Exploratory Analysis of Associations Between Whole Blood Mitochondrial Gene Expression and Cancer-Related Fatigue Among Breast Cancer Survivors.

BACKGROUND: Cancer-related fatigue is a prevalent, debilitating, and persistent condition. Mitochondrial dysfunction is a putative contributor to cancer-related fatigue, but relationships between mitochondrial function and cancer-related fatigue are not well understood. OBJECTIVES: We investigated the relationships between mitochondrial DNA (mtDNA) gene expression and cancer-related fatigue, as well as the effects of fish and soybean oil supplementation on these relationships. METHODS: A secondary analysis was performed on data from a randomized controlled trial of breast cancer survivors 4-36 months posttreatment with moderate-severe cancer-related fatigue. Participants were randomized to take 6 g fish oil, 6 g soybean oil, or 3 g each daily for 6 weeks. At pre- and postintervention, participants completed the Functional Assessment of Chronic Illness Therapy-Fatigue questionnaire and provided whole blood for assessment of mtDNA gene expression. The expression of 12 protein-encoding genes was reduced to a single dimension using principal component analysis for use in regression analysis. Relationships between mtDNA expression and cancer-related fatigue were assessed using linear regression. RESULTS: Among 68 participants, cancer-related fatigue improved and expression of all mtDNA genes decreased over 6 weeks with no effect of treatment group on either outcome. Participants with lower baseline mtDNA gene expression had greater improvements in cancer-related fatigue. No significant associations were observed between mtDNA gene expression and cancer-related fatigue at baseline or changes in mtDNA gene expression and changes in cancer-related fatigue. DISCUSSION: Data from this exploratory study add to the growing literature that mitochondrial dysfunction may contribute to the etiology and pathophysiology of cancer-related fatigue.

Two graphs walk into a bar: Readout-based measurement reveals the Bar-Tip Limit error, a common, categorical misinterpretation of mean bar graphs.

How do viewers interpret graphs that abstract away from individual-level data to present only summaries of data such as means, intervals, distribution shapes, or effect sizes? Here, focusing on the mean bar graph as a prototypical example of such an abstracted presentation, we contribute three advances to the study of graph interpretation. First, we distill principles for Measurement of Abstract Graph Interpretation (MAGI principles) to guide the collection of valid interpretation data from viewers who may vary in expertise. Second, using these principles, we create the Draw Datapoints on Graphs (DDoG) measure, which collects drawn readouts (concrete, detailed, visuospatial records of thought) as a revealing window into each person's interpretation of a given graph. Third, using this new measure, we discover a common, categorical error in the interpretation of mean bar graphs: the Bar-Tip Limit (BTL) error. The BTL error is an apparent conflation of mean bar graphs with count bar graphs. It occurs when the raw data are assumed to be limited by the bar-tip, as in a count bar graph, rather than distributed across the bar-tip, as in a mean bar graph. In a large, demographically diverse sample, we observe the BTL error in about one in five persons; across educational levels, ages, and genders; and despite thoughtful responding and relevant foundational knowledge. The BTL error provides a case-in-point that simplification via abstraction in graph design can risk severe, high-prevalence misinterpretation. The ease with which our readout-based DDoG measure reveals the nature and likely cognitive mechanisms of the BTL error speaks to the value of both its readout-based approach and the MAGI principles that guided its creation. We conclude that mean bar graphs may be misinterpreted by a large portion of the population, and that enhanced measurement tools and strategies, like those introduced here, can fuel progress in the scientific study of graph interpretation.

Nutritional Interventions for Treating Cancer-Related Fatigue: A Qualitative Review.

Cancer-related fatigue (CRF) is a debilitating syndrome that persists for many cancer survivors for years after treatment. Symptoms include early and persistent fatigue, functional decline, depression, and cognitive difficulties. Inflammation, assessed using pro-inflammatory biomarkers, is increased in cancer survivors with fatigue and treatments for fatigue are often aimed at reducing inflammation. Additionally, cancer and its treatment lead to nutritional complications, changes in body composition, and nutritional deficiencies that potentially weaken the cancer survivor and impact CRF. We conducted a qualitative review of clinical trials that assessed nutritional interventions for preventing and treating CRF. Further studies were examined that used nutritional interventions to address inflammation and fatigue, due to the dearth of nutrition research directly related to CRF. Dietary intake prior to, during, and after cancer treatment appears to affect fatigue levels. Increased protein intake may help preserve lean mass and body composition. Dietary patterns that reduce inflammation, such as the Mediterranean diet and other plant-based diets, appear tolerable to cancer survivors and may reduce fatigue. Supplementation with ginseng, ginger, or probiotics may improve cancer survivors' energy levels. Nutritional interventions, alone or in combination with other interventions should be considered as therapy for fatigue in cancer survivors.

Common genetic variation associated with increased susceptibility to prostate cancer does not increase risk of radiotherapy toxicity.

BACKGROUND: Numerous germline single-nucleotide polymorphisms increase susceptibility to prostate cancer, some lying near genes involved in cellular radiation response. This study investigated whether prostate cancer patients with a high genetic risk have increased toxicity following radiotherapy. METHODS: The study included 1560 prostate cancer patients from four radiotherapy cohorts: RAPPER (n=533), RADIOGEN (n=597), GenePARE (n=290) and CCI (n=150). Data from genome-wide association studies were imputed with the 1000 Genomes reference panel. Individuals were genetically similar with a European ancestry based on principal component analysis. Genetic risks were quantified using polygenic risk scores. Regression models tested associations between risk scores and 2-year toxicity (overall, urinary frequency, decreased stream, rectal bleeding). Results were combined across studies using standard inverse-variance fixed effects meta-analysis methods. RESULTS: A total of 75 variants were genotyped/imputed successfully. Neither non-weighted nor weighted polygenic risk scores were associated with late radiation toxicity in individual studies (P>0.11) or after meta-analysis (P>0.24). No individual variant was associated with 2-year toxicity. CONCLUSION: Patients with a high polygenic susceptibility for prostate cancer have no increased risk for developing late radiotherapy toxicity. These findings suggest that patients with a genetic predisposition for prostate cancer, inferred by common variants, can be safely treated using current standard radiotherapy regimens.

Radiogenomics: the search for genetic predictors of radiotherapy response.

'Radiogenomics' is the study of genetic variation associated with response to radiotherapy. Radiogenomics aims to uncover the genes and biologic pathways responsible for radiotherapy toxicity that could be targeted with radioprotective agents and; identify genetic markers that can be used in risk prediction models in the clinic. The long-term goal of the field is to develop single nucleotide polymorphism-based risk models that can be used to stratify patients to more precisely tailored radiotherapy protocols. The field has evolved over the last two decades in parallel with advances in genomics, moving from narrowly focused candidate gene studies to large, collaborative genome-wide association studies. Several confirmed genetic variants have been identified and the field is making progress toward clinical translation.

KDM3B Single-Nucleotide Polymorphisms Impact Radiation Therapy Toxicity Through Circular RNA-Mediated KDM3B Expression and Inflammatory Responses.

PURPOSE: Genome-wide association studies have identified single-nucleotide polymorphisms (SNPs) associated with radiation therapy (RT) toxicities in patients with prostate cancer. SNP rs17599026 in intron 21 of KDM3B is significantly associated with the development of late urinary toxicity, specifically in the increase in urinary frequency 2 years after RT compared with pretreatment conditions. The present study aimed to provide mechanistic insights for this association. METHODS AND MATERIALS: Using human tissues and cell lines, we examined the protein expression of KDM3B and molecular mechanisms underlying the SNP modulation by variants of KDM3B SNP alleles. In animals with normal and heterozygous expressions of Kdm3b, we examined the relationship between Kdm3b expression and radiation toxicity. RESULTS: KDM3B rs17599026 lies in a motif important for circular RNA expression that is responsible for sponging miRNAs to regulate KDM3B expression. Using a murine model with heterozygous deletion of the Kdm3b gene, we found that lower Kdm3b expression is associated with altered pattern of urination after bladder irradiation, which is related to differential degrees of tissue inflammation as measured by analyses of gene expression, lymphocyte infiltration, and noninvasive ultrasound imaging. CONCLUSIONS: KDM3B SNPs can impact its expression through regulating noncoding RNA expression. Differential KDM3B expression underlies radiation toxicity through tissue inflammation at the molecular and physiological level. Our study outcome offers a foundation for mechanism-based mitigation for radiation toxicity for prostate cancer survivors.

Association of Daily Step Count and Postoperative Complication among All of Us Research Participants.

BACKGROUND: The association between preoperative wearable device step counts and surgical outcomes has not been examined using commercial devices linked to electronic health records (EHR). This study measured the association between daily preoperative step counts and postoperative complications. STUDY DESIGN: Data was obtained using the All of Us (AOU) Research program, a nationwide initiative to collect EHR and health-related data from the population. Included were patients who underwent a surgical procedure included in the National Surgical Quality Improvement Program (NSQIP) targeted procedures dataset. Excluded were patients who did not have available physical activity FitBit data. Primary outcome was the development of a postoperative complication. All analyses were performed in the AOU researcher workbench. RESULTS: Of 27,150 patients who underwent a surgical procedure, 475 participants with preoperative wearable data were included. 74.7% were female and 85.2% were White. The average age was 57.2 years. The overall rate of postoperative complications was 12.6%. Patients averaging fewer than 7,500 daily steps were at increased odds for developing a postoperative complication (OR 1.83, 95% CI [1.01, 3.31]). Following adjustment for age, sex, race, comorbid disease, body mass index (BMI), and relative procedure risk, patients with a baseline average steps/day < 7,500 were at increased odds for postoperative complication (aOR = 2.06, 95% CI [1.05, 4.06]). CONCLUSIONS: This study found an increase in overall postoperative complication rate in patients recording lower average preoperative step counts. Patients with a baseline of less than 7,500 steps per day had increased odds of postoperative complications in this cohort. This data supports the use of wearable devices for surgical risk stratification and suggests step count may measure preoperative fitness.

Changes in Daily Apparent Diffusion Coefficient on Fully Quantitative Magnetic Resonance Imaging Correlate With Established Genomic Pathways of Radiation Sensitivity and Reveal Novel Biologic Associations.

PURPOSE: Changes in quantitative magnetic resonance imaging (qMRI) are frequently observed during chemotherapy or radiation therapy (RT). It is hypothesized that qMRI features are reflective of underlying tissue responses. It's unknown what underlying genomic characteristics underly qMRI changes. We hypothesized that qMRI changes may correlate with DNA damage response (DDR) capacity within human tumors. Therefore, we designed the current study to correlate qMRI changes from daily RT treatment with underlying tumor transcriptomic profiles. METHODS AND MATERIALS: Study participants were prospectively enrolled (National Clinical Trial 03500081). RNA expression levels for 757 genes from pretreatment biopsies were obtained using a custom panel that included signatures of radiation sensitivity and DDR. Daily qMRI data were obtained from a 1.5 Tesla MR linear accelerator. Using these images, d-slow, d-star, perfusion, and apparent diffusion coefficient-mean values in tumors were plotted per-fraction, over time, and associated with genomic pathways. RESULTS: A total of 1022 qMRIs were obtained from 39 patients and both genomic data and qMRI data from 27 total patients. For 20 of those patients, we also generated normal tissue transcriptomic data. Radio sensitivity index values most closely associated with tissue of origin. Multiple genomic pathways including DNA repair, peroxisome, late estrogen receptor responses, KRAS signaling, and UV response were significantly associated with qMRI feature changes (P < .001). CONCLUSIONS: Genomic pathway associations across metabolic, RT sensitivity, and DDR pathways indicate common tumor biology that may correlate with qMRI changes during a course of treatment. Such data provide hypothesis-generating novel mechanistic insight into the biologic meaning of qMRI changes during treatment and enable optimal selection of imaging biomarkers for biologically MR-guided RT.

A 2-stage genome-wide association study to identify single nucleotide polymorphisms associated with development of urinary symptoms after radiotherapy for prostate cancer.

PURPOSE: We identified single nucleotide polymorphisms associated with change in the AUA Symptom Score after radiotherapy for prostate cancer. MATERIALS AND METHODS: A total of 723 patients treated with brachytherapy with or without external beam radiation therapy were assessed at baseline and annually after radiotherapy using the AUA Symptom Score. A 2-stage genome-wide association study was performed with the primary end point of change in AUA Symptom Score from baseline at each of 4 followup periods. Single nucleotide polymorphism associations were assessed using multivariable linear regression adjusting for pre-radiotherapy AUA Symptom Score severity category and clinical variables. Fisher's trend method was used to calculate combined p values from the discovery and replication cohorts. RESULTS: A region on chromosome 9p21.2 containing 8 single nucleotide polymorphisms showed the strongest association with change in AUA Symptom Score (combined p values 8.8×10(-6) to 6.5×10(-7) at 2 to 3 years after radiotherapy). These single nucleotide polymorphisms form a haplotype block that encompasses the inflammation signaling gene IFNK. These single nucleotide polymorphisms were independently associated with change in AUA Symptom Score after adjusting for clinical predictors including smoking history, hypertension, α-blocker use and pre-radiotherapy AUA Symptom Score. An additional 24 single nucleotide polymorphisms showed moderate significance for association with change in AUA Symptom Score. Several of these single nucleotide polymorphisms were more strongly associated with change in specific AUA Symptom Score items, including rs13035033 in the MYO3B gene, which was associated with straining (beta coefficient 0.9, 95% CI 0.6-1.2, p = 5.0×10(-9)). CONCLUSIONS: If validated, these single nucleotide polymorphisms could provide insight into the biology underlying urinary symptoms following radiotherapy and could lead to development of an assay to identify patients at risk for experiencing these effects.

Genetic predictors of cervical dysplasia in African American HIV-infected women: ACTG DACS 268.

OBJECTIVE: To examine genome-wide associations in HIV-infected women with a history of cervical dysplasia compared with HIV-infected women with no history of abnormal Papanicolaou (Pap) tests. DESIGN: Case-control study using data from women analyzed for the HIV Controllers Study and enrolled in HIV treatment-naïve studies in the AIDS Clinical Trials Group (ACTG). METHODS: Genotyping utilized Illumina HumanHap 650 Y or 1MDuo platforms. After quality control and principal component analysis, ~610,000 significant single nucleotide polymorphisms (SNPs) were tested for association. Threshold for significance was P < 5 × 10(-8) for genome-wide associations. RESULTS: No significant genomic association was observed between women with low-grade dysplasia and controls. The genome-wide association study (GWAS) analysis between women with high-grade dysplasia or invasive cervical cancer and normal controls identified significant SNPs. In the analyses limited to African American women, 11 SNPs were significantly associated with the development of high-grade dysplasia or cancer after correcting for multiple comparisons. The model using significant SNPs alone had improved accuracy in predicting high-grade dysplasia in African American women compared to the use of clinical data (area under the receiver operating characteristic curve for genetic and clinical model = 0.9 and 0.747, respectively). CONCLUSIONS: These preliminary data serve as proof of concept that there may be a genetic predisposition to developing high-grade cervical dysplasia in African American HIV-infected women. Given the small sample size, the results need to be validated in a separate cohort.

Temporal patterns of selected late toxicities in patients treated with brachytherapy or brachytherapy plus external beam radiation for prostate adenocarcinoma.

UNLABELLED: What's known on the subject? and What does the study add? While the frequencies and severity of late toxicities following prostate brachytherapy are well known, less has been published with regard to time to first onset. Several series with limited median follow-up have published time to onset. An extensive analysis of timing to late toxicity following brachytherapy for cervical cancer has also been published. This study is the largest of its kind with the longest median follow-up to capture very late events. It can provide a basis for physician and patient education about when late toxicities can reasonably be expected to occur. The study also shows that a significant amount of erectile dysfunction might be more age related than radiation induced. OBJECTIVES: • To assess the timing of first onset of late rectal bleeding, late haematuria and erectile dysfunction (ED) following brachytherapy with or without external beam radiation therapy (EBRT) for prostate adenocarcinoma. • To identify treatment factors and patient characteristics that affect the time to first onset. PATIENTS AND METHODS: • In all, 2046 patients were definitively treated for prostate adenocarcinoma with a full (125) I or (103) Pd implant or a partial (103) Pd implant followed by EBRT with 6 years median follow-up (range 2-17 years). • Patients were selected for an event of Radiation Therapy Oncology Group (RTOG) grade 2 or greater rectal bleeding, ≥RTOG grade 2 haematuria, or a drop in the Mount Sinai Erectile Dysfunction Score from potent to impotent (excluding patients who received androgen deprivation therapy). • Life tables were generated to calculate actuarial incidence rates of toxicity. • Wilcoxon rank sum and Cox regression were utilized to identify treatment factors affecting time to onset. RESULTS: • The incidence rate per 1000 patients for 0-2 years, 2-5 years and 5-10 years following radiation for rectal bleeding is 14.3, 15.9 and 6.5, respectively; for haematuria, 14.0, 8.2 and 1.3, respectively; and for ED, 82.4, 48.2 and 42.2, respectively. • Just 5% of rectal bleeding occurs after 5 years from radiation vs 18% of haematuria cases and 22% of ED. • On multivariate analysis, time to first onset of rectal bleeding was affected by the addition of EBRT only whereas the time to onset of haematuria was affected by the biological effective dose of the radiation and the addition of EBRT. • The only factor on multivariate analysis to affect time to onset of ED was the age of the patient at treatment, independent of radiation dose or technique. CONCLUSIONS: • Unique temporality to first onset of selected toxicities was observed in patients after radioactive implant for prostate adenocarcinoma with or without EBRT. • Clinicians and patients should be counselled when to expect late toxicities. • The only factor to affect time to onset of ED is the age of the patient, suggesting possible over-reporting of radiation-induced ED in the light of normal age-related events.

Quantification of radiation-induced lung damage with CT scans: the possible benefit for radiogenomics.

BACKGROUND: Radiation-induced lung damage (RILD) is an important problem. Although physical parameters such as the mean lung dose are used in clinical practice, they are not suited for individualised radiotherapy. Objective, quantitative measurements of RILD on a continuous instead of on an ordinal, semi-quantitative, semi-subjective scale, are needed. METHODS: Hounsfield unit (HU) changes before versus three months post-radiotherapy were correlated per voxel with the radiotherapy dose in 95 lung cancer patients. Deformable registration was used to register pre- and post-CT scans and the density increase was quantified for various dose bins. The dose-response curve for increased HU was quantified using the slope of a linear regression (HU/Gy). The end-point for the toxicity analysis was dyspnoea ≥ grade 2. RESULTS: Radiation dose was linearly correlated with the change in HU (mean R(2) = 0.74 ± 0.28). No differences in HU/Gy between groups treated with stereotactic radiotherapy, conventional radiotherapy alone, sequential or concurrent chemo- radiotherapy were observed. In the whole patient group, 33/95 (34.7%) had dyspnoea ≥ G2. Of the 48 patients with a HU/Gy below the median, 16 (33.3%) developed dyspnoea ≥ G2, while in the 47 patients with a HU/Gy above the median, 17 (36.1%) had dyspnoea ≥ G2 (not significant). Individual patients showed a nearly 21-fold difference in radiosensitivity, with HU/Gy ranging from 0 to 10 HU/Gy. CONCLUSIONS: HU changes identify objectively the whole range of individual radiosensitivity on a continuous, quantitative scale. CT density changes may allow more robust and accurate radiogenomics studies.

Modeling normal bladder injury after radiation therapy.

PURPOSE: For decades, Dr. John Moulder has been a leading radiation biologist and one of the few who consistently supported the study of normal tissue responses to radiation. His meticulous modeling and collaborations across the field have offered a prime example of how research can be taken from the bench to the bedside and back, with the ultimate goal of providing benefit to patients. Much of the focus of John's work was on mitigating damage to the kidney, whether as the result of accidental or deliberate clinical exposures. Following in his footsteps, we offer here a brief overview of work conducted in the field of radiation-induced bladder injury. We then describe our own preclinical experimental studies which originated as a response to reports from a clinical genome-wide association study (GWAS) investigating genomic biomarkers of normal tissue toxicity in prostate cancer patients treated with radiotherapy. In particular, we discuss the use of Renin-Angiotensin System (RAS) inhibitors as modulators of injury, agents championed by the Moulder group, and how RAS inhibitors are associated with a reduction in some measures of toxicity. Using a murine model, along with precise CT-image guided irradiation of the bladder using single and fractionated dosing regimens, we have been able to demonstrate radiation-induced functional injury to the bladder and mitigation of this functional damage by an inhibitor of angiotensin-converting enzyme targeting the RAS, an experimental approach akin to that used by the Moulder group. We consider our scientific trajectory as a bedside-to-bench approach because the observation was made clinically and investigated in a preclinical model; this experimental approach aligns with the exemplary career of Dr. John Moulder. CONCLUSIONS: Despite the differences in functional endpoints, recent findings indicate a commonality between bladder late effects and the work in kidney pioneered by Dr. John Moulder. We offer evidence that targeting the RAS pathway may provide a targetable pathway to reducing late bladder toxicity.

Normal Tissue Toxicity Prediction: Clinical Translation on the Horizon.

Improvements in radiotherapy delivery have enabled higher therapeutic doses and improved efficacy, contributing to the growing number of long-term cancer survivors. These survivors are at risk of developing late toxicity from radiotherapy, and the inability to predict who is most susceptible results in substantial impact on quality of life and limits further curative dose escalation. A predictive assay or algorithm for normal tissue radiosensitivity would allow more personalized treatment planning, reducing the burden of late toxicity, and improving the therapeutic index. Progress over the last 10 years has shown that the etiology of late clinical radiotoxicity is multifactorial and informs development of predictive models that combine information on treatment (eg, dose, adjuvant treatment), demographic and health behaviors (eg, smoking, age), co-morbidities (eg, diabetes, collagen vascular disease), and biology (eg, genetics, ex vivo functional assays). AI has emerged as a useful tool and is facilitating extraction of signal from large datasets and development of high-level multivariable models. Some models are progressing to evaluation in clinical trials, and we anticipate adoption of these into the clinical workflow in the coming years. Information on predicted risk of toxicity could prompt modification of radiotherapy delivery (eg, use of protons, altered dose and/or fractionation, reduced volume) or, in rare instances of very high predicted risk, avoidance of radiotherapy. Risk information can also be used to assist treatment decision-making for cancers where efficacy of radiotherapy is equivalent to other treatments (eg, low-risk prostate cancer) and can be used to guide follow-up screening in instances where radiotherapy is still the best choice to maximize tumor control probability. Here, we review promising predictive assays for clinical radiotoxicity and highlight studies that are progressing to develop an evidence base for clinical utility.

Prevention of Radiation-Induced Bladder Injury: A Murine Study Using Captopril.

PURPOSE: Pelvic radiation therapy (RT) can cause debilitating bladder toxicities but few clinical interventions exist to prevent injury or alleviate symptoms. From a large genome-wide association study in patients with prostate cancer it was previously reported that SNPs tagging AGT, part of the renin-angiotensin system (RAS), correlated with patient-reported late hematuria, identifying a potential targetable pathway to prevent RT-induced bladder injury. To investigate this association, we performed a preclinical study to determine whether RAS modulation protected the bladder against RT injury. METHODS AND MATERIALS: C57BL/6 male mice were treated with an oral angiotensin converting enzyme inhibitor (ACEi: 0.3g/L captopril) 5 days before focal bladder X-irradiation with either single dose (SD) 30 Gy or 3 fractions of 8 Gy (8 Gy × 3 in 5 days). RT was delivered using XStrahl SARRP Muriplan CT-image guidance with parallel-opposed lateral beams. ACEi was maintained for 20 weeks post RT. Bladder toxicity was assessed using assays to identify local injury that included urinalysis, functional micturition, bladder-released exosomes, and histopathology, as well as an assessment of systemic changes in inflammatory-mediated circulating immune cells. RESULTS: SD and fractionated RT increased urinary frequency and reduced the volume of individual voids at >14 weeks, but not at 4 weeks, compared with nonirradiated animals. Urothelial layer width was positively correlated with mean volume of individual voids (P = .0428) and negatively correlated with number of voids (P = .028), relating urothelial thinning to changes in RT-mediated bladder dysfunction. These chronic RT-induced changes in micturition patterns were prevented by captopril treatment. Focal bladder irradiation significantly increased the mean particle count of urine extracellular vesicles and the monocyte and neutrophil chemokines CCL2 and MIP-2, and the proportions of circulating inflammatory-mediated neutrophils and monocytes, which was also prevented by captopril. Exploratory transcriptomic analysis of bladder tissue implicated inflammatory and erythropoietic pathways. CONCLUSIONS: This study demonstrated that systemic modulation of the RAS protected against and alleviated RT-induced late bladder injury but larger confirmatory studies are needed.

Predicting the germline dependence of hematuria risk in prostate cancer radiotherapy patients.

BACKGROUND AND PURPOSE: Late radiation-induced hematuria can develop in prostate cancer patients undergoing radiotherapy and can negatively impact the quality-of-life of survivors. If a genetic component of risk could be modeled, this could potentially be the basis for modifying treatment for high-risk patients. We therefore investigated whether a previously developed machine learning-based modeling method using genome-wide common single nucleotide polymorphisms (SNPs) can stratify patients in terms of the risk of radiation-induced hematuria. MATERIALS AND METHODS: We applied a two-step machine learning algorithm that we previously developed for genome-wide association studies called pre-conditioned random forest regression (PRFR). PRFR includes a pre-conditioning step, producing adjusted outcomes, followed by random forest regression modeling. Data was from germline genome-wide SNPs for 668 prostate cancer patients treated with radiotherapy. The cohort was stratified only once, at the outset of the modeling process, into two groups: a training set (2/3 of samples) for modeling and a validation set (1/3 of samples). Post-modeling bioinformatics analysis was conducted to identify biological correlates plausibly associated with the risk of hematuria. RESULTS: The PRFR method achieved significantly better predictive performance compared to other alternative methods (all p < 0.05). The odds ratio between the high and low risk groups, each of which consisted of 1/3 of samples in the validation set, was 2.87 (p = 0.029), implying a clinically useful level of discrimination. Bioinformatics analysis identified six key proteins encoded by CTNND2, GSK3B, KCNQ2, NEDD4L, PRKAA1, and TXNL1 genes as well as four statistically significant biological process networks previously shown to be associated with the bladder and urinary tract. CONCLUSION: The risk of hematuria is significantly dependent on common genetic variants. The PRFR algorithm resulted in a stratification of prostate cancer patients at differential risk levels of post-radiotherapy hematuria. Bioinformatics analysis identified important biological processes involved in radiation-induced hematuria.

Comparing symptom reporting by prostate cancer patients and healthcare professionals in the international multicentre REQUITE study.

INTRODUCTION: Previous studies showed that healthcare professionals and patients had only moderate to low agreement on their assessment of treatment-related symptoms. We aimed to determine the levels of agreement in a large cohort of prostate cancer patients. METHODS: Analyses were made of data from 1,756 prostate cancer patients treated with external beam radiotherapy (RT) and/or brachytherapy in Europe and the USA and recruited into the prospective multicentre observational REQUITE study. Eleven pelvic symptoms at the end of RT were compared after translating patient-reported outcomes (PROs) into CTCAE-based healthcare professional ratings. Gwet's AC2 agreement coefficient and 95% confidence intervals were calculated for each symptom. To compare severity of grading between patients and healthcare professionals, percent agreement and deviations for each symptom were graphically depicted. Stratified and sensitivity analyses were conducted to identify potential influencing factors and to assess heterogeneity and robustness of results. RESULTS: The agreement for the 11 pelvic symptoms varied from very good (AC2 > 0.8: haematuria, rectal bleeding, management of sphincter control) to poor agreement (AC2 ≤ 0.2: proctitis and urinary urgency). Fatigue had a negative impact on the agreement. Patients tended to grade symptoms more severely than healthcare professionals. Information on sexual dysfunction was missing more frequently in healthcare professional assessment than PROs. CONCLUSION: Agreement was better for observable than subjective symptoms, with patients usually grading symptoms more severely than healthcare professionals. Our findings emphasize that PROs should complement symptom assessment by healthcare professionals and be taken into consideration for clinical decision-making to incorporate the patient perspective.

Relationships between cytokines and cognitive function from pre- to post-chemotherapy in patients with breast cancer.

Cancer-related cognitive decline (CRCD) is a clinically important problem and negatively affects daily functioning and quality of life. We conducted a pilot longitudinal study from pre- to post-chemotherapy in patients with breast cancer to assess changes in inflammation and cognition over time, as well as the impact of baseline cytokine level on post-chemotherapy cognitive scores. We found that concentrations of IL-6, MCP-1, sTNFRI, and sTNFRII significantly increased in patients, while IL-1ß significantly decreased (p < 0.05). After controlling for covariates, increases in IL-6 and MCP-1 were associated with worse executive function and verbal fluency in patients from pre- to post-chemotherapy (p < 0.05). Higher baseline IL-6 was associated with better performance on executive function and verbal fluency post chemotherapy (p < 0.05). Overall, these results suggest that chemotherapy-associated increases in cytokines/receptors is associated with worse cognitive function. Larger studies are needed to confirm these findings.

No Association Between Polygenic Risk Scores for Cancer and Development of Radiation Therapy Toxicity.

PURPOSE: Our aim was to test whether updated polygenic risk scores (PRS) for susceptibility to cancer affect risk of radiation therapy toxicity. METHODS AND MATERIALS: Analyses included 9,717 patients with breast (n=3,078), prostate (n=5,748) or lung (n=891) cancer from Radiogenomics and REQUITE Consortia cohorts. Patients underwent potentially curative radiation therapy and were assessed prospectively for toxicity. Germline genotyping involved genome-wide single nucleotide polymorphism (SNP) arrays with nontyped SNPs imputed. PRS for each cancer were generated by summing literature-identified cancer susceptibility risk alleles: 352 breast, 136 prostate, and 24 lung. Weighted PRS were generated using log odds ratio (ORs) for cancer susceptibility. Standardized total average toxicity (STAT) scores at 2 and 5 years (breast, prostate) or 6 to 12 months (lung) quantified toxicity. Primary analysis tested late STAT, secondary analyses investigated acute STAT, and individual endpoints and SNPs using multivariable regression. RESULTS: Increasing PRS did not increase risk of late toxicity in patients with breast (OR, 1.000; 95% confidence interval [CI], 0.997-1.002), prostate (OR, 0.99; 95% CI, 0.98-1.00; weighted PRS OR, 0.93; 95% CI, 0.83-1.03), or lung (OR, 0.93; 95% CI, 0.87-1.00; weighted PRS OR, 0.68; 95% CI, 0.45-1.03) cancer. Similar results were seen for acute toxicity. Secondary analyses identified rs138944387 associated with breast pain (OR, 3.05; 95% CI, 1.86-5.01; P = 1.09 × 10-5) and rs17513613 with breast edema (OR, 0.94; 95% CI, 0.92-0.97; P = 1.08 × 10-5). CONCLUSIONS: Patients with increased polygenic predisposition to breast, prostate, or lung cancer can safely undergo radiation therapy with no anticipated excess toxicity risk. Some individual SNPs increase the likelihood of a specific toxicity endpoint, warranting validation in independent cohorts and functional studies to elucidate biologic mechanisms.

Treatment time and circadian genotype interact to influence radiotherapy side-effects. A prospective European validation study using the REQUITE cohort.

BACKGROUND: Circadian rhythm impacts broad biological processes, including response to cancer treatment. Evidence conflicts on whether treatment time affects risk of radiotherapy side-effects, likely because of differing time analyses and target tissues. We previously showed interactive effects of time and genotypes of circadian genes on late toxicity after breast radiotherapy and aimed to validate those results in a multi-centre cohort. METHODS: Clinical and genotype data from 1690 REQUITE breast cancer patients were used with erythema (acute; n=340) and breast atrophy (two years post-radiotherapy; n=514) as primary endpoints. Local datetimes per fraction were converted into solar times as predictors. Genetic chronotype markers were included in logistic regressions to identify primary endpoint predictors. FINDINGS: Significant predictors for erythema included BMI, radiation dose and PER3 genotype (OR 1.27(95%CI 1.03-1.56); P < 0.03). Effect of treatment time effect on acute toxicity was inconclusive, with no interaction between time and genotype. For late toxicity (breast atrophy), predictors included BMI, radiation dose, surgery type, treatment time and SNPs in CLOCK (OR 0.62 (95%CI 0.4-0.9); P < 0.01), PER3 (OR 0.65 (95%CI 0.44-0.97); P < 0.04) and RASD1 (OR 0.56 (95%CI 0.35-0.89); P < 0.02). There was a statistically significant interaction between time and genotypes of circadian rhythm genes (CLOCK OR 1.13 (95%CI 1.03-1.23), P < 0.01; PER3 OR 1.1 (95%CI 1.01-1.2), P < 0.04; RASD1 OR 1.15 (95%CI 1.04-1.28), P < 0.008), with peak time for toxicity determined by genotype. INTERPRETATION: Late atrophy can be mitigated by selecting optimal treatment time according to circadian genotypes (e.g. treat PER3 rs2087947C/C genotypes in mornings; T/T in afternoons). We predict triple-homozygous patients (14%) reduce chance of atrophy from 70% to 33% by treating in mornings as opposed to mid-afternoon. Future clinical trials could stratify patients treated at optimal times compared to those scheduled normally. FUNDING: EU-FP7.