Jürgen Böhm

Potential of fecal microbiota for early-stage detection of colorectal cancer

Several bacterial species have been implicated in the development of colorectal carcinoma (CRC), but CRC‐associated changes of fecal microbiota and their potential for cancer screening remain to be explored. Here, we used metagenomic sequencing of fecal samples to identify taxonomic markers that distinguished CRC patients from tumor‐free controls in a study population of 156 participants. Accuracy of metagenomic CRC detection was similar to the standard fecal occult blood test (FOBT) and when both approaches were combined, sensitivity improved > 45% relative to the FOBT, while maintaining its specificity. Accuracy of metagenomic CRC detection did not differ significantly between early‐ and late‐stage cancer and could be validated in independent patient and control populations (N = 335) from different countries. CRC‐associated changes in the fecal microbiome at least partially reflected microbial community composition at the tumor itself, indicating that observed gene pool differences may reveal tumor‐related host–microbe interactions. Indeed, we deduced a metabolic shift from fiber degradation in controls to utilization of host carbohydrates and amino acids in CRC patients, accompanied by an increase of lipopolysaccharide metabolism.

Dynamic plasma microRNAs are biomarkers for prognosis and early detection of recurrence in colorectal cancer

Background:Plasma microRNAs (miRNAs) are promising non-invasive biomarkers for colorectal cancer (CRC) prognosis. However, the published studies to date have yielded conflicting and inconsistent results for specific plasma miRNAs.Methods:We have conducted a study using robust assays to assess a panel of nine miRNAs for CRC prognosis and early detection of recurrence. Plasma samples from 144 patients in a prospective CRC cohort study were collected at diagnosis, 6, 12, and 24 months after diagnosis. miRNAs were assayed by Taqman qRT–PCR to generate miRNA normalised copy numbers.Results:Preoperative high plasma miRNA levels were associated with increased recurrence risk for miR-200b (HR [95% CI]=2.04 [1.00, 4.16], P=0.05), miR-203 (HR=4.2 [1.48, 11.93], P=0.007), miR-29a (HR=2.61 [1.34,5.07], P=0.005), and miR-31 (HR=4.03 [1.76, 9.24], P=0.001). Both plasma miR-31 (AUC: 0.717) and miR-29a (AUC: 0.703) could discriminate recurrence from these patients without recurrence. In addition, high levels of miR-31 during surveillance was associated with a three-fold increased risk of recurrence across all time points. Dynamic postoperative plasma miR-141 and 16 levels correlated with recurrence in the surveillance samples.Conclusions:Pre-operative plasma miR-29a, 200b, 203, and 31 are potential CRC prognosis biomarkers. In addition, dynamic postoperative miR-31, 141 and 16 levels are potential biomarkers for the early detection of recurrence during CRC surveillance.

Smoking is associated with hypermethylation of the APC 1A promoter in colorectal cancer: the ColoCare Study

Smoking tobacco is a known risk factor for the development of colorectal cancer and for mortality associated with the disease. Smoking has been reported to be associated with changes in DNA methylation in blood and in lung tumour tissues, although there has been scant investigation of how epigenetic factors may be implicated in the increased risk of developing colorectal cancer. To identify epigenetic changes associated with smoking behaviours, we performed epigenome‐wide analysis of DNA methylation in colorectal tumours from 36 never‐smokers, 47 former smokers, and 13 active smokers, and in adjacent mucosa from 49 never‐smokers, 64 former smokers, and 18 active smokers. Our analyses identified 15 CpG sites within the APC 1A promoter that were significantly hypermethylated and 14 CpG loci within the NFATC1 gene body that were significantly hypomethylated (pLIS < 1 × 10−5) in the tumours of active smokers. The APC 1A promoter was hypermethylated in 7 of 36 tumours from never‐smokers (19%), 12 of 47 tumours from former smokers (26%), and 8 of 13 tumours from active smokers (62%). Promoter hypermethylation was positively associated with duration of smoking (Spearman rank correlation, ρ = 0.26, p = 0.03) and was confined to tumours, with hypermethylation never being observed in adjacent mucosa. Further analysis of adjacent mucosa revealed significant hypomethylation of four loci associated with the TNXB gene in tissue from active smokers. Our findings provide exploratory evidence for hypermethylation of the key tumour suppressor gene APC being implicated in smoking‐associated colorectal carcinogenesis. Further work is required to establish the validity of our observations in independent cohorts. Copyright

Discovery of novel plasma proteins as biomarkers for the development of incisional hernias after midline incision in patients with colorectal cancer: The ColoCare study

Background. Ventral incisional hernia is the most common long‐term complication after an abdominal operation. Among newly diagnosed colorectal cancer patients, we screened the preoperative plasma proteome to explore predictive markers for the development of an incisional hernia. Methods. We utilized preoperative plasma samples of 72 newly diagnosed colorectal cancer patients who underwent midline incision for tumor resection between 2010 and 2013. A total of 21 patients with incisional hernia occurrence were matched with 51 patients with at least 18 months follow‐up without an incisional hernia by sex, age, and body mass index. To assess predictive markers of incisional hernia risk, we screened the plasma proteome for >2,000 distinct proteins using a well‐validated antibody microarray test. Paired t tests were used to compare protein levels between cases and controls. A gene‐set‐enrichment analysis (Gene Ontology and Kyoto Encyclopedia of Genes and Genomes) was applied to test for differences in signaling pathways between the 2 groups. Results. The proteome screen identified 25 proteins that showed elevated or reduced plasma levels in the hernia group compared to the control group (nominal P values < .05). Several proteins were in pathways associated with wound healing (CCL21, SHBG, BRF2) or cell adhesion (PCDH15, CDH3, EPCAM). Conclusion. Our study shows that there are multiple individual and groups of plasma proteins that could feasibly predict the personal hernia risk prior to undergoing an operation. Further investigations in larger, independent sample sets are warranted to replicate findings and validate clinical utility of potential biomarkers. After validation, such a biomarker could be incorporated into a multifactorial risk model to guide clinical decision‐making.

Plasma 25-Hydroxyvitamin D3 Levels in Colorectal Cancer Patients and Associations with Physical Activity.

ABSTRACT Physical activity (PA) and vitamin D are thought to affect colorectal cancer prognosis. The present study investigates associations between 25(OH)D3 and PA in prospectively followed colorectal cancer patients in the ColoCare study. At 6, 12, and 24 mo after surgery, patients donated a blood sample, wore an accelerometer for 10 consecutive days, and completed a PA questionnaire. Plasma 25-hydroxyvitamin D3 (25(OH)D3) levels were measured by high-performance liquid chromatography. We tested associations using partial correlations and multivariate linear regression analysis, adjusted for season, age, and body mass index. A total of 137 assessments of 25(OH)D3 levels and PA were conducted (58 at 6 mo, 51 at 12 mo, and 28 at 24 mo). More than 60% of the patients were vitamin D-deficient (25(OH)D3 ≤20 ng/ml), independent of study time point. At 6-mo follow-up, accelerometry-based vigorous and moderate-to-vigorous PAs were positively associated with 25(OH)D3 levels (P = 0.04; P = 0.006,). PA together with season was a significant predictor of elevated 25(OH)D3 levels. Our results suggest that the majority of colorectal cancer patients may suffer from vitamin D deficiency. Engaging in PA may be an effective approach to increase their 25(OH)D3 levels.

Abstract A26: Body fatness and adipose tissue subtypes are associated with circulating biomarkers of inflammation and angiogenesis in colorectal cancer patients: The ColoCare Study

Background: Adiposity has been linked to both risk and prognosis of colorectal cancer; however, the impact of different compartments of adipose tissue (visceral vs. subcutaneous) is unclear. In healthy individuals, adiposity is associated with elevated biomarkers of inflammation, which provides a mechanistic link between adiposity and cancer risk. For prognosis, the downstream effects of inflammation on angiogenesis may be central. We investigated associations between adiposity and biomarkers of inflammation, as well as angiogenesis, in colorectal cancer patients enrolled in the ColoCare Study, an international multicenter patient cohort. Methods: We utilized preoperatively obtained serum samples of patients with newly diagnosed colorectal cancer [n=164; (stage I-IV)] from the ColoCare Study in Heidelberg, Germany, with available diagnostic multi-detector-CT images for adipose tissue quantification. Abdominal adipose tissue was assessed by area-based quantification of visceral (VAT), and subcutaneous adipose tissue (SAT), as well as their ratio (VAT/SAT) on levels L3/L4 and L4/L5. Body mass index (BMI) was calculated (kg/m2) and demographic and clinical-surgical data were abstracted from medical records. Circulating CRP, SAA, VEGF-A, VEGF-D, sICAM-1 and sVCAM-1 levels were assessed on the Meso Scale Discoveries platform with V-plex assays at the Huntsman Cancer Institute (average intra-plate CVs 2.9%, inter-plate CVs 7.9%). Partial correlations and regression analyses, adjusting for age, sex and tumor stage were performed. Results: While overall obesity (BMI) was only significantly associated with sVCAM (r=0.23, p=0.006), visceral adiposity (VAT) was associated with both CRP and SAA (r=0.21, p=0.01 and r=0.17, p=0.04, respectively). There was no association between SAT and the measured biomarkers. Most predictive was the ratio of VAT/SAT on level L3/L4, which was associated with CRP (r=0.18, p=0.04), SAA (r=0.24, p=0.006), sICAM-1 (r=0.18, p=0.04), and particularly VEGF-A (r=0.28, p=0.0008). Similar associations were observed for the VAT/SAT ratio on level L4/5. Conclusions: We demonstrated a link between specifically visceral adiposity and biomarkers of inflammation in colorectal cancer patients. In addition, we showed that visceral adiposity also affects circulating VEGF-A levels. This protein has various effects, including the induction of angiogenesis, vasculogenesis and endothelial cell growth, as well as the promotion of cell migration, and the inhibition of apoptosis. Our findings support a mechanistic role of visceral adipose tissue in colorectal cancer risk and potentially prognosis. Citation Format: Cornelia M. Ulrich, Jurgen Bohm, Christy Warby, Tengda Lin, Mariam Salou, Biljana Gigic, Dominique Scherer, Johanna Nattenmueller, Jennifer Ose, Lin Zielske, Petra Schrotz-King, Torsten Kolsch, Erin Siegel, Christopher Li, Alexis Ulrich, Hanno Glimm, Jewel Samadder, Stephen Hursting, Hans-Ulrich Kauczor. Body fatness and adipose tissue subtypes are associated with circulating biomarkers of inflammation and angiogenesis in colorectal cancer patients: The ColoCare Study. [abstract]. In: Proceedings of the AACR Special Conference: Improving Cancer Risk Prediction for Prevention and Early Detection; Nov 16-19, 2016; Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(5 Suppl):Abstract nr A26.

Abstract 4921: Plasma proteomics for the discovery of biomarkers of incisional hernia in colorectal cancer patients in the ColoCare Study

Background Incisional hernia is the most common long-term complication after laparotomy for colorectal cancer resection with an incidence of 9-20%. Predisposing factors have been identified. Nevertheless, there are limited approaches to precisely predict individual risk, creating a need for predictive biomarkers of incisional hernia development. Methods We utilized pre-operative plasma samples of patients with newly diagnosed colorectal cancer [n = 72; (stage I-IV)] from the ColoCare Study in Heidelberg, Germany, who underwent laparoscopic tumor resection between 2010 and 2013. Patient questionnaires and telephone-interviews were used to assess the incidence of an incisional hernia, and demographic and clinical-surgical data were abstracted from medical records. 21 patients with incisional hernia occurrence were matched with 51 patients without an incisional hernia ( = controls) by gender, age, and BMI with at least 18 months follow-up. To assess predictive markers of incisional hernia risk we screened the plasma proteome for 3061 proteins using a well-validated antibody microarray test. Paired t-tests were used to compare protein levels between cases and controls. A gene-set-enrichment analysis (Gene Ontology and KEGG) was applied to test for differences in signaling pathways between the two groups. Results The proteome screen identified 27 proteins that showed elevated or reduced plasma levels in the hernia group compared to the control group (nominal p-values Conclusion To date no predictive blood-based biomarkers of incisional hernia risk are available. We discovered several candidate protein biomarkers which, after validation in further studies, could be incorporated into a multifactorial risk model to guide clinical decision making. This could enable the initiation of prophylactic treatments such as a mesh implantation and individualized patient recommendations to prevent incisional hernia occurrence in high-risk patients. Citation Format: Jurgen Bohm, Frank Pianka, Nina Stuttgen, Biljana Gigic, Yuzheng Zhang, Petra Schrotz-King, Nina Habermann, Alexis Ulrich, Martin Schneider, Paul Lampe, Markus Diener, Cornelia M. Ulrich. Plasma proteomics for the discovery of biomarkers of incisional hernia in colorectal cancer patients in the ColoCare Study. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4921.

Abstract 3437: Visceral abdominal fat is associated with incisional hernia occurrence after colorectal cancer surgery - the ColoCare Study

Proceedings: AACR 106th Annual Meeting 2015; April 18-22, 2015; Philadelphia, PA Introduction: Abdominal surgery for tumor removal is essential in the treatment of colorectal cancer (CRC). Incisional hernias (IH) are a common long-term complication after abdominal surgery with an incidence of 9-20%. Several risk factors for developing IH have been identified, including a higher body mass index (BMI). However, it is unknown whether specific abdominal fat compartments, such as subcutaneous or visceral fat, are associated with IH occurrence. Thus, the aim of this study was to explore whether subcutaneous or visceral fat compartments might be predictors of IH occurrence in CRC patients after oncologic surgery. Methods: This study was conducted on 139 newly-diagnosed colorectal cancer patients of the prospective cohort study ColoCare (NCT, Heidelberg, Germany) who underwent oncologic surgery at the surgical clinics of the University Hospital Heidelberg. Self-administered questionnaires were used to assess hernia occurrence at 3, 6, 12 and 24 months post-surgery. BMI was calculated (kg/m^2) and abdominal fat compartments were assessed by routine computed tomography (CT) scans. The total (TFA), subcutaneous (SFA) and visceral fat area (VFA) was quantified as area (cm^2) on level L3/L4 and L4/L5. Before analyses, fat data were grouped into two categories (high vs. low) by the median. Logistic regression was used to measure the association between BMI, TFA, SFA or VFA and IH occurrence. Results: Patients were on average 61.3 (±12.5) years old with 37% being female and 63% being male. Patients were diagnosed with either colon/rectosigmoid (53%) or rectal (47%) primary cancer. CT data on abdominal fat compartments were available for 56% (n = 80) of patients as CT scans were not performed on every subject during clinical routine. BMI was a statistically significant predictor of IH occurrence after adjusting for gender and age (Wald p-value <0.001, OR = 1.19). Of all fat values, only VFA on level L3/L4 was statistically significant associated with IH occurrence after adjusting for gender and age (Wald p-value <0.05, OR = 2.36), while TFA and SFA on level L3/L4 and all level L4/L5 fat values were not associated with IH occurrence. Conclusion: Our findings underline BMI as a known predictive risk factor for IH. In addition, our study newly identified visceral, but not total or subcutaneous fat, as risk factors for IH. Further studies with an increased sample size are needed to test these associations in subgroups of patients, e.g. by gender or surgical procedures. In the future, these findings may help to preoperatively decide on prophylactic interventions, such as intraoperative mesh implantations, to reduce hernia occurrence. Citation Format: Jurgen Bohm, Johanna Nattenmuller, Frank Pianka, Biljana Gigic, Yesilda Balavarca, Nina Stuttgen, Petra Schrotz-King, Dominique Scherer, Alexis Ulrich, Markus K. Diener, Hans-Ulrich Kauczor, Cornelia M. Ulrich. Visceral abdominal fat is associated with incisional hernia occurrence after colorectal cancer surgery - the ColoCare Study. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3437. doi:10.1158/1538-7445.AM2015-3437