Oncological outcomes of partial nephrectomy for tumours larger than 4 cm: A systematic review

Introduction: Many medical associations recommend nephron-sparing surgery (NSS) for tumours larger than 4 cm amenable to partial nephrectomy (PN). These recommendations are, however, mostly based on isolated reports. We systematically review the oncological outcomes of partial nephrectomy procedures performed for tumours larger than 4-cm. Methods: A PubMed search was carried out using keywords "partial nephrectomy" and "nephron sparing" for records dating back to 1995. In total, 2136 abstracts were analyzed; from these, 174 studies were scrutinized. We identified 32 manuscripts reporting size-specific cancer-specific survival rates for masses greater than 4 cm. From each of these studies, we recorded the number of PN, tumour diameter, follow-up duration, 5- and 10-year recurrence, overall and cancer-specific survival rates (OS, CSS). We also calculated weighted OS and CSS rates. Results: This systematic review includes 2445 patients with renal tumours larger than 4 cm who underwent PN: 1858 patients with tumours between 4 to 7 cm, 410 patients with tumours larger than 7 cm and 177 patients with tumours greater than 4 cm (exact size unknown). Our analysis revealed weighted 5-year CSS rates of 95.4%, 86.2% and 93.9% for tumours 4 to 7 cm, >7 cm, and all tumours >4 cm, respectively. The respective 5-year OS rates were 84.7%, 76.4%, and 84.7%. Conclusions: We found excellent 5-year CSS and OS rates for patients with tumours 4 to 7 cm treated with PN. These outcomes compare favourably to those reported in historical radical nephrectomy (RN) series for similarly sized tumours. Thus, PN is an acceptable and often preferred treatment for renal masses >4 cm which are amenable to nephron-sparing procedures.