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11503 Background: Adjuvant imatinib improves recurrence-free survival (RFS) when administered after surgery to selected patients with operable gastrointestinal stromal tumor (GIST). It is uncertain whether overall survival (OS) improves, since imatinib improved OS in only one of the 3 large randomized trials conducted, and in this trial (the Scandinavian Sarcoma Group XVIII/German trial; SSGXVIII/AIO; NCT00116935) the statistical significance for OS remained borderline. The objective of the present analysis was to evaluate long-term OS of patients who participated in the SSGXVIII/AIO trial. Methods: SSGXVIII/AIO is an open-label, randomized (1:1), multicenter phase 3 trial. Four hundred patients who underwent macroscopically complete surgery for GIST with a high estimated risk for recurrence according to the modified National Institutes of Health Consensus Criteria were accrued between February 2004 and September 2008. Imatinib was scheduled to be administered 400 mg/day orally for either 12 months or 36 months after surgery. The patients were scheduled to be followed up for 10 years after study entry. Imaging of the abdomen was carried out periodically. The primary end point was RFS; the secondary objectives included OS and treatment safety. Results: The median follow-up time was 119 months. In the Intention-To-Treat Population 194 RFS events and 96 OS events were recorded. In the 36-month group, 5-year and 10-year RFS was 71.4% and 52.5%, and in the 12-month group, 53.0% and 41.8%, respectively (HR 0.66, 95% CI 0.49-0.87; P = .003). In the 36-month group, the 5-year and 10-year OS rates were 92.0% and 79.0%, and in the 12-month group, 85.5% and 65.3%, respectively (HR 0.55, 95% CI 0.37-0.83; P = .004). In the Efficacy Population, from which 15 patients who did not have GIST in central pathology review and 24 patients who had intra-abdominal metastases removed at surgery were excluded, 10-year OS was 81.6% in the 36-month group and 66.8% in the 12-month group (HR, 0.50, 95% CI 0.32-0.80; P = .003). No new safety signals were detected. Conclusions: About 50% of deaths can be avoided during the first decade of follow-up after surgery with 3-year imatinib treatment as compared to 1-year treatment. Clinical trial information: NCT00116935 .

LBA1 Background: Adjuvant IM administered for 12 months (mos) after surgery improves recurrence-free survival (RFS) of patients (pts) diagnosed with operable GIST. We compared 12 vs 36 mos of adjuvant IM as treatment of pts with a high risk for GIST recurrence after surgery. Methods: Pts with histologically diagnosed KIT-positive GIST were entered to this prospective, open-label, multicenter, randomized Phase III study (identifier NCT00116935 ). The risk of recurrence was estimated according to the modified Consensus Criteria. The primary objective was RFS. The secondary objectives included survival (OS) and treatment safety. The key exclusion criteria were ECOG PS >2, metastatic or inoperable GIST, and >12 wks from surgery to the study entry. IM was administered orally 400 mg/d. The sample size (n =200 in each group to obtain ≥110 events) was estimated by simulating log-rank tests assuming an overall hazard ratio (HR) of 0.44, a 20% drop-out rate, 2-sided type-I error rate of .05 and power 0.80. Analysis was based on the intention-to-treat population (ITT). Tumor histology was centrally reviewed. Results: 400 pts were entered to the study from Feb 2004 to Sep 2008. Three pts were excluded due to lack of consent from the ITT, which includes 15 pts who did not have GIST at a central review. The median FU time was 54 mos. RFS was longer in the 36-mo group compared to the 12-mo group (HR 0.46, 95% CI 0.32-0.65; p

10014 Background: Poor response to induction chemotherapy negatively affects prognosis for Ewing's sarcoma (ES) patients. To improve outcome, high-dose chemotherapy (HDCT) with stem cell rescue was added to conventional chemotherapy in patients poor responders after induction treatment. Methods: Non-metastatic ES patients aged 2-cyclofosfamide 1,200 mg/m2) weeks 0 and 6, IVAc (ifosfamide 9g/m2-vincristin 2 mg-actinomycin 2 mg) week 3 and IE (ifosfamide 9g/m2-etoposide 450 mg/m2) week 9 as induction therapy. Poor response was histologically defined as persistence of microfoci of viable tumor cells and radiologically as persistence of soft tissue mass. As maintenance treatment good responders (GR) received three cycles of VAC-IVAc-IE. Poor responders (PR) received VAC (weeks 13,19), IE (week 22), CE (mobilizing cycle, cyclophoshamide 4g/m2, etoposide 600 mg/m2, week 16) and HDCT with BuMel (busulfan 4 mg/kg × 4 days orally and melphalan 140 mg/m2 with stem cell support week 25). Results: Starting from 1999, 296 patients were enrolled with a median age of 15 years (3–40). 54 % of the tumors were located to the extremities and 46% in the axial skeleton. 274 patients underwent local treatment: surgery in 222 (81%) patients (with post operative Rxt in 70), RxT alone in 52 (19%). 10 patients progressed during treatment. No toxic deaths were recorded. Response evalutation was available for 262 patients: 135 (52%) were PR. 116 of them completed protocol treatment and 19 did not receive HDCT (5 poor harvest, 5 medical contraindication, 9 refusal).With a median follow-up of 37 months (1–89) 5-year overall and event-free survival were 74 % and 65.5% respectively. 5-year event-free survival was 71% (95% CI 62–81%) for GR, 68% (95% CI 58–78%) for PR treated with HDCT and 35% (95% CI 10–60%) for PR who did not receive HDCT. Conclusions: The preliminary survival data show for PR similar outcome as for GR. The treatment including HDCT is feasible with no toxic death recorded. Longer follow-up will confirm its efficacy. No significant financial relationships to disclose.

9002 Background: The ISG-SSG II study was undertaken to explore the effect of adding high-dose chemotherapy (HDCT) with peripheral blood stem cells support (PBSC) to conventional chemotherapy (CT) ...

9004 Background: Metastates at diagnosis are the worst prognostic factor in Ewing’s sarcoma. To ameliorate the prognosis of patients (pts) with lung-pleural and/or solitary bone metastases, ISG-SSG...

From January 1981 to February 1986, a total of 240 patients with primary, malignancy-grade III or IV soft tissue sarcoma were entered into an adjuvant chemotherapy multicenter trial conducted by the Scandinavian Sarcoma Group (SSG). Of these patients, 181 were evaluable. The tumor was located in the extremities in 155 patients. After radical surgery (wide and compartmental) the patients were randomized to treatment with single-agent doxorubicin 60 mg/m2 administered as an intravenous (IV) bolus once a month for 9 months (group 1, n = 77) or to control (group 2, n = 77). If the surgical procedure was marginal, the patients initially received postoperative radiotherapy, followed by doxorubicin (group 3, n = 16) or control (group 4, n = 11). The control groups did not receive any adjuvant chemotherapy. Adjuvant therapy was initiated within 6 weeks of surgery (group 1) or within 10 weeks of surgery for patients receiving postoperative radiotherapy (group 3). With a median follow-up of 40 months, there was no significant difference between the four treatment groups in overall survival (group 1, 75%; group 2, 70%; group 3, 69%; group 4, 73%), disease-free survival (group 1, 62%; group 2, 56%; group 3, 62%; group 4, 64%), or local tumor control (group 1, 92%; group 2, 92%; group 3, 87%; group 4, 90%). The conclusions were the same whether the total group or evaluable patients only were included in the analysis. The local recurrence rate for patients undergoing radical surgery was 8% and for patients undergoing marginal surgery followed by radiotherapy was 12%. This study indicates that the use of single-agent doxorubicin as postoperative adjuvant chemotherapy has no significant clinical benefit in patients with high-grade soft tissue sarcoma.

From 1981 to 1986, a total of 240 patients with a primary soft tissue sarcoma with malignancy grade III or IV were entered into an adjuvant chemotherapy multicenter trial conducted by the Scandinavian Sarcoma Group (SSG). Histopathologic peer review of all the specimens was performed by an expert pathology committee. The most common soft tissue sarcoma after review was malignant fibrous histiocytoma (MFH) (40%), followed by synovial sarcoma (15%), leiomyosarcoma (9%), liposarcoma (8%), and malignant Schwannoma (6%). In 25% of the cases the histologic type of sarcoma was reclassified, and in 40% of the cases the malignancy grade was changed. By survival analyses, the reclassification of malignancy grade seemed to be valid. Also, grading highly malignant soft tissue sarcoma in two grades (III and IV) increased the prognostic information. Of 164 tumors from the centers with the most reported cases (five centers with 25 to 51 tumors each), eight tumors were found to be ineligible for the adjuvant study (5%); of 76 tumors from 13 centers with few tumors (one to 16 tumors per center), 12 tumors were ineligible (16%). We conclude that histologic peer review is important in studies of soft tissue sarcoma.