Radical nephrectomy is generally the preferred method to treat advanced kidney cancers, while partial nephrectomy is performed when the disease is localised, or if the patient has a genetic predisposition to developing kidney tumours. However, a recent study suggests that wherever possible, partial nephrectomy should be used, as the risk of subsequent cardiovascular events is reduced in these patients (Capitanio et al., 2014).
In order to investigate whether the two surgical approaches led to different outcomes, the researchers performed a retrospective review of 1331 patients who had had surgery for kidney cancer at one of four different hospitals between 1987 and 2013. All patients had tumours below 7 cm in diameter, with no metastasis or lymph node involvement; 462 (34.7%) patients had undergone radical nephrectomy, while 869 (65.3%) had undergone nephron sparing surgery.
The researchers analysed these patients’ medical records for pre- and post-surgical glomerular filtration rate, age, BMI, gender, smoking habits, co-morbidities, and cardiovascular events requiring hospitalisation. Cardiovascular events included coronary artery disease, cardiomyopathy, vasculopathy, hypertension, heart failure, dysrhythmias, and cerebrovascular disease. No patients in this study had been diagnosed with any cardiovascular disease prior to their kidney cancer surgery.
Overall, 21.8% of patients had experienced a cardiovascular event within 10 years following surgery. However, when the two groups of patients were analysed separately, 25.9% of the radical nephrectomy patients experienced a cardiovascular event within 10 years following surgery, compared to only 9.9% of the partial nephrectomy patients. Multivariate analysis accounting for the clinical characteristics and cardiovascular profiles of the two groups showed that patients who underwent nephron-sparing surgery were nearly half as likely to develop cardiovascular symptoms after surgery (hazard ratio = 0.57).
Reduced glomerular filtration (GFR) rate post-surgery was also highly correlated with increased risk of cardiovascular events. As radical nephrectomy significantly reduces GFR compared with partial nephrectomy, it is likely that this is responsible for the increased risk of cardiovascular disease in these patients. Interestingly, year of surgery was also correlated with risk of cardiovascular event, suggesting that as surgical techniques have improved over time, the risk of cardiovascular events has fallen. This could also reflect a trend towards increased use of partial nephrectomy to treat localised tumours.
This study suggests that the risk of having a cardiovascular event following kidney surgery is significant, but that the risk is greatly reduced following nephron-sparing surgery. This underscores the importance of improving diagnosis rates, as identifying tumours at an earlier stage will increase the likelihood that a nephron-sparing approach will be curative with respect to the kidney cancer, and will furthermore protect the patient’s cardiovascular health. It additionally provides evidence of the benefit of active surveillance approaches for benign tumours, as removing these tumours is of little clinical benefit to patients, but may increase their risk of developing cardiovascular disease.
- Capitanio, U., Terrone, C., Antonelli, A., Minervini, A., Volpe, A., Furlan, M., Matloob, R., Regis, F., Fiori, C., Porpiglia, F., Di Trapani, E., Zacchero, M., Serni, S., Salonia, A., Carini, M., Simeone, C., Montorsi, F., & Bertini, R (2014). Nephron-sparing Techniques Independently Decrease the Risk of Cardiovascular Events Relative to Radical Nephrectomy in Patients with a T1a-T1b Renal Mass and Normal Preoperative Renal Function. European Urolology (Epub ahead of print) PMID: 25282367
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