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28
TH
CONGRESS OF THE ESPU
08:00–08:05
S13-2 (LO)
EFFECT OF WILMS TUMOR HISTOLOGY ON TUMOR
VOLUME REDUCTION DURING PRE-OPERATIVE
CHEMOTHERAPY
Seppo TASKINEN
1
, Outi LESKINEN
2
, Jouko LOHI
3
, Minna KOSKENVUO
4
and Mervi TASKINEN
4
1) Children’s Hospital, Helsinki University Hospital, Paediatric surgery, Helsinki, FINLAND - 2) Helsinki University
Hospital, Radiology, Helsinki, FINLAND - 3) Helsinki University Hospital, Pathology, Helsinki, FINLAND -
4) Children’s Hospital, Helsinki University Hospital, Department of Hematology, Oncology and Stem Cell Transplantation,
Helsinki, FINLAND
PURPOSE
To evaluate the association between the Wilms tumor histology at diagnosis and the change in
Wilms tumor volume during pre-operative chemotherapy.
MATERIAL AND METHODS
Ninety pediatric patients were operated at our institution for renal tumors in 1988-2015. We included
all 50 patients who were operated for Wilms tumor and who had both pathology samples and
either CT or MRI-images before and after preoperative chemotherapy, available for re-evaluation.
Different cellular components in pathology samples were calculated by a pathologist and tumor
volumes were evaluated by a radiologist.
RESULTS
The median tumor volume was 586 (IQR 323-903) ml and the greatest dimension 120 (IQR 97-
144) mm at the time of diagnosis. The median tumor volume change was -75 (IQR -86--43) %
during 2 week- 3 month pre-operative chemotherapy (p<0.001). The length of chemotherapy did
not have significant effect on the tumor volume change. There was a significant positive correlation
between the blastemal cell content in pre-chemotherapy cutting needle (CNB) samples and the
degree of tumor volume reduction (p<0.001). In contrast, high stromal and epithelial cell contents
in CNB samples were negatively associated with the reduction of tumor volumes (p=0.006 and
0.041 respectively). However, the actual viable cell volume of all three different cellular components
decreased significantly with preoperative chemotherapy.
CONCLUSIONS
Median Wilms tumor volume reduced significantly with preoperative chemotherapy. The reduction
in the volume was observed in all three cellular components. However, the chemotherapy response
was most marked in the blastemal component and accordingly the blastemal rich tumors shrinked
most.