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Construction of histology images of cell density and blood vessel density.

The usefulness of mechanistic models to disentangle complex multiscale cancer processes, such as treatment response, has been widely acknowledged. However, a major barrier for multiscale models to predict treatment outcomes in individual patients lies in their initialization and parametrization, which needs to reflect individual cancer characteristics accurately. In this study, we use multitype measurements acquired routinely on a single breast tumor, including histopathology, MRI, and molecular profiling, to personalize parts of a complex multiscale model of breast cancer treated with chemotherapeutic and antiangiogenic agents. The model accounts for drug pharmacokinetics and pharmacodynamics. We developed an open-source computer program that simulates cross-sections of tumors under 12-week therapy regimens and used it to individually reproduce and elucidate treatment outcomes of 4 patients. Two of the tumors did not respond to therapy, and model simulations were used to suggest alternative regimens with improved outcomes dependent on the tumor's individual characteristics. It was determined that more frequent and lower doses of chemotherapy reduce tumor burden in a low proliferative tumor while lower doses of antiangiogenic agents improve drug penetration in a poorly perfused tumor. Furthermore, using this model, we were able to correctly predict the outcome in another patient after 12 weeks of treatment. In summary, our model bridges multitype clinical data to shed light on individual treatment outcomes.Significance:Mathematical modeling is used to validate possible mechanisms of tumor growth, resistance, and treatment outcome.

Pimonidazole immunoscore versus time after administration, DWI parameters and histology parameters

Development of the image integration algorithm.

Supplementary text to the main article detailing mathematical model, model initialisation and parametrisation, computational details and overview of clinical data .

The established role of hypoxia-induced signaling in prostate cancer growth, metastasis, and response to treatment suggests that a method to image hypoxia in tumors could aid treatment decisions. Here, we present consumption and supply-based hypoxia (CSH) imaging, an approach that integrates images related to oxygen consumption and supply into a single image. This integration algorithm was developed in patients with prostate cancer receiving hypoxia marker pimonidazole prior to prostatectomy. We exploited the intravoxel incoherent motion (IVIM) signal in diagnostic diffusion-weighted (DW) magnetic resonance (MR) images to generate separate images of the apparent diffusion coefficient (ADC) and fractional blood volume (fBV). ADC and fBV correlated with cell density (CD) and blood vessel density (BVD) in histology and whole-mount sections from 35 patients, thus linking ADC to oxygen consumption and fBV to oxygen supply. Pixel-wise plots of ADC versus fBV were utilized to predict the hypoxia status of each pixel in a tumor and to visualize the predicted value in a single image. The hypoxic fraction (HFDWI) of CSH images correlated strongly (R2 = 0.66; n = 41) with pimonidazole immunoscore (HSPimo); this relationship was validated in a second pimonidazole cohort (R2 = 0.54; n = 54). We observed good agreement between CSH images and pimonidazole staining in whole-mount sections. HFDWI correlated with tumor stage and lymph node status, consistent with findings for HSPimo. Moreover, CSH imaging could be applied on histologic CD and BVD images, demonstrating transferability to a histopathology assay. Thus, CSH represents a robust approach for hypoxia imaging in prostate cancer that could easily be translated into clinical practice.Significance: These findings present a novel imaging strategy that indirectly measures tumor hypoxia and has potential application in a wide variety of solid tumors and other imaging modalities.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/16/4774/F1.large.jpg. Cancer Res; 78(16); 4774–85. ©2018 AACR.

Clinical characteristics, pimonidazole immunoscore and DWI parameters versus clinicopathological markers

Background Several imaging modalities are used in the early work-up of patients with gastrointestinal stromal tumor (GIST) receiving tyrosine kinase inhibitor (TKI) treatment and there is a need to establish whether they provide similar or complimentary information. Purpose To compare 18F-fluorodeoxyglucose positron emission tomography (FDG PET), computed tomography (CT) and magnetic resonance imaging (MRI) as early predictors of three-month outcomes for patients with GIST receiving TKI treatment. Material and Methods Thirty-five patients with advanced GIST were prospectively included between February 2011 and June 2017. FDG PET, contrast-enhanced CT (CECT), and MRI were performed before and early after onset of TKI treatment (range 8–18 days). Early response was categorized according to mRECIST (CT), the Choi criteria (CECT), and PERCIST (FDG PET/CT). For MRI, volumetry from T2-weighted images and change in apparent diffusion coefficient (ADC) from diffusion-weighted imaging was used. The reference standard for early assessment was the three-month mRECIST evaluation based on CT. At three months, both stable disease (SD) and partial response (PR) were categorized as response. Clinical usefulness was defined as agreement between early and three-month assessment. Results At the three-month assessment, 91% (32/35) were responders, 37% (13/35) PR, 54% (19/35) SD, and 9% (3/35) had progressive disease (PD). Early assessment correctly predicted three-month response in 93% (27/29) for MRI, 80% (28/35) for PERCIST, 74% (26/35) for Choi, and 23% (8/35) for mRECIST. Six patients had non-FDG-avid tumors. For the FDG-avid tumors, PET/CT correctly predicted three-month response in 97% (28/29). Conclusion MRI was superior to CECT for early assessment of TKI-treatment response in GIST. If the tumor was FDG-avid, PET and MRI were equally good. Changes in functional parameters were superior to changes in longest tumor diameter (mRECIST).

The PET tracer 18F-fluciclovine (Axumin) was recently approved in the United States and Europe for men with suspected prostate cancer recurrence following prior treatment. This article summarizes studies where systematic sector-based histopathology was used as reference standard to assess the diagnostic accuracy of the tracer 18F-fluciclovine PET in patients with prostate cancer.

Prostate-specific membrane antigen PET is a promising diagnostic tool in prostate cancer. The gold standard for the detection of prostate tumor and lymph node metastases is histopathology. The aim of the present review was to investigate accuracy measures of 68Ga/18F-labeled prostate-specific membrane antigen PET tracers in primary and recurrent prostate cancer with systematic sector-based histopathology as the reference standard. A systematic literature search was performed and 34 studies were included. Overall, prostate-specific membrane antigen PET showed high specificity, but variable sensitivity to localize known prostate cancer and detect pelvic lymph node metastases.

Background Dose escalated radiation therapy (RT) combined with long-term androgen deprivation therapy (ADT) is a standard of care option for men with high-risk and locally advanced prostate cancer (PCa). However, the optimal dose of escalated RT and ADT is not known. Here we assessed the impact of radiation dose and length of ADT on biochemical recurrence in a multi-institutional cohort stratified by the Cambridge prognostic group (CPG). We hypothesized that radiation dose and length of ADT would impact outcome in similar risk groups of our patients. Methods Two-hundred and forty-four patients were included, 132 from Oslo University Hospital, Department of Oncology and 112 from Johns Hopkins Hospital, Department of Radiation Oncology. Biochemical recurrence was defined as prostate-specific antigen (PSA) nadir +2 ng/mL. Time to recurrence was estimated using Kaplan-Meier analysis and when stratified by CPG the log-rank test was used. Cox regression analysis was performed to identify factors associated with risk of recurrence. Site of recurrence was investigated. Results The median follow-up time was 7.4 years. The vast majority (71%) of patients were classified as high-risk (CPG 4) or very high-risk features (CPG 5). Significantly more PSA recurrences occurred in CPG 5 (41%) compared with CPG 4 (25%) (P = .04) and five-year cumulative recurrence-free survival was lower for CPG 4 and 5 (89% and 68%) compared with CPG 1, 2, and 3 (100%, 100%, and 93%). The recurrence-free survival for CPG 5 was significantly higher for prostate irradiation of 80 Gy as compared with 74 Gy (P = .011). For CPG 4 and 5 no local recurrences were detected in patients receiving 80 Gy. On stepwise Cox regression analysis neither age nor length of ADT were independent prognostic factors for recurrence free survival. Conclusion Prostate dose escalation from 74 to 80 Gy decreases risk of recurrence in high-risk PCa. Further studies are needed to identify the optimal combination of ADT and RT.

The optimal quantification of PET in assessment of head and neck squamous cell carcinoma (HNSCC) is still under development. The effect of partial volume correction (PVC) on the evaluation of survival in the HNSCC patients has not been investigated yet.Pretreatment 18F-FDG-PET/CT scans of a selected group of 57 patients with advanced stage HNSCC were collected. Conventional (SUVmean and SUVmax) and volumetric [total lesion glycolysis (TLG) and metabolic tumor volume (MTV)] PET metrics were calculated. The ROVER software (ABX GmbH, Radeberg, Germany) automatically applied PVC to the PET metrics. Cox proportional hazards regression model calculated hazard ratio (HR) for assessment of predictive parameters of progression-free survival (PFS).In multivariate Cox regression analysis, including age, gender, race, human papillomavirus status, and stage, the only significant predictors of PFS were the volumetric PET parameters (TLG: HR, 1.003; 95% CI, 1.001-1.005; P = 0.02), pvcTLG (HR, 1.002; 95% CI, 1.001-1.004; P = 0.01) and MTV (HR, 1.050; 95% CI, 1.024-1.077; P0.01). The partial volume-corrected values were significantly higher than the noncorrected values (Wilcoxon sign test; P0.05). However, there was not a statistically significant difference between the nonpartial volume corrected and partial volume-corrected PET metrics for assessment of PFS.Volumetric PET metrics were predictors of PFS in Cox regression analysis. Applying PVC could not significantly improve the accuracy of PET metrics for assessment of PFS.

Little is known about the transport mechanism of anti-3-18F-fluorocyclobutane-1-carboxylic acid (FACBC) into prostate tumors. Because of the structural similarity to natural amino acids, FACBC is anticipated to cross the cell membrane via amino acid transporters, and preclinical studies have suggested that ASCT2, LAT1 and SNAT2 are involved. In 16 patients with intermediate or high-risk prostate cancer we matched the FACBC uptake from clinical PET to the location of punch biopsies from resected prostatectomy specimens and compared maximum standardized uptake value (SUVmax) with the gene expression of 40 amino acid transporters. The study also included immunohistochemistry for the three amino acid transporters ASCT2, LAT1 and SNAT2. Furthermore, we performed global gene expression analysis of the biopsies to investigate biological processes associated with FACBC uptake. Several amino acid transporters had a higher gene expression level than the others, but we found no significant correlations between SUVmax and the gene expression levels of any of 40 different amino acid transporters. In the immunohistochemical analyses, ASCT2 and SNAT2 were highly expressed, but not correlated to SUVmax. LAT1 had low gene- and protein expression. Global gene expression analyses identified 153 unique genes that were positively correlated to SUVmax. These genes were found to be associated with gene sets reflecting intracellular transport and high metabolic activity. Based on the study findings we propose that the uptake mechanism of FACBC is more complex than mediated by a few amino acid transporters.

Background Gene signatures measured in a biopsy have been proposed as hypoxia biomarkers in prostate cancer. We assessed a previously developed signature, and aimed to determine its relationship to hypoxia and its heterogeneity within the dominant (index) lesion of prostate cancer. Methods The 32-gene signature was assessed from gene expression data of 141 biopsies from the index lesion of 94 patients treated with prostatectomy. A gene score calculated from the expression levels was applied in the analyses. Hypoxic fraction from pimonidazole immunostained whole-mount and biopsy sections was used as reference standard for hypoxia. Results The gene score was correlated with pimonidazole-defined hypoxic fraction in whole-mount sections, and the two parameters showed almost equal association with clinical markers of tumour aggressiveness. Based on the gene score, incorrect classification according to hypoxic fraction in whole-mount sections was seen in one third of the patients. The incorrect classifications were apparently not due to intra-tumour heterogeneity, since the score had low heterogeneity compared to pimonidazole-defined hypoxic fraction in biopsies. The score showed prognostic significance in uni-and multivariate analysis in independent cohorts. Conclusions Our signature from the index lesion reflects tumour hypoxia and predicts prognosis in prostate cancer, independent of intra-tumour heterogeneity in pimonidazole-defined hypoxia.

Prostate-specific membrane antigen PET is a promising diagnostic tool in prostate cancer. The gold standard for the detection of prostate tumor and lymph node metastases is histopathology. The aim of the present review was to investigate accuracy measures of

Purpose To assess the safety and performance of a MRI-directed diagnostic pathway for patients with first-time suspicion of prostate cancer in a non-university hospital. Methods Between May 2017 and December 2018 all biopsy-naive patients examined in our hospital followed a MRI-directed diagnostic work-up algorithm based on PI-RADS score. In short, PI-RADS 1–2 was generally not biopsied and PI-RADS 3–5 was reviewed by a multidisciplinary team. Patients with PI-RADS 4-5 were all referred to biopsy, either transrectal ultrasound-guided biopsy or MRI in-bore biopsy for small tumors and for sites difficult to access. PI-RADS scores were compared to the histopathology from biopsies and surgical specimens for patients who had prostatectomy. Non-biopsied patients were referred to a safety net monitoring regimen. Results Two hundred and ninety-eight men were enrolled. 97 (33%) had PI-RADS 1–2, 44 (15%) had PI-RADS 3, and 157 (53%) had PI-RADS 4–5. 116 (39%) of the patients avoided biopsy. None of these were diagnosed with significant cancer within 2–3.5 years of safety net monitoring. Almost all high ISUP grade groups (≥ 3) were in the PI-RADS 4–5 category (98%). Prostatectomy specimens and systematic biopsies from MRI-negative areas indicated that very few clinically significant cancers were missed by the MRI-directed diagnostic pathway. Conclusion Our findings add to evidence that a MRI-directed diagnostic pathway can be safely established in a non-university hospital. The pathway reduced the number of biopsies and reliably detected the site of the most aggressive cancers. Graphic abstract

Introduction A significant proportion of ischemic strokes are caused by emboli from unstable atherosclerotic carotid artery plaques. Inflammation is a key feature of plaque instability. Positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-( 18 F)-fluoro-D-glucose ( 18 F-FDG) is a promising technique to quantify plaque inflammation, but a consensus on the methodology has not been established. High inter-reader agreement is essential if 18 F-FDG PET/CT is to be used as a clinical tool for the assessment of unstable plaques and stroke risk. Methods We assessed the inter-reader variability of different methods for quantification of 18 F-FDG uptake in 43 patients with carotid artery stenosis ≥70%. Two independent readers delineated the plaque and collected maximum standardized uptake value (SUV max ) from all axial PET slices containing the atherosclerotic plaque. Results Uptake values with and without background correction were calculated and intraclass correlation coefficients were highest for uncorrected uptake values (0.97–0.98) followed by those background corrected by subtraction (0.89–0.94) and lowest for those background corrected by division (0.74–0.79). Conclusion Quantification methods without background correction have the highest inter-reader agreement for 18 F-FDG PET of carotid artery plaque inflammation. The use of the single highest uptake value (max SUV max ) from the plaque will facilitate the method’s clinical utility in stroke prevention.

The purpose of the present study is to investigate if consumption and supply hypoxia (CSH) MR-imaging can depict breast cancer hypoxia, using the CSH-method initially developed for prostate cancer. Furthermore, to develop a generalized pan-cancer application of the CSH-method that doesn’t require a hypoxia reference standard for training the CSH-parameters. In a cohort of 69 breast cancer patients, we generated, based on the principles of intravoxel incoherent motion modelling, images reflecting cellular density (apparent diffusion coefficient; ADC) and vascular density (perfusion fraction; fp). Combinations of the information in these images were compared to a molecular hypoxia score made from gene expression data, aiming to identify a way to apply the CSH-methodology in breast cancer. Attempts to adapt previously proposed models for prostate cancer included direct transfers and model parameter rescaling. A novel approach, based on rescaling ADC and fp data to give more nuanced response in the relevant physiologic range, was also introduced. The new CSH-method was validated in a prostate cancer cohort with known hypoxia status. The proposed CSH-method gave estimates of hypoxia that was strongly correlated to the molecular hypoxia score in breast cancer, and hypoxia as measured in pathology slices stained with pimonidazole in prostate cancer. The generalized approach to CSH-imaging depicted hypoxia in both breast and prostate cancers and requires no model training. It is easy to implement using readily available technology and encourages further investigation of CSH-imaging in other cancer entities and in other settings, with the goal being to overcome hypoxia-induced resistance to treatment.

Background Focal treatment of prostate cancer recurrence is emerging and increases the demand for precision in imaging; pure detection is no longer enough and accurate localization is needed. Purpose To investigate the ability of anti-1-amino-3-[18F]fluorocyclobutane-1-carboxylic acid (FACBC) PET/CT to localize radio-recurrences within the prostate, compared to multiparametric magnetic resonance imaging (mpMRI) and with histopathology as the reference standard. Material and Methods This prospective salvage focal brachytherapy protocol included 20 patients (mean age = 66 years; age range = 57–72 years) with biochemical recurrence after primary radiotherapy. All patients underwent mpMRI, FACBC PET/CT, prostate biopsies, and bone marrow aspiration. The mean time between mpMRI and FACBC PET/CT was 68 days (range = 5–147 days). Two radiologists and two nuclear medicine physicians independently interpreted MRI and PET. Based on schematic drawings, the quadrant (right, left, anterior, posterior) and the level (apex, mid, base) of tumor recurrence were compared and correlated to histopathology. Written informed consent was obtained from all patients. Results PET correctly localized the recurrence in 15 of 20 patients and MRI correctly localized 19 of 20 patients. MRI and PET were concordant for 14 of these 20 patients. There was perfect agreement between the MRI radiologists. Except for one case in which the lesion was only detected by one of the readers, there was also agreement between the nuclear medicine physicians. Conclusions FACBC PET/CT detected fewer histological verified radio-recurrences within the prostate than mpMRI. In accordance with previous studies, we found that the limitations of FACBC PET were small tumor amounts and uptake in hyperplastic benign tissue.

Graphical abstract, Highlights • DCE MRI and dynamic FACBC PET of prostate cancer were co-registered with histology. • Dynamic FACBC and DCE MRI showed similar wash-in time curve characteristics. • At later time points, FACBC plateaued whereas MR contrast medium washed out. • Added value of the wash-in information from dynamic FACBC remains to be documented., Background and purpose Multimodal imaging is increasingly included in the assessment of prostate cancer patients, and there is a need to study whether different techniques provide similar or complementary information. In the initial perfusion phase contrast agents and radioactive labelled tracers act as blood-pool agents and may show similar characteristics. The purpose of the current work was to compare time-activity- and time-concentration-curves (TCs) of dynamic 18F-fluciclovine (18F-anti-1-amino-2-[F]-fluorocyclobutane-1-carboxylic acid, FACBC) positron emission tomography (PET) and dynamic contrast-enhanced magnetic resonance imaging (DCE MRI). Materials and methods Dynamic FACBC PET and DCE MRI were performed on 22 patients with intermediate or high-risk prostate cancer within 23 days prior to robot-assisted laparoscopic prostatectomy. Index tumour was delineated in the images using whole mount tissue sections as reference standard. Tumour TCs from PET and MRI were compared visually and quantitatively by calculating correlation coefficients between the curves at different time points after injection. Results For the first minute post injection, the mean correlation coefficient between the TCs from PET and MRI was 0.92 (range; 0.75–0.99). After the first minute, MRI showed washout while PET showed plateau kinetics. Conclusion Dynamic FACBC and DCE MRI showed similar wash-in time curve characteristics. At later time points, FACBC plateaued whereas MR contrast medium washed out. In DCE MRI, the usefulness of wash-in information is well documented. Whether wash-in information from dynamic FACBC can provide added value remains to be documented.

The established role of hypoxia-induced signaling in prostate cancer growth, metastasis, and response to treatment suggests that a method to image hypoxia in tumors could aid treatment decisions. Here, we present consumption and supply-based hypoxia (CSH) imaging, an approach that integrates images related to oxygen consumption and supply into a single image. This integration algorithm was developed in patients with prostate cancer receiving hypoxia marker pimonidazole prior to prostatectomy. We exploited the intravoxel incoherent motion (IVIM) signal in diagnostic diffusion-weighted (DW) magnetic resonance (MR) images to generate separate images of the apparent diffusion coefficient (ADC) and fractional blood volume (fBV). ADC and fBV correlated with cell density (CD) and blood vessel density (BVD) in histology and whole-mount sections from 35 patients, thus linking ADC to oxygen consumption and fBV to oxygen supply. Pixel-wise plots of ADC versus fBV were utilized to predict the hypoxia status of each pixel in a tumor and to visualize the predicted value in a single image. The hypoxic fraction (HFDWI) of CSH images correlated strongly (R2 = 0.66; n = 41) with pimonidazole immunoscore (HSPimo); this relationship was validated in a second pimonidazole cohort (R2 = 0.54; n = 54). We observed good agreement between CSH images and pimonidazole staining in whole-mount sections. HFDWI correlated with tumor stage and lymph node status, consistent with findings for HSPimo. Moreover, CSH imaging could be applied on histologic CD and BVD images, demonstrating transferability to a histopathology assay. Thus, CSH represents a robust approach for hypoxia imaging in prostate cancer that could easily be translated into clinical practice. Significance: These findings present a novel imaging strategy that indirectly measures tumor hypoxia and has potential application in a wide variety of solid tumors and other imaging modalities. Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/16/4774/F1.large.jpg. Cancer Res; 78(16); 4774–85. ©2018 AACR.

There is currently no consensus on the methodology for quantification of 18F-FDG uptake in inflammation in atherosclerosis. In this study, we explore different methods for quantification of 18F-FDG uptake in carotid atherosclerotic plaques and correlate the uptake values to histological assessments of inflammation. Forty-four patients with atherosclerotic stenosis ≥70% of the internal carotid artery underwent 18F-FDG PET/CT. Maximum standardized uptake values (SUVmax) from all plaque-containing slices were collected. SUVmax for the single highest and the mean of multiple slices with and without blood background correction (by subtraction (cSUV) or by division (target-to-background ratio (TBR)) were calculated. Following endarterectomy 30 plaques were assessed histologically. The length of the plaques at CT was 6-32 mm. The 18F-FDG uptake in the plaques was 1.15-2.66 for uncorrected SUVs, 1.16-3.19 for TBRs, and 0.20-1.79 for cSUVs. There were significant correlations between the different uptake values (r = 0.57-0.99, P

BackgroundA significant proportion of ischemic strokes are caused by emboli from unstable atherosclerotic carotid artery plaques with inflammation being a key feature of plaque instability and stroke risk. Positron emission tomography (PET) depicting the uptake of 2-deoxy-2-(18F)-fluoro-D-glucose (18F-FDG) in carotid artery plaques is a promising technique to quantify plaque inflammation. A consensus on the methodology for plaque localization and quantification of inflammation by 18F-FDG PET/computed tomography (CT) in atherosclerosis has not been established. High inter-reader agreement is essential if 18F-FDG PET/CT is to be used as a clinical tool for the assessment of unstable plaques and stroke risk. The aim of our study was to assess the inter-reader variability of different methods for quantification of 18F-FDG uptake in carotid atherosclerotic plaques with a separate CT angiography (CTA) providing anatomical guidance.Methods and resultsForty-three patients with carotid artery stenosis ≥70% underwent 18F-FDG PET/CT. Two independent readers separately delineated the plaque in all axial PET slices containing the atherosclerotic plaque and the maximum standardized uptake value (SUVmax) from each slice was measured. Uptake values with and without background correction were calculated. Intraclass correlation coefficients were highest for uncorrected uptake values (0.97-0.98) followed by those background corrected by subtraction (0.89-0.94) and lowest for those background corrected by division (0.74-0.79). There was a significant difference between the two readers definition of plaque extension, but this did not affect the inter-reader agreement of the uptake parameters.ConclusionsQuantification methods without background correction have the highest inter-reader agreement for 18F-FDG PET of carotid artery plaque inflammation. The use of the single highest uptake value (max SUVmax) from the plaque will facilitate the method’s clinical utility in stroke prevention.

Background and purpose We investigated how features relating to pelvic cavity anatomy and tumor hemodynamic factors may influence systemic failure in rectal cancer. Materials and methods Rectal cancer patients (207 women, 343 men), who had been prospectively enrolled onto six cohorts and given curative-intent therapy, were analyzed for the first metastatic event. In one of the cohorts, the diameter of the inferior mesenteric vein (IMV) was assessed on diagnostic abdominal computed tomography images (n = 113). Tumor volume (n = 193) and histologic response to neoadjuvant therapy (n = 445) were recorded from diagnostic magnetic resonance images and surgical specimens, respectively. Results More women than men developed lung metastasis (p = 0.037), while the opposite was the case for liver metastasis (p = 0.040). Wider IMV diameter correlated with larger tumor volume (r = 0.481, p < 0.001) and male sex (p < 0.001). Female sex was the only adverse prognostic factor for lung metastasis. When sex, tumor volume, and histologic response were taken into consideration, poor tumor response remained the only determinant for liver metastasis (p = 0.002). Conclusions In a diverse rectal cancer population given curative-intent treatment, women and men had different outcome with regard to the primary metastatic site. Tumor hemodynamic factors should be considered in rectal cancer risk stratification. (C) 2019 The Author(s). Published by Elsevier B.V. on behalf of European Society for Radiotherapy and Oncology. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

The objective of our study was to investigate whether phosphatase and tensin homolog (PTEN) expression is associated with clinicopathologic features and multiparametric MRI findings in prostate cancer.Forty-three patients with prostate cancer who underwent radical prostatectomy were included. Index tumor was identified on pretreatment MRI and delineated in the area that correlated best with histopathology results. The apparent diffusion coefficient (ADC) from DWI and pharmacokinetic parameters derived from dynamic contrast-enhanced MRI (DCE-MRI) using the extended Tofts model (KBased on bead arrays (p = 0.006) and RT-qPCR (p = 0.03) data, a significantly lower ADC was found in tumors with low PTEN expression. Moreover, PTEN expression was negatively associated with lymph node metastases (bead arrays, p = 0.008; RT-qPCR, p0.001). A weak but significant association between PTEN expression, EPE (p = 0.048), and Gleason score (p = 0.028) was revealed on bead arrays. ADC was negatively correlated with Gleason score (p = 0.001) and tumor size (p = 0.023). No association among DCE parameters, PTEN expression, and clinicopathologic features was found.ADC derived from DWI may be useful in selecting patients with potentially aggressive tumor caused by PTEN deficiency.

Background Neoadjuvant treatment of locally advanced rectal cancer (LARC) involves chemoradiotherapy (CRT), which may cause significant toxicity, and the potential role and sequential placement of neoadjuvant chemotherapy (NACT) relative to CRT is under debate. Patients and methods In a non-randomized study of 72 LARC patients, short-course oxaliplatin-containing NACT was administered prior to CRT. Tumor volumes were calculated from magnetic resonance images before and after NACT, and four weeks after CRT, and associations between tumor volume responses and outcome were analyzed. Additionally, the impact of oxaliplatin exposure on radiosensitivity was examined in colorectal carcinoma cell lines. Results All tumors except one responded to NACT, with better responses in T3 than T4 cases, and 69/72 patients obtained additional tumor volume reduction after subsequent CRT. However, no associations were found between tumor volume reduction and long-term outcome. Of note, oxaliplatin-resistant cells were significantly more radiosensitive than the oxaliplatin-sensitive counterparts. Conclusions Oxaliplatin-containing NACT led to substantial tumor volume reduction with particularly good responses in T3 cases. NACT did not impede subsequent CRT response, and experimental results rather suggested enhanced radiosensitivity in oxaliplatin-exposed cells, encouraging studies to explore the administration of NACT prior to CRT. Data are still lacking to support omitting radiation in LARC management.

Background: Following curative-intent neoadjuvant therapy in locally advanced rectal cancer, metastatic progression is still dominant. We investigated if patients’ circulating 25-hydroxyvitamin D [25(OH)D] levels were associated with outcome. Methods: Serum 25(OH)D concentration was assessed by liquid chromatography-mass spectrometry in samples collected from 84 patients at baseline, completion of the neoadjuvant therapy, and treatment evaluation before surgery, and analyzed with respect to season, disease presentation, and treatment effects. Results: In the cohort of patients residing at latitude 58–62°N, baseline 25(OH)D differed significantly over the seasons, with highest measures (mean of 71.2±5.6nmol/L) in summer and lowest (48.7±4.5nmol/L) in spring, and changed over the three-month neoadjuvant period till response evaluation solely owing to season. The patient subgroup with slightly reduced performance status, anemia, and T4 disease that did not respond to the neoadjuvant therapy (ypT4 cases), had significantly lower baseline 25(OH)D (below 50nmol/L) than T4 cases with response (ypT0–3) and T2–3 cases (above 60nmol/L). Compared to the T4 patients with levels above 50nmol/L, regarded as sufficient for a healthy bone status, those presenting levels below had significantly heightened risk of disease progression (mainly metastasis) and death, with hazard ratio of 3 and 17, respectively, on adjustment for age, sex, body mass index, and season. Conclusion: Rectal cancer T4 cases had high risk of metastatic progression and death if circulating 25(OH)D levels were insufficient but obtained short-term and long-term outcome to neoadjuvant treatment no worse than patients with T2–3 disease when 25(OH)D was sufficient. Trial registration: ClinicalTrials.gov NCT00278694; registration date: 16 January 2006, retrospective to enrollment of the first 10 patients of the current report. © 2019 Open Access Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Objective High rates of systemic failure in locally advanced rectal cancer call for a rational use of conventional therapies to foster tumor-defeating immunity. Methods We analyzed the high-mobility group box-1 (HMGB1) protein, a measure of immunogenic cell death (ICD), in plasma sampled from 50 patients at the time of diagnosis and following 4 weeks of induction chemotherapy and 5 weeks of sequential chemoradiotherapy, both neoadjuvant modalities containing oxaliplatin. The patients had the residual tumor resected and were followed for long-term outcome. Results Patients who met the main study end point—freedom from distant recurrence—showed a significant rise in HMGB1 during the induction chemotherapy and consolidation over the chemoradiotherapy. The higher the ICD increase, the lower was the metastatic failure risk (hazard ratio 0.26, 95% confidence interval 0.11–0.62, P = 0.002). However, patients who received the full-planned oxaliplatin dose of the chemoradiotherapy regimen had poorer metastasis-free survival (P = 0.020) than those who had the oxaliplatin dose reduced to avert breach of the radiation delivery, which is critical to maintain efficient tumor cell kill and in the present case, probably also protected the ongoing radiation-dependent ICD response from systemic oxaliplatin toxicity. Conclusion The findings indicated that full-dose induction oxaliplatin followed by an adapted oxaliplatin dose that was compliant with full-intensity radiation caused induction and maintenance of ICD and as a result, durable disease-free outcome for a patient population prone to metastatic progression.

Tumor hypoxia contributes to therapy resistance and metastatic progression of locally advanced rectal cancer (LARC). We postulated that the tumor mitochondrial metabolism, manifested by reactive oxygen species (ROS) and mitochondrial DNA (mtDNA) damage, reflects how hypoxic conditions connect to cancer-induced systemic inflammation and poor outcome. Levels of ROS and mtDNA damage were analyzed in three colorectal cancer (CRC) cell lines cultured for 24 hours under normoxia (21% O2) or hypoxia (0.2% O2) and serum sampled at the time of diagnosis from 35 LARC patients participating in a prospective therapy study. Compared with normoxia, ROS were significantly repressed and mtDNA damage was significantly enhanced in the hypoxic CRC cell lines; hence, a low ratio of ROS to mtDNA damage was an indicator of hypoxic conditions. In the LARC patients, low serum ROS were associated with elevated levels of circulating carcinoembryonic antigen and tumor choline concentration, both indicative of unfavorable biology, as well as adverse progression-free and overall survival. A low ratio of ROS to mtDNA damage in serum was associated with poor local tumor response to the neoadjuvant treatment and, of note, elevated systemic inflammation factors (C-reactive protein, the interleukin-1 receptor antagonist, and factors involved in tumor necrosis factor signaling), indicating that deficient treatment response locally and detrimental inflammation systemically link to a hypoxic mitochondrial metabolism. In conclusion, serum ROS and damaged mtDNA may be markers of the mitochondrial metabolism driven by the state of oxygenation of the primary tumor and possibly implicated in systemic inflammation and adverse outcome of LARC. © 2018 The Authors. Published by Elsevier Inc. on behalf of Neoplasia Press, Inc. Thisis an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Background and purpose Recognizing the link between altered tumor metabolism and disease aggressiveness, this study aimed to identify associations between tumor metabolic profiles and therapeutic outcome in locally advanced rectal cancer (LARC). Materials and methods Pretreatment tumor metabolic profiles from 54 LARC patients receiving combined-modality neoadjuvant treatment and surgery were acquired by high-resolution magic angle spinning magnetic resonance spectroscopy (HR MAS MRS). Metabolite concentrations were correlated to TNM and the presence of disseminated tumor cells (DTC) at diagnosis, ypTN and tumor regression grade (TRG) following neoadjuvant treatment, and progression-free survival (PFS). Results Pretreatment tumor metabolite concentrations showed no significant associations to TNM, DTC, ypTN or TRG. In univariate regression analysis, high concentrations of glycine, creatine and myo-inositol were significantly associated with poor PFS, with metastasis as main PFS event. In multivariate analysis, high glycine concentration remained most significantly associated with poor PFS (hazard ratio=4.4, 95% confidence interval=1.4–14.3, p =0.008). Conclusions High tumor glycine concentration was identified as adverse prognostic factor for PFS in LARC. In a patient population treated with curative intent but with metastatic disease as main PFS event further investigations of glycine as early predictor of metastatic progression and therapeutic target are warranted.

Exosomes have recently appeared as a novel source of non-invasive cancer biomarkers since tumour-specific molecules can be found in exosomes isolated from biological fluids. We have here investigated the proteome of urinary exosomes by using mass spectrometry to identify proteins differentially expressed in prostate cancer patients compared to healthy male controls. In total, 15 control and 16 prostate cancer samples of urinary exosomes were analyzed. Importantly, 246 proteins were differentially expressed in the two groups. The majority of these proteins (221) were up-regulated in exosomes from prostate cancer patients. These proteins were analyzed according to specific criteria to create a focus list that contained 37 proteins. At 100% specificity, 17 of these proteins displayed individual sensitivities above 60%. Even though several of these proteins showed high sensitivity and specificity for prostate cancer as individual biomarkers, combining them in a multi-panel test has the potential for full differentiation of prostate cancer from non-disease controls. The highest sensitivity, 94%, was observed for transmembrane protein 256 (TM256; chromosome 17 open reading frame 61). LAMTOR proteins were also distinctly enriched with very high specificity for patient samples. TM256 and LAMTOR1 could be used to augment the sensitivity to 100%. Other prominent proteins were V-type proton ATPase 16 kDa proteolipid subunit (VATL), adipogenesis regulatory factor (ADIRF), and several Rab-class members and proteasomal proteins. In conclusion, this study clearly shows the potential of using urinary exosomes in the diagnosis and clinical management of prostate cancer.

Background The radiographers' role in ultrasound (US) has been debated due to the operator-dependent aspect of diagnostic US. With standardized cine-loop ultrasound (SCUS) a reliable diagnosis can be achieved by reading SCUS independently from performing the procedure. Purpose To study the correlation between sonographic findings when SCUS is performed and read by a radiologist and when SCUS is performed by a radiographer and read by a radiologist, and to assess the radiologists' confidence when reading SCUS examinations performed by a radiographer. Material and Methods Thirty-four patients (64 kidneys) who underwent SCUS of the kidneys were included in this study. All patients underwent two consecutive SCUS examinations, one performed by an experienced radiologist reading his own examination (online), and one performed by a SCUS-trained radiographer, read by an experienced radiologist who was not involved in the examination of the patient (offline). Study reports were made using a structured report form designed for this study. Confidence was measured on a visual analog scale ranging from 0 (no confidence) to 100 (extremely confident). The final diagnosis (the reference standard) was defined as the consensus between two US-experienced radiologists. All personnel were blinded to each other's results. Results We found discordance between image findings for online and offline in eight out of 64 kidneys. There was no systematic difference between online and offline reading. There was a good correlation between online and offline, kappa 0.75 (95% CI 0.60–0.90, P Conclusion There is a high degree of correlation between reported findings in radiologist and radiographer performed SCUS examinations.

The recurrence patterns of high-risk, N1 prostate cancer after radiation therapy (RT) including the pelvic lymph nodes have not been fully investigated.We have a prospective clinical study since 2004 that has followed 138 men with locally advanced prostate cancer (T1-T4N0-N1M0) treated with definitive RT encompassing the prostate and pelvic lymph nodes and long-term androgen deprivation therapy (ADT). Forty nine of the 52 patients that developed recurrence were imaged at biochemical failure to detect the site of recurrence.Imaging identified the site of recurrence in 46 patients. Twenty five patients had prostatic recurrence only, none had local lymph node recurrence only, 11 had distant metastases only, 7 had prostatic recurrence and distant metastases, 2 had prostatic recurrence, local nodal recurrence and distant metastases, and 1 had local nodal recurrence with distant metastases. The mean time to recurrence was 62 months for prostate only, 40 months for distant only and 50 months for prostate and distant recurrence. There was a 69% recurrence rate for patients with magnetic resonance imaging -detected N1 disease. There was significantly longer survival for patients with prostate recurrence only compared to patients with distant recurrence (P0.018). Five-year prostate cancer-specific survival were 85% for prostate only, 44% for distant only and 48% for prostate and distant recurrence (prostate only vs. distant only; P = 0.008, prostate only vs. prostate and distant; P = 0.018, distant vs. prostate and distant; P = 0.836).The predominant recurrence pattern for high-risk, N1 prostate cancer was prostatic recurrence and distant spread after pelvic RT and androgen deprivation therapy. Our data argue for further local dose escalation and pelvic nodal radiation to prevent recurrence in these sites. Lymph node metastasis at initial staging with an magnetic resonance imaging was a strong predictor of recurrence and poor survival and may identify patients in need of more aggressive treatment.

Background Systemic failure remains a challenge in rectal cancer. We investigated the possible systemic anti-tumour immune activity invoked within oxaliplatin-based neoadjuvant therapy. Methods In two high-risk patient cohorts, we assessed the circulating levels of the fms-like tyrosine kinase 3 ligand (Flt3L), a factor reflecting both therapy-induced myelosuppression and activation of tumour antigen-presenting dendritic cells, at baseline and following induction chemotherapy and sequential chemoradiotherapy, both modalities containing oxaliplatin. The primary end point was progression-free survival (PFS). Results In both cohorts, the median Flt3L level was significantly higher at completion of each sequential modality than at baseline. The 5-year PFS (most events being metastatic progression) was 68% and 71% in the two cohorts consisting of 33% and 52% T4 cases. In the principal cohort, a high Flt3L level following the induction chemotherapy was associated with low risk for a PFS event (HR: 0.15; P

Background: The hypoxia marker pimonidazole is a candidate biomarker of cancer aggressiveness. We investigated the transcriptional programme associated with pimonidazole staining in prostate cancer. Methods: Index tumour biopsies were taken by image guidance from an investigation cohort of 52 patients, where 43 patients received pimonidazole before prostatectomy. Biopsy location within the index tumour was verified for 46 (88%) patients, who were included for gene expression profiling and immunohistochemistry. Two independent cohorts of 59 and 281 patients were used for validation. Results: Expression of genes in proliferation, DNA repair and hypoxia response was a major part of the transcriptional programme associated with pimonidazole staining. A signature of 32 essential genes was constructed and showed positive correlation to Ki67 staining, confirming the increased proliferation in hypoxic tumours as suggested from the gene data. Positive correlations were also found to tumour stage and lymph node status, but not to blood prostate-specific antigen level, consistent with the findings for pimonidazole staining. The association with aggressiveness was confirmed in validation cohorts, where the signature correlated with Gleason score and had independent prognostic impact, respectively. Conclusions: Pimonidazole staining reflects an aggressive hypoxic phenotype of prostate cancer characterised by upregulation of proliferation, DNA repair and hypoxia response genes.

Purpose To explore possible associations between in vivo pharmacokinetic dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters and the presence of disseminated tumor cells (DTCs) in bone marrow in breast cancer patients at the time of diagnosis. Materials and Methods Thirty-seven women with breast cancer (stage T2–4N0–1M0) were included. Patients were classified as DTC+ if one or more DTCs were detected by immunocytochemistry. DCE-MRI was acquired with a radial 3D T1-weighted spoiled gradient echo sequence with k-space weighted image contrast. Ktrans, kep, and ve were calculated using the extended Tofts model and a population-derived arterial input function. The nonparametric Mann–Whitney U-test was used to compare the histogram distributions of the pharmacokinetic parameters for the DTC+ and the DTC− patients. Results DTCs were detected in 7 of the 37 patients (19%). In DTC+ patients, the distribution of tumor Ktrans and kep were significantly (P < 0.01) more shifted towards lower values than in DTC− patients. Conclusion An association between vascular dependent pharmacokinetic DCE-MRI parameters and the presence of DTCs were found. Compared to DTC− patients, DTC+ patients had poorer perfusion and permeability, indicative of hypoxia. Thus, pharmacokinetic parameters might be surrogate biomarkers of metastatic potential and future relapse.J. Magn. Reson. Imaging 2014;40:1382–1391. © 2014 Wiley Periodicals, Inc.

Purpose We explored changes in hypoxia-inducible factor 1 (HIF1) signaling during androgen deprivation therapy (ADT) of androgen-sensitive prostate cancer xenografts under conditions in which no significant change in immunostaining of the hypoxia marker pimonidazole had occurred. Methods and Materials Gene expression profiles of volume-matched androgen-exposed and androgen-deprived CWR22 xenografts, with similar pimonidazole-positive fractions, were compared. Direct targets of androgen receptor (AR) and HIF1 transcription factors were identified among the differentially expressed genes by using published lists. Biological processes affected by ADT were determined by gene ontology analysis. HIF1α protein expression in xenografts and biopsy samples from 35 patients receiving neoadjuvant ADT was assessed by immunohistochemistry. Results A total of 1344 genes showed more than 2-fold change in expression by ADT, including 35 downregulated and 5 upregulated HIF1 targets. Six genes were shared HIF1 and AR targets, and their downregulation was confirmed with quantitative RT-PCR. Significant suppression of the biological processes proliferation, metabolism, and stress response in androgen-deprived xenografts was found, consistent with tumor regression. Nineteen downregulated HIF1 targets were involved in those significant biological processes, most of them in metabolism. Four of these were shared AR and HIF1 targets, including genes encoding the regulatory glycolytic proteins HK2, PFKFB3, and SLC2A1. Most of the downregulated HIF1 targets were induced by hypoxia in androgen-responsive prostate cancer cell lines, confirming their role as hypoxia-responsive HIF1 targets in prostate cancer. Downregulation of HIF1 targets was consistent with the absence of HIF1α protein in xenografts and downregulation in patients by ADT ( P Conclusions AR repression by ADT may lead to downregulation of HIF1 signaling independently of hypoxic fraction, and this may contribute to tumor regression. HIF1α expression is probably not a useful hypoxia biomarker during ADT in prostate cancer.

Dynamic (18)F-FDG PET allows the study of glucose distribution in tissues as a function of time and space. Using pharmacokinetics, the temporal uptake pattern of (18)F-FDG may be separated into components reflecting perfusion and metabolism. Bevacizumab is an angiogenesis inhibitor which prevents the growth of new blood vessels, and may potentially lead to normalization of the blood circulation in the tumor. The purpose of the study was to explore the use of dynamic PET as a tool for monitoring treatment effect, reflected by changes in perfusion and metabolism.Twelve athymic nude mice, bearing the bilateral triple-negative human breast cancer xenograft MAS98.12 were treated with bevacizumab (5 mg/kg i.p.). Dynamic PET data was acquired prior to and 24 and 72 hours after treatment for 1 hour after injection of 10 MBq (18)F-FDG and fitted with a FDG two-tissue compartment model. The changes in the rate constants k1, k3, MRFDG and the vascular fraction νB were assessed. To evaluate the effect of treatment regimes, 30 mice, randomized in 5 groups, received either vehicle (0.9% NaCl), bevacizumab (5 mg/kg i.p.), doxorubicin (8 mg/kg i.v.) or bevacizumab and doxorubicin either together, or doxorubicin 24 hours after bevacizumab treatment. Tumor volume was measured twice a week.The perfusion-related rate parameter k1 and the metabolic rate constant k3 decreased significantly 24 hours after treatment. This decrease was followed by an increase, albeit non-significant, at 72 hours post treatment. Doxorubicin given 24 hours after bevacizumab showed less antitumor effect compared to concomitant treatment.Dynamic PET can detect changes in tumor perfusion and metabolism following anti-angiogenic therapy in mouse xenograft models. Longitudinal dynamic PET, used to assess the efficacy of anti-angiogenic treatment, can identify the time frame of potential tumor vasculature re-normalization and allow optimal timing of supplementary therapy (radiation or chemotherapy).

To compare dynamic 2-deoxy-2-[(18) F]fluoro-D-glucose positron emission tomography ((18) F-FDG PET) parameters in two selected human breast cancer xenografts and to evaluate associations with immunohistochemistry and histology.Dynamic (18) F-FDG PET of luminal-like MAS98.06 and basal-like MAS98.12 xenografts was performed, and the compartmental transfer rates (k 1 ,k 2 ,k 3 ), blood volume fraction (v B ) and metabolic rate of (18) F-FDG(MR FDG ) were estimated from pharmacokinetic model analysis. After sacrifice, analyses of hypoxia (pimonidazole), proliferation (Ki-67), vascularization (CD31), glucose transport receptor (GLUT1) and necrosis (HE) was performed. The level of hexokinase 2 (HK2) was estimated from Western blot analysis.The (18) F-FDG uptake curves for the two xenografts were significantly different (p 0.05). k 1 and v B were higher for MAS98.12 (p 0.01), while k 3 was higher for MAS98.06 (p 0.01). MAS98.12 had a higher fraction of stromal tissue and higher microvessel density (MVD), and it was less necrotic and hypoxic than MAS98.06. MAS98.12 had stronger positive GLUT1 staining and lower Ki-67 than MAS98.06. In both models significant correlations were found between k 1 and the GLUT1 score, between k 3 and the level of HK2, and between v B and MVD.Significant differences in dynamic (18) F-FDG parameters between the two human breast cancer xenografts were found. The differences could be explained by underlying histological and physiological characteristics.