Proceedings of the 52nd Annual ASTRO Meeting specific survival (CSS) comparing the two groups. Univariate and multivariate analysis using Cox Proportional Hazards models were generated. Results: A total of 47,284 patients were included. The median follow-up time was 37 months. The 5-year CSS of 2009 stage IA and IB were 96.6% and 89.9%, respectively (p \ 0.0001). After accounting for age (. or \/ = 60), tumor grade, and race, this survival difference remained significant (HR, 1.97; 95% CI, 1.74-2.24; p \0.0001). There was no survival difference shown between 1988 stage IA and IB disease in the multivariate model (HR, 0.93; 95% CI, 0.80-1.08; p = 0.36). Patients with 1988 stage IIA disease had similar CSS outcomes to patients with 1988 stage IC disease, with 5-year CSS of 88.6% versus 89.9%, respectively (p = 0.09). Patients with positive pelvic washings had 5-year CSS similar to patients staged as IIIA with the 2009 system, with five-year CSS estimates of 74.2% versus 72.1% (p = 0.37). No difference was shown in CSS between patients with positive washings and 2009 stage IIIA disease in the multivariate model (HR, 0.98; 95% CI, 0.81-1.20; p = 0.87). CSS of patients staged as IIIC1 was significantly improved compared with patients staged as IIIC2. Five year estimates were 68.2% versus 57.3%, respectively (p \ 0.0001). In the multivariate model, the survival difference between stage IIIC1 and IIIC2 remained after adjusting for age, tumor grade and race (HR, 1.49; 95% CI, 1.26-1.76; p \ 0.0001). Conclusions: Recent recommendations for changes to the endometrial cancer staging system are validated in this dataset. For patients with involved lymph nodes, positive pelvic nodes portend a better survival outcome than involvement of the paraaortic chain. In this dataset of over 47,000 patients with endometrial adenocarcinoma, the 2009 staging system produced better discrimination in CSS outcomes compared with the old system. Author Disclosure: E.W. Cooke, None; L. Pappas, None; D.K. Gaffney, None.
1011
Survival Analysis of FIGO Stage IIIC Endometrial Cancer Patients
A. P. Brown1, D. K. Gaffney2, M. K. Dodson2,1, A. P. Soisson2,1, W. T. Sause1 1
Intermountain Medical Center, Murray, UT, 2Huntsman Cancer Hospital, University of Utah, Salt Lake City, UT
Purpose/Objective(s): Approximately 1 in 40 women will be diagnosed with endometrial cancer in their lifetime. Most endometrial cancers are diagnosed when the disease is localized and only approximately 7% of patients have nodal involvement at the time of diagnosis (FIGO stage IIIC disease). These patients with locally advanced disease have a substantially worse prognosis. There is a lack of consensus about appropriate adjuvant therapy for stage IIIC patients. This study seeks to provide data to guide future clinical trials and patient care. Materials/Methods: This multi-institution, IRB approved, study is a retrospective review of surgically staged IIIC endometrial cancer patients treated at hospitals within the Intermountain Health Care system and the University of Utah/Huntsman Cancer Hospital from 1995 to 2008. Of 1875 patients evaluated, 118 patients had stage IIIC disease. Five patients were excluded from analysis for previously diagnosed cancers within five years of endometrial cancer diagnosis and one patient was excluded because of death at the time of surgery, leaving 112 patients for analysis. The study cohort was evaluated using Kaplan-Meier estimates and proportional hazards modeling. Results: The median age at diagnosis was 65 with a range of 26 to 88. Five-year survival was 45% for patients treated with surgery alone (n = 25, 22%), 60% for patients treated with surgery and adjuvant radiation therapy (n = 43, 38%), 33% for patients treated with surgery and adjuvant chemotherapy (n = 6, 5%) and 54% for patients treated with adjuvant radiation therapy and chemotherapy (n = 38, 34%). Patients who received adjuvant radiation therapy (n = 81) had a 5-year survival of 57% compared to 43% for patients who did not get adjuvant radiation (n = 31; p = 0.002). Patients who had adjuvant chemotherapy (n = 44) had a 5-year survival of 51% compared to 54% for patients who did not get adjuvant chemotherapy (n = 68) (p = 0.525). After controlling for age at diagnosis, grade, and the presence of a recurrence on multivariate analysis, the administration of adjuvant radiation therapy resulted in a trend toward improved overall survival, although the difference was not statistically significant (p = 0.087). Conclusions: This multicenter study reviewed a large population of node-positive endometrial cancer patients. Univariate analysis showed that administration of adjuvant radiation therapy improves 5 year survival of stage IIIC endometrial cancer. However, after controlling for covariates, the survival benefit of adjuvant radiation does not achieve statistical significance. This study is subject to the limitations of any retrospective review of data collected in a clinical context. Further work is being done to define the role of adjuvant therapies in stage IIIC endometrial cancer and to identify subpopulations that may benefit from specific adjuvant therapies. Author Disclosure: A.P. Brown, None; D.K. Gaffney, None; M.K. Dodson, None; A.P. Soisson, None; W.T. Sause, None.
1012
Epithelial Ovarian Cancer: Definitive Radiotherapy for Limited Recurrence after Complete Remission 1
K. Yahara , T. Ohguri1, H. Imada2, S. Moon1, S. Yamaguchi1, H. Narisada1, Y. Matsuura3, N. Toki3, T. Hachisuga3, Y. Korogi1 1
Department of Radiology, University of Occupational and Environmental Health, Kitakyushu, Japan, 2Cancer Therapy Center, Tobata Hospital, Kitakyushu, Japan, 3Department of Obstetrics and Gynecology, University of Occupational and Environmental Health, Kitakyushu, Japan Purpose/Objective(s): The high complete response rates have been achieved after aggressive front-line therapy, including surgery and chemotherapy, for epithelial ovarian cancer. However, the response rate of the second-line chemotherapy for recurrent ovarian cancer is still low, and the clinical indication for secondary surgery is limited. The purpose of this study was to assess the efficacy and toxicity of definitive radiotherapy for the recurrence of epithelial ovarian cancer, which was limited in one or two regions, after complete remission achieved with aggressive front-line therapy. Materials/Methods: Twenty-seven patients with one or two gross recurrent lesions were treated with definitive radiotherapy and were retrospectively analyzed. The time from the front-line therapy to radiotherapy was median 22 months. The sites of the irradiated lesion were as follows; the pelvic lesion alone (n = 12), the extrapelvic lymph node lesion alone (n = 8), the pelvic lesion plus extrapelvic lymph node lesion (n = 5), the pelvic lesion plus liver (n = 1) and the pelvic lesion plus spleen (n = 1). The median tumor
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size was 3.0 cm (range, 1.0-6.1). Twenty-five (93%) patients received external irradiation alone; the median total dose of 60 Gy, and the median daily dose of 2 Gy. No prophylactic regional or nodal irradiation was administered. The remaining 2 patients received high-dose rate intracavitary irradiation. Six (22%) of the patients received concurrent chemotherapy, and 7 (26%) of the patients also underwent regional hyperthermia. Results: Twenty-two (82%) patients had an objective response (CR of 11, PR of 11). The infield or marginal failure occurred in 2 patients (7%), while failure of outside of the irradiated field was recognized in 14 patients (52%). The median progression-free survival time was 15 months. The median overall survival time was 19 months, and the 5-year overall survival rate was 47%. The toxicities were mild; anemia of Grade 3 was detected in one patient, and Grade 3 or higher non-hematologic toxicity was not observed. Conclusions: The definitive radiotherapy for limited recurrence of epithelial ovarian cancer seems feasible with a relatively longerterm survival. The results justify further evaluation to clarify the benefits of this treatment. Author Disclosure: K. Yahara, None; T. Ohguri, None; H. Imada, None; S. Moon, None; S. Yamaguchi, None; H. Narisada, None; Y. Matsuura, None; N. Toki, None; T. Hachisuga, None; Y. Korogi, None.
1013
Combination External Beam Radiation and Brachytherapy Boost with Androgen Suppression for Treatment of Intermediate-risk Prostate Cancer: Long-term Results of CALGB 99809
M. Hurwitz1, S. Halabi2, L. Archer2, L. S. McGinnis3, M. R. Kuettel4, S. J. DiBiase5, E. J. Small6 1
Dana-Farber/Brigham & Women’s Cancer Center, Boston, MA, 2Duke University Medical Center, Durham, NC, 3Presbyterian Hospital, Charlotte, NC, 4Roswell Park Cancer Institute, Buffalo, NY, 5Robert Wood Johnson School of Medicine, Cherry Hill, NJ, 6University of California San Francisco, San Francisco, CA Purpose/Objective(s): Transperineal prostate brachytherapy (TPPB) is commonly used with external beam radiation (EBRT) to provide a high-dose conformal boost to the prostate. Long-term efficacy and toxicity results of a multicenter Phase II trial assessing combination of EBRT and TPPB boost with androgen suppression therapy (AST) in treatment of intermediate-risk prostate cancer are presented here. Materials/Methods: Intermediate-risk patients (cT1/T2, PSA .10-\20ng/mL, Gleason #6; or cT1/T2, PSA #10ng/mL and Gleason $7; or cT3a with PSA #10ng/mL and Gleason #6) received six months of AST and EBRT to the prostate and seminal vesicles to 45 Gy followed by TPPB using either 125I or 103Pd to deliver an additional 100 Gy or 90 Gy, respectively. Toxicity was graded using the NCI CTC version 2 and RTOG late radiation morbidity scoring systems. Disease-free survival (DFS) was defined as time from enrollment to first observed progression (biochemical, local, distant, or prostate cancer death). In addition to the protocol definition of biochemical failure (3 consecutive PSA rises over 1.0ng/mL after 18 months from start of treatment), the 1997 ASTRO consensus definition, and Phoenix (nadir + 2) definition were also assessed in defining DFS to facilitate comparison with other studies. The Kaplan-Meier method was used to estimate the DFS and overall survival distributions. Results: Sixty-one of 63 enrolled patients were evaluable. Median follow-up was 71 months. Long-term grade 2 and 3 toxicity, excluding sexual dysfunction, occurred in 20% and 3% of patients, respectively. Six-year DFS applying the protocol definition, 1997 ASTRO consensus definition, and Phoenix definition of biochemical failure was 88.3%, 75.7%, and 85.9%, respectively. There were 7 deaths, only one of which was attributed to prostate cancer. Six-year overall survival rate was 93.5% (95% CI = 80.8-97.9). Conclusions: In a cooperative group setting, combination of EBRT and TPPB boost with 6 months of AST resulted in excellent DFS with acceptable long-term toxicity for patients with intermediate-risk prostate cancer. Author Disclosure: M. Hurwitz, None; S. Halabi, None; L. Archer, None; L.S. McGinnis, None; M.R. Kuettel, None; S.J. DiBiase, None; E.J. Small, None.
1014
A Matched-Pair Analysis of Dose-Escalated Adaptive Image-guided Radiotherapy (IGRT) vs. Pelvic Irradiation with Brachytherapy Boost for Intermediate- and High-risk Prostate Cancer
C. S. Shah, L. L. Kestin, F. Vicini, G. Gustafson, D. Brabbins, M. Wallace, K. Marvin, H. Ye, A. Martinez William Beaumont Hospital, Royal Oak, MI Purpose/Objective(s): The purpose of this study was to compare clinical outcomes in a cohort of intermediate and high risk prostate cancer patients treated with either dose escalated adaptive IGRT or pelvic external beam RT with high dose rate brachytherapy boost (EBRT+HDR). Materials/Methods: One thousand five hundred twenty patients with clinical stage T1-T3 N0 M0 prostate cancer were treated with either CT-based offline adaptive IGRT (n = 1037) or EBRT+HDR, n = 438) at a single institution (1994-2008). Risk groups were defined based on NCCN criteria. For IGRT, the CTV included the prostate and proximal seminal vesicles only. A patient-specific confidence-limited PTV (cl-PTV) was constructed based on 5 CT scans. Median dose (minimum to clPTV) delivered via 3D conformal RT or intensity-modulated RT was 75.6 Gy (range, 73.8-79.2 Gy, median isocenter dose = 79.7 Gy). For EBRT+HDR, the whole pelvis was treated to 46 Gy + 2 HDR implants with a median of 10.5 Gy (8.7511.5 Gy) per implant. Two hundred eight EBRT+HDR patients were randomly matched with 208 IGRT patients based on criteria of pre-treatment PSA ± 4 ng/mL, same Gleason score, T stage ± 2 sublevels, and use of neoadjuvant androgen deprivation therapy (ADT). Results: Mean follow-up was 5.1 years for IGRT vs. 7.0 years for EBRT+HDR. Mean pretreatment PSA was 9 for both groups. Mean Gleason was 7 for both groups. EBRT+HDR patients were younger (67 vs. 71 years, p \ 0.01) with a higher percentage of positive biopsy cores (51% vs. 39%, p \ 0.01). Intermediate risk patients comprised 78% and 76% for IGRT and EBRT+HDR, respectively (p = 0.56). 42% in each treatment group received neoadjuvant or concurrent ADT. Median nadir was 0.2 vs. 0.1 ng/mL (p = 0.20). 5-year biochemical control (BC) based on the Phoenix definition was 91% for IGRT vs. 87% for EBRT+HDR (p = 0.60). For intermediate-risk, 5-year BC was 94% vs. 87% (p = 0.71) and was 86% vs. 86% (p = 0.83) for high-risk patients.