Salvage Radiotherapy for Relapsed Prostate Cancer after Radical Prostatectomy Is Associated with Normal Life Expectancy.

In patients with prostate cancer (PCa), salvage radiotherapy (SRT) for biochemical progression (BP) after radical prostatectomy (RP) improves PCa-specific survival. However, no prospective randomized trials have compared the effect of SRT with untreated patients. In this analysis of 151 patients who received SRT for post-RP BP, we compared their overall survival (OS) with virtual, age-matched controls (n = 151,000) retrieved from government life tables. We also investigated the risk factors associated with BP and OS and compared the prostate-specific antigen (PSA) doubling times (DTs) before and after SRT for patients with BP. The median follow-up was 9.3 years for BP and 17.4 years for OS. The risk factors significantly affecting BP were Gleason score (p < 0.001), pre-SRT PSA (p = 0.003), and negative surgical margins (p = 0.003). None of these risk factors were associated with OS. In 93 patients with BP after SRT, the median PSADT was significantly prolonged compared with pre-SRT values (3.7 vs. 8.3 months, p < 0.001). The OS did not differ between patients and controls (p = 0.112), and life expectancy was similar, likely due to the survival benefit of SRT. The prolonged PSADT after SRT further supports the beneficial role of SRT in this patient population. However, subsequent treatments were not systematically recorded, which may have affected the results.

Multi-institutional Development and External Validation of a Machine Learning Model for the Prediction of Distant Metastasis in Patients Treated by Salvage Radiotherapy for Biochemical Failure After Radical Prostatectomy.

BACKGROUND: Up to 40% of patients with prostate cancer may develop biochemical recurrence after surgery, with salvage radiation therapy (SRT) being the only curative option. In 2016, Tendulkar et al. (Contemporary update of a multi-institutional predictive nomogram for salvage radiotherapy after radical prostatectomy. J Clin Oncol 2016;34:3648-54) published a nomogram to predict distant metastasis in a cohort of patients treated with SRT with pre-SRT prostate-specific antigen (PSA) of 0.5 ng/ml after radical prostatectomy. In modern practice, SRT is delivered at lower PSA values. OBJECTIVE: To train and externally validate a machine learning model to predict the risk of distant metastasis at 5 yr in a contemporary cohort of patients receiving SRT. DESIGN, SETTING, AND PARTICIPANTS: We trained a machine learning model on data from 2418 patients treated with SRT at one institution, with a median PSA value of 0.27 ng/ml. External validation was done in 475 patients treated at two different institutions. Patients with cM1, pN1, or pT4 disease were excluded, as were patients with PSA >2 ng/ml or PSA 0, and patients with radiation dose <60 or ≥80 Gy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Model performance was assessed using calibration and time-dependent area under the receiver operating curve (tAUC). RESULTS AND LIMITATIONS: Our model had better calibration and showed improved discrimination (tAUC = 0.72) compared with the Tendulkar model (tAUC = 0.60, p < 0.001). The main limitations of this study are its retrospective design and lack of validation on patients who received hormone therapy. CONCLUSIONS: The updated model can be used to provide more individualized risk assessments to patients treated with SRT at low PSA values, improving decision-making. PATIENT SUMMARY: Up to 40% of patients with prostate cancer may develop biochemical recurrence after surgery, with salvage radiation therapy as the only potentially curative option. We trained and validated a machine learning model using clinical and surgical data to predict a patient's risk of distant metastasis at 5 yr after treatment. Our model outperformed the reference tool and can improve clinical decision-making by providing more personalized risk assessment.

European Association of Urology Biochemical Recurrence Risk Classification as a Decision Tool for Salvage Radiotherapy-A Multicenter Study.

BACKGROUND: The European Association of Urology (EAU) has proposed a risk stratification for patients harboring biochemical recurrence (BCR) after radical prostatectomy (RP). OBJECTIVE: To assess whether this risk stratification helps in choosing patients for salvage radiotherapy (SRT). DESIGN, SETTING, AND PARTICIPANTS: Analyses of 2379 patients who developed BCR after RP (1989-2020), within ten European high-volume centers, were conducted. Early and late SRT were defined as SRT delivered at prostate-specific antigen values <0.5 and ≥0.5 ng/ml, respectively. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Multivariable Cox models tested the effect of SRT versus no SRT on death and cancer-specific death. The Simon-Makuch method tested for survival differences within each risk group. RESULTS AND LIMITATIONS: Overall, 805 and 1574 patients were classified as having EAU low- and high-risk BCR. The median follow-up was 54 mo after BCR for survivors. For low-risk BCR, 12-yr overall survival was 87% versus 78% (p = 0.2) and cancer-specific survival was 100% versus 96% (p = 0.2) for early versus no SRT. For high-risk BCR, 12-yr overall survival was 81% versus 66% (p < 0.001) and cancer-specific survival was 98% versus 82% (p < 0.001) for early versus no SRT. In multivariable analyses, early SRT decreased the risk for death (hazard ratio [HR]: 0.55, p < 0.01) and cancer-specific death (HR: 0.08, p < 0.001). Late SRT was a predictor of cancer-specific death (HR: 0.17, p < 0.01) but not death (p = 0.1). CONCLUSIONS: Improved survival was recorded within the high-risk BCR group for patients treated with early SRT compared with those under observation. Our results suggest recommending early SRT for high-risk BCR men. Conversely, surveillance might be suitable for low-risk BCR, since only nine patients with low-risk BCR died from prostate cancer during follow-up. PATIENT SUMMARY: The impact of salvage radiotherapy (SRT) on cancer-specific outcomes stratified according to the European Association of Urology biochemical recurrence (BCR) risk classification was assessed. While men with high-risk BCR should be offered SRT, surveillance might be a suitable option for those with low-risk BCR.

Advanced lung cancer patient benefits from minimally invasive costal resection and reconstruction: an effective palliative approach for costal metastasis.

We hereby describe the resection and reconstruction of a rib infiltrated by a lung cancer metastasis. Despite prior radiation therapy aimed at mitigating pain from rib infiltration in a stage IV non-small cell lung cancer patient, results were unsatisfactory. Employing a minimally invasive palliative strategy, we executed a successful operation to address this issue. This technique presents a viable alternative for patients experiencing recurrent pain post radiation therapy.

Management, risk factors and prognostic impact of checkpoint-inhibitor pneumonitis (CIP) in lung cancer - A multicenter observational analysis.

INTRODUCTION: Checkpoint-inhibitor pneumonitis (CIP) represents a major immune-related adverse event (irAE) in patients with lung cancer. We aimed for the clinical characterization, diagnostics, risk factors, treatment and outcome in a large cohort of patients from everyday clinical practice. PATIENTS AND METHODS: For this retrospective analysis, 1,376 patients having received checkpoint inhibitors (CPI) in any line of therapy from June 2015 until February 2020 from three large-volume lung cancer centers in Berlin, Germany were included and analyzed. RESULTS: With a median follow-up of 35 months, all-grade, high-grade (CTCAE ≥ 3) and fatal CIP were observed in 83 (6.0%), 37 (2.7%) and 12 (0.9%) patients, respectively, with a median onset 4 months after initiation of CPI therapy. The most common radiologic patterns were organizing pneumonia (OP) and non-specific interstitial pneumonia (NSIP) (37% and 31%). All except 7 patients with G1-2 CIP interrupted treatment. Corticosteroids were administered to 74 patients with a median starting dose of 0.75 mg/kg. After complete restitution (n = 67), re-exposure to CPI (n = 14) led to additional irAE in 43% of the cases. Thoracic radiotherapy targeting the lung was the only independent risk factor for CIP (odds ratio 2.8, p < 0.001) and pretherapeutic diffusing capacity for carbon monoxide inversely correlated with CIP severity. Compared with patients without CIP and non-CIP irAE, CIP was associated with impaired overall survival (hazard ratios 1.23, p = 0.24 and 2.01, p = 0.005). CONCLUSIONS: High-grade CIP accounts for almost half of all CIP cases in an allcomer lung cancer population. A continuous vigilance, rapid diagnostics and adequate treatment are key to prevent disease progression associated with impaired survival.

Development and External Validation of a Machine Learning Model for Prediction of Lymph Node Metastasis in Patients with Prostate Cancer.

BACKGROUND: Pelvic lymph node dissection (PLND) is the gold standard for diagnosis of lymph node involvement (LNI) in patients with prostate cancer. The Roach formula, Memorial Sloan Kettering Cancer Center (MSKCC) calculator, and Briganti 2012 nomogram are elegant and simple traditional tools used to estimate the risk of LNI and select patients for PLND. OBJECTIVE: To determine whether machine learning (ML) can improve patient selection and outperform currently available tools for predicting LNI using similar readily available clinicopathologic variables. DESIGN, SETTING, AND PARTICIPANTS: Retrospective data for patients treated with surgery and PLND between 1990 and 2020 in two academic institutions were used. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We trained three models (two logistic regression models and one gradient-boosted trees-based model [XGBoost]) on data provided from one institution (n = 20267) with age, prostate-specific antigen (PSA) levels, clinical T stage, percentage positive cores, and Gleason scores as inputs. We externally validated these models using data from another institution (n = 1322) and compared their performance to that of the traditional models using the area under the receiver operating characteristic curve (AUC), calibration, and decision curve analysis (DCA). RESULTS AND LIMITATIONS: LNI was present in 2563 patients (11.9%) overall, and in 119 patients (9%) in the validation data set. XGBoost had the best performance among all the models. On external validation, its AUC outperformed that of the Roach formula by 0.08 (95% confidence interval [CI] 0.042-0.12), the MSKCC nomogram by 0.05 (95% CI 0.016-0.070), and the Briganti nomogram by 0.03 (95% CI 0.0092-0.051; all p < 0.05). It also had better calibration and clinical utility in terms of net benefit on DCA across relevant clinical thresholds. The main limitation of the study is its retrospective design. CONCLUSIONS: Taking all measures of performance together, ML using standard clinicopathologic variables outperforms traditional tools in predicting LNI. PATIENT SUMMARY: Determining the risk of cancer spread to the lymph nodes in patients with prostate cancer allows surgeons to perform lymph node dissection only in patients who need it and avoid the side effects of the procedure in those who do not. In this study, we used machine learning to develop a new calculator to predict the risk of lymph node involvement that outperformed traditional tools currently used by oncologists.

Management of the Contralateral Neck in Unilateral Node-Positive Oral Squamous Cell Carcinoma.

INTRODUCTION: In lateralized oral squamous cell carcinoma (OSCC) with ipsilateral cervical lymph node metastasis (CLNM), the surgical management of the unsuspicious contralateral neck remains a matter of debate. The aim of this study was to analyze this cohort and to compare the outcomes of patients with and without contralateral elective neck dissection (END). MATERIAL AND METHODS: A retrospective analysis of patients with lateralized OSCC, ipsilateral CLNM (pN+) and contralateral cN0-stage was performed. Patients were divided into two groups according to the surgical management of the contralateral neck: I: END; and II: no END performed. Adjuvant radiotherapy was applied bilaterally in both groups according to individual risk. RESULTS: A total of 65 patients (group I: 16 (24.6%); group II: 49 (75.4%)) with a median follow-up of 28 months were included. Initially, there was no case of contralateral CLNM after surgery. During follow-up, 6 (9.2%) patients presented with recurrent CLNM. In 5 of these cases (7.7%), the contralateral neck (group I: 3/16 (18.8%); group II: 2/49 (4.1%)) was affected. Increased ipsilateral lymph node ratio was associated with contralateral CLNM (p = 0.07). END of the contralateral side showed no significant benefit regarding OS (p = 0.59) and RFS (p = 0.19). CONCLUSIONS: Overall, the risk for occult contralateral CLNM in patients with lateralized OSCC ipsilateral CLNM is low. Our data suggest that END should not be performed routinely in this cohort. Risk-adapted radiotherapy of the contralateral neck alone seems to be sufficient from the oncological point of view.

Proton Therapy for 166 Patients with Iris Melanoma: Side Effects and Oncologic Outcomes.

OBJECTIVE: To investigate the oncologic and functional outcomes of a large cohort of patients with a favorable stage of circumscribed and diffuse iris melanoma who underwent primary proton treatment and the risk factors related to initial tumor characteristics and the treatment field architecture. DESIGN: Retrospective, single-center, case study. PARTICIPANTS: We reviewed 225 patients with iris melanoma who were consecutively treated with proton beam therapy at our institution between 1998 and 2020. METHODS: We performed Kaplan-Meier time-to-event analyses and multivariate Cox proportional hazard analyses to identify the impacts of tumor characteristics and target volumes on oncologic and functional outcomes. MAIN OUTCOME MEASURES: We measured local tumor control, eye preservation rates, metastasis-free survival, cataract and glaucoma-directed surgery, intraocular pressure, and changes in visual acuity. RESULTS: Of the 192 patients with tumors confined to the iris (T1a-c) who underwent proton therapy as primary treatment, a total of 166 patients (mean age, 58.4 years; 88 women) with a minimum follow-up of 6 months were included. Multifocal or diffuse tumor spread was present in 77 (46.4%) patients. The median follow-up time was 54.0 (interquartile range, 27.4-91.8 months) months. Local recurrence occurred in 2 patients (1.2%) with circumscribed iris melanoma. Enucleation was a rare event (n = 5, 3%) and no patient developed metastatic disease. A large-treatment field (full aperture, involving > 10 clock hours) was identified as a risk factor for the development of secondary glaucoma (hazard ratio [HR], 6.3; P < 0.001) and subsequent surgical interventions (HR, 10.85; P < 0.001). The large-treatment field group showed a significant decline in visual acuity (logarithm of the minimum angle of resolution > 0.3; log-rank P < 0.0001), which was associated with secondary glaucoma (HR, 3.40; P = 0.002). CONCLUSIONS: Proton therapy provides an effective, noninvasive treatment option for patients with a favorable stage of iris melanoma. Irradiation of the anterior segment for up to 10 clock hours is associated with a low risk of the development of secondary glaucoma and vision loss. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

The Treatment of Metastatic, Hormone-Sensitive Prostatic Carcinoma.

BACKGROUND: For many years, the standard treatment of metastatic, hormone-sensitive prostatic carcinoma (mHSPC) was androgen deprivation therapy (ADT) alone. By lowering the testosterone level into the castration range, ADT deprives the tumor of a key growth factor. METHODS: For this article, we evaluated the treatment recommendations contained in national and international guidelines (German S3 guidelines and those of the European Society for Medical Oncology [ESMO], European Association of Urology [EAU], and National Comprehensive Cancer Network [NCCN]), as well as pertinent publications revealed by a PubMed search and the congress abstracts of the ESMO and of the American Society of Clinical Oncology [ASCO]. RESULTS: The past few years have witnessed fundamental changes in the treatment of mHSPC. Treatment intensification with docetaxel or with the new drugs directed against the androgen receptor signal pathway (abiraterone, apalutamide and enzalutamide) has been found to lower mortality by 19-40% and is now an integral component of first-line therapy. Relevant new findings have also been obtained with threefold combinations of ADT, docetaxel, and abiraterone or darolutamide. For patients with a light tumor burden, local radiotherapy of the primary tumor improves the probability of survival at 3 years by 8% (45.4 versus 49.1 months, difference 3.6 months; 95% confidence interval, 1.0 to 6.2 months). CONCLUSION: The treatment of mHSPC is constantly changing. Phase III trials that are now in the recruitment stage, as well as our continually improving understanding of the underlying molecular-pathological mechanisms, will be altering the treatment landscape still further in the years to come.

Impact of Adjuvant Ocular Interventions on the Quality of Life of Patients with Uveal Melanoma after Proton Beam Therapy.

Introduction: Proton beam therapy is an established primary treatment for patients with nonmetastasized uveal melanoma. Adjuvant local interventions, like intravitreal injections or surgery, were shown to improve long-term eye preservation; however, their impact on the patient's quality of life (QOL) remains unknown. Methods: In a post-radiotherapeutic follow-up, we prospectively collected data on QOL, visual acuity, and interventional adjuvant procedures. QOL was measured with QOL-C30 questionnaire and quality of life questionnaire OPT30 at baseline, and at 3 and 12 months after proton therapy. Patients were grouped by the type of adjuvant treatment. The impact on QOL was analyzed by comparing changes in the mean score values and visual acuity for different interventional subgroups, with generalized linear mixed models and Wilcoxon signed-rank tests. Results: We received 108 (100%) and 95 (88.0%) questionnaires at 3 and 12 months post-therapy, respectively. Adjuvant interventions included observation (n = 61, 56.5%), intravitreal injections (n = 17, 15.7%), and an intraocular surgical procedure (n = 30, 27.8%). In the latter group, several QOL items significantly declined after the 3-month adjuvant interval, but they partially recovered at the 12-month follow-up. In all adjuvant-intervention groups, global QOL scores returned to baseline levels at 12 months. Conclusion: Posttreatment adjuvant interventions had no long-lasting effects on QOL in patients with uveal melanoma.

Recurrence patterns and impact of brain metastases in synchronous single organ oligometastatic lung cancer following local ablative treatment - A multicenter analysis.

INTRODUCTION: Local ablative therapy (LAT) improves survival in oligometastatic lung cancer (OMD), but there is limited information on recurrence patterns, re-treatments and in particular the role of brain metastases during the course of disease. We therefore conducted a retrospective multicenter analysis to evaluate course of disease, sequence of therapies and predictors for long-term disease-control in the brain and survival endpoints. PATIENTS AND METHODS: Clinical data of patients with synchronous, single organ OMD with ≤4 metastases were collected from 5 certified German lung cancer centers. All patients underwent thorough initial staging including a 18FDG-PET/CT scan, brain imaging and mediastinal staging, if necessary, and received LAT to all sites of disease. RESULTS: In total, 164 patients were included (median age 62 years [range 41-84], non-squamous histology 80%, N0-1 64%, single metastasis 84%), 103 had brain (cohort A), 61 extracranial metastases (cohort B). With a median follow-up of 66 months, 115 patients (70%) experienced recurrent disease with a different distribution of sites: In cohort A vs. B, brain relapses occurred in 56% vs. 18% and new distant metastases in 5% vs. 40%. In total, LAT for every relapse was possible for 25% (29/115) of the patients. Patients with initial and secondary onset brain metastases experienced long-term disease-control in the brain and subsequently favorable survival with the application of repeated LAT (disease in the brain controlled vs. not-controlled, HR 0.21, p < 0.001). Comparable long-term overall survival was observed in patients with no or isolated brain relapses (5-years OS 74% and 92%) in contrast to patients with extracranial relapses (5-years OS 19.6%, p < 0.001). CONCLUSIONS: Repeated LAT for recurrent synchronous single organ OMD results in a long-term favorable outcome. Disease control in the brain appears crucial and likely determines survival.

Radiotherapy for hormone-sensitive prostate cancer with synchronous low burden of distant metastases.

PURPOSE: The DEGRO Expert Commission on Prostate Cancer has revised the indication for radiation therapy of the primary prostate tumor in patients with synchronous distant metastases with low metastatic burden. METHODS: The current literature in the PubMed database was reviewed regarding randomized evidence on radiotherapy of the primary prostate tumor with synchronous low metastatic burden. RESULTS: In total, two randomized trials were identified. The larger study, the STAMPEDE trial, demonstrated an absolute survival benefit of 8% after 3 years for patients with low metastatic burden treated with standard of care (SOC) and additional radiotherapy (RT) (EQD2 ≤ 72 Gy) of the primary tumor. Differences in the smaller Horrad trial were not statistically significant, although risk reduction in the subgroup (< 5 bone metastases) was equal to STAMPEDE. The STOPCAP meta-analysis of both trials demonstrated the benefit of local radiotherapy for up to 4 bone lesions and an additional subanalysis of STAMPEDE also substantiated this finding in cases with M1a-only metastases. CONCLUSION: Therefore, due to the survival benefit after 3 years, current practice is changing. New palliative SOC is radiotherapy of the primary tumor in synchronously metastasized prostate cancer with low metastatic burden (defined as ≤ 4 bone metastases, with or without distant nodes) or in case of distant nodes only detected by conventional imaging.

Impact of Dose Escalation on the Efficacy of Salvage Radiotherapy for Recurrent Prostate Cancer-A Risk-Adjusted, Matched-Pair Analysis.

Previous randomized trials have not provided conclusive evidence about dose escalations and associated toxicities for salvage radiotherapy (SRT) in prostate cancer. Here, we retrospectively analyzed whether dose escalations influenced progression-free survival in 554 patients that received salvage radiotherapy for relapses or persistently elevated prostate cancer antigen (PSA) after a radical prostatectomy. Patients received SRT between 1997 and 2017 at two University Hospitals in Germany. We compared patient groups that received radiation doses <7000 cGy (n = 225) or ≥7000 cGy (n = 329) to analyze the influence of radiation dose on progression-free survival. In a second matched-pair analysis of 216 pairs, we evaluated prognostic factors (pT2 vs. pT3−4, Gleason score [GS] ≤ 7 vs. GS ≥ 8, R0 vs. R1, and pre-SRT PSA <0.5 vs. ≥0.5 ng/mL). After a median follow-up of 6.8 (4.2−9.2) years, we found that escalated doses significantly improved progression-free survival (p = 0.0042). A multivariate analysis indicated that an escalated dose, lower tumor stages (pT2 vs. pT3/4), and lower GSs (≤7 vs. 8−10) were associated with improved progression-free survival. There was no significant effect on overall survival. Our data suggested that escalating the radiation dose to ≥7000 cGy for SRT after a prostatectomy significantly improved progression-free survival. Longer follow-ups are needed for a comprehensive recommendation.

German S3 Evidence-Based Guidelines on Focal Therapy in Localized Prostate Cancer: The First Evidence-Based Guidelines on Focal Therapy.

BACKGROUND: Focal therapy (FT) is an option to treat localized prostate cancer (PCa) and preserve healthy prostate tissue in order to reduce known side effects from primary whole-gland treatment. The available FT modalities are manifold. Until now, national and international PCa guidelines have been cautious to propose recommendations regarding FT treatment since data from prospective controlled trials are lacking for most FT modalities. Moreover, none of the international guidelines provides a separate section on FT. In this purpose, we provide a synopsis of the consensus-based German S3 guidelines for a possible international use. SUMMARY: The recently published update of the German S3 guidelines, an evidence- and consensus-based guideline, provides a section on FT with recommendations for diagnostic work-up, indications, modalities, and follow-up. This section consists of 12 statements and recommendations for FT in the treatment of localized PCa. KEY MESSAGE: The German S3 guidelines on PCa are the first to incorporate recommendations for FT based on evidence and expert consensus including indication criteria for FT, pretreatment, and follow-up diagnostic pathways as well as an extended overview of FT techniques and the current supportive evidence.

Salvage Radiotherapy versus Observation for Biochemical Recurrence following Radical Prostatectomy for Prostate Cancer: A Matched Pair Analysis.

BACKGROUND: Salvage radiotherapy (SRT) improves oncologic outcomes in prostate cancer (PCa) patients who develop biochemical recurrence (BCR) after radical prostatectomy (RP). However, evidence on hard clinical endpoints is scarce. We compare long-term oncologic outcomes of SRT versus no radiotherapy (noRT) in patients with BCR after RP. PATIENTS AND METHODS: Within a multi-institutional database, we identified patients with BCR after RP between 1989 and 2016 for PCa. Patients with lymph node invasion, with adjuvant radiotherapy, or with additional androgen deprivation therapy at BCR were excluded. In all patients with SRT, SRT was delivered to the prostatic bed only. Propensity score matching (PSM) was performed to account for differences in pathologic tumor characteristics. Kaplan-Meier analyses and Cox regression models tested the effect of SRT versus no RT on metastasis-free (MFS) and overall survival (OS). RESULTS: Of 1832 patients with BCR, 32.9% (n = 603) received SRT without ADT. The median follow-up was 95.9 months. Median total SRT dose was 70.2 Gy. After 1:1 PSM, at 15 years after RP, MFS and OS rates were 84.3 versus 76.9% (p < 0.001) and 85.3 versus 74.4% (p = 0.04) for SRT and noRT, respectively. In multivariable Cox regression models, SRT was an independent predictor for metastasis (HR: 0.37, p < 0.001) and OS (HR: 0.64, p = 0.03). CONCLUSION: This is the first matched-pair analysis investigating the impact of SRT versus observation only in post-RP recurrent PCa. After compensating for established risk factors, SRT was associated with better long-term MFS and OS. These results on clinical endpoints underline the curative potential of SRT.

Thymidine phosphorylase induction by ionizing radiation antagonizes 5-fluorouracil resistance in human ductal pancreatic adenocarcinoma.

Chemoresistance in pancreatic ductal adenocarcinoma (PDAC) frequently contributes to failure of systemic therapy. While the radiosensitizing properties of 5-fluorouracil (FU) are well known, it is unknown whether ionizing radiation (IR) sensitizes towards FU cytotoxicity. Here, we hypothesize that upregulation of thymidine phosphorylase (TP) by IR reverses FU chemoresistance in PDAC cells. The FU resistant variant of the human PDAC cell line AsPC-1 (FU-R) was used to determine the sensitizing effects of IR. Proliferation rates of FU sensitive parental (FU-S) and FU-R cells were determined by WST-1 assays after low (0.05 Gy) and intermediate dose (2.0 Gy) IR followed by FU treatment. TP protein expression in PDAC cells before and after IR was assessed by Western blot. To analyze the specificity of the FU sensitizing effect, TP was ablated by siRNA. FU-R cells showed a 2.7-fold increase of the half maximal inhibitory concentration, compared to FU-S parental cells. Further, FU-R cells showed a concomitant IR resistance towards both doses applied. When challenging both cell lines with FU after IR, FU-R cells had lower proliferation rates than FU-S cells, suggesting a reversal of chemoresistance by IR. This FU sensitizing effect was abolished when TP was blocked by anti-TP siRNA before IR. An increase of TP protein expression was seen after both IR doses. Our results suggest a TP dependent reversal of FU-chemoresistance in PDAC cells that is triggered by IR. Thus, induction of TP expression by low dose IR may be a therapeutic approach to potentially overcome FU chemoresistance in PDAC.

Moderately hypofractionated radiotherapy as definitive treatment for localized prostate cancer: Pattern of practice in German-speaking countries : A survey of the Prostate Cancer Expert Panel of the German Society of Radiation Oncology (DEGRO) and the Working Party on Radiation Oncology of the German Cancer Society (DKG-ARO).

PURPOSE: Various randomized phase III clinical trials have compared moderately hypofractionated to normofractionated radiotherapy (RT). These modalities showed similar effectiveness without major differences in toxicity. This project was conducted by the Prostate Cancer Expert Panel of the German Society of Radiation Oncology (DEGRO) and the Working Party on Radiation Oncology of the German Cancer Society. We aimed to investigate expert opinions on the use of moderately hypofractionated RT as a definitive treatment for localized prostate cancer in German-speaking countries. METHODS: A 25-item, web-based questionnaire on moderate-hypofractionation RT was prepared by an internal committee. The experts of the DEGRO were asked to complete the questionnaire. RESULTS: Fourteen active members of DEGRO completed the questionnaire. The questions described indications for selecting patients eligible to receive moderate hypofractionation based on clinical and pathological factors such as age, urinary symptoms, and risk-group. The questions also collected information on the technical aspects of selection criteria, including the definition of a clinical target volume, the use of imaging, protocols for bladder and rectal filling, the choice of a fractionation schedule, and the use of image guidance. Moreover, the questionnaire collected information on post-treatment surveillance after applying moderately hypofractionated RT. CONCLUSION: Although opinions varied on the use of moderate-hypofractionation RT, the current survey reflected broad agreement on the notion that moderately hypofractionated RT could be considered a standard treatment for localized prostate cancer in German-speaking countries.

Adjuvant Versus Early Salvage Radiation Therapy for Men at High Risk for Recurrence Following Radical Prostatectomy for Prostate Cancer and the Risk of Death.

PURPOSE: Adjuvant compared with early salvage radiation therapy (sRT) following radical prostatectomy (RP) has not been shown to reduce progression-free survival in randomized controlled trials. However, these trials might have missed a benefit in men with adverse pathology at RP given that these men were under-represented and immortal time bias might have been present; herein, we investigate this possibility. METHODS: We evaluated the impact of adjuvant versus early sRT on all-cause mortality (ACM) risk in men with adverse pathology defined as positive pelvic lymph nodes (pN1) or pGleason score 8-10 prostate cancer (PC) and disease extending beyond the prostate (pT3/4). We used a treatment propensity score to minimize potential treatment selection bias when estimating the causal effect of adjuvant versus early sRT on ACM risk and a sensitivity analysis to assess the impact that varying definitions of adverse pathology had on ACM risk adjusting for age at RP, PC prognostic factors, site, and the time-dependent use of post-RP androgen deprivation therapy. RESULTS: After a median follow-up (interquartile range) of 8.16 (6.00-12.10) years, of the 26,118 men in the study cohort, 2,104 (8.06%) died, of which 539 (25.62%) were from PC. After excluding men with a persistent prostate-specific antigen, adjuvant compared with early sRT was associated with a significantly lower ACM risk among men with adverse pathology at RP when men with pN1 PC were excluded (0.33 [0.13-0.85]; P = .02) or included (0.66 [0.44-0.99]; P = .04). CONCLUSION: Adjuvant radiation therapy should be considered in men with pN1 or pGleason score 8 to 10 and pT3/4 PC given the possibility that a significant reduction in ACM risk exists.