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At least 559 records · Page 31

Phase 2 Study of Erlotinib Combined With Adjuvant Chemoradiation and Chemotherapy in Patients With Resectable Pancreatic Cancer

Purpose: Long-term survival rates for patients with resected pancreatic ductal adenocarcinoma (PDAC) have stagnated at 20% for more than a decade, demonstrating the need to develop novel adjuvant therapies. Gemcitabine-erlotinib therapy has demonstrated a survival benefit for patients with metastatic PDAC. Here we report the first phase 2 study of erlotinib in combination with adjuvant chemoradiation and chemotherapy for resected PDAC. Methods and Materials: Forty-eight patients with resected PDAC received adjuvant erlotinib (100 mg daily) and capecitabine (800 mg/m{sup 2} twice daily Monday-Friday) concurrently with intensity modulated radiation therapy (IMRT), 50.4 Gy over 28 fractions followed by 4 cycles of gemcitabine (1000 mg/m{sup 2} on days 1, 8, and 15 every 28 days) and erlotinib (100 mg daily). The primary endpoint was recurrence-free survival (RFS). Results: The median follow-up time was 18.2 months (interquartile range, 13.8-27.1). Lymph nodes were positive in 85% of patients, and margins were positive in 17%. The median RFS was 15.6 months (95% confidence interval [CI], 13.4-17.9), and the median overall survival (OS) was 24.4 months (95% CI, 18.9-29.7). Multivariate analysis with adjustment for known prognostic factors showed that tumor diameter >3 cm was predictive for inferior RFS (hazard ratio, 4.01; P=.001) and OS (HR, 4.98; P=.02), and the development of dermatitis was associated with improved RFS (HR, 0.27; P=.009). During CRT and post-CRT chemotherapy, the rates of grade 3/4 toxicity were 31%/2% and 35%/8%, respectively. Conclusion: Erlotinib can be safely administered with adjuvant IMRT-based CRT and chemotherapy. The efficacy of this regimen appears comparable to that of existing adjuvant regimens. Radiation Therapy Oncology Group 0848 will ultimately determine whether erlotinib produces a survival benefit in patients with resected pancreatic cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Distant Metastasis Risk Stratification for Patients Undergoing Curative Resection Followed by Adjuvant Chemoradiation for Extrahepatic Bile Duct Cancer

Purpose: To analyze the prognostic factors predicting distant metastasis in patients undergoing adjuvant chemoradiation for extrahepatic bile duct (EHBD) cancer. Methods and Materials: Between January 1995 and August 2006, 166 patients with EHBD cancer underwent resection with curative intent, followed by adjuvant chemoradiation. There were 120 males and 46 females, and median age was 61 years (range, 34-86). Postoperative radiotherapy was delivered to tumor bed and regional lymph nodes (median dose, 40 Gy; range, 34-56 Gy). A total of 157 patients also received fluoropyrimidine chemotherapy as a radiosensitizer, and fluoropyrimidine-based maintenance chemotherapy was administered to 127 patients. Median follow-up duration was 29 months. Results: The treatment failed for 97 patients, and the major pattern of failure was distant metastasis (76 patients, 78.4%). The 5-year distant metastasis-free survival rate was 49.4%. The most common site of distant failure was the liver (n = 36). On multivariate analysis, hilar tumor, tumor size {>=}2 cm, involved lymph node, and poorly differentiated tumor were associated with inferior distant metastasis-free survival (p = 0.0348, 0.0754, 0.0009, and 0.0078, respectively), whereas T stage was not (p = 0.8081). When patients were divided into four groups based on these risk factors, the 5-year distant metastasis-free survival rates for patients with 0, 1, 2, and 3 risk factors were 86.4%, 59.9%, 32.5%, and 0%, respectively (p < 0.0001). Conclusion: Despite maintenance chemotherapy, distant metastasis was the major pattern of failure in patients undergoing adjuvant chemoradiation for EHBD cancer after resection with curative intent. Intensified chemotherapy is warranted to improve the treatment outcome, especially in those with multiple risk factors.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Association Between Radiation Necrosis and Tumor Biology After Stereotactic Radiosurgery for Brain Metastasis

Background: The primary dose-limiting toxicity of stereotactic radiosurgery (SRS) is radiation necrosis (RN), which occurs after approximately 5% to 10% of treatments. This adverse event may worsen neurologic deficits, increase the frequency and cost of imaging, and necessitate prolonged treatment with steroids or antiangiogenic agents. Previous investigations have primarily identified lesion size and dosimetric constraints as risk factors for RN in small populations. We hypothesized that disease histology, receptor status, and mutational status are associated with RN. Methods and Materials: All patients presenting with brain metastasis between 1997 and 2015 who underwent SRS and subsequent radiographic follow-up at a single tertiary-care institution were eligible for inclusion. The primary outcome was the cumulative incidence of radiographic RN. Multivariate competing risks regression was used to identify biological risk factors for RN. Results: 1939 patients (5747 lesions) were eligible for inclusion; 285 patients (15%) experienced radiographic RN after the treatment of 427 (7%) lesions. After SRS, the median time to RN was 7.6 months. After multivariate analysis, graded prognostic assessment, renal pathology, lesion diameter, and the heterogeneity index remained independently predictive of RN in the pooled cohort. In subset analyses of individual pathologies, HER2-amplified status (hazard ratio [HR] 2.05, P=.02), BRAF V600+ mutational status (HR 0.33, P=.04), lung adenocarcinoma histology (HR 1.89, P=.04), and ALK rearrangement (HR 6.36, P<.01) were also associated with RN. Conclusions: In the present investigation constituting the largest series of RN, several novel risk factors were identified, including renal histology, lung adenocarcinoma histology, HER2 amplification, and ALK/BRAF mutational status. These risk factors may be used to guide clinical trial design incorporating biological risk stratification or dose escalation. Future studies determining the optimal timing of targeted therapies are warranted to further define the risk of RN.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Health-Related Quality of Life After Single-Fraction High-Dose-Rate Brachytherapy and Hypofractionated External Beam Radiotherapy for Prostate Cancer

Purpose: To investigate the change in health-related quality of life for men after high-dose-rate brachytherapy and external beam radiotherapy for prostate cancer and the factors associated with this change. Methods and Materials: Eligible patients had clinically localized intermediate-risk prostate cancer. The patients received high-dose-rate brachytherapy as a single 15-Gy implant, followed by external beam radiotherapy to 37.5 Gy in 15 fractions. The patients were monitored prospectively for toxicity (Common Terminology Criteria for Adverse Events, version 3.0) and health-related quality of life (Expanded Prostate Cancer Index Composite [EPIC]). The proportion of patients developing a clinically significant difference in the EPIC domain score (minimally important difference of >0.5 standard deviation) was determined and correlated with the baseline clinical and dosimetric factors. The study accrued 125 patients, with a median follow-up of 24 months. Results: By 24 months, 23% had Grade 2 urinary toxicity and only 5% had Grade 2 bowel toxicity, with no Grade 3 toxicity. The proportion of patients reporting a significant decrease in EPIC urinary, bowel, sexual, and hormonal domain scores was 53%, 51%, 45%, and 40% at 12 months and 57%, 65%, 51%, and 30% at 24 months, respectively. The proportion with a >1 standard deviation decrease in the EPIC urinary, bowel, sexual, and hormonal domain scores was 38%, 36%, 24%, and 20% at 12 months and 46%, 48%, 19%, and 8% at 24 months, respectively. On multivariate analysis, the dose to 10% of the urethra was associated with a decreasing EPIC urinary domain score (p = .0089) and, less strongly (p = .0312) with a decreasing hormonal domain score. No association was found between the prostate volume, bladder dose, or high-dose volume and urinary health-related quality of life. A high baseline International Index of Erectile Function score was associated (p = .0019) with a decreasing sexual domain score. The optimal maximal dose to 10% of the urethra cutpoint for urinary health-related quality of life was 120% of the prescription dose. Conclusion: EPIC was a more sensitive tool for detecting the effects on function and bother than were the generic toxicity scales. The urethral dose had the strongest association with a deteriorating urinary quality of life.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Occult Pelvic Lymph Node Involvement in Bladder Cancer: Implications for Definitive Radiation

Purpose: To inform radiation treatment planning for clinically staged, node-negative bladder cancer patients by identifying clinical factors associated with the presence and location of occult pathologic pelvic lymph nodes. Methods and Materials: The records of patients with clinically staged T1-T4N0 urothelial carcinoma of the bladder undergoing radical cystectomy and pelvic lymphadenectomy at a single institution were reviewed. Logistic regression was used to evaluate associations between preoperative clinical variables and occult pathologic pelvic or common iliac lymph nodes. Percentages of patient with involved lymph node regions entirely encompassed within whole bladder (perivesicular nodal region), small pelvic (perivesicular, obturator, internal iliac, and external iliac nodal regions), and extended pelvic clinical target volume (CTV) (small pelvic CTV plus common iliac regions) were calculated. Results: Among 315 eligible patients, 81 (26%) were found to have involved pelvic lymph nodes at the time of surgery, with 38 (12%) having involved common iliac lymph nodes. Risk of occult pathologically involved lymph nodes did not vary with clinical T stage. On multivariate analysis, the presence of lymphovascular invasion (LVI) on preoperative biopsy was significantly associated with occult pelvic nodal involvement (odds ratio 3.740, 95% confidence interval 1.865-7.499, P<.001) and marginally associated with occult common iliac nodal involvement (odds ratio 2.307, 95% confidence interval 0.978-5.441, P=.056). The percentages of patients with involved lymph node regions entirely encompassed by whole bladder, small pelvic, and extended pelvic CTVs varied with clinical risk factors, ranging from 85.4%, 95.1%, and 100% in non-muscle-invasive patients to 44.7%, 71.1%, and 94.8% in patients with muscle-invasive disease and biopsy LVI. Conclusions: Occult pelvic lymph node rates are substantial for all clinical subgroups, especially patients with LVI on biopsy. Extended coverage of pelvic lymph nodes up to the level of the common iliac nodes may be warranted in subsets of patients.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

A search for point sources of EeV photons

Measurements of air showers made using the hybrid technique developed with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for point sources of EeV photons anywhere in the exposed sky. A multivariate analysis reduces the background of hadronic cosmic rays. The search is sensitive to a declination band from –85° to +20°, in an energy range from 10{sup 17.3} eV to 10{sup 18.5} eV. No photon point source has been detected. An upper limit on the photon flux has been derived for every direction. The mean value of the energy flux limit that results from this, assuming a photon spectral index of –2, is 0.06 eV cm{sup –2} s{sup –1}, and no celestial direction exceeds 0.25 eV cm{sup –2} s{sup –1}. These upper limits constrain scenarios in which EeV cosmic ray protons are emitted by non-transient sources in the Galaxy.

79 ASTRONOMY AND ASTROPHYSICS↗

Disparities in the Use of Postmastectomy Radiation Therapy for Inflammatory Breast Cancer

Purpose: Although radiation therapy improves locoregional control and survival for inflammatory breast cancer (IBC), it is underused in this population. The purpose of this study was to identify variables associated with the underuse of postmastectomy radiation therapy (PMRT) for IBC. Methods and Materials: Using the 1998 to 2011 National Cancer Data Base, we identified 8273 women who underwent mastectomy for nonmetastatic IBC. We used logistic regression modeling to determine the demographic, tumor, and treatment variables associated with the underuse of PMRT. Results: Although the use of PMRT increased over time, a total of 30.3% of our cohort did not receive PMRT. On multivariate analysis, variables associated with the underuse of PMRT for IBC included the following (all P<.05): Medicare insurance (odds ratio [OR] = 0.70), annual income <$34,999 (<$30,000: OR=0.79; $30,000-$34,999: OR=0.82), cN2 and cN0 disease (cN2: OR=0.71; cN0: OR=0.63), failure to receive chemotherapy and hormone therapy (chemotherapy: OR=0.15; hormone therapy: OR=0.35), treatment at lower-volume centers (OR=0.83), and treatment in the South and West (South: OR=0.73; West: OR=0.80). Greater distance between patient's residence and radiation facility was also associated with the underuse of PMRT (P=.0001). Conclusions: Although the use of PMRT for IBC has increased over time, it continues to be underused. Disparities related to a variety of variables impact which IBC patients receive PMRT. A concerted effort must be made to address these disparities in order to optimize the outcomes for IBC.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Long-Term Outcomes in Patients With Isolated Supraclavicular Nodal Recurrence After Mastectomy and Doxorubicin-Based Chemotherapy for Breast Cancer

Purpose: To examine the outcome of patients who developed an isolated locoregional recurrence (LRR) involving the supraclavicular fossa (SCV) after initial treatment with modified radical mastectomy and chemotherapy. Methods and Materials: Records from 140 breast cancer patients treated on five prospective trials with mastectomy and doxorubicin-based chemotherapy, with or without radiation, who developed a LRR were reviewed. Kaplan-Meier survival times were calculated using date of LRR as time zero. Results: The median follow-up after LRR was 2.9 years (N = 140; interquartile range, 1.3-6.6 years). In all, 47 of 140 patients (34%) had an SCV component to their LRR. These patients had lower 3-y distant metastasis-free survival (40% vs. 54%, p = 0.003) and overall survival (49% vs. 69%, p = 0.04) than patients without an SCV component. Multivariate analysis revealed that LRR involving an SCV component (hazard ratio, 1.96, p = 0.004) and patients with lymphovascular space invasion in their primary tumors (hazard ratio, 1.65, p = 0.029) were independently associated with a poor distant metastasis-free survival. However, among 23 patients with isolated SCV recurrence, Overall survival was not statistically significantly different between isolated chest wall recurrence and isolated SCV recurrence. Patients with isolated SCV recurrence displayed a median follow-up of 3.3 years (IR, 1.2-5.2). Only 6 LRR of 23 patients were treated with aggressive local therapy, including surgery, chemotherapy, and radiation (alone or in combination). Conclusions: Although breast cancer recurrence with SCV involvement carries a high risk of distant metastasis and death, among women with recurrence limited to the SCV alone, overall survival after isolated SCV recurrence can be long (25% >5 years).

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Reirradiation of Head and Neck Cancers With Intensity Modulated Radiation Therapy: Outcomes and Analyses

Purpose: To review our 15-year institutional experience using intensity modulated radiation therapy (IMRT) to reirradiate patients with head and neck squamous cell carcinomas (HNSCC) and identify predictors of outcomes and toxicity. Methods and Materials: We retrospectively reviewed the records of 227 patients who received head and neck reirradiation using IMRT from 1999 to 2014. Patients treated with noncurative intent were excluded. Radiation-related acute and late toxicities were recorded. Prognostic variables included performance status, disease site, disease-free interval, chemotherapy, and RT dose and volume. Correlative analyses were performed separately for surgery and nonsurgery patients. Results: Two hundred six patients (91%) were retreated with curative intent, and 173 had HNSCC histology; 104 (50%) underwent salvage resection, and 135 (66%) received chemotherapy. Median follow-up after reirradiation was 24.7 months. Clinical outcomes were worse for HNSCC patients, with 5-year locoregional control, progression-free survival, and overall survival rates of 53%, 22%, and 32%, respectively, compared with 74%, 59%, and 79%, respectively, for non-HNSCC patients. On multivariate analysis, concurrent chemotherapy and retreatment site were associated with tumor control, whereas performance status was associated with survival. Favorable prognostic factors specific to surgery patients were neck retreatment and lack of extracapsular extension, whereas for nonsurgery patients, these were a nasopharynx subsite and complete response to induction chemotherapy. Actuarial rates of grade ≥3 toxicity were 32% at 2 years and 48% at 5 years, with dysphagia or odynophagia being most common. Increased grade ≥3 toxicity was associated with retreatment volume >50 cm{sup 3} and concurrent chemotherapy. Conclusions: Reirradiation with IMRT either definitively or after salvage surgery can produce promising local control and survival in selected patients with head and neck cancers. Treatment-related toxicity remains significant. Prognostic factors are emerging to guide multidisciplinary treatment approaches and clinical trial design.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Role of Systemic Therapy in the Development of Lung Sequelae After Conformal Radiotherapy in Breast Cancer Patients

Purpose: To analyze the risk of radiogenic lung damage in breast cancer patients after conformal radiotherapy and different forms of systemic treatment. Methods and Materials: In 328 patients receiving sequential taxane-based chemotherapy, concomitant hormone therapy (tamoxifen or aromatase inhibitors), or no adjuvant systemic therapy, symptomatic and asymptomatic lung sequelae were prospectively evaluated via the detection of visible CT abnormalities, 3 months or 1 year after the completion of the radiotherapy. Results: Significant positive associations were detected between the development of both pneumonitis and fibrosis of Grade 1 and patient age, ipsilateral mean lung dose, volume of the ipsilateral lung receiving 20 Gy, and irradiation of the regional lymph nodes. In multivariate analysis, age and mean lung dose proved to be independent predictors of early (odds ratio [OR] = 1.035, 95% confidence interval [CI] 1.011-1.061 and OR = 1.113, 95% CI 1.049-1.181, respectively) and late (OR = 1.074, 95% CI 1.042-1.107 and OR = 1.207, 95% CI 1.124-1.295, respectively) radiogenic lung damage, whereas the role of systemic therapy was significant in the development of Grade 1 lung fibrosis (p = 0.01). Among the various forms of systemic therapy, tamoxifen increased the risk of late lung sequelae (OR = 2.442, 95% CI 1.120-5.326, p = 0.025). No interaction was demonstrated between the administration of systemic therapy and the other above-mentioned parameters as regards the risk of radiogenic lung damage. Conclusions: Our analyses demonstrate the independent role of concomitant tamoxifen therapy in the development of radiogenic lung fibrosis but do not suggest such an effect for the other modes of systemic treatment.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Disordered glycometabolism involved in pathogenesis of Kashin–Beck disease, an endemic osteoarthritis in China

Kashin–Beck disease (KBD) is a chronic endemic osteoarthritis in China. Previous studies have suggested a role of metabolic dysfunction in causation of this disease. In this investigation, the metabolomics approach and cell experiments were used to discover the metabolic changes and their effects on KBD chondrocytes. Nuclear magnetic resonance ({sup 1}H NMR) spectroscopy was used to examine serum samples from both the KBD patients and normal controls. The pattern recognition multivariate analysis (OSC–PLS) and quantitative analysis (QMTLS iterator) revealed altered glycometabolism in KBD, with increased glucose and decreased lactate and citrate levels. IPA biological analysis showed the centric location of glucose in the metabolic network. Massive glycogen deposits in chondrocytes and increased uptake of glucose by chondrocytes further confirmed disordered glycometabolism in KBD. An in vitro study showed the effects of disordered glycometabolism in chondrocytes. When chondrocytes were treated with high glucose, expression of type II collagen and aggrecan were decreased, while TNF-α expression, the level of cellular reactive oxygen species and cell apoptosis rates all were increased. Therefore, our results demonstrated that disordered glycometabolism in patients with KBD was linked to the damage of chondrocytes. This may provide a new basis for understanding the pathogenesis of KBD. - Highlights: • Disordered glycometabolism in KBD was demonstrated by combining serum metabolomics and chondrocyte studies. • Glucose and TNF-α were key molecules linked to altered metabolism and inflammation in the pathophysiology of KBD. • The glycometabolism disorder was linked to expression of type II collagen and aggrecan, ROS and apoptosis of KBD chondrocytes.

60 APPLIED LIFE SCIENCES↗

Microscopic Disease Extension in Three Dimensions for Non-Small-Cell Lung Cancer: Development of a Prediction Model Using Pathology-Validated Positron Emission Tomography and Computed Tomography Features

Purpose: One major uncertainty in radiotherapy planning of non-small-cell lung cancer concerns the definition of the clinical target volume (CTV), meant to cover potential microscopic disease extension (MDE) around the macroscopically visible tumor. The primary aim of this study was to establish pretreatment risk factors for the presence of MDE. The secondary aim was to establish the impact of these factors on the accuracy of positron emission tomography (PET) and computed tomography (CT) to assess the total tumor-bearing region at pathologic examination (CTV{sub path}). Methods and Materials: 34 patients with non-small-cell lung cancer who underwent CT and PET before lobectomy were included. Specimens were examined microscopically for MDE. The gross tumor volume (GTV) on CT and PET (GTV{sub CT} and GTV{sub PET}, respectively) was compared with the GTV and the CTV at pathologic examination, tissue deformations being taken into account. Using multivariate logistic regression, image-based risk factors for the presence of MDE were identified, and a prediction model was developed based on these factors. Results: MDE was found in 17 of 34 patients (50%). The MDE did not exceed 26 mm in 90% of patients. In multivariate analysis, two parameters (mean CT tumor density and GTV{sub CT}) were significantly associated with MDE. The area under the curve of the two-parameter prediction model was 0.86. Thirteen tumors (38%, 95% CI: 24-55%) were identified as low risk for MDE, being potential candidates for reduced-intensity therapy around the GTV. In the low-risk group, the effective diameter of the GTV{sub CT/PET} accurately represented the CTV{sub path}. In the high-risk group, GTV{sub CT/PET} underestimated the CTV{sub path} with, on average, 19.2 and 26.7 mm, respectively. Conclusions: CT features have potential to predict the presence of MDE. Tumors identified as low risk of MDE show lower rates of disease around the GTV than do high-risk tumors. Both CT and PET accurately visualize the CTV{sub path} in low-risk tumors but underestimate it in high-risk tumors.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Predictors of Survival in Contemporary Practice After Initial Radiosurgery for Brain Metastases

Purpose: The number of brain metastases (BM) is a major consideration in determining patient eligibility for stereotactic radiosurgery (SRS), but the evidence for this popular practice is equivocal. The purpose of this study was to determine whether, following multivariate adjustment, the number and volume of BM held prognostic significance in a cohort of patients initially treated with SRS alone. Methods and Materials: A total of 251 patients with primary malignancies, including non-small cell lung cancer (34%), melanoma (30%), and breast carcinoma (16%), underwent SRS for initial treatment of BM. SRS was used as the sole management (62% of patients) or was combined with salvage treatment with SRS (22%), whole-brain radiation therapy (WBRT; 13%), or resection (3%). Median follow-up time was 9.4 months. Survival was determined using the Kaplan-Meier method. Cox regression was used to assess the effects of patient factors on distant brain failure (DBF), local control (LC), and overall survival (OS). Results: LC at 1 year was 94.6%, and median time to DBF was 10 months. Median OS was 11.1 months. On multivariate analysis, statistically significant predictors of OS were presence of extracranial disease (hazard ratio [HR], 4.2, P<.001), total tumor volume greater than 2 cm{sup 3} (HR, 1.98; P<.001), age ≥60 years (HR, 1.67; P=.002), and diagnosis-specific graded prognostic assessment (HR, 0.71; P<.001). The presence of extracranial disease was a statistically significant predictor of DBF (HR, 2.15), and tumor volume was predictive of LC (HR, 4.56 for total volume >2 cm{sup 3}). The number of BM was not predictive of DBF, LC, or OS. Conclusions: The number of BM is not a strong predictor for clinical outcomes following initial SRS for newly diagnosed BM. Other factors including total treatment volume and systemic disease status are better determinants of outcome and may facilitate appropriate use of SRS or WBRT.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

The long non-coding RNA HOTAIR promotes the proliferation of serous ovarian cancer cells through the regulation of cell cycle arrest and apoptosis

HOX transcript antisense RNA (HOTAIR) is a well-known long non-coding RNA (lncRNA) whose dysregulation correlates with poor prognosis and malignant progression in many forms of cancer. Here, we investigate the expression pattern, clinical significance, and biological function of HOTAIR in serous ovarian cancer (SOC). Clinically, we found that HOTAIR levels were overexpressed in SOC tissues compared with normal controls and that HOTAIR overexpression was correlated with an advanced FIGO stage and a high histological grade. Multivariate analysis revealed that HOTAIR is an independent prognostic factor for predicting overall survival in SOC patients. We demonstrated that HOTAIR silencing inhibited A2780 and OVCA429 SOC cell proliferation in vitro and that the anti-proliferative effects of HOTAIR silencing also occurred in vivo. Further investigation into the mechanisms responsible for the growth inhibitory effects by HOTAIR silencing revealed that its knockdown resulted in the induction of cell cycle arrest and apoptosis through certain cell cycle-related and apoptosis-related proteins. Together, these results highlight a critical role of HOTAIR in SOC cell proliferation and contribute to a better understanding of the importance of dysregulated lncRNAs in SOC progression. - Highlights: • HOTAIR overexpression correlates with an aggressive tumour phenotype and a poor prognosis in SOC. • HOTAIR promotes SOC cell proliferation both in vitro and in vivo. • The proliferative role of HOTAIR is associated with regulation of the cell cycle and apoptosis.

60 APPLIED LIFE SCIENCES↗

High-Density and Very-Low-Density Lipoprotein Have Opposing Roles in Regulating Tumor-Initiating Cells and Sensitivity to Radiation in Inflammatory Breast Cancer

Purpose: We previously demonstrated that cholesterol-lowering agents regulate radiation sensitivity of inflammatory breast cancer (IBC) cell lines in vitro and are associated with less radiation resistance among IBC patients who undergo postmastectomy radiation. We hypothesized that decreasing IBC cellular cholesterol induced by treatment with lipoproteins would increase radiation sensitivity. Here, we examined the impact of specific transporters of cholesterol (ie lipoproteins) on the responses of IBC cells to self-renewal and to radiation in vitro and on clinical outcomes in IBC patients. Methods and Materials: Two patient-derived IBC cell lines, SUM 149 and KPL4, were incubated with low-density lipoproteins (LDL), very-low-density lipoproteins (VLDL), or high-density lipoproteins (HDL) for 24 hours prior to irradiation (0-6 Gy) and mammosphere formation assay. Cholesterol panels were examined in a cohort of patients with primary IBC diagnosed between 1995 and 2011 at MD Anderson Cancer Center. Lipoprotein levels were then correlated to patient outcome, using the log rank statistical model, and examined in multivariate analysis using Cox regression. Results: VLDL increased and HDL decreased mammosphere formation compared to untreated SUM 149 and KPL4 cells. Survival curves showed enhancement of survival in both of the IBC cell lines when pretreated with VLDL and, conversely, radiation sensitization in all cell lines when pretreated with HDL. In IBC patients, higher VLDL values (>30 mg/dL) predicted a lower 5-year overall survival rate than normal values (hazard ratio [HR] = 1.9 [95% confidence interval [CI]: 1.05-3.45], P=.035). Lower-than-normal patient HDL values (<60 mg/dL) predicted a lower 5-year overall survival rate than values higher than 60 mg/dL (HR = 3.21 [95% CI: 1.25-8.27], P=.015). Conclusions: This study discovered a relationship among the plasma levels of lipoproteins, overall patient response, and radiation resistance in IBC patients and IBC patient-derived cell lines. A more expansive study is needed to verify these observations.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Improved Clinical Outcomes With High-Dose Image Guided Radiotherapy Compared With Non-IGRT for the Treatment of Clinically Localized Prostate Cancer

Purpose: To compare toxicity profiles and biochemical tumor control outcomes between patients treated with high-dose image-guided radiotherapy (IGRT) and high-dose intensity-modulated radiotherapy (IMRT) for clinically localized prostate cancer. Materials and Methods: Between 2008 and 2009, 186 patients with prostate cancer were treated with IGRT to a dose of 86.4 Gy with daily correction of the target position based on kilovoltage imaging of implanted prostatic fiducial markers. This group of patients was retrospectively compared with a similar cohort of 190 patients who were treated between 2006 and 2007 with IMRT to the same prescription dose without, however, implanted fiducial markers in place (non-IGRT). The median follow-up time was 2.8 years (range, 2-6 years). Results: A significant reduction in late urinary toxicity was observed for IGRT patients compared with the non-IGRT patients. The 3-year likelihood of grade 2 and higher urinary toxicity for the IGRT and non-IGRT cohorts were 10.4% and 20.0%, respectively (p = 0.02). Multivariate analysis identifying predictors for grade 2 or higher late urinary toxicity demonstrated that, in addition to the baseline Internatinoal Prostate Symptom Score, IGRT was associated with significantly less late urinary toxicity compared with non-IGRT. The incidence of grade 2 and higher rectal toxicity was low for both treatment groups (1.0% and 1.6%, respectively; p = 0.81). No differences in prostate-specific antigen relapse-free survival outcomes were observed for low- and intermediate-risk patients when treated with IGRT and non-IGRT. For high-risk patients, a significant improvement was observed at 3 years for patients treated with IGRT compared with non-IGRT. Conclusions: IGRT is associated with an improvement in biochemical tumor control among high-risk patients and a lower rate of late urinary toxicity compared with high-dose IMRT. These data suggest that, for definitive radiotherapy, the placement of fiducial markers and daily tracking of target positioning may represent the preferred mode of external-beam radiotherapy delivery for the treatment of prostate cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Late Radiation and Cardiovascular Adverse Effects After Androgen Deprivation and High-Dose Radiation Therapy in Prostate Cancer: Results From the DART 01/05 Randomized Phase 3 Trial

Purpose: To present data on the late toxicity endpoints of a randomized trial (DART 01/05) conducted to determine whether long-term androgen deprivation (LTAD) was superior to short-term AD (STAD) when combined with high-dose radiation therapy (HDRT) in patients with prostate cancer (PCa). Patients and Methods: Between November 2005 and December 2010, 355 eligible men with cT1c-T3aN0M0 PCa and intermediate-risk and high-risk factors (2005 National Comprehensive Cancer Network criteria) were randomized to 4 months of AD combined with HDRT (median dose, 78 Gy) (STAD) or the same treatment followed by 24 months of AD (LTAD). Treatment-related complications were assessed using European Organization for Research and Treatment of Cancer–Radiation Therapy Oncology Group and Common Terminology Criteria for Adverse Events v3.0 scoring schemes. Multivariate analyses for late toxicity were done using the Fine-Gray method. Results: The 5-year incidence of grade ≥2 rectal and urinary toxicity was 11.1% and 8.2% for LTAD and 7.6% and 7.3% for STAD, respectively. Compared with STAD, LTAD was not significantly associated with a higher risk of late grade ≥2 rectal toxicity (hazard ratio [HR] 1.360, 95% confidence interval [CI] 0.660-2.790, P=.410) or urinary toxicity (HR 1.028, 95% CI 0.495-2.130, P=.940). The multivariate analysis showed that a baseline history of intestinal comorbidity (HR 3.510, 95% CI 1.560-7.930, P=.025) and the rectal volume receiving >60 Gy (Vr60) (HR 1.030, 95% CI 1.001-1.060, P=.043) were the only factors significantly correlated with the risk of late grade ≥2 rectal complications. A history of previous surgical prostate manipulations was significantly associated with a higher risk of grade ≥2 urinary complications (HR 2.427, 95% CI 1.051-5.600, P=.038). Long-term AD (HR 2.090; 95% CI 1.170-3.720, P=.012) and a history of myocardial infarction (HR 2.080; 95% CI 1.130-3.810, P=.018) were significantly correlated with a higher probability of cardiovascular events. Conclusion: Long-term AD did not significantly impact urinary or rectal radiation-induced toxicity, although it was associated with a higher risk of cardiovascular events. Longer follow-up is needed to measure the impact of AD on late morbidity and non-PCa mortality.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Preoperative Chemoradiotherapy (CRT) Followed by Laparoscopic Surgery for Rectal Cancer: Predictors of the Tumor Response and the Long-Term Oncologic Outcomes

Purpose: We have evaluated the predictors of a tumor response to chemoradiotherapy (CRT) and the long-term oncologic outcomes of preoperative CRT and laparoscopic surgery for patients who suffer from rectal cancer. Methods and Materials: The study involved 274 patients with locally advanced rectal cancer and who had been treated with preoperative CRT and curative laparoscopic total mesorectal excision between January 2003 and January 2009. We assessed the long-term oncologic outcomes, in terms of recurrence and survival, of the treated patients. Results: Forty-two (15.3%) of the 274 patients had complete pathologic responses (pCR). The pre-CRT carcinoembryonic antigen level was the only significant predictor of a pCR on the multivariate analysis (p = 0.01). The overall survival at 5 years was 73.1%, with a mean survival period of 59.7 months (95% CI, 57.1-62.3). The disease-free survival at 5 years was 67.3% with a mean survival period of 54.7 months (95% CI, 51.7-57.8). The pCR group had a higher rate of overall survival at 5 years than did the non-pCR group, and the difference was significant (86.0% vs. 71.2%; hazard ratio = 0.87; 95% CI, 0.78-0.96; p = 0.03). The cumulative incidences of local and distant recurrences at 5 years were 5.8% and 28.3%, respectively. A total of 84.5% (234 of 274) of the patients had their anal sphincters preserved. Grade 3 or 4 acute and long-term toxic effects occurred in 22.2% and 8.4% of the patients, respectively. Conclusion: Preoperative CRT and laparoscopic surgery seems safe and feasible with favorable long-term outcomes and a high rate of sphincter preservation for the patients with low-lying tumors of the rectum.

62 RADIOLOGY AND NUCLEAR MEDICINE↗