Marth, Christian

5593 Background: We conducted an international survey to evaluate the differences in the systemic, radiotherapeutic and operative management of endometrial cancer (EC) in different regions of the world. Methods: In 2009 avalidated 15-item-questionnaire regarding surgical and adjuvant procedures of EC was sent to all German gynaecological clinics and in 2010 the English adapted questionnaire was set online as well as sent per post in most major gynaecological cancer societies. Results: 316 German institutions and 302 Institutions from 24 countries participated. We combined the different countries into regional groups: Central Europe (CE), southern Europe (SE), Asia and USA/UK. In Asian countries and in CE a lymph node dissection (LND) was performed routinely in 72.8% and in 55.6% of the cases, whereas in the USA/UK and in SE a LND was done mainly in selected cases when specific risk factors such as high-grade or non-endometrioid-histology applied (62.8% and 72.5%) than routinely (p < 0.001). A systematic pelvic and paraaortic LND was performed most frequently in CE 91.0%, in SE 76.9%, in Asia 70.9% and in USA/UK 68.6% (p < 0.001). A systematic LND with the intention of both adequate staging and for therapeutic value was performed in countries of central Europe to 74.6% and in Asia to 67.2%. In USA/UK the LND was seen merely as a staging instrument by 53.5% (p < 0.001). The LND was performed up to renal veins in CE in 86.8%, in Asia in 80.8%, in USA/UK in 51.2% and in SE in 45.1 %. A significant difference war found in the treatment for FIGO stage I (high risk factors (high grade, L1,V1)) and stage II disease between the countries: chemotherapy was applied in 84.8% of the participated centers in Asia,42.3% in SE, 21.2% in CE and only 13.6% in USK/UK (p<0.001).Vaginal brachytherapy was indicated as follows: USA/UK 84.1%, CE 78.8%, SE 78.8%, Asia 5.6% (p < 0.001). Conclusions: There is a large variety in the operative therapy and the clinical management of EC in different regions of the world. Future international prospective trials, will be necessary to improve and harmonize the evidence based treatment guidelines for EC- disease.

5087 Background: Indication, technique and extent of lymph-node-dissection (LND) in endometrial cancer (EC) remains controversial and is strongly debated in cancer community. We conducted a national- and at a second step an international-survey evaluating the current status-quo of the surgical and medical management of EC. Methods: A validated 15-item-questionnaire regarding surgical and adjuvant procedures of EC was sent to all major gynaecological cancer societies and study groups worldwide. The questionnaire could also be answered online. Results: In a phase-I-national trial, the questionnaire was validated on basis of 316 German institutions. On the phase-II-international survey a total of 302 questionnaires were answered from 24 countries, mainly from Japan (38.7%), Spain (8.3%), Austria (7%), United-Kingdom (6.3%), Italy (6%), USA (4.3%) and Canada (4%). The vast majority of the participating clinics were academic (62.8%), while 75.2% of them belonged to gynaecology. Only 0.7% of the clinics internationally reported never performing LND in EC. 62.3% of the clinics perform both a pelvic and paraaortic lymph node dissection. 59.1% of the participants performed a systematic lymph node dissection with the intention of both adequate staging and for therapeutic value. 15.05% of the clinics perform LND up to the common-iliac-arteries, 9.03% up to the inferior-mesenteric-artery and 70.6% up to the renal-veins. The most common risk-factors to indicate LND were: high-grading (93%), non-endometrioid-histology (90.1%), lymphovascular-invasion (55.3%), blood-vessel invasion (45.4%) and tumor-diameter >2cm (38.4%). For advanced stage III&IV disease the vast majority (60% and 80%, respectively) of the physicians indicated systemic chemotherapy alone. Conclusions: This study presents the large variety in clinical management of EC worldwide, underlining so the high need of future prospective randomised trials which will establish standard and evidence based treatment guidelines for EC- disease.

Abstract Abstract #57 Background: ABCSG 8 is the only prospective trial examining the value of switching patients (pts) to an aromatase inhibitor after tamoxifen (Tam) in which randomization occurred prior to therapy. This trial demonstrated that 2 years (yrs) of Tam followed by 3 yrs of anastrozole (TAM to A) was superior to 5 yrs of Tam (Jakesz SABC 2005). Tam is metabolically activated by CYP2D6 to endoxifen and pts with impaired CYP2D6 metabolism have a higher risk of recurrence (Goetz JCO 2005). The HOXB13/IL17BR (H/I) index (Ma Cancer Cell 2004) is associated with Tam resistance while a 5-gene molecular grade index (MGI) distinguishes outcome in grade II tumors. H/I and MGI are complementary prognostic factors that define low (low MGI), intermediate (low H/I, high MGI) and high risk groups (high H/I and MGI) (Ma Clin Cancer Res 2008). We sought to validate these biomarkers in ABCSG Trial 8, and hypothesized that they may predict the benefit of sequencing TAM to A versus Tam alone.&#x2028; Methods: From 1996-2004, ABCSG 8 randomized 3,901 pts with ER positive breast cancer. The primary endpoint was event-free survival. Assuming 40% of pts had reduced CYP2D6 metabolism, we designed a nested case control study in which 110 Tam treated cases matched to 2 controls would yield 80% power to detect a relative risk of 2.3 for pts with reduced CYP2D6 metabolism. Additionally, we sought to perform an exploratory analysis of the benefit of switching from Tam to A in pts with impaired vs non-impaired CYP2D6 metabolism. DNA and RNA derived from paraffin embedded sections were used to genotype for CYP2D6 and to obtain H/I and MGI RT-PCR profiles.&#x2028; Findings: Thus far, CYP2D6 genotyping is complete in 345 pts corresponding to 53 cases/106 controls (Tam) and 62 cases/124 controls (Tam to A). DNA and RNA yields were excellent with a CYP2D6 genotype call rate of &gt;95%. CYP2D6 allele frequencies were as expected: *3 (.01), *4, (.23), *6 (.01), *10 (.02), *17 (.00), and *41 (.10). 44% of pts had reduced CYP2D6 metabolism (at least one CYP2D6 null allele or intermediate metabolizer) and 8% were CYP2D6 poor metabolizers. For H/I and MGI, 340 pts were profiled with 64%, 20% and 16% in the low, intermediate, and high risk groups, respectively. Tissue sectioning/genotyping for additional cases/controls is ongoing.&#x2028; Discussion: This is the first retrospective analysis of a large Tam versus Tam to A trial to evaluate the association between 1) CYP2D6, HOXB13/IL17BR, and MGI with TAM treatment outcome and 2) the predictive benefit of these biomarkers in pts randomized to switch from Tam to AI versus Tam alone. Final results will be presented at the meeting. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 57.