Ιστική μελέτη στην επιθήλιο-μεσεγχυματική μετατροπή σε νεφροκυτταρικό καρκίνωμα

Το φαινόμενο της επιθηλιομεσεγχυματικής μετατροπής είναι η διεργασία κατά την οποία ένα επιθηλιακό κύτταρο αποκτά φαινότυπο μεσεγχυματικού κυττάρου. Η μετατροπή αυτή στον φαινότυπο του επιθηλιακού κυττάρου απαιτεί την δημιουργία ενός νέου μοριακού προγράμματος του επιθηλιακού ιστού με νέες βιοχημικές οδηγίες. Η ΕΜΤ συμμετέχει σε φυσιολογικές καθώς και σε παθολογικές διεργασίες του οργανισμού. Σκοπό της παρούσας ερευνητικής δραστηριότητας αποτέλεσε η διερεύνηση της ανοσοιστοχημικής πρωτεινικής συνέκφρασης των μορίων ε-καντχερίνης και βιμεντίνης σε σειρά καρκινωμάτων νεφρού διάφορης ιστολογικής τυποποίησης και η συσχέτισή τους με τα κλινικοεργαστηριακά χαρακτηριστικά τους γνωρίσματα. Το υλικό αναδύθηκε από την αρχειακή ιστική βάση του Παθολογο-ανατομικού Τμήματος του Γενικού Νοσοκομείου Αθηνών ‘’ΕΛΠΙΣ’’ και αφορούσε σε - εμπεδωμένα σε κύβους παραφίνης – εκατό (n=100) σποραδικά πρωτοπαθή καρκινώματα νεφρού (RCC), προιόντα νεφρεκτομής. Παθολογοανατομικά ταξινομημένα σύμφωνα με τα ιστολογικά κριτήρια της WHO και όσον αφορά τη διαφοροποίηση βαθμονομημένα με το σύστημα κατά Furhman. Τα εξετασθέντα καρκινώματα αφορούσαν σε 75 διαυγοκυτταρικού τύπου (clear cell RCC), 13 θηλώδους τύπου (papillary RCC) και 12 χρωμόφοβου τύπου (chromophobe RCC). Σύμφωνα με τη συνδυασμένη συμβατική και ψηφιακή ανάλυση, υποέκφραση ή απώλεια της έκφρασης της ε-καντχερίνης παρατηρήθηκε σε 52 περιπτώσεις (52%), ενώ οι υπόλοιπες 48 (48%) χαρακτηρίστηκαν από μετρίου εώς ισχυρού βαθμού ανοσοέκφραση. Όσον αφορά τον ιστολογικό τύπο των εξετασθέντων περιστατικών, απώλεια της έκφρασης της ε-καντχερίνης συσχετίσθηκε περισσότερο με τα διαυγοκυτταρικά και θηλώδους τύπου (p=0.001). Ενδιαφέρουσα παρατήρηση αποτελεί ακόμη η προοδευτική απώλεια της έκφραση του μορίου σε σχέση με το βαθμό διαφοροποίησης του νεοπλάσματος κατά ταξινόμηση Fuhrman’s grade classification (p=0.002). Yποέκφραση ή απώλεια της έκφρασης της βιμεντίνης παρατηρήθηκε σε 19 περιπτώσεις (19%), ενώ οι υπόλοιπες 81 (81%) χαρακτηρίστηκαν από μετρίου εώς ισχυρού βαθμού ανοσοέκφραση. Όσον αφορά τον ιστολογικό τύπο των εξετασθέντων περιστατικών, απώλεια της έκφρασης της βιμεντίνης συσχετίσθηκε περισσότερο με τα διαυγοκυτταρικά και θηλώδους τύπου (p=0.001).

The prognostic value of galactosylceramide-sulfotransferase (Gal3ST1) in human renal cell carcinoma

Renal cell carcinoma (RCC) is the deadliest primary genitourinary malignancy typically associated with asymptomatic initial presentation and poorly predictable survival. Next to established risk factors, tumor microenvironment may alter metastatic capacity and immune landscape. Due to their high concentrations, sulfoglycolipids (sulfatides) were among the first well-described antigens in RCC that are associated with worse prognosis. As sulfatide detection in routine diagnostics is not possible, we aimed to test the prognostic value of its protein counterpart, sulfatide-producing enzyme Gal3ST1. We performed retrospective long-term follow up analysis of Gal3ST1 expression as prognostic risk factor in a representative RCC patient cohort. We observed differentially regulated Gal3ST1 expression in all RCC types, being significantly more associated with clear cell RCC than to chromophobe RCC (p = 0.001). Surprisingly, in contrast to published observations from in vitro models, we could not confirm an association between Gal3ST1 expression and a malignant clinical behaviour of the RCC. In our cohort, Gal3ST1 did not significantly influence progression-free survival (Hazard Ratio (HR): 1.7 95% CI (0.6–4.9), p = 0.327). Particularly after adjusting for histology, T-stage, N-status and M-status at baseline, we observed no independent prognostic effect (HR = 1.0 95% CI (0.3–3.3), p = 0.96). The analysis of Gal3ST1 mRNA expression in a TCGA dataset supported the results of our cohort. Thus, Gal3ST1 might help to differentiate between chromophobe RCC and other frequent RCC entities but—despite previously published data from cell culture models—does not qualify as a prognostic marker for RCC. Further investigation of regulatory mechanisms of sulfatide metabolism in human RCC microenvironment is necessary to understand the role of this quantitatively prominent glycosphingolipid in RCC progression.

Diffusion kurtosis imaging features of renal cell carcinoma: a preliminary study

Objective: To explore the feasibility of diffusion kurtosis imaging (DKI) in differentiating different types of renal cell carcinoma (RCC). Methods: 36 patients with clear cell RCC (CCRCC, low-grade,n = 20 and high-grade, n = 16), 19 with papillary RCC, 11 with chromophobe RCC, and 9 with collecting duct carcinoma (CDC) were examined with DKI technique. b values of 0, 500 and 1000 s/mm2 were adopted. The DKI parameters, i.e., mean diffusivity (MD), mean kurtosis (MK), kurtosis anisotropy (KA), radial kurtosis (RK) and signa-to-noise ration (SNR) of DKI images at different b values were used. Results: The mean SNRs of DKI images at b = 0, 500 and 1000 s/mm2 were 32.8, 14.2 and 9.18, respectively. For MD parameter, a significant higher value was shown in CCRCC than those of papillary RCC, chromophobe RCC and CDC (p < 0.05). In addition, both chromophobe RCC and CDC have larger MD values than papillary RCC (p < 0.05), however, there was no significant differences between chromophobe RCC and CDC (p > 0.05). For MK, KA and RK parameters, a significant higher value was shown in papillary RCC than those of CCRCC, chromophobe RCC and CDC (p < 0.05). Moreover, both chromophobe RCC and CDC have significantly larger values of MK, KA and RK than CCRCC (p < 0.05). Conclusion: Our preliminary study demonstrated significant differences in the DKI parameters between the subtypes of RCCs, given an adequate SNR of DKI images. Advances in knowledge: 1.The MD value is the best parameter to distinguish CCRCC from other RCCs. 2.The MK, KA and RK values are the best parameters to distinguish papillary RCC from other RCCs. 3.DKI is able to provide images with sufficient SNRs in kidney disease.

Splenic metastasis from recurrent chromophobe renal cell carcinoma 12 years post-nephrectomy: a case report

Background Renal cell carcinoma metastases to the spleen are rare. At the time of this report, only 20 cases of splenic metastases from RCC have been published in the literature. To our knowledge, our report is the first splenic metastasis from a chromophobe RCC. Case presentation A 44-year-old woman presented with clinical and radiological features of splenic metastasis from RCC, 12 years after radical nephrectomy for chromophobe RCC. Computed tomography, laparotomy and splenectomy revealed metastases to the spleen and retroperitoneal lymph nodes. Conclusion Splenic metastasis from RCC is uncommon, and rarer still from a chromophobe subtype of RCC. Surgical management of the metastasis is recommended.

Comparative Assessment of the WNT/β-Catenin Pathway, CacyBP/SIP, and the Immunoproteasome Subunit LMP7 in Various Histological Types of Renal Cell Carcinoma

ObjectiveThe Wnt/ß-catenin pathway plays an important role in pathogenesis of variety cancers. Most studies on changes in WNT/β-catenin pathway in renal cell carcinoma (RCC) apply only to clear cell RCC, while there are no comparative assessments of this signaling pathway in various histological types of renal tumors in the available literature. Additionally, considering the close relationship between WNT/β-catenin signaling, CacyBP/SIP and proteasomal activity, it seemed worth comparing WNT/β-catenin pathway, CacyBP/SIP and LMP7 immunoproteasome subunit in human samples of clear cell, papillary, and chromophobe RCC.MethodsTests were performed on sections of three types of kidney tumors together with surrounding unchanged tissue fragments collected from 50 patients. Samples were divided into three groups depending on the histological type of cancer: clear cell, papillary and chromophobe RCC. Immunohistochemistry and PCR methods were used to identify WNT10A, Fzd5, β-catenin, GSK-3ß, CacyBP/SIP, LMP7, and gene expression.ResultsImmunoreactivity and expression of WNT10A, Fzd5, β-catenin, GSK-3ß, CacyBP/SIP, LMP7 in clear cell RCC was markedly increased compared to non-cancerous kidney tissue. In papillary RCC, immunoreactivity and expression of WNT/β-catenin pathway, CacyBP/SIP, LMP7 was also increased compared to non-malignant kidneys, but it was less pronounced than in clear cell RCC. The least substantial increase in immunoreactivity and expression of WNT/β-catenin pathway, CacyBP/SIP, LMP7 was found in chromophobe RCC, compared to other RCC histological subtypes studied.ConclusionsStudy results suggest an important role of WNT/β-catenin pathway, CacyBP/SIP and LMP7 in RCC carcinogenesis, and may indicate new aspects of pathomechanisms leading to differences in the biology of clear cell, papillary and chromophobe RCC.

Radiomic Features and Machine Learning for the Discrimination of Renal Tumor Histological Subtypes: A Pragmatic Study Using Clinical-Routine Computed Tomography

This study evaluates the diagnostic performance of radiomic features and machine learning algorithms for renal tumor subtype assessment in venous computed tomography (CT) studies from clinical routine. Patients undergoing surgical resection and histopathological assessment of renal tumors at a tertiary referral center between 2012 and 2019 were included. Preoperative venous-phase CTs from multiple referring imaging centers were segmented, and standardized radiomic features extracted. After preprocessing, class imbalance handling, and feature selection, machine learning algorithms were used to predict renal tumor subtypes using 10-fold cross validation, assessed as multiclass area under the curve (AUC). In total, n = 201 patients were included (73.7% male; mean age 66 ± 11 years), with n = 131 clear cell renal cell carcinomas (ccRCC), n = 29 papillary RCC, n = 11 chromophobe RCC, n = 16 oncocytomas, and n = 14 angiomyolipomas (AML). An extreme gradient boosting algorithm demonstrated the highest accuracy (multiclass area under the curve (AUC) = 0.72). The worst discrimination was evident for oncocytomas vs. AML and oncocytomas vs. chromophobe RCC (AUC = 0.55 and AUC = 0.45, respectively). In sensitivity analyses excluding oncocytomas, a random forest algorithm showed the highest accuracy, with multiclass AUC = 0.78. Radiomic feature analyses from venous-phase CT acquired in clinical practice with subsequent machine learning can discriminate renal tumor subtypes with moderate accuracy. The classification of oncocytomas seems to be the most complex with the lowest accuracy.

Tissue-Based Immunohistochemical Markers for Diagnosis and Classification of Renal Cell Carcinoma

The development and description of renal cell carcinoma (RCC) subtypes has led to an increase in demand for tissue biomarkers. This has implications not only in informing diagnosis, but also in guiding treatment selection and in prognostication. Although historically, many immunohistochemical (IHC) stains have been widely characterized for RCC subtypes, challenges may arise in interpreting these results. These may include variations in tumor classification, specimen collection and processing, and IHC techniques. In light of the reclassification of RCC subtypes in 2016, there remains a requirement for a comprehensive outline of tissue biomarkers that may be used to differentiate between RCC subtypes and distinguish these from other non-renal neoplasms. In this review, concise summaries of the commonest RCC subtypes, including clear cell, papillary, and chromophobe RCC, have been provided. Important differences have been highlighted between chromophobe RCC and renal oncocytomas. An overview of the current landscape of tissue biomarkers in other RCC subtypes has also been explored, revealing the variable staining results reported for some markers, whilst highlighting the essential markers for diagnosis in other subtypes.

Urinary Metabolomics Validates Metabolic Differentiation Between Renal Cell Carcinoma Stages and Reveals a Unique Metabolic Profile for Oncocytomas

Renal cell carcinoma (RCC) is a heterogeneous malignancy which often develops and progresses asymptomatically. Benign oncocytomas are morphologically similar to malignant chromophobe RCC and distinguishing between these two forms on cross-sectional imaging remains a challenge. Therefore, RCC-specific biomarkers are urgently required for accurate and non-invasive, pre-surgical diagnosis of benign lesions. We have previously shown that dysregulation in glycolytic and tricarboxylic acid cycle intermediates can distinguish benign lesions from RCC in a stage-specific manner. In this study, preoperative fasting urine samples from patients with renal masses were assessed by ¹H nuclear magnetic resonance (NMR). Significant alterations in levels of tricarboxylic acid cycle intermediates, carnitines and its derivatives were detected in RCC relative to benign masses and in oncocytomas vs. chromophobe RCC. Orthogonal Partial Least Square Discriminant Analysis plots confirmed stage discrimination between benign vs. pT1 (R2 = 0.42, Q2 = 0.27) and benign vs. pT3 (R2 = 0.48, Q2 = 0.32) and showed separation for oncocytomas vs. chromophobe RCC (R2 = 0.81, Q2 = 0.57) and oncocytomas vs. clear cell RCC (R2 = 0.32, Q2 = 0.20). This study validates our previously described metabolic profile distinguishing benign tumors from RCC and presents a novel metabolic signature for oncocytomas which may be exploited for diagnosis before cross-sectional imaging.

Compare fuhrman nuclear and chromophobe tumor grade on chromophobe RCC

BackgroundChromophobe renal cell carcinoma (chRCC) has a favorable prognosis. Due to irregular nuclei and nuclear pleomorphism, chRCC has a high Fuhrman nuclear grade (FNG). The chromophobe tumor grade (CTG) is a novel three-tier grading system that has been reported to be a better prognosticator than the traditional FNG. We compared the two nuclear grading systems in terms of patients’ clinical outcomes.Patients and MethodWe performed this retrospective chart review of all patients with chRCC from 2000 to 2017. All pathologic features and CTG and FNG results were re-evaluated.ResultEighteen patients’ records were reviewed with a mean follow-up of 70.6 months. The nuclear grading distribution was as follows: FNG 2, 56%; FNG 3, 39%; FNG 4, 5%; CTG 1, 78%; CTG 2, 17%; and CTG 3, 6%. Only one patient died. This patient had adrenal invasion, lung metastasis, sarcomatoid change and tumor necrosis, and the tumor was graded as FNG 4 and CTG 3. Overall survival was associated with both FNG and CTG.ConclusionChromophobe RCC was associated with a low rate of cancer-specific death and sarcomatoid differentiation. Both FNG and CTG were associated with overall survival.

Chromophobe Renal Cell Carcinoma With Retrograde Venous Invasion and Gain of Chromosome 21: Potential Harbingers of Aggressive Clinical Behavior

Occasionally, renal cell carcinoma (RCC) with renal vein extension spreads against the flow of blood within vein branches into the kidney, forming multifocal nodules throughout the renal parenchyma. These foci are not regarded as multiple tumors but rather reverse spread of tumor along the venous system. This intravascular spread has previously been reported in clear cell RCC and RCC unclassified. However, to our knowledge, this has never been reported in chromophobe RCC. Chromophobe RCC is a unique histologic subtype of renal cancer, generally thought to have less aggressive behavior. However, it nonetheless has the potential to undergo sarcomatoid dedifferentiation, which is associated with poor prognosis. We report a unique case of a 65-year-old man with chromophobe RCC (pT3a) showing classic morphology (nonsarcomatoid), yet presenting with retrograde venous invasion and hilar lymph node metastasis at the time of right radical nephrectomy. Fluorescence in situ hybridization revealed gain of chromosome 21 with loss of multiple other chromosomes. Partial hepatectomy was performed to resect metastatic RCC 7 months after nephrectomy, revealing chromophobe RCC with classic morphology. Bone biopsy confirmed skeletal metastases 38 months after initial diagnosis. Although invasion of the renal vein and retrograde venous invasion are characteristically seen in clear cell RCC, this unusual phenomenon may also occur in chromophobe RCC, despite its unique tumor biology. This and gain of chromosome 21, which was postulated to be associated with aggressive behavior in a previous report, were associated with adverse behavior in our patient, who had short-term progression to multi-organ metastatic disease.