Increased microvascular density predicts relapse in Wilms' tumor.
OBJECTIVE
Tumor stage and histology are the most important prognostic criteria in Wilms' tumors; however, a subset of patients remains who have favorable histology tumors and unexpectedly relapse. The authors postulated that increased microvascular density (MVD), a hallmark for angiogenesis, could identify patients at risk for relapse.


METHODS
A case-control study was used to compare relapse (n = 15) with nonrelapse tumors (n = 35). Tumor MVD was counted in 5 random high-powered fields (hpf) using anti-Factor VIII antibody and expressed as mean vessel count/hpf +/- SEM. MVD and clinical data were evaluated using univariate analysis and student's t test.


RESULTS
The relapse group had higher MVD than the nonrelapse group (34.9 +/- 2.9 v 22.4 +/- 2; P <.05). When evaluating the favorable histology (FH) group alone, there was higher MVD in the relapse group (32.4 +/- 2.7 v 19 +/- 1.8; P <.05). MVD was found to be the only predictor of relapse when compared with age, sex, tumor weight, and histology.


CONCLUSIONS
These results suggest that increased MVD can identify Wilms' tumor patients at high risk for relapse, especially those patients with favorable histology tumors. A larger study is warranted to determine the potential utility of MVD in stratification of Wilms' tumor patients.
Abramson
Lisa P
LP
Division of Pediatric Surgery, Children's Memorial Hospital, Department of Biostatistics, Northwestern University Medical School, Chicago, Illinois 60611, USA.
Grundy
Paul E
PE
Rademaker
Alfred W
AW
Helenowski
Irene
I
Cornwell
Mona
M
Katzenstein
Howard M
HM
Reynolds
Marleta
M
Arensman
Robert M
RM
Crawford
Susan E
SE
D002196:Capillaries / Q000473:pathology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007680:Kidney Neoplasms / Q000098:blood supply* / Q000401:mortality / Q000473:pathology; D008113:Liver Neoplasms / Q000556:secondary; D008175:Lung Neoplasms / Q000556:secondary; D008297:Male; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D009389:Neovascularization, Pathologic / Q000473:pathology*; D016017:Odds Ratio; D012306:Risk; D009396:Wilms Tumor / Q000098:blood supply* / Q000401:mortality / Q000473:pathology / Q000556:secondary