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Prognostic Significance of Rising Prostate-Specific Antigen (PSA) Levels Following Radiation Therapy for Localized Prostate Cancer—Comparison Between PSA Bounce Versus PSA Recurrence
Volume 96 Number 2S Supplement 2016 Purpose/Objective(s): In addition to the cure rate, quality of life is now very important in cancer therapy. For prostate cancer patients, urinary and intestinal symptoms after radiation therapy including intensity-modulated radiation therapy and proton therapy (PT) have been discussed. However, testosterone levels and sexual function after PT have not been well studied. This is a prospective evaluation of serum testosterone level and sexual function before and after PT. Materials/Methods: Between February 2013 and July 2014, 198 patients were treated with proton therapy. Among them, 171 patients consented to testosterone measurement, provided a sufficient response to a questionnaire, and received treatment exactly per protocol; they were fully evaluable for this study. There were 36 low-risk patients, 60 intermediate-risk patients and 75 high-risk patients, according to the National Comprehensive Cancer Network. For low-risk patients, 74 GyE/37 Fr was delivered without combined androgen blockade therapy (CAB). Intermediate-risk patients received 78 GyE/39 Fr after neo-adjuvant CAB for 6-8 months. High-risk patients received 78 GyE/39 Fr after neo-adjuvant CAB. They were basically treated with CAB for more than 1 year after PT. The serum testosterone, IIEF-5 (International Index of Erectile Function-5) and EHS (Erection Hardness Score) were evaluated before and after PT. Results: In low-risk patients, the average serum testosterone level was 428 (ng/dl) before PT, 450 at 3 months after PT (P Z 0.21), 442 at 6 months (P Z 0.46), 439 at 9 months (P Z 0.6), and 444 at 12 months (P Z 0.47). The median IIEF-5 score was 14 before PT and at 1 and 6 months, and 12 at 12 months (P < 0.001). The median EHS was 2 before PT and at 1 and 6 months, and 1 at 12 months (P Z 0.003). In intermediate-risk patients, the average serum testosterone was 8.2 (ng/dl) before PT, 145 at 3 months (P < 0.001), 244 at 6 months (P < 0.001), 295 at 9 months (P < 0.001), and 335 at 12 months (P < 0.001). The median IIEF-5 score did not change from 9 before and after PT. The median EHS score was 0 before PT and at 1 month, and 1 at 6 (P Z 0.01) and 12 months (P Z 0.006). In high-risk patients, the average serum testosterone was 6.6 (ng/dl) before PT, 21.2 at 3 months (P Z 0.13), 28.4 at 6 months (P Z 0.07), 41.1 at 9 months (P Z 0.02), 42.2 at 12 months (P Z 0.04), 82.3 at 15 months (P Z 0.004), and 98.8 at 18 months (P Z 0.002). The median IIEF5 score and EHS did not change from 9 and 0, respectively. Conclusion: Without CAB, PT did not decrease the serum testosterone level and had a smaller influence on sexual function. The serum testosterone returned quickly to the normal level after the treatment in intermediate-risk patients, but sexual quality did not improve remarkably. In high-risk patients, the testosterone was suppressed and sexual function did not change in worse scores while they were treated with CAB. Combination of CAB and PT seems to have a greater influence on sexual function. Author Disclosure: Y. Hattori: None. M. Nakanishi: None. S. Hashimoto: None. H. Iwata: None. H. Ogino: None. M. Iwana: None. F. Baba: None. Y. Shibamoto: None. J. Mizoe: None.
2696 Association Between Dose-Volume Histograms and Health-Related Quality of Life in Patients with Prostate Cancer Treated with External Beam Radiation Therapy A. Boladeras,1 F. Ferrer,1 V. Navarro,2 R. De Blas,3 O. Cunillera,4 D. Mateo,5 C. Gutierrez,1 S. Villa,6 E. Martinez,1 J. Pera,1 M. Ferrer,7 and F. Guedea1; 1Radiation Oncology Department. Catalan Institute of Oncology, L’Hospitalet-Barcelona, Spain, 2Institut Catala d’Oncologia, Hospitalet, Spain, 3Physics Department. Catalan Institute of Oncology, L’Hospitalet-Barcelona, Spain, 4Institut Hospital de Mar, Barcelona, Spain, 5Institut Catala d’Oncologia, Hospitalet, Spain, 6Catalan Institute of Oncology. HU Germans Trias, Badalona Catalonia, Spain, 7Hopsital del Mar, Barcelona, Spain Purpose/Objective(s): Few studies have evaluated the association between doseevolume histograms (DVH) and toxicity in prostate cancer and even fewer have studied the association between DVH and health-related quality of life (HRQL). The aim of this study was to assess the correlation between DVH in organs at risk (OAR) outcomes as measured with a specific HRQL questionnaire
Poster Viewing E285 Materials/Methods: The study included 154 patients treated with external beam radiation therapy for clinically-localized prostate cancer at our institution between January 2003 and November 2005.Inclusion criteria were stage T1-T2 and a confirmed diagnosis of low-risk prostate cancer. HRQL was evaluated by Expanded Prostate Cancer Index (EPIC) among other questionnaires. DVH for OARs (penile bulb, rectum and bladder) were created for 119 of the 154 patients to assess the correlation between DVH and HRQL using the Functional Data Analysis method and HRQL calculating the mean functions through Functional Data Analysis methods. Results: A worsening of urinary incontinence and obstructive symptoms on the EPIC items correlated with a higher DVH dose distribution at 24 months. Similarly, increased rectal bleeding at both 24 and 60 months correlated with a higher DVH dose distribution (from 40-70 Gy).Patients with worsening rectal incontinence (uncontrolled leakage) presented a higher DVH distribution (between 40-70 Gy at 24 months and throughout the curve at 60 months) versus patients without this side effect. No significant association was found between the presence or not of erectile dysfunction and penile bulb DVH values. Conclusion: These findings demonstrate that DVH and HRQL are closely correlated and also correlate with published data on the association between DVH and toxicity. Functional Data Analysis was a valuable tool to properly analyze the DVH data. These results could help radiation-oncologists to select the best treatment from among the various treatment strategies in order to achieve the best quality of life outcomes. Author Disclosure: A. Boladeras: None. F. Ferrer: None. V. Navarro: None. R. De Blas: None. O. Cunillera: None. D. Mateo: None. C. Gutierrez: None. S. Villa: None. E. Martinez: None. J. Pera: None. M. Ferrer: None. F. Guedea: None.
2697 Prognostic Significance of Rising Prostate-Specific Antigen (PSA) Levels Following Radiation Therapy for Localized Prostate CancerdComparison Between PSA Bounce Versus PSA Recurrence C. Freiberger, V. Schmitt, M.J. Eble, and M. Pinkawa; RWTH Aachen University Hospital, Department of Radiation Oncology, Aachen, Germany Purpose/Objective(s): Rising PSA levels are often detected following radiation therapy (RT) for localized prostate cancer, worrying patients as well as treating physicians. However, this increase frequently does not meet the definition of a biochemical recurrence according to the Phoenix definition (nadir + 2ng/mL) and corresponds to a PSA bounce. The aim of this study was to evaluate the long-term prognostic significance of rising PSA levels. Materials/Methods: In the years 2000-2003, 295 patients with localized prostate cancer were treated in our department. Therapeutic alternatives were a low-dose-rate (LDR) brachytherapy with I-125 seeds as monotherapy (n Z 94; 145Gy), high-dose-rate (HDR) brachytherapy with Ir192 as a boost to external beam RT (n Z 66; 50.4Gy in 1.8Gy fractions EBRT + 18Gy in 9Gy fractions HDR) and EBRT alone (70.2Gy in 1.8Gy fractions; n Z 135). PSA recurrence was defined according to the Phoenix definition, PSA bounce as an increase of at least 0.2ng/ml with a consecutive spontaneous decrease. Primary aim of the study was to analyze the significance of rising PSA levels for overall survival. Results: Median follow-up after the end of RT was 108 months. 10-year PSA recurrence-free, metastasis-free, disease-specific and overall survival rates in this patient population were 53%, 89%, 90% und 66% (significantly higher recurrence-free survival in low/intermediate risk patients for LDR vs. EBRT and EBRT+HDR vs. EBRT, respectively). PSA bounce was found in 84 patients, PSA recurrence in 119 patients. PSA recurrence was detected significantly later than a PSA bounce (interquartile range/median Z IQ/M of 18-51/32 months vs. 13-26/20 months after RT; P<0.01). The nadir before the increase was lower in case of a PSA bounce (IQ/M of 0.20.8/0.5 ng/mL vs. 0.6-2.5/1.2 ng/mL; P<0.01). However, PSA doubling times were similar: 3.0-9.2/5.6 months for PSA bounce vs. 2.5-8.1/5.0 months for PSA recurrence. A PSA bounce proved to be a prognostically favorable factor (10-year overall survival of 82% vs. 59%; P<0.01), whereas PSA recurrence was unfavorable (10-year overall survival of 54% vs. 74%; P<0.01). Both factors proved to be independent in multivariate
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Cox regression analysis. PSA doubling time and nadir before increase were prognostically significant in case of PSA recurrence (10-year overall survival of 71% vs. 41% with PSA doubling time >6 months vs. <6 months; P Z 0.01; 63% vs. 46% with a nadir <1ng/mL vs. >1ng/mL; P Z 0.02). Conclusion: Rising PSA levels particularly in the second year following RT after reaching a nadir <1ng/mL indicates a prognostically favorable PSA bounce. A short PSA doubling time and a higher nadir are associated with an adverse prognosis in case of a PSA recurrence. Author Disclosure: C. Freiberger: None. V. Schmitt: None. M.J. Eble: None. M. Pinkawa: None.
therapy to a minimum dose of 45.0 Gy encompassing primary tumor and regional pelvic lymphatics. Boost SBRT treatment planning then followed, and GTV delineation was aided by coregistration of the boost planning CT set to a PET/CT scan and MRI. Prior to each SBRT fraction, target setup was verified by matching to organ-implanted radio-opaque fiducial markers and by assessing for deformations using cone beam CT imaging. A total radiation dose of 40.0 Gy was prescribed to the primary tumor and delivered over a 10day schedule of 5 fractions of 8.0 Gy each. Disease control response was assessed pathologically by 3-month post-therapy biopsy and radiographically by biannual PET/CT imaging. Acute and chronic toxicities were assessed using the National Cancer Institute’s CTCAE v3 toxicity scales. Quality-oflife assessment was determined using FACT-G measurements. Results: Forty-two patients with primary endometrial (n Z 12) or cervical (n Z 30) cancer have been treated since June 2007 and have been followed for a median of 62.0 months and a minimum of 36.0 months. Post-SBRT biopsy was negative for 35 of 42 patients, or 83.3% of all patients. At 5 years, estimated local disease control by pathologic and radiographic (i.e., SUVmax < 2.5) criteria at the SBRT treatment site is 78.6% for all patients and 88.2% for stages I e II patients. No grade 3 or greater urinary or bowel toxicities have been observed to date. Pre and post SBRT FACT-G scores were statistically similar in all studied domains: physical, social, emotional and functional well-being. Conclusion: At a median follow-up greater than 5 years and with a minimum follow-up of 3 years, SBRT appears to offer an effective and welltolerated boost modality for the management of selected gynecologic cancer patients otherwise contraindicated for brachytherapy or surgery. Author Disclosure: C.A. Mantz: None.
2698 Prostate-Specific Antigen Kinetics After Hypofractionated Stereotactic Body Radiation Therapy Boost and Whole-Pelvic Radiation Therapy for Intermediate- and High-Risk Prostate Cancer H.J. Kim1 and W.C. Kim2; 1Inha University Hospital Inchon, Korea, The Republic of Korea, 2inha University Hospital, Inchon, Korea, The Republic of Korea Purpose/Objective(s): Stereotactic body radiation therapy (SBRT) has emerged as an effective treatment for localized prostate cancer. However, prostate specific antigen (PSA) kinetics after SBRT has not been well characterized. The objective of the current study is to analyze the rate of PSA decline and PSA nadir following SBRT boost after whole pelvis radiation therapy (WPRT) in intermediate- and high-risk prostate cancer. Materials/Methods: From March 2008 to July 2014, forty-two patients newly diagnosed, intermediate- and high-risk (NCCN definition) localized prostate cancer were treated with SBRT boost using robotic radiosurgery after WPRT. The whole pelvis dose was 45 Gy (25 fractions of 1.8 Gy) and the SBRT boost dose was 21 Gy (3 fractions of 7 Gy). No one received androgen deprivation therapy (ADT) before biochemical relapse. PSA nadir and rate of change in PSA (slope) were calculated and compared. Results: With a median follow-up of 53.6 months (range, 14-74), the median rates of decline of PSA were -0.605, -0.229 and -0.166 ng/mL/ month, respectively, for durations of 1, 2 and 3 years post radiation therapy, respectively. The median PSA nadir was 0.32 ng/mL after a median 36 months. 5-year biochemical failure (BCF) free survival was 100% for intermediate-risk and 71.4% for high-risk patients (P Z 0.002). Conclusion: In this report of intermediate- and high-risk prostate cancer, continuously greater rates of decline PSA for duration 1, 2 and 3 year following SBRT boost after WPRT resulted in lower PSA nadir. In addition, SBRT boost after WBPT leads to favorable BCF-free survival. Author Disclosure: H. Kim: None. W. Kim: None.
2699 Stereotactic Body Radiation Therapy as a Boost Alternative for Nonmetastatic Cancer of the Cervix and Endometrium: Disease Control and Quality of Life Outcomes From a Phase 2 Trial at 3 Years’ Minimum Follow-up C.A. Mantz; 21st Century Oncology, Fort Myers, FL Purpose/Objective(s): Stereotactic body radiation therapy (SBRT) has been applied as a radioablative modality to multiple disease sites, achieving local control rates proximate to those observed following surgery. However, very little experience with SBRT in the management of gynecologic cancers has been reported to date. For patients contraindicated for brachytherapy or surgery, external beam radiation therapy alone offers historically poor disease control outcomes. To our knowledge, this prospective phase II study reports the largest cohort of endometrial and cervical cancer cases treated with curative intent using SBRT as a boost modality in place of brachytherapy. Materials/Methods: Protocol eligibility criteria included the following: (1) pathologically confirmed endometrial or cervical squamous cell carcinoma or adenocarcinoma (serous and clear cell histologies were excluded); (2) no radiographic evidence of extra-pelvic disease; (3) technical or medical contraindication to surgical therapy and brachytherapy; and (4) primary GTV volume less than 125 cm3. All patients first received external beam radiation
2700 Chemoradiation Versus Chemotherapy or Radiation Alone in Stage III Endometrial Cancer: Patterns of Care and Impact on Overall Survival D. Boothe,1 A. Orton,1 B. Odei,2 G. Suneja,1 T. Werner,3 and D.K. Gaffney1; 1Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, 2University of California Los Angeles, Los Angeles, CA, 3 University of Utah Huntsman Cancer Institute, Department of Medical Oncology, Salt Lake City, UT Purpose/Objective(s): In advanced endometrial cancer, the benefit of combining adjuvant chemotherapy and radiation (aCRT) is unclear. We aimed to investigate the patterns-of-care and overall survival (OS) benefit of aCRT versus monotherapy (aMT), defined as either chemotherapy or radiation alone, utilizing a large national registry of patients. Materials/Methods: Adult patients with stage III endometrial adenocarcinoma diagnosed from 2004-2013 were included. Logistic and Cox regression modeling was used to identify factors predictive of receipt of aCRT and OS, respectively. Survival analysis was performed with Kaplan Meier and log-rank analysis. Propensity score matching and sensitivity analysis was performed to address selection bias and presence of potential confounding variables. Results: A total of 11,435 (54.4%) received aMT, while 9,592 (45.6%) received adjuvant aCRT. Utilization of aCRT increased over the study period (P<0.01). Factors predictive of receiving aCRT include private insurance (OR 1.67, 95% CI 1.30-2.14), Medicare (OR 1.33, 95% CI 1.011.75), FIGO stage IIIC disease (OR 1.36, 95% CI 1.19-1.54), lymphovascular space invasion (OR 1.14, 95% CI 1.03-1.27), and lymph node surgery performed (OR 1.42, 95% CI 1.15-1.74). Median survival in years for aCRT, RT, and CT was 10.3, 7.1, and 5.6, respectively (P<0.001). Compared to aMT, aCRT was associated with a decrease risk of death on multivariate analysis (HR 0.62, 95% CI 0.56-0.70). The benefit of aCRT over aMT persisted after propensity score matching. Conclusion: The use of aCRT for stage III endometrial cancer is increasing. When compared to chemotherapy or radiation alone, aCRT is associated with an OS benefit. Author Disclosure: D. Boothe: None. A. Orton: None. B. Odei: None. G. Suneja: None. T. Werner: None. D. Gaffney: Oversee the organization; American Brachytherapy Society.
2696 Association Between Dose-Volume Histograms and Health-Related Quality of Life in Patients with Prostate Cancer Treated with External Beam Radiation Therapy A. Boladeras,1 F. Ferrer,1 V. Navarro,2 R. De Blas,3 O. Cunillera,4 D. Mateo,5 C. Gutierrez,1 S. Villa,6 E. Martinez,1 J. Pera,1 M. Ferrer,7 and F. Guedea1; 1Radiation Oncology Department. Catalan Institute of Oncology, L’Hospitalet-Barcelona, Spain, 2Institut Catala d’Oncologia, Hospitalet, Spain, 3Physics Department. Catalan Institute of Oncology, L’Hospitalet-Barcelona, Spain, 4Institut Hospital de Mar, Barcelona, Spain, 5Institut Catala d’Oncologia, Hospitalet, Spain, 6Catalan Institute of Oncology. HU Germans Trias, Badalona Catalonia, Spain, 7Hopsital del Mar, Barcelona, Spain Purpose/Objective(s): Few studies have evaluated the association between doseevolume histograms (DVH) and toxicity in prostate cancer and even fewer have studied the association between DVH and health-related quality of life (HRQL). The aim of this study was to assess the correlation between DVH in organs at risk (OAR) outcomes as measured with a specific HRQL questionnaire
Poster Viewing E285 Materials/Methods: The study included 154 patients treated with external beam radiation therapy for clinically-localized prostate cancer at our institution between January 2003 and November 2005.Inclusion criteria were stage T1-T2 and a confirmed diagnosis of low-risk prostate cancer. HRQL was evaluated by Expanded Prostate Cancer Index (EPIC) among other questionnaires. DVH for OARs (penile bulb, rectum and bladder) were created for 119 of the 154 patients to assess the correlation between DVH and HRQL using the Functional Data Analysis method and HRQL calculating the mean functions through Functional Data Analysis methods. Results: A worsening of urinary incontinence and obstructive symptoms on the EPIC items correlated with a higher DVH dose distribution at 24 months. Similarly, increased rectal bleeding at both 24 and 60 months correlated with a higher DVH dose distribution (from 40-70 Gy).Patients with worsening rectal incontinence (uncontrolled leakage) presented a higher DVH distribution (between 40-70 Gy at 24 months and throughout the curve at 60 months) versus patients without this side effect. No significant association was found between the presence or not of erectile dysfunction and penile bulb DVH values. Conclusion: These findings demonstrate that DVH and HRQL are closely correlated and also correlate with published data on the association between DVH and toxicity. Functional Data Analysis was a valuable tool to properly analyze the DVH data. These results could help radiation-oncologists to select the best treatment from among the various treatment strategies in order to achieve the best quality of life outcomes. Author Disclosure: A. Boladeras: None. F. Ferrer: None. V. Navarro: None. R. De Blas: None. O. Cunillera: None. D. Mateo: None. C. Gutierrez: None. S. Villa: None. E. Martinez: None. J. Pera: None. M. Ferrer: None. F. Guedea: None.
2697 Prognostic Significance of Rising Prostate-Specific Antigen (PSA) Levels Following Radiation Therapy for Localized Prostate CancerdComparison Between PSA Bounce Versus PSA Recurrence C. Freiberger, V. Schmitt, M.J. Eble, and M. Pinkawa; RWTH Aachen University Hospital, Department of Radiation Oncology, Aachen, Germany Purpose/Objective(s): Rising PSA levels are often detected following radiation therapy (RT) for localized prostate cancer, worrying patients as well as treating physicians. However, this increase frequently does not meet the definition of a biochemical recurrence according to the Phoenix definition (nadir + 2ng/mL) and corresponds to a PSA bounce. The aim of this study was to evaluate the long-term prognostic significance of rising PSA levels. Materials/Methods: In the years 2000-2003, 295 patients with localized prostate cancer were treated in our department. Therapeutic alternatives were a low-dose-rate (LDR) brachytherapy with I-125 seeds as monotherapy (n Z 94; 145Gy), high-dose-rate (HDR) brachytherapy with Ir192 as a boost to external beam RT (n Z 66; 50.4Gy in 1.8Gy fractions EBRT + 18Gy in 9Gy fractions HDR) and EBRT alone (70.2Gy in 1.8Gy fractions; n Z 135). PSA recurrence was defined according to the Phoenix definition, PSA bounce as an increase of at least 0.2ng/ml with a consecutive spontaneous decrease. Primary aim of the study was to analyze the significance of rising PSA levels for overall survival. Results: Median follow-up after the end of RT was 108 months. 10-year PSA recurrence-free, metastasis-free, disease-specific and overall survival rates in this patient population were 53%, 89%, 90% und 66% (significantly higher recurrence-free survival in low/intermediate risk patients for LDR vs. EBRT and EBRT+HDR vs. EBRT, respectively). PSA bounce was found in 84 patients, PSA recurrence in 119 patients. PSA recurrence was detected significantly later than a PSA bounce (interquartile range/median Z IQ/M of 18-51/32 months vs. 13-26/20 months after RT; P<0.01). The nadir before the increase was lower in case of a PSA bounce (IQ/M of 0.20.8/0.5 ng/mL vs. 0.6-2.5/1.2 ng/mL; P<0.01). However, PSA doubling times were similar: 3.0-9.2/5.6 months for PSA bounce vs. 2.5-8.1/5.0 months for PSA recurrence. A PSA bounce proved to be a prognostically favorable factor (10-year overall survival of 82% vs. 59%; P<0.01), whereas PSA recurrence was unfavorable (10-year overall survival of 54% vs. 74%; P<0.01). Both factors proved to be independent in multivariate
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Cox regression analysis. PSA doubling time and nadir before increase were prognostically significant in case of PSA recurrence (10-year overall survival of 71% vs. 41% with PSA doubling time >6 months vs. <6 months; P Z 0.01; 63% vs. 46% with a nadir <1ng/mL vs. >1ng/mL; P Z 0.02). Conclusion: Rising PSA levels particularly in the second year following RT after reaching a nadir <1ng/mL indicates a prognostically favorable PSA bounce. A short PSA doubling time and a higher nadir are associated with an adverse prognosis in case of a PSA recurrence. Author Disclosure: C. Freiberger: None. V. Schmitt: None. M.J. Eble: None. M. Pinkawa: None.
therapy to a minimum dose of 45.0 Gy encompassing primary tumor and regional pelvic lymphatics. Boost SBRT treatment planning then followed, and GTV delineation was aided by coregistration of the boost planning CT set to a PET/CT scan and MRI. Prior to each SBRT fraction, target setup was verified by matching to organ-implanted radio-opaque fiducial markers and by assessing for deformations using cone beam CT imaging. A total radiation dose of 40.0 Gy was prescribed to the primary tumor and delivered over a 10day schedule of 5 fractions of 8.0 Gy each. Disease control response was assessed pathologically by 3-month post-therapy biopsy and radiographically by biannual PET/CT imaging. Acute and chronic toxicities were assessed using the National Cancer Institute’s CTCAE v3 toxicity scales. Quality-oflife assessment was determined using FACT-G measurements. Results: Forty-two patients with primary endometrial (n Z 12) or cervical (n Z 30) cancer have been treated since June 2007 and have been followed for a median of 62.0 months and a minimum of 36.0 months. Post-SBRT biopsy was negative for 35 of 42 patients, or 83.3% of all patients. At 5 years, estimated local disease control by pathologic and radiographic (i.e., SUVmax < 2.5) criteria at the SBRT treatment site is 78.6% for all patients and 88.2% for stages I e II patients. No grade 3 or greater urinary or bowel toxicities have been observed to date. Pre and post SBRT FACT-G scores were statistically similar in all studied domains: physical, social, emotional and functional well-being. Conclusion: At a median follow-up greater than 5 years and with a minimum follow-up of 3 years, SBRT appears to offer an effective and welltolerated boost modality for the management of selected gynecologic cancer patients otherwise contraindicated for brachytherapy or surgery. Author Disclosure: C.A. Mantz: None.
2698 Prostate-Specific Antigen Kinetics After Hypofractionated Stereotactic Body Radiation Therapy Boost and Whole-Pelvic Radiation Therapy for Intermediate- and High-Risk Prostate Cancer H.J. Kim1 and W.C. Kim2; 1Inha University Hospital Inchon, Korea, The Republic of Korea, 2inha University Hospital, Inchon, Korea, The Republic of Korea Purpose/Objective(s): Stereotactic body radiation therapy (SBRT) has emerged as an effective treatment for localized prostate cancer. However, prostate specific antigen (PSA) kinetics after SBRT has not been well characterized. The objective of the current study is to analyze the rate of PSA decline and PSA nadir following SBRT boost after whole pelvis radiation therapy (WPRT) in intermediate- and high-risk prostate cancer. Materials/Methods: From March 2008 to July 2014, forty-two patients newly diagnosed, intermediate- and high-risk (NCCN definition) localized prostate cancer were treated with SBRT boost using robotic radiosurgery after WPRT. The whole pelvis dose was 45 Gy (25 fractions of 1.8 Gy) and the SBRT boost dose was 21 Gy (3 fractions of 7 Gy). No one received androgen deprivation therapy (ADT) before biochemical relapse. PSA nadir and rate of change in PSA (slope) were calculated and compared. Results: With a median follow-up of 53.6 months (range, 14-74), the median rates of decline of PSA were -0.605, -0.229 and -0.166 ng/mL/ month, respectively, for durations of 1, 2 and 3 years post radiation therapy, respectively. The median PSA nadir was 0.32 ng/mL after a median 36 months. 5-year biochemical failure (BCF) free survival was 100% for intermediate-risk and 71.4% for high-risk patients (P Z 0.002). Conclusion: In this report of intermediate- and high-risk prostate cancer, continuously greater rates of decline PSA for duration 1, 2 and 3 year following SBRT boost after WPRT resulted in lower PSA nadir. In addition, SBRT boost after WBPT leads to favorable BCF-free survival. Author Disclosure: H. Kim: None. W. Kim: None.
2699 Stereotactic Body Radiation Therapy as a Boost Alternative for Nonmetastatic Cancer of the Cervix and Endometrium: Disease Control and Quality of Life Outcomes From a Phase 2 Trial at 3 Years’ Minimum Follow-up C.A. Mantz; 21st Century Oncology, Fort Myers, FL Purpose/Objective(s): Stereotactic body radiation therapy (SBRT) has been applied as a radioablative modality to multiple disease sites, achieving local control rates proximate to those observed following surgery. However, very little experience with SBRT in the management of gynecologic cancers has been reported to date. For patients contraindicated for brachytherapy or surgery, external beam radiation therapy alone offers historically poor disease control outcomes. To our knowledge, this prospective phase II study reports the largest cohort of endometrial and cervical cancer cases treated with curative intent using SBRT as a boost modality in place of brachytherapy. Materials/Methods: Protocol eligibility criteria included the following: (1) pathologically confirmed endometrial or cervical squamous cell carcinoma or adenocarcinoma (serous and clear cell histologies were excluded); (2) no radiographic evidence of extra-pelvic disease; (3) technical or medical contraindication to surgical therapy and brachytherapy; and (4) primary GTV volume less than 125 cm3. All patients first received external beam radiation
2700 Chemoradiation Versus Chemotherapy or Radiation Alone in Stage III Endometrial Cancer: Patterns of Care and Impact on Overall Survival D. Boothe,1 A. Orton,1 B. Odei,2 G. Suneja,1 T. Werner,3 and D.K. Gaffney1; 1Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, 2University of California Los Angeles, Los Angeles, CA, 3 University of Utah Huntsman Cancer Institute, Department of Medical Oncology, Salt Lake City, UT Purpose/Objective(s): In advanced endometrial cancer, the benefit of combining adjuvant chemotherapy and radiation (aCRT) is unclear. We aimed to investigate the patterns-of-care and overall survival (OS) benefit of aCRT versus monotherapy (aMT), defined as either chemotherapy or radiation alone, utilizing a large national registry of patients. Materials/Methods: Adult patients with stage III endometrial adenocarcinoma diagnosed from 2004-2013 were included. Logistic and Cox regression modeling was used to identify factors predictive of receipt of aCRT and OS, respectively. Survival analysis was performed with Kaplan Meier and log-rank analysis. Propensity score matching and sensitivity analysis was performed to address selection bias and presence of potential confounding variables. Results: A total of 11,435 (54.4%) received aMT, while 9,592 (45.6%) received adjuvant aCRT. Utilization of aCRT increased over the study period (P<0.01). Factors predictive of receiving aCRT include private insurance (OR 1.67, 95% CI 1.30-2.14), Medicare (OR 1.33, 95% CI 1.011.75), FIGO stage IIIC disease (OR 1.36, 95% CI 1.19-1.54), lymphovascular space invasion (OR 1.14, 95% CI 1.03-1.27), and lymph node surgery performed (OR 1.42, 95% CI 1.15-1.74). Median survival in years for aCRT, RT, and CT was 10.3, 7.1, and 5.6, respectively (P<0.001). Compared to aMT, aCRT was associated with a decrease risk of death on multivariate analysis (HR 0.62, 95% CI 0.56-0.70). The benefit of aCRT over aMT persisted after propensity score matching. Conclusion: The use of aCRT for stage III endometrial cancer is increasing. When compared to chemotherapy or radiation alone, aCRT is associated with an OS benefit. Author Disclosure: D. Boothe: None. A. Orton: None. B. Odei: None. G. Suneja: None. T. Werner: None. D. Gaffney: Oversee the organization; American Brachytherapy Society.