A case-control study of occupational sunlight exposure and renal cancer risk

Imaging of Renal Transplant Complications throughout the Life of the Allograft: Comprehensive Multimodality Review

The kidney is the most commonly transplanted solid organ. Advances in surgical techniques, immunosuppression regimens, surveillance imaging, and histopathologic diagnosis of rejection have allowed prolonged graft survival times. However, the demand for kidneys continues to outgrow the available supply, and there are efforts to increase use of donor kidneys with moderate- or high-risk profiles. This highlights the importance of evaluating the renal transplant patient in the context of both donor and recipient risk factors. Radiologists play an integral role within the multidisciplinary team in care of the transplant patient at every stage of the transplant process. In the immediate postoperative period, duplex US is the modality of choice for evaluating the renal allograft. It is useful for establishing a baseline examination for comparison at future surveillance imaging. In the setting of allograft dysfunction, advanced imaging techniques including MRI or contrast-enhanced US may be useful for providing a more specific diagnosis and excluding nonrejection causes of renal dysfunction. When a pathologic diagnosis is deemed necessary to guide therapy, US-guided biopsy is a relatively low-risk, safe procedure. The range of complications of renal transplantation can be organized temporally in relation to the time since surgery and/or according to disease categories, including immunologic (rejection), surgical or iatrogenic, vascular, urinary, infectious, and neoplastic complications. The unique heterotopic location of the renal allograft in the iliac fossa predisposes it to a specific set of complications. As imaging features of infection or malignancy may be nonspecific, awareness of the patient's risk profile and time since transplantation can be used to assign the probability of a certain diagnosis and thus guide more specific diagnostic workup. It is critical to understand variations in vascular anatomy, surgical technique, and independent donor and recipient risk factors to make an accurate diagnosis and initiate appropriate treatment.^©RSNA, 2019.

The Vitamin D status is associated with serum C-reactive protein and adhesion molecules in patients with renal cell carcinoma

Low vitamin D status is associated with an increased risk of renal cell carcinoma (RCC). This study investigated the association of vitamin D status with serum C-reactive protein (CRP) and adhesion molecules among RCC patients. Fifty newly diagnosed RCC patients and 100 age- and sex-matched controls were recruited. As expected, serum 25(OH)D level was lower in RCC patients than in controls. By contrast, serum levels of CRP, an inflammatory molecule, and ICAM, LAMA4 and EpCAM, three adhesion molecules, were higher in RCC patients than in controls. All RCC patients were divided into two groups: H-VitD (>20 ng/ml) or L-VitD (<20 ng/ml). Interestingly, the levels of serum CRP and all adhesion molecules were higher in RCC patients with L-VitD than those with H-VitD. Nuclear vitamin D receptor (VDR) was downregulated and nuclear factor kappa B (NF-κB) was activated in cancerous tissues. The in vitro experiments found that VitD3 suppressed NF-κB activation and adhesion molecules in RCC cells. Moreover, VitD3 suppressed NF-κB through reinforcing physical interaction between VDR and NF-κB p65 subunit in RCC cells. These results provide a mechanistic explanation for the association among low vitamin D status, local inflammation and increased expression of adhesion molecules among RCC patients.

The correlation between low vitamin D status and renal interleukin-6/STAT3 hyper-activation in patients with clear cell renal cell carcinoma

Low vitamin D status has been associated with increased risks of renal cell carcinoma (RCC). This study aimed to analyze the link between low vitamin D status and interleukin (IL)-6/STAT3 hyper-activation in clear cell RCC (ccRCC) patients. Forty-three newly diagnosed ccRCC patients and 86 age- and sex-matched controls were recruited. The association between low vitamin D status and IL-6/STAT3 hyper-activation was analyzed. Proliferation makersand STAT3 signal were evaluated. As expected, serum IL-6 level was higher in ccRCC patients than in controls. Moreover, serum IL-6 level was reversely correlated with serum 25(OH)D in ccRCC patients but not in controls. In addition, STAT3 signaling was hyper-activated in cancerous tissue. CcRCC patients were divided into three groups according to serum 25(OH)D level: vitamin D sufficiency (VitD-S, ≥30 ng/ml), vitamin D insufficiency (VitD-I, ≥20 and <30 ng/ml) or vitamin D deficiency (VitD-D, <20 ng/ml). Serum IL-6 was higher in ccRCC patients with VitD-D than those with VitD-S/VitD-I. Cancerous pSTAT3 level was higher in ccRCC patients with VitD-D than those with VitD-S/VitD-I. The number of pSTAT3⁺ nuclei in cancerous tissue was more in ccRCC patients with VitD-D than those with VitD-S/VitD-I. The expressions of cancerous PCNA, cyclin D1 and Ki-67, three markers of proliferation, were higher in ccRCC patients with VitD-D than those with VitD-S/VitD-I. The in vitro experiments showed that active vitamin D3 inhibited LPS-induced STAT3 phosphorylation in ACHN cells. Our results provide evidence that low vitamin D status is correlated with hyper-activation of cancerous IL-6/STAT3 and proliferation in ccRCC patients.

Does sunlight protect us from cancer?

The Ultraviolet (UV) radiation contained in sunlight is a powerful mutagen and immune suppressant which partly explains why exposure to solar UV is the biggest risk factor for the development of cutaneous tumours. Evidence is building that sunlight may be protective against some internal malignancies. Because patients with these tumours are often vitamin D deficient, this has led some to propose that vitamin D supplementation will be beneficial in the treatment of these cancers. However, the results from already completed trials have been disappointing which has given weight to the argument that there must be something else about sunlight that explains its cancer-protecting properties.