title: Incidental vs symptomatic renal tumours: Survival outcomes.
abstract: OBJECTIVE
  Currently there is an increase in the incidental diagnosis of renal cell carcinoma (RCC). Our aim was to assess the survival of patients with incidental and symptomatic renal tumours who had undergone nephrectomy.
  
  
  METHODS
  We retrospectively assessed 604 patients who underwent renal surgery for RCC between 1983 and 2005. Patients were divided in two groups; group 1 had incidental and group 2 had symptomatic tumours. The median follow-up was 4 and 3.3 years for groups 1 and 2, respectively. All patients had surgery in the form of radical or partial nephrectomy. Sex, age, tumour size, type of surgery, pathological characteristics and patient survival in both groups were evaluated. The statistical analysis included the log-rank, Kaplan-Meier and Cox regression tests.
  
  
  RESULTS
  There were 85 patients (14%) in group 1 (mean age 49.6 years) and 519 (86%) in group 2 (mean age 50 years). The mean (SEM, range) tumour size was 7.4 (0.4, 1.5-20) cm in group 1 and 9.7 (0.2, 2-38) cm in group 2 (P < 0.001). The most common stage was T1 (52%) and T2 (44%) in groups 1 and 2, respectively, with a predominance of G2 grade and the conventional type histology in both the groups. There was a significant difference in cancer-specific survival (CSS) between the groups (log-rank, P = 0.017). The 5- and 10-year CSS was 94% and 94% for group 1, and 82.5% and 79.5% for group 2. Cox regression analysis showed that in group 1, only the tumour mid-zonal location (P = 0.093), tumour stage pT (P < 0.001), grade 1 (P = 0.03), grade 2 (P = 0.01), grade 4 (P = 0.01) and the papillary histological type (P = 0.019) had significant effects on CSS. In group 2, only tumour size (P = 0.022) and stage pN (P = 0.003) had significant effects on CSS. The tumour recurrence rate was 18% and 29% for groups 1 and 2, respectively.
  
  
  CONCLUSIONS
  This large study supports the findings of other smaller studies published previously, confirming that at presentation incidental renal tumours are smaller and their diagnosis provides a better prognosis and longer CSS.
authors.affiliation: Sultan Qaboos University, Oman.
authors.forename: Mohammed S
authors.initials: MS
authors.lastname: Al-Marhoon
authors.affiliation: Urology and Nephrology Center, Mansoura, Egypt.
authors.forename: Ahmed Mosbah
authors.initials: AM
authors.lastname: Osman
authors.affiliation: Urology and Nephrology Center, Mansoura, Egypt.
authors.forename: Mohammed M
authors.initials: MM
authors.lastname: Kamal
authors.affiliation: Urology and Nephrology Center, Mansoura, Egypt.
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Shokeir
keywords: CSS, cancer-specific survival; Incidental; Renal cell carcinoma; Survival