Long-Term Outcome of Nephron-Sparing Surgery Compared to Radical Nephrectomy for Renal Cell Carcinoma ≥4 cm - A Matched-Pair Single Institution Analysis.

PURPOSE: We investigated the long-term oncological and functional outcome of nephron-sparing surgery/partial nephrectomy (PN) versus radical nephrectomy (RN) for any renal cell carcinoma (RCC) ≥4 cm. PATIENTS AND METHODS: Between 1997 and 2013, we identified 128 patients undergoing PN for RCC ≥4 cm and matched this collective to 128 patients undergoing RN. We then compared overall survival (OS), cancer-specific survival (CSS), progression-free survival (PFS) and functional parameters in both groups. The median follow-up time was 58 months (3-210 months). RESULTS: Compared to RN, patients with a PN showed a significantly higher 10-year OS (77.0 vs. 63.0%, p = 0.04), CSS (90.6 vs. 71.7%, p = 0.002) and PFS (82.9 vs. 57.4%, p ≤ 0.001). Renal function preservation was better in the PN group (24 months estimated glomerular filtration rate: 68.2 ml/min for PN vs. 40.6 ml/min for RN, p ≤ 0.01) with significantly less new onset chronic kidney diseases. Total complication rate was comparable, whereas PN procedures showed more Clavien-Dindo grade I + II complications, portraying the technical challenge of PN in larger RCCs. CONCLUSIONS: Whenever feasible, PN should be considered for renal masses ≥4 cm, as this technique shows better long-term results regarding disease-specific survival and renal function preservation in our study group.

Aldosterone activates transcription factor Nrf2 in kidney cells both in vitro and in vivo.

AIMS: An increased kidney cancer risk was found in hypertensive patients, who frequently exhibit hyperaldosteronism, known to contribute to kidney injury, with oxidative stress playing an important role. The capacity of kidney cells to up-regulate transcription factor nuclear factor-erythroid-2-related factor 2 (Nrf2), a key regulator of the cellular antioxidative defense, as a prevention of aldosterone-induced oxidative damage was investigated both in vitro and in vivo. RESULTS: Aldosterone activated Nrf2 and increased the expression of enzymes involved in glutathione (GSH) synthesis and detoxification. This activation depended on the mineralocorticoid receptor (MR) and oxidative stress. In vitro, Nrf2 activation, GSH amounts, and target gene levels decreased after 24 h, while oxidant levels remained high. Nrf2 activation could not protect cells against oxidative DNA damage, as aldosterone-induced double-strand breaks and 7,8-dihydro-8-oxo-guanine (8-oxodG) lesions steadily rose. The Nrf2 activator sulforaphane enhanced the Nrf2 response both in vitro and in vivo, thereby preventing aldosterone-induced DNA damage. In vivo, Nrf2 activation further had beneficial effects on the aldosterone-caused blood pressure increase and loss of kidney function. INNOVATION: This is the first study showing the activation of Nrf2 by aldosterone. Moreover, the results identify sulforaphane as a substance that is capable of preventing aldosterone-induced damage both in vivo and in vitro. CONCLUSION: Aldosterone-induced Nrf2 adaptive response cannot neutralize oxidative actions of chronically increased aldosterone, which, therefore could be causally involved in the increased cancer incidence of hypertensive individuals. Enhancing the cellular antioxidative defense with sulforaphane might exhibit beneficial effects.

Blood pressure has only minor influence on aldosterone-induced oxidative stress and DNA damage in vivo.

Epidemiological studies found an increased kidney cancer risk in hypertensive patients. These patients frequently present an increase in the mineralocorticoid aldosterone (Ald) due to a stimulated renin angiotensin aldosterone system (RAAS). Recently, we showed pro-oxidative and genotoxic effects of Ald in vitro. Here, we investigated the influence of blood pressure on aldosterone-induced oxidative damage. To distinguish whether effects in Sprague-Dawley rats treated with Ald were caused by Ald or by increased blood pressure, the mineralocorticoid receptor (MR) antagonist spironolactone was administered in a subtherapeutical dose, not lowering the blood pressure, and hydralazine, a RAAS-independent vasodilator, was given to normalize the pressure. With the antioxidant tempol, oxidative stress-dependent effects were demonstrated. Ald treatment caused kidney damage and oxidative and nitrative stress. Structural DNA damage and the mutagenic oxidative base modification 7,8-dihydro-8-oxoguanine were increased, as well as DNA repair activity and nuclear NF-κB translocation. Spironolactone and tempol decreased all markers significantly, whereas hydralazine had just slight effects. These data comprise the first report of essentially blood pressure-independent tissue- and DNA-damaging effects of Ald. A fully activated MR and the production of reactive oxygen and nitrogen species were crucial for these effects.