Current pathology keys of renal cell carcinoma

Constitutional genetic variants as predictors of antiangiogenic therapy outcome in renal cell carcinoma

The development of specific angiogenesis inhibitors has drastically improved renal cancer treatment in recent years. Currently, four VEGF receptor inhibitors (sorafenib, sunitinib, pazopanib and axitinib), one anti-VEGF monoclonal antibody (bevacizumab) and two inhibitors of the mTOR pathway (temsirolimus and everolimus) have been approved to treat renal cell carcinoma (RCC), and several other molecules are under investigation. However, lack of response to antiangiogenic drugs and adverse drug reactions leading to treatment suspension are critical clinical problems that need to be solved. Because antiangiogenic drugs act on nonmalignant endothelial cells, the genetic background of the patient may play a crucial role determining the efficacy of these drugs. This article focuses on the identification of polymorphisms associated with antiangiogenic drugs outcome in RCC patients. It reviews and summarizes our current knowledge on this area and discusses future strategies to identify new biomarkers that could be used to personalize RCC management.

Rare (<1%) histological subtypes of renal cell carcinoma: an update

Recent advances in genetics and pathology have allowed description of several new histological subtypes of renal cell carcinoma (RCC) as well as better characterization of other rare subtypes. We herein present a comprehensive review of taxonomy, epidemiology, pathology, imaging findings, and natural history of a wide spectrum of rare subtypes of RCCs that individually constitute <1% of all the RCCs.

Characterization of N-diethylnitrosamine-initiated and ferric nitrilotriacetate-promoted renal cell carcinoma experimental model and effect of a tamarind seed extract against acute nephrotoxicity and carcinogenesis

Renal cell carcinoma (RCC), the commonest malignancy in adult kidney, lacks of early signs, resulting often in metastasis at first diagnosis. N-Diethylnitrosamine (DEN)-initiated and ferric nitrilotriacetate (FeNTA)-promoted RCC may be a useful experimental model, but it is not well characterized. In this study, histological alterations and oxidative stress markers were analyzed at different times throughout RCC development, histological subtype was re-evaluated in the light of current classification, and a tamarind seed extract (TSE) effect was examined. Male Wistar rats experimental groups were control, TSE, DEN, DEN+FeNTA, and TSE+DEN+FeNTA. TSE was given 2 weeks before DEN administration (200 mg/kg) and throughout the experiment. Fourteen days after DEN treatment, two FeNTA doses (9 mg Fe/kg) for acute nephrotoxicity study, and increasing FeNTA doses (3-9 mg Fe/kg) twice a week for 16 weeks for carcinogenesis protocol, were administered. In acute study, necrosis and renal failure were observed and TSE ameliorated them. Throughout carcinogenesis protocol, preneoplastic lesions were observed since 1 month of FeNTA treatment, which were more evident at 2 months, when also renal cysts and RCC were already detected. RCC tumors were obtained without changes in renal function, and clear cell histological subtype was identified in all cases. 4-Hydroxy-2-nonenal and 3-nitro-L: -tyrosine levels increased progressively throughout protocol. TSE decreased both oxidative stress markers and, although there was no statistical difference, it delayed RCC progress and decreased its incidence (21 %). This study brings an insight of the time course events in this carcinogenesis model, identifies clear cell subtype and establishes TSE renoprotective effects.

Vasoactive intestinal peptide (VIP) inhibits human renal cell carcinoma proliferation

Clear renal cell carcinoma (cRCC) is an aggressive and fatal neoplasm. The present work was undertaken to investigate the antiproliferative potential of vasoactive intestinal peptide (VIP) exposure on non-tumoral (HK2) and tumoral (A498, cRCC) human proximal tubular epithelial cell lines. Reverse transcription and semiquantitative PCR was used at the VIP mRNA level whereas enzyme immunoanalysis was performed at the protein level. Both renal cell lines expressed VIP as well as VIP/pituitary adenylate cyclase-activating peptide (VPAC) receptors whereas only HK2 cells expressed formyl peptide receptor-like 1 (FPRL-1). Receptors were functional, as shown by VIP stimulation of adenylyl cyclase activity. Treatment with 0.1μM VIP (24h) inhibited proliferation of A498 but not HK2 cells as based on a reduction in the incorporation of [(3)H]-thymidine and BrdU (5'-Br-2'-deoxyuridine), PCNA (proliferating-cell nuclear antigen) expression and STAT3 (signal transducer and activator of transcription 3) expression and activation. VPAC(1)-receptor participation was established using JV-1-53 antagonist and siRNA transfection. Growth-inhibitory response to VIP was related to the cyclic adenosine monophosphate (cAMP)/exchange protein directly activated by cAMP (EPAC)/phosphoinositide 3-kinase (PI3-K) signaling systems as shown by studies on adenylate cyclase stimulation, and using the EPAC-specific compound 8CPT-2Me-cAMP and specific kinase inhibitors such as H89, wortmannin and PD98059. The efficacy of VIP on the prevention of tumor progression was confirmed in vivo using xenografted athymic mouse. These actions support a potential role of this peptide and its agonists in new therapies for cRCC.

End stage and chronic kidney disease: associations with renal cancer

There is a well known association between end stage renal disease and the development of kidney cancer in the native kidney of patients requiring renal replacement therapy. There is now emerging evidence that lesser degrees of renal insufficiency (chronic kidney disease, CKD) are also associated with an increased likelihood of cancer in general and kidney cancer in particular. Nephropathological changes are commonly observed in the non-tumor bearing portions of kidney resected at the time of partial and radical nephrectomy (RN). In addition, patients with renal cancer are more likely to have CKD at the time of diagnosis and treatment than the general population. The exact mechanism by which renal insufficiency transforms normal kidney cells into tumor cells is not known. Possible mechanisms include uremic immune inhibition or increased exposure to circulating toxins not adequately cleared by the kidneys. Surgeons managing kidney tumors must have an increased awareness of their patient's renal functional status as they plan their resection. Kidney sparing approaches, including partial nephrectomy (PN) or active surveillance in older and morbidly ill patients, can prevent CKD or delay the further decline in renal function which is well documented with RN. Despite emerging evidence that PN provides equivalent local tumor control to RN while at the same time preventing CKD, this operation remains under utilized in the United States and abroad. Increased awareness of the bi directional relationship between kidney function and kidney cancer is essential in the contemporary management of kidney cancer.