Percentage of high-grade carcinoma as a prognostic indicator in patients with renal cell carcinoma

Value of energy spectrum CT parameters in the differential diagnosis of high-grade clear cell renal cell carcinoma and type II papillary renal cell carcinoma

BACKGROUND

Energy spectrum computed tomography (CT) has become a promising approach for the differential diagnosis of tumor subtypes.

PURPOSE

To explore the value of energy spectrum CT parameters in the differential diagnosis of high-grade clear cell renal cell carcinoma (ccRCC) and type II papillary renal cell carcinoma (pRCC).

MATERIAL AND METHODS

Forty-two cases of high-grade ccRCC and 28 cases of type II pRCC were retrospectively reviewed. All region of interest (ROI) measurements were maintained consistently between the two-phase contrast-enhanced examinations. The ROIs encompassed as much of the enhancing areas of the lesions as possible. Energy spectrum CT parameters of all cases, including the 70 keV (HU) value, normalized iodine concentration (NIC), and energy spectrum curve slope were recorded by two radiologists with over 10 years of experience in abdominal CT diagnosis.

RESULTS

In the cortical phase (CP) and parenchymal phase (PP), the 70 keV (HU) value, NIC, and slope value of the energy spectrum curve of high-grade ccRCC were significantly higher than those of type II pRCC. In the CP, NIC showed the highest differential diagnosis efficiency for the two group tumors, with a sensitivity of 78.9% and a specificity of 77.0%. There was no statistical difference in tumor hemorrhage, tumor envelope, tumor morphology, tumor border, lymph node metastasis, embolism, renal pelvis invasion, or tumor calcification between the two tumor types. However, there was significant difference in the number of tumors (P = 0.019).

CONCLUSION

Energy spectrum CT parameters are valuable for the differential diagnosis of high-grade ccRCC and type II pRCC.

A MUCINs expression signature impacts overall survival in patients with clear cell renal cell carcinoma

Background

Kidney cancer, especially clear cell renal cell carcinoma (ccRCC), is one of the most common cancers in the urinary system. Previous studies suggested that certain members of MUCINs could serve as independent predictors for the survival of ccRCC patients. None of them, however, is robust enough to predict prognosis accurately.

Objective

To analyze the correlation of MUCINs alterations and their expression levels with the prognosis of ccRCC patients and develop a prognosis‐related predictor.

Methods

We applied whole‐exome sequencing in samples from 22 Chinese ccRCC patients to identify genetic alterations in MUCIN genes and analyzed their genetic alterations, expression, and correlation with survival using the TCGA, GSE73731, and GSE29069 datasets.

Result

Genetic alternations in MUCINs were identified in 91% and 51% of ccRCC patients in our cohort and the TCGA database, respectively. No correlation with survival was found for the genetic alterations. Using unsupervised clustering analysis of gene expression, we identified two major clusters of MUCIN expression patterns. Cluster 1 was characterized by a global overexpression of MUC1, MUC12, MUC13, MUC16, and OVGP1; and cluster 2 was characterized by a global overexpression of MUC4, MUC5B, MUC6, MUC20, EMCN, and MCAM. Patients with cluster 1 expression pattern had significantly shorter overall survival time and worse clinical features, including higher tumor grades and metastasis. Meanwhile, they had a higher level of mutation counts and more infiltrated immune cells, but lower enrichment in angiogenesis signature genes. A five‐MUCINs expression signature was constructed from cluster 1, and notably, it was demonstrated to be associated with shorter overall survival. A similar worse clinical feature, lower angiogenesis but the more immune signature, was identified in samples presented with signature 1. In the validation data set GSE29069, patients with signature 1 were also associated with a trend of poor survival outcomes.

Conclusion

We established a five‐MUCINs expression signature as a new prognostic marker for ccRCC. The distinct tumor microenvironment feature between the two signatures may further affect ccRCC patients’ clinical management.

Data set for the reporting of carcinoma of renal tubular origin: recommendations from the International Collaboration on Cancer Reporting (ICCR)

AIMS

The International Collaboration on Cancer Reporting (ICCR) has provided detailed data sets based upon the published reporting protocols of the Royal College of Pathologists, the Royal College of Pathologists of Australasia and the College of American Pathologists.

METHODS AND RESULTS

The data set for carcinomas of renal tubular origin treated by nephrectomy was developed to provide a minimum structured reporting template suitable for international use, and incorporated recommendations from the 2012 Vancouver Consensus Conference of the International Society of Urological Pathology (ISUP) and the fourth edition of the World Health Organisation Bluebook on tumours of the urinary and male genital systems published in 2016. Reporting elements were divided into those, which are required and recommended components of the report. Required elements are: specimen laterality, operative procedure, attached structures, tumour focality, tumour dimension, tumour type, WHO/ISUP grade, sarcomatoid/rhabdoid morphology, tumour necrosis, extent of invasion, lymph node status, surgical margin status, AJCC TNM staging and co-existing pathology. Recommended reporting elements are: pre-operative treatment, details of tissue removed for experimental purposes prior to submission, site of tumour(s) block identification key, extent of sarcomatoid and/or rhabdoid component, extent of necrosis, presence of tumour in renal vein wall, lymphovascular invasion and lymph node status (size of largest focus and extranodal extension).

CONCLUSIONS

It is anticipated that the implementation of this data set in routine clinical practice will inform patient treatment as well as provide standardised information relating to outcome prediction. The harmonisation of data reporting should also facilitate international research collaborations.

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.

Clinicopathological characteristics of surgically treated localized renal masses in patients previously exposed to chemotherapy

Purpose:

To explore the potential association between renal mass characteristics and a history of chemotherapy.

Materials and methods:

A retrospective review of records of patients surgically treated for a localized renal mass between 2000 and 2012 was undertaken following an institutional review board approval. Patients age and sex, renal mass clinical characteristics (radiological size and mode of presentation) and pathological characteristics (diagnosis, renal cell carcinoma subtype, Fuhrman grade and stage) were compared between patients with and without a history of chemotherapy, using Fisher's exact test, Student's t-test and Wilcoxon rank sum test. A multivariate logistic analysis was performed to evaluate the independent association of chemotherapy and tumor pathology.

Results:

Of the 1,038 eligible patients, 33 (3%) had a history of chemotherapy. The distribution of clinical stage, renal mass diagnosis, renal cell carcinoma subtype, Fuhrman grade, pathological stage, sex and median age were similar between the general population and the chemotherapy group. However, the latter had a higher rate of incidental presentation (P = 0.003) and a significantly smaller median radiological tumor size (P = 0.01). In a subset analysis of T1a renal cell carcinoma, the chemotherapy group presented an increased rate of high Fuhrman grade (P = 0.03). On multivariate analysis adjusted for radiological tumor size, sex and age the chemotherapy cohort had a 3.92 higher odds for high Fuhrman grade.

Conclusion:

Patients with a history of chemotherapy typically present with smaller renal masses that, if malignant, have higher odds of harboring a high Fuhrman grade and thus may not be suitable for active surveillance.

Pathological Bases and Clinical Impact of Intratumor Heterogeneity in Clear Cell Renal Cell Carcinoma

PURPOSE OF REVIEW

Intratumor heterogeneity is an inherent event in tumor development that is receiving much attention in the last years since it is responsible for most failures of current targeted therapies. The purpose of this review is to offer clinicians an updated insight of the multiple manifestations of a complex event that impacts significantly patient's life.

RECENT FINDINGS

Clear cell renal cell carcinoma is the most common renal tumor and a paradigmatic example of a heterogeneous neoplasm. Next-generation sequencing has demonstrated that intratumor heterogeneity encompasses genetic, epigenetic, and microenvironmental variability. Currently accepted protocols of tumor sampling seem insufficient in unveiling intratumor heterogeneity with reliability and need to be updated. This variability challenges the precise morphological diagnosis, its molecular characterization, and the selection of optimal personalized therapies in clear cell renal cell carcinoma, a neoplasm traditionally considered chemo- and radio-resistant. We review the state of the art of the different approaches to intratumor heterogeneity in clear cell renal cell carcinomas, from the simple morphology to the most sophisticated massive sequencing tools.

Intracellular lipid in clear cell renal cell carcinoma tumor thrombus and metastases detected by chemical shift (in and opposed phase) MRI: radiologic-pathologic correlation

BACKGROUND

Clear cell renal cell carcinoma (RRC) characteristically contain intracellular lipid which is also detectable in tumor thrombus and metastases.

PURPOSE

To assess the incidence of intracellular lipid in clear cell RCC metastases and tumor thrombus using chemical shift MRI.

MATERIAL AND METHODS

With REB approval, 33 consecutive patients with clear cell RCC and tumor thrombus/metastatic disease underwent magnetic resonance imaging (MRI) over a 10-year period. Diagnosis was established by histopathology for tumor thrombi (n = 25) and metastases (n = 15) or growth for metastases (n = 14). Two blinded radiologists independently assessed for a signal intensity (SI) drop at chemical shift MRI (indicative of intracellular lipid) and a third radiologist established consensus. Chemical shift SI (CS-SI) index ([SItumorIP - SItumorOP]/SITumorIP x 100) was calculated. Inter-observer agreement was assessed using intra-class correlation (ICC) and tests of association were performed using the Chi-square test and Spearman correlation.

RESULTS

Using CS-MRI, intracellular lipid was detected in 36.4% of clear cell RCC, with moderate agreement, (ICC = 0.5). Intracellular lipid was detected in 20% of tumor thrombi and 20% of metastases with strong agreement (ICC = 0.73). Intracellular lipid within tumor thrombi/metastases was not associated with lipid within the primary tumor (P = 0.09). There was a correlation in CS-SI index between primary tumor and thrombi/metastases when lipid was detected in both lesions (r = 0.91, P = 0.005); however, there was no correlation when lipid was not detected in both lesions (r = -0.09, P = 0.72).

CONCLUSION

The presence of intracellular lipid in tumor thrombus and metastases from clear cell RCC is uncommon and, is not necessarily associated with lipid within the primary tumor at chemical shift MRI.

Intratumor heterogeneity in clear cell renal cell carcinoma: a review for the practicing pathologist

Intertumor heterogeneity, defined as the spectrum of morphological differences found in similar tumors in different patients, is a well-known event for pathologists. However, recent molecular studies have pointed to intratumor heterogeneity as one of the most important issues in human neoplasia in the next years. Clear cell renal cell carcinoma is an example of an intrinsically heterogeneous neoplasm, and some of the most salient advances in the knowledge of intratumor heterogeneity have been developed on it. This review intends to analyze this phenomenon in this tumor from the practicing pathologist's point of view. A careful study of the surgical specimen and an exhaustive tumor sampling are mandatory to keep relevant information. Currently accepted protocols designed for renal tumor sampling may be insufficient. As a result, a different approach to tumor sampling is advisable to ascertain that intratumor heterogeneity, if present, will be well represented in the selected material.

How should clinicians address intratumour heterogeneity in clear cell renal cell carcinoma?

PURPOSE OF REVIEW

Despite the availability of multiple targeted therapies, the 5-year survival rate of patients with metastatic clear cell renal cell carcinoma (ccRCC) rarely exceeds 10%. Recent insights into the mutational landscape and evolutionary dynamics of ccRCC have offered up a plausible explanation for these outcomes. The purpose of this review is to link the research findings to potential changes in clinical practice.

RECENT FINDINGS

Intratumour heterogeneity (ITH) dominates the evolutionary landscape in ccRCC at the genetic, transcriptomic and proteomic level. Spatial and temporal separation of tumour subclones within the primary tumour as well as between primary and metastatic sites has been demonstrated at single nucleotide resolution. In the cases analysed to date, approximately two-thirds of somatic mutations are not shared between multiple biopsies from the same primary tumour. Very few of the key disease-driving events are shared across all primary tumour regions (with the exception of VHL and loss of chromosome 3p), whereas the majority are restricted to one or more tumour regions (TP53, SETD2, BAP1, PTEN, mTOR, PIK3CA and KDM5C).

SUMMARY

ITH must be considered in the management of ccRCC with respect to diagnostic procedures, prognostic and predictive biomarkers and drug development.

Nephron-sparing surgery for multifocal and hereditary renal tumors

PURPOSE OF REVIEW

Despite the controversy surrounding the benefits of nephron-sparing surgery, multiple absolute indications for nephron-sparing surgery still exist, including the classic indications of hereditary and bilateral kidney tumors.

RECENT FINDINGS

Multiple genetic mutations have been identified which lead to hereditary kidney cancer conditions. These are briefly reviewed because the surgical management of hereditary kidney tumors depends on the genetic and histologic subtypes involved. Clear understanding of these hereditary conditions is crucial for proper surgical management of these tumors.

SUMMARY

Complex partial nephrectomy for multiple renal tumors, or multiplex partial nephrectomy, requires not only exceptional surgical skills but expertise of numerous nonsurgical methodologies, such as hands-on intraoperative ultrasonography and interpretation of multiple imaging modalities. In addition, multidisciplinary management is crucial for optimal outcomes in patient care. This review evaluates the most advanced surgical techniques and perioperative management required to successfully care for these challenging cases.

Papillary renal cell carcinoma revisited: a comprehensive histomorphologic study with outcome correlations

Papillary renal cell carcinoma (P-RCC) is the second most common type of malignant renal epithelial tumor and can be subclassified into type 1, which demonstrates simple cuboidal low-grade epithelium and type 2, which demonstrates pseudostratified high-grade epithelium with abundant eosinophilic cytoplasm. Despite this clinically useful subclassification, P-RCCs exhibit considerable histomorphologic diversity, with many cases having features differing from classically described type 1 and type 2 tumors. To our knowledge, there has been no recent study that has methodically evaluated the histomorphologic features of a series of P-RCCs. To address this, we evaluated a cohort of P-RCCs diagnosed between 1997 and 2004 with long-term clinical follow-up data (n = 56). Histomorphologic features previously described in the spectrum of type 1 and type 2 P-RCCs were recorded for each tumor, including nuclear grade, complete tumor capsule, and cytoplasmic eosinophilia as well as several other features. The current TNM staging (American Joint Committee on Cancer, seventh edition) was assigned to all cases. Histomorphologic features were diverse, demonstrating classic type 1 P-RCC and classic type 2 P-RCC morphology and several tumors with nonclassic features. Four patients in this cohort had distant metastasis. The primary tumor was equally divided between type 1 (2 cases) and type 2 (2 cases) morphology in the cases with metastasis. All P-RCC cases with metastases demonstrated presence of high nuclear grade and high tumor stage in the primary tumor. Cluster analysis using staging parameters and histomorphologic features divided tumors into 2 primary clusters. All primary tumors associated with metastasis were in the same cluster.

Utility of Renal Mass Biopsy in a UK Tertiary Referral Centre

Objective:

To determine the value of percutaneous biopsy in a UK cohort of patients with renal mass lesions, with particular reference to its utility for the prediction of histological cell-type, Fuhrman nuclear grade and necrosis.

Patients and methods:

From May 1999 to September 2009, 71 patients underwent renal mass biopsy (RMB), most for indeterminate renal masses or in those with a mass lesion and extrarenal malignancy. Approximately one-third were for small renal masses (≤4cm). Biopsy results were correlated with final surgical specimen pathology or with the outcome of surveillance in those not receiving surgery.

Results:

Of 71 biopsies, there were 65 (91.5%) considered diagnostic biopsies, of which 59 (90.8%) were malignant and 6 (9.2%) were benign. 30 patients with biopsy-proven malignancy underwent extirpative surgery, with a diagnostic accuracy for biopsy of 100%. Accuracy of RMB for histological sub-type, Fuhrman nuclear grade and tumour necrosis was 80.0%, 52.3% and 80.0%, respectively. Bleeding complications were seen in 2 (2.8%) patients, and there were no cases of needle track seeding.

Conclusion:

RMB is a safe and accurate method for determining underlying malignancy, with an acceptable non-diagnostic rate. Although concordance for histological tumour sub-type and necrosis was reasonable, values for nuclear grade were less reliable.

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.