Multifocal renal cell carcinoma (RCC) has been reported in 5-25% of cases worldwide. Although management of patients with multifocal RCC has not been clearly defined, presence of multifocal renal masses in one kidney and a normal contralateral kidney has often been considered a reason for performing radical nephrectomy. This study reviews the world literature to provide an accurate estimate of the prevalence of multifocal RCC and evaluates the oncologic outcomes of multifocal RCC after exclusion of patients with known hereditary and familial renal syndromes. A PubMed search of the literature was performed for articles in the English language using the following terms for the query: "multifocal RCC," "multifocality and RCC," "multicentric RCC," or "bilateral RCC." The references of the published articles were also reviewed for additional publications. Articles that did not specifically exclude patients with familial RCC or known hereditary RCC syndromes were excluded for estimation of multifocality prevalence and oncologic outcomes. After applying our exclusion criteria, nine articles were selected and form the basis of the current analysis. Weighted averages were used to calculate the prevalence of multifocality. Multifocal RCC was found in 6.8% of cases (373 of 5433 patients). Ipsilateral multifocality was found in 6.8% of cases. Bilateral multifocality was found in 11.7% of cases. Of all cases reported in this study, only 10% underwent partial nephrectomy. The rest of the study cohort underwent radical nephrectomy. The review of the literature showed that the use of nephron-sparing techniques in patients with multifocal disease did not compromise oncologic outcomes, despite the need for reoperation in certain cases. In conclusion, multifocal RCC remains a prevalent entity. Most clinicians still prefer to perform radical nephrectomies in these patients despite proven equivalent oncologic outcomes compared to nephron-sparing techniques. Urologists should be aware of these data when proposing treatment options to patients with multifocal RCC.
Keywords: bilateral RCC; multifocal RCC; multifocality; nephron-sparing surgery; outcomes; partial nephrectomy.