title: Microvascular tumor invasion: prognostic significance in low-stage renal cell carcinoma.
abstract: OBJECTIVE
  To evaluate the role of microvascular tumor invasion (MVI) in clinical behavior and prognosis of low-stage renal cell carcinoma.
  
  
  METHODS
  We retrospectively reviewed the records of patients who had undergone radical nephrectomy from 1990 to 2004 for clinically confined kidney tumors (Stage T1-T2N0M0) with a minimal follow-up period of 1 year. The pathology slides were reviewed regarding tumor diameter, pathologic tumor stage, histologic cell type, nuclear grade, macroscopic or MVI, perirenal fat invasion, and neoplastic lymph node involvement.
  
  
  RESULTS
  A total of 48 patients, 22 men and 26 women (mean +/- SD age 50.73 +/- 13.03 years, range 20-80) were included in the study. The patients were followed up for a mean +/- SD of 37.65 +/- 18.19 months (range 12-60). MVI was encountered in 8 patients (16.7%); 50% developed treatment failure in the form of distant metastases. Of the 40 patients without MVI, only 2 (5%) had treatment failure. MVI had a statistically significant association with sex (P = 0.017) and stage (P = 0.039). On comparing treatment failure with different patient and histologic parameters, a statistically significant association was noted with sex (P = 0.006) and MVI (P = 0.005). The 5-year disease-free survival rate was estimated at 45% and 90% when MVI was and was not present. Only MVI showed an independent statistically significant impact (P = 0.007) on multivariate analysis considering the impact of MVI, stage, grade, cell type, perirenal fat invasion, tumor size, and patient age on disease-free survival.
  
  
  CONCLUSIONS
  The results of our study have shown that MVI is an independent and relevant prognostic parameter for clinically low-stage renal cell carcinoma.
authors: Department of Surgery, Division of Urology, King Fahad National Guard Hospital, Riyadh, Saudi Arabia. k_madbouly@yahoo.com
authors: Khaled
authors: K
authors: Madbouly
authors: Saeed M
authors: SM
authors: Al-Qahtani
authors: Yahia
authors: Y
authors: Ghazwani
authors: Saeed
authors: S
authors: Al-Shaibani
authors: Mostafa K
authors: MK
authors: Mansi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000473:pathology* / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology* / Q000601:surgery; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D009392:Nephrectomy; D011379:Prognosis; D012189:Retrospective Studies; D019043:Vascular Neoplasms / Q000473:pathology*