS) (p = .037) and progression-free survival (PFS) (p = .043). Multivariate survival analysis revealed that PD-L1 expression was independently associated with poor OS (p = .038) and PFS (p = .013) in addition to tumor necrosis (p = .006; p = .029, respectively) and Memorial Sloan Kettering Cancer Center score (p = .018; p = .032, respectively). PD-L2 expression was neither associated with VEGF-TKI responsiveness nor patients' outcome.

CONCLUSION

PD-L1 expression was significantly related to lack of VEGF-TKI responsiveness and independently associated with shorter survival in mCCRCC patients after VEGF-TKI treatment. PD-L1 may have a predictive and prognostic value for determining the value of VEGF-TKI treatment in patients with mCCRCC.

IMPLICATIONS FOR PRACTICE

Vascular endothelial growth factor pathway (VEGF)-tyrosine kinase inhibitors (TKIs) are essential for the treatment of metastatic renal cell carcinoma patients, but the treatment suffers from a lack of predictive markers. This study demonstrates that PD-L1 expression is a predictor for unfavorable response to VEGF-TKI and a prognostic indicator for poor overall survival and progression-free survival in patients with metastatic clear cell renal cell carcinoma receiving VEGF-TKI.

miR-221/222 Are Involved in Response to Sunitinib Treatment in Metastatic Renal Cell Carcinoma

Sunitinib is a multitargeting tyrosine kinase inhibitor used for metastatic renal cancer. There are no biomarkers that can predict sunitinib response. Such markers are needed to avoid administration of costly medication with side effects to patients who would not benefit from it. We compared global miRNA expression between patients with a short (≤12 months) versus prolonged (>12 months) progression-free survival (PFS) under sunitinib as first-line therapy for metastatic renal cell carcinoma. We identified a number of differentially expressed miRNAs and developed miRNA statistical models that can accurately distinguish between the two groups. We validated our models in the discovery set and an independent set of 57 patients. Target prediction and pathway analysis showed that these miRNAs are involved in vascular endothelial growth factor (VEGF), TGFβ, and mammalian target of rapamycin (mTOR)-mediated signaling and cell-cell communication. We tested the effect of these miRNAs on cellular proliferation and angiogenesis. We validated the negative correlation between miR-221 and its target, VEGFR2.miR-221 overexpression was associated with a poor PFS while its target, VEGFR2 was associated with longer survival. Gain of function experiments showed that miR-221 and miR-222 decreased angiogenesis and cellular proliferation in human umbilical vein endothelial cells (HUVEC) while increasing cellular proliferation in ACHN cells. miRNAs represent potential predictive markers for sunitinib response.

The association of platelet count with clinicopathological significance and prognosis in renal cell carcinoma: a systematic review and meta-analysis

OBJECTIVE

Elevated platelet count (PC), a measure of systemic inflammatory response, is inconsistently reported to be associated with poor prognosis in patients with renal cell carcinoma (RCC). We conducted a systematic review and meta-analysis to clarify the significance of PC in RCC prognosis.

METHODS

PubMed, Embase, and Web of Science databases were searched to identify eligible studies to evaluate the associations of PC with patient survival and clinicopathological features of RCC.

RESULTS

We analyzed 25 studies including 11,458 patients in the meta-analysis and categorized the included articles into three groups based on RCC stage. An elevated PC level was associated with poor overall survival (OS, hazard ratio [HR] 2.24, 95% confidence interval [CI] 1.87-2.67, P<0.001) and cancer-specific survival (CSS, HR 2.59, 95% CI 1.92-3.48, P<0.001) when all stages were examined together; with poor CSS (HR 5.09, 95% CI 2.41-10.73, P<0.001) and recurrence-free survival (HR 6.68, 95% CI 3.35-13.34, P<0.001) for localized RCC; with poor OS (HR 2.00, 95% CI 1.75-2.28, P<0.001) for metastatic RCC; and with poor OS (HR 2.05, 95% CI 1.04-4.03, P = 0.038), CSS (HR 3.38, 95% CI 1.86-6.15, P<0.001), and PFS (HR 2.97, 95% CI 1.47-6.00, P = 0.002) for clear cell RCC. Furthermore, an elevated PC level was significantly associated with TNM stage (OR 3.11, 95% CI 1.59-6.06, P = 0.001), pathological T stage (OR 3.13, 95% CI 2.60-3.77, P<0.001), lymph node metastasis (OR 4.01, 95% CI 2.99-5.37, P<0.001), distant metastasis (OR 3.85, 95% CI 2.46-6.04, P<0.001), Fuhrman grade (OR 3.70, 95% CI 3.00-4.56, P<0.001), tumor size (OR 4.69, 95% CI 2.78-7.91, P<0.001) and Eastern Cooperative Oncology Group score (OR 5.50, 95% CI 3.26-9.28, P<0.001).

CONCLUSION

An elevated PC level implied poor prognosis in patients with RCC and could serve as a readily available biomarker for managing this disease.

Using percentage of sarcomatoid differentiation as a prognostic factor in renal cell carcinoma

BACKGROUND

The objective of this study was to determine if the percentage of sarcomatoid differentiation (%Sarc) in renal cell carcinoma (RCC) can be used for prognostic risk stratification, because sarcomatoid RCC (sRCC) is an aggressive variant of kidney cancer.

PATIENTS AND METHODS

We performed a retrospective analysis of patients who underwent surgery for RCC at our institution between 1999 and 2012. Pathology slides for all sRCC cases were reexamined by a single pathologist and %Sarc was calculated. %Sarc was analyzed as a continuous variable and as a categorical variable at cut points of 5%, 10%, and 25%. Potential prognostic factors associated with overall survival (OS) were determined using the Cox regression model. OS curves were generated using Kaplan-Meier methods and survival differences compared using the log-rank test.

RESULTS

One thousand three hundred seven consecutive cases of RCC were identified, of which 59 patients had sRCC (4.5%). As a continuous variable %Sarc was inversely associated with OS (P = .023). Predictors of survival on multivariable analysis included pathologic (p) T status, tumor size, clinical (c) M status and %Sarc at the 25% level. OS was most dependent on the presence of metastatic disease (4 months vs. 21.2 months; P = .001). In cM0 patients with locally advanced (≥ pT3) tumors, OS was significantly diminished in patients with > 25 %Sarc (P = .045). However, %Sarc did not influence OS in patients with cM1 disease.

CONCLUSION

Patients with sRCC have a poor overall outcome as evidenced by high rates of recurrence and death, indicating the need for more effective systemic therapies. In nonmetastatic patients, the incorporation of %Sarc in predictive nomograms might further improve risk stratification.