Prognostic significance of laterality in renal cell carcinoma: A population‐based study from the surveillance, epidemiology, and end results (SEER) database

BACKGROUND: Various prognostic characteristics have been established in the renal cell carcinoma (RCC). However, the impact of tumor laterality is unknown. The objective of the current study was to explore the predictive and prognostic impact of tumor laterality of RCC after surgery. METHODS: This investigation was a population‐based retrospective cohort study of patients with RCC from the surveillance, epidemiology, and end results (SEER) database in the USA. All patients received surgical treatment between January 2010 and December 2014. Cancer‐specific survival (CSS) measured from the time of surgery. RESULTS: This study identified 41 138 surgically treated RCC patients: Of these patients, 50.6% had right‐sided RCC, 59.5% were younger than 65 years of age, 63.8% were male, and 81.0% were Caucasian. The stage distribution was 67.0% (I), 9.5% (II), 17.1% (III), and 6.4% (IV). Patients with right‐sided RCC were more likely to have favorable clinicopathological features compared with patients with left‐sided RCC. In adjusted analyses, patients with right‐sided RCC showed significantly better CSS than those with left‐sided RCC within different subgroups including tumor size ≥10 cm (P = .004), age <65 years (P = .002), male gender (P = .001), Caucasian race (P = .001), clear cell carcinoma type (P = .024), and radical nephrectomy (P = 0.008). Moreover, in the subgroup of tumor size ≥10 cm, right‐sided cancer was an independent predictor of CSS (P = .022). CONCLUSION: Right‐sided RCC is associated with more early‐stage, low‐grade disease and shows better CSS than left‐sided RCC. Moreover, laterality remained as an independent prognostic factor for cancer‐specific survival in subgroup of tumor size ≥10 cm RCC.