It is estimated that approximately 20% of SRMs are benign. The majority (55-60%) of those considered "malignant" exhibit a rather indolent clinical behaviour and only about 20-25% demonstrate an aggressive clinical course. The risk of malignancy is related to the diameter of a tumour. It has been shown that 46% of tumours smaller than 1 cm in diameter are benign and only 2.3% of them are high grade [6]. It has also been estimated that an increase of 1cm in diameter correlates with a 16% increase in the risk of malignancy [7].
The Morbidity of Radical NephrectomyRecently there has been significant controversy regarding the indications for radical nephrectomy in the management of T1 stage renal tumours, especially SRMs. The low possibility of malignancy and the relative indolent behaviour of the majority of SRMs makes radical nephrectomy a very aggressive treatment option even more so considering that partial nephrectomy provides equivalent oncological efficacy [8]. There is a known association between CKD and cardiovascular morbidity (CAD, MI, peripheral arterial disease), hospitalization and death [9]. Studies have shown that radical nephrectomy is associated with a 22% risk of developing CKD at 10 years of follow up (defined as eGFR<60ml/min/1.73m2 and/or creatinine>2mg/dl) compared to a 12% risk of CKD for partial nephrectomy [10,11]. Huang et al showed that the possibility of maintaining a normal renal function (GFR>60ml/min/1.73m2) at 10 years of follow up is 80% for partial nephrectomy compared to only 35% for radical nephrectomy [12].Chang et al. [13] used the analytical Markov model of a 65-year old patient with a unilateral small renal tumor and normal renal function in order to predict the long-term outcomes of partial versus radical nephrectomy. The study showed that partial nephrectomy is more cost-effective and provides better quality of life compared to radical nephrectomy for patients with SRMs mainly due to the lower risk of CKD. The issue of mortality following radical nephrectomy for SRMs was addressed in a study using data from the SEER database. 4.216 patients with renal tumors smaller than 2 cm were subjected to either partial nephrectomy (PN) or radical nephrectomy (RN) and followed for 10 years. The study revealed an exponential increase in the utilization of PN, from 27% in 1998 to 66% in 2007. The study findings corroborated that RN is associated with a worst overall survival and an increased cardiovascular morbidity compared to partial nephrectomy for renal masses smaller than 2 cm [14].Current guidelines state that partial nephrectomy is an absolute indication in cases of a localized renal tumour in a patient for whom radical nephrectomy would necessitate renal dialysis [15,16]. This clinical scenario applies not only to cases of bilateral renal tumours but also to those of a unilateral renal tumour in the presence of a contralateral anatomically or functionally compromised kidney. A recent review article, considered a total of 27 publications from 1995 to 2010, relevant to PN and RN fo...