1. Wilms’ tumour gene 1 (WT1) is a new prognostic marker in high grade uterine sarcoma
A. Coosemans, B. Van Calster, L. Verbist, Ph. Moerman, I. Vergote, S.W. Van Gool, F. Amant
Laboratory of Experimental Gynaecology and Immunology, UZ Gasthuisberg, Katholieke Universiteit Leuven, Belgium
Department of Electric Engineering (ESAT), Katholieke Universiteit Leuven, Belgium
Department of human pathology, UZ Gasthuisberg, Katholieke Universiteit Leuven, Belgium

2. Background (1) WT1 : Wilms’ tumour gene 1 located on #11p13
1990 : discovered in Wilms tumour (paediatric kidney cancer)
Complex molecular function : transcription and translation on DNA and RNA level
Role :
Embryogenic : role in development of urogenital system, central nervous system, heart, blood
Adult life : role in carcinogenesis – overexpression of wild type in several haematological and solid malignancies
Depending on the type of tumour : behaviour as a oncogene or supressor gene

3. Background (2) Uterine sarcoma : Rare type of uterine tumour
4 subtypes :
Carcinosarcoma (CS), leiomyosarcoma (LMS), undifferentiated sarcoma (US) : high grade
Endometrial stromal sarcoma (ESS) : low grade
Poor prognosis : 5 year survival :
Stage I-II : 50%
Stage III-IV : 10%
Surgery is the corner stone - no clear benefits from adjuvant therapy in early stages – shortlasting therapeutic options in advanced stages

4. Background (3) WT1 and uterine sarcoma IHC RT-PCR CS ESS LMS US AS
Agoff, 2001
9/10
Dupont, 2004
7/10
Sumathi, 2004
13/14
Sotobori, 2006
5/5
Coosemans, 2007
12/27
7/15
29/38
4/7
6/6
4/4
3/4
Soslow, 2008
6/7

5. Materials and methods (1)
54 women with high grade uterine sarcoma
Follow up of at least 12 months
No. of patients
n (%)
Age
Tumoural size
<52 yrs
10 (18,5)
<5cm
8 (15)
≥ 52 yrs
44 (81,5)
≥5cm
32 (59)
Sarcoma subtype
unknown
14 (26)
LMS
20 (37)
Recurrent disease CS
27 (50) No US
7 (13)
Yes
40 (74)
Stage
Death I
22 (41)
18 (33) II
6 (11)
36 (67)
III
12 (22) IV

6. Materials and methods (2)
IMMUNOHISTOCHEMISTRY
WT1 immunohistochemistry on 1 slide of each tumour (monoclonal mouse anti-human Wilms’ Tumor 1 clone 6F-H2 (DAKO))
STATISTICAL ANALYSIS
Survival curves by Kaplan Meier
Univariate and multivariate analysis by Cox regression analysis

7. Materials and methods (3)
: 26 studies on prognosis in uterine sarcoma, including multivariate analysis in more than 40 patients
Most frequently studied parameters :
Stage : 24 studies
Age : 23 studies
Grade : 15 studies
Subtype : 11 studies
Menopauzal status : 10 studies
Size : 9 studies
Mitotic index : 8 studies
Adjuvant therapy : 6 studies

8. Results (1) WT1 positive tumors 34 (63) WT1 negative tumors 20 (37)
Age
Tumoral size
<52 yrs
6 (18)
4 (20)
<5cm
5 (15)
3 (15)
≥ 52 yrs
28 (82)
16 (80)
≥5cm
22 (65)
10 (50)
Sarcoma subtype
unknown
7 (21)
7 (35)
LMS
16 (47)
Recurrent disease CS
14 (41)
13 (65) No
12 (60) US
4 (12)
Yes
8 (40)
Stage
Death I
10 (29)
9 (45)
II-IV
24 (71)
27 (79)
11 (55)

9. Results (2) : univariate analysis
Kaplan Meier survival curves

10. Results (3) : univariate analysis
LR p=0,0058
LR p <0,0001

11. Results (4) : multivariate analysis
Variable
Hazard ratio
95% CI on HR
LR P-value
WT1 status
2.381
0.019
Stage
2.953
0.010
Age
1.053
0.742
Sarcoma subtype
CS vs US
0.486
0.442
LMS vs US
0.743
Size
1.775
0.385
PFS
Variable
Hazard ratio
95% CI on HR
LR P-value
WT1 status
2.990
0.011
Stage
4.995
0.001
Age
1.194
0.315
Sarcoma subtype
CS vs US
0.272
0.100
LMS vs US
0.325
Size
1.493
0.572 OS

12. Conclusion WT1 independently worsens the prognosis of uterine sarcoma
The stronger the WT1 expression, the worse the prognosis
Similar observations have been made in breast carcinoma (Miyoshi, 2002), leukaemia (Inoue, 1994) and hepatocellular carcinoma (Sera, 2008)