Search

Purpose Triplet chemotherapy might be more effective than doublet chemotherapy in metastatic colorectal cancer (mCRC), but it may also be marked by increased toxicity. To investigate whether δ-tocotrienol, a vitamin E analogue, with its possible neuroprotective and anti-inflammatory effects reduces the toxicity of triplet chemotherapy, we conducted a randomized, double-blind, placebo controlled trial in mCRC patients receiving first line 5-fluorouracil, oxaliplatin and irinotecan (FOLFOXIRI).Methods We randomly assigned 70 mCRC patients to FOLFOXIRI plus δ-tocotrienol or FOLFOXIRI plus placebo. FOLFOXIRI was given in eight cycles followed by four cycles of 5-fluorouracil. δ-tocotrienol 300 mg or placebo x 3 daily was added during chemotherapy and for a maximum of two years. The primary endpoint was time to hospitalization or death during treatment with chemotherapy.Results Median time to first hospitalization or death was 3.7 months in the placebo group (95% CI 1.93-not reached (NR)), and NR in the δ-tocotrienol group (95% CI 1.87-NR) with a hazard ratio (HR) of 0.70 (95% CI 0.36-1.36, p=0.29)). In the placebo group 24 patients (71%) had oxaliplatin dose reductions compared to 17 patients (47%) in the δ-tocotrienol group (p=0.047).Conclusion The addition of δ-tocotrienol to FOLFOXIRI did not significantly prolong the time to first hospitalization or death compared to FOLFOXIRI plus placebo. Toxicity was manageable and not statistically different between the two groups. There was a statistically significant difference in dose reductions of oxaliplatin pointing to a possible neuroprotective effect of δ-tocotrienol.Clinicaltrials.gov identifier NCT02705300. Date of registration March 10, 2016.

Despite several limitations, the Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1) are still the gold standard in response evaluation of metastatic colorectal cancer (mCRC). The aim of the present study was to investigate hypermethylated neuropeptide Y circulating tumor DNA (meth-NPY) as an early biomarker for treatment effect and monitoring in 70 mCRC patients receiving first-line treatment in the FOLFOXIRI-Toco trial. Meth-NPY was analyzed using droplet digital PCR, and the response rate was defined as the fraction of patients converting from a baseline detectable level to an undetectable level after the first treatment cycle (responders). A significant increase in meth-NPY was defined as a value with no overlap between the 95% CI of the current and preceding measurement. Progression-free survival (PFS) was significantly longer in meth-NPY responders compared to non-responders, 10.1 and 7.6 months, respectively (p = 0.02, HR = 0.43). Patients with response according to RECIST 1.1 had a PFS of 10.1 compared to 7.3 months for non-responders (p = 0.17, HR = 0.65). A significant increase in meth-NPY was found with a median of 49 days before radiological progression. In conclusion, early meth-NPY response proved superior to response according to RECIST 1.1 with respect to predicting improved PFS. Meth-NPY is an early indicator of progression, allowing treatment reorientation at an earlier timepoint.

Simple Summary The primary treatment modality for anal cancer is chemoradiotherapy, but patients with locally advanced disease (i.e., large tumors and/or involvement of regional lymph nodes) have a high risk of treatment failure. The use of chemotherapy prior to radiotherapy (induction chemotherapy) can potentially shrink the tumor and/or eradicate small cancer cells with metastatic potential, with a chance of a better outcome. With this paper, the authors present 20 years of nationwide experience with intensified induction chemotherapy in the treatment of locally advanced anal cancer, which indicates a role for further investigation in the most advanced cases. Abstract Locally advanced squamous cell carcinoma of the anus (LASCCA) has a poor prognosis with a high risk of treatment failure calling for intensified therapy. We present the long-term follow-up of a nationwide cohort of LASCCA treated with intensified induction chemotherapy (ICT). The study included patients with LASCCA (T3-4N0 or T1-4N+) treated with at least one cycle of ICT (cisplatin, ifosfamide, leucoverin, and 5-flourouracil) between 1998–2018. Data were retrospectively collected from medical records, and statistics were performed in STATA 16.1. In total, 166 patients with LASCCA were identified. Following ICT, 157 patients (95%) received primary curative treatment with either radiotherapy (70%), chemoradiotherapy (27%), or abdominal perineal resection (3%). The overall local tumor response rate after ICT was 76% with 20 (13%) achieving complete local tumor response. After the primary treatment, 123 patients (79%) obtained complete response, and 27 underwent salvage surgery due to persistent disease. The median follow-up time was 6 years, local and distant failure rates 22% and 13%, respectively. The 3- and 5-year disease-free survival rates were 70% and 67%, and the 3- and 5-year overall survival rates were 76% and 70%, respectively. Intensified ICT regimen could be a supplementary treatment option in the most advanced cases of LASCCA. Prospective randomized trials are needed to investigate this approach further.

e15567 Background: Precision oncology based on in-vitro, functional assays has potential advantages compared to the much more common molecular approach, but the clinical benefit is unknown. We here report the results from the largest prospective interventional clinical trial testing the clinical outcome in colorectal cancer patients treated with drugs showing cytotoxic effect in matched patient-derived tumoroids. Methods: This single-center, phase II trial included patients with metastatic colorectal cancer previously exposed to all standard therapies. Specimens from one to three 18-16 G core needle biopsies were manually dissected, enzymatically treated, cultivated, and incubated to form 3D spherical microtumors, i.e. tumoroids. In the assay for in-vitro sensitivity testing, the tumoroids were challenged with single drugs and combinations thereof to determine patient-specific responses. Using tumoroid screening technology (IndiTreat, 2cureX, Copenhagen, Denmark), results were generated by comparing the sensitivity of the individual patient’s tumoroids with a reference panel from other patients. The testing included standard cytostatics and drugs with proven effect in previous early-phase clinical trials, a total of 15 drugs. The primary endpoint was the fraction of patients with progression-free survival (PFS) at two months. Based on placebo arms in randomized last-line trials, a minimal relevant difference of 20% (20% to 40%) was stated. Using Simon's two-stage design, a sample size of 45 patients was calculated with at least 14 PFS at two months (significance 5%, power 90%). Results: Ninety patients were enrolled from 9/2017 to 9/2020. Biopsies from 82 patients were obtained and sent for tumoroid formation of which 44 (54%, 95% CI 42-65) were successful and at least one treatment was suggested. Thirty-four patients initiated treatment according to the response obtained in the drug assays within a median of 51 days from inclusion (IQR 39-63). The primary endpoint, PFS at two months, was met in 17 of 34 patients (50%, 95%CI 32-68). There were no radiological responses. Median PFS was 81 days (95% CI 51-112) and median OS was 189 days (95% CI 103-277). Conclusions: Precision oncology using a functional approach with patient-derived tumoroids and in-vitro drug sensitivity testing seems feasible. The approach is limited by the fraction of patients with successful tumoroid development. The primary endpoint was met, as half of the patients were without progression at two months. Further clinical studies are justified. Clinical trial information: NCT03251612.

LBA3514 Background: Organ preserving treatment strategies based on chemoradiotherapy may spare rectal cancer patients of major surgery and stoma. We suggest substantially improved tumor control by increasing the radiotherapy dose, without significant increase in the rate of late effects. We designed a prospective phase II trial to test high-dose radiotherapy of low rectal cancer for organ preservation in a multicenter setting. Methods: We enrolled patients with localized T1-3 N0-1 M0 rectal cancer within 6 cm from the anal verge and in performance status 0-2. Any N1-nodes had to be at the level of the tumor and included in the primary tumor-volume. Radiotherapy consisted of 62 Gy to the tumor and 50.4 Gy to the regional lymph nodes, delivered in 28 fractions using intensity modulated radiation therapy and daily image guidance. Capecitabine 825 mg/m2 BID. Patients with clinical complete response (cCR) 6–12 weeks after end of treatment were allocated to follow-up. Surgery was offered only in case of residual cancer or later re-growth. The primary endpoint was the proportion of patients with locoregional tumor control after two years by chemoradiation alone. Secondary endpoints included long-term side effects (CTCAE grading), cCR, rate of distant metastases, and overall survival. Results: Three Danish centers enrolled 107 patients between 2015 and 2019. Baseline classifications were T1/T2/T3 and N1 in 15%/54%/31% and 29%, respectively. The median age was 71 years and 64% were male. 92 (86.0%) had cCR and were allocated to observation. Four patients drew consent or died leaving 103 observed for at least 2 years. 23 had regrowth after cCR, five of whom had organ preserving transanal endoscopic microsurgery, 15 other curative surgery, and three palliation. 63 had no locoregional regrowth. Thus 61% (63/103) of patients with 2 years of follow-up had locoregional tumor control with chemoradiation alone. The actuarial estimate of locoregional control at 2 years from start of observation was 73.8% (95%CI 63.2-81.8). Calculated from time of enrollment, metastasis-free and overall survival at 30 months was 85.4% (95%CI 76.5-91.1) and 94.8% (95%CI 87.8-97.8). In the 63 patients with complete response at 2 years, ‘Low Anterior Resection Syndrome-score’ was None=37%, Minor=28%, and Major=35%. The most severe toxicity was erectile dysfunction grade 3 (n=3), grade 2 (n=4), grade 1 (n=6), and grade 0 (n=26). Grade 2 diarrhea, constipation, fecal incontinence, rectal bleeding and decreased libido were each reported in one case, while urinary frequency grade 2 was seen in four patients. Conclusions: The vast majority of patients with low rectal cancer can be cured by modern radiotherapy 62 Gy in 28 fractions with excellent patient-reported outcomes, toxicity, tumor control, and survival. The treatment is feasible in a multicenter setting. We suggest this approach as a standard of care option. Clinical trial information: NCT02438839.

The treatment for locally advanced rectal carcinomas (LARC) is based on neoadjuvant chemoradiotherapy (nCRT) and surgery, which results in pathological complete response (pCR) in up to 30% of patients. Since epigenetic changes may influence response to therapy, we aimed to identify DNA methylation markers predictive of pCR in LARC patients treated with nCRT. We used high-throughput DNA methylation analysis of 32 treatment-na&iuml, ve LARC biopsies and five normal rectal tissues to explore the predictive value of differentially methylated (DM) CpGs. External validation was carried out with The Cancer Genome Atlas-Rectal Adenocarcinoma (TCGA-READ 99 cases). A classifier based on three-CpGs DM (linked to OBSL1, GPR1, and INSIG1 genes) was able to discriminate pCR from incomplete responders with high sensitivity and specificity. The methylation levels of the selected CpGs confirmed the predictive value of our classifier in 77 LARCs evaluated by bisulfite pyrosequencing. Evaluation of external datasets (TCGA-READ, GSE81006, GSE75546, and GSE39958) reproduced our results. As the three CpGs were mapped near to regulatory elements, we performed an integrative analysis in regions associated with predicted cis-regulatory elements. A positive and inverse correlation between DNA methylation and gene expression was found in two CpGs. We propose a novel predictive tool based on three CpGs potentially useful for pretreatment screening of LARC patients and guide the selection of treatment modality.

There is a need for biomarkers to improve the clinical benefit from systemic treatment of colorectal cancer. We designed a prospective, clinical study where patients receiving regorafenib as last-line treatment had sequential blood samples drawn. Effect and toxicity was monitored. The primary clinical endpoint was progression free survival (PFS). Cell-free circulating tumor (ct) DNA was measured as either the fraction with Neuropeptide Y (NPY) methylated DNA or KRAS/NRAS/BRAF mutated ctDNA. One hundred patients were included from three Danish centers. Among 95 patients who received regorafenib for at least two weeks, the median PFS was 2.1 months (95% confidence interval (CI) 1.8&ndash, 3.3) and the median overall survival (OS) was 5.2 months (95% CI 4.3&ndash, 6.5). Grade 3&ndash, 4 toxicities were reported 51 times, most frequently hypertension, hand-food syndrome, and skin rash. In the biomarker population of 91 patients, 49 could be monitored using mutated DNA and 90 using methylated DNA. There was a strong correlation between mutated and methylated DNA. The median survival for patients with a level of methylated ctDNA above the median was 4.3 months compared to 7.6 months with ctDNA below the median, p &lt, 0.001. The median time from increasing methylated ctDNA to disease progression was 1.64 months (range 0.46&ndash, 8.38 months). In conclusion, NPY methylated ctDNA was a universal liquid biopsy marker in colorectal cancer patients treated with regorafenib. High baseline levels correlated with short survival and changes during treatment may predict early effect and later progression. We suggest plasma NPY methylation analysis as an easy and universally applicable method for longitudinal monitoring of ctDNA in metastatic colorectal cancer patients.

Background Tumour tissue from individual patients with colorectal cancer may be cultured in vitro as three-dimensional tumoroids that resembles the biological features in vivo including chemotherapy sensitivity and resistance. Tumoroid formation is well-established for resected tumour tissue, but there is a lack of detailed descriptions of cultivating tumoroids from liver biopsies. The purpose of this study was to compare metastasis, imaging, biopsy histology and tumoroid yield. Methods Patients exposed to all standard medical treatment for metastatic colorectal cancer were included within an ongoing phase II clinical trial (NCT03251612). Biopsies from liver were obtained with 16G needles and other localizations 18G. Microscopy was used to evaluate necrosis (present or not) and to quantify the fraction of vital carcinoma cells: 0 (0%), 1 (0-10%), 2 (10-50%) or 3 (50-100%). Tumoroid formation was quantified as 0 (0 tumoroids), 1 (1-10), 2 (10-100), 3 (100-1000) or 4 (>1000). Biopsies of low quality were pooled up to three together for tumoroid formation. Elastography during ultrasound were used to measure the tissue stiffness of a subset of liver metastases and was together with metastasis size other explorative variables. Results A total of 78 biopsies from 27 biopsy sessions were included from liver (22), lung (2), carcinomatosis (1), muscle (1) or kidney (1). No serious adverse events related to biopsy procedures were observed. 37 (49%) of 76 biopsies for histology contained vital carcinoma cells and necrosis was present in 43 (57%). The number of tumoroids after cultivation correlated with the level of vital carcinoma cells in biopsies (p = 0.008) and trend-wise inversely with the stiffness of the tumour (p = 0.05) but not the size of metastasis (p = 0.97) nor presence of necrosis (0.98). Conclusions The tumoroid yield after cultivation of biopsies from chemo-refractory colorectal cancer patients correlates with the level of carcinoma cells determined by microscopy and probably with the stiffness of the metastasis. Necrosis and size of metastasis were not related. These findings may have great implications for selecting and evaluating biopsies for tumoroid formation in precision medicine to colorectal cancer patients. Clinical trial identification NCT03251612. Legal entity responsible for the study The authors. Funding 2cureX. Disclosure L.H. Jensen: Research grant / Funding (institution): MSD; Research grant / Funding (institution): BMS; Research grant / Funding (institution): Incyte; Research grant / Funding (institution): 2cureX. G. Hagel: Shareholder / Stockholder / Stock options, Full / Part-time employment: 2cureX. H. Harling: Advisory / Consultancy: 2cureX. O. Thastrup: Leadership role, Shareholder / Stockholder / Stock options, Full / Part-time employment, Officer / Board of Directors: 2cureX. All other authors have declared no conflicts of interest.

Made available in DSpace on 2019-10-06T17:12:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-12-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Most patients with locally advanced rectal cancer (LARC) present incomplete pathological response (pIR) to neoadjuvant chemoradiotherapy (nCRT). Despite the efforts to predict treatment response using tumor-molecular features, as differentially expressed genes, no molecule has proved to be a strong biomarker. The tumor secretome analysis is a promising strategy for biomarkers identification, which can be assessed using transcriptomic data. We performed transcriptomic-based secretome analysis to select potentially secreted proteins using an in silico approach. The tumor expression profile of 28 LARC biopsies collected before nCRT was compared with normal rectal tissues (NT). The expression profile showed no significant differences between complete (pCR) and incomplete responders to nCRT. Genes with increased expression (pCR = 106 and pIR = 357) were used for secretome analysis based on public databases (Vesiclepedia, Human Cancer Secretome, and Plasma Proteome). Seventeen potentially secreted candidates (pCR = 1, pIR = 13 and 3 in both groups) were further investigated in two independent datasets (TCGA and GSE68204) confirming their over-expression in LARC and association with nCRT response (GSE68204). The expression of circulating amphiregulin and cMET proteins was confirmed in serum from 14 LARC patients. Future studies in liquid biopsies could confirm the utility of these proteins for personalized treatment in LARC patients. International Research Center - CIPE A.C.Camargo Cancer Center Department of Clinical Genetics University Hospital of Southern Denmark Department of Morphology – Institute of Bioscience São Paulo State University (UNESP) Department of Pelvic Surgery A.C.Camargo Cancer Center Department of Pathology A.C.Camargo Cancer Center Molecular Oncology Research Center Barretos and Diagnósticos da América (DASA) Department of Biochemistry and Immunology University Hospital of Southern Denmark Danish Colorectal Cancer Center South Institute of Regional Health Research Faculty of Health Sciences University of Southern Denmark Department of Oncology University Hospital of Southern Denmark Department of Morphology – Institute of Bioscience São Paulo State University (UNESP) FAPESP: 2008/57887-9 FAPESP: 2014/06323-9 FAPESP: 2015/25803-4 CNPq: 573589/08-9

The aim of the present study was to investigate the influence of fixation delay and the perioperative ischemia on hypoxia inducible factor (HIF)-1α gene expression, HIF-1α protein expression, and immunohistochemical (IHC) expression of HIF-1α, GLUT-1, Bcl-2, and Ki-67 in colorectal cancer. The study included 25 surgically removed colorectal tumors. Three sets of samples were collected readily after removal and exposed to 0, 30, and 60 minutes of delay of fixation or freezing. The perioperative ischemia time was registered. In each set of the samples, HIF-1α gene expression was analyzed by quantitative real time polymerase chain reaction, protein concentration of HIF-1α was assessed by enzyme-linked immunosorbent assay, and IHC staining of HIF-1α, GLUT-1, Bcl-2, and Ki-67 was performed. Preoperative formalin-fixed paraffin-embedded biopsies and whole sections of the entire tumor were analyzed by IHC. We found that the HIF-1α gene expression, HIF-1α protein concentration, and IHC expression of HIF-1α, GLUT-1, Ki-67, and Bcl-2 were not systematically affected by either the fixation or freezing delay of the tissue, the perioperative ischemia time, or the total ischemia time (perioperative ischemia+delay of fixation or freezing) in colorectal tumors. However, the intraindividual variation was quite large, which may question the use of individually, non-standardized-handled single biopsies or small tissue samples for analysis of often rather heterogenously expressed biomarkers.

Objective: The aim of this study was to investigate the feasibility of 18F-fluoroazomycinarabinofuranoside ( 18F-FAZA) positron emission tomography (PET)/computed tomography (CT) in patients with locally advanced rectal cancer. Materials and Methods: The study included 14 patients with locally advanced rectal cancer. Before chemoradiotherapy, PET/CT with F-FAZA was performed with static 15 min images 2 h after injection of 18F-FAZA. Attenuation correction was obtained with a low-dose CT, and a contrast-enhanced CT was performed immediately after the PET scan. Results: 18F-FAZA uptake [mean and maximum standardized uptake value (SUVmean) and (SUVmax)] was significantly higher in rectal tumours than in both muscles (Pmax, SUV mean, T/M and T/I values were significantly higher in the entire tumour volume compared with the tumour volume adjusted for scatter from the urinary bladder (P18F-FAZA PET/CT is feasible for visualization of hypoxia in patients with rectal cancer, but scattered activity from the urinary bladder should be taken into consideration.

e15541Background: Regorafenib has a proven but small significant effect in refractory colorectal cancer. The objective of the present, post-marketing trial was to investigate the clinical outcome i...

Purpose/Objective(s) Mature data on tumor control and survival are presented from a randomized trial of the addition of a brachytherapy boost to long-course neoadjuvant chemoradiation therapy (CRT) for locally advanced rectal cancer. Methods and Materials Between March 2005 and November 2008, 248 patients with T3-4N0-2M0 rectal cancer were prospectively randomized to either long-course preoperative CRT (50.4 Gy in 28 fractions, per oral tegafur-uracil and L-leucovorin) alone or the same CRT schedule plus a brachytherapy boost (10 Gy in 2 fractions). The primary trial endpoint was pathologic complete response (pCR) at the time of surgery; secondary endpoints included overall survival (OS), progression-free survival (PFS), and freedom from locoregional failure. Results Results for the primary endpoint have previously been reported. This analysis presents survival data for the 224 patients in the Danish part of the trial. In all, 221 patients (111 control arm, 110 brachytherapy boost arm) had data available for analysis, with a median follow-up time of 5.4 years. Despite a significant increase in tumor response at the time of surgery, no differences in 5-year OS (70.6% vs 63.6%, hazard ratio [HR] = 1.24, P =.34) and PFS (63.9% vs 52.0%, HR=1.22, P =.32) were observed. Freedom from locoregional failure at 5 years were 93.9% and 85.7% (HR=2.60, P =.06) in the standard and in the brachytherapy arms, respectively. There was no difference in the prevalence of stoma. Explorative analysis based on stratification for tumor regression grade and resection margin status indicated the presence of response migration. Conclusions Despite increased pathologic tumor regression at the time of surgery, we observed no benefit on late outcome. Improved tumor regression does not necessarily lead to a relevant clinical benefit when the neoadjuvant treatment is followed by high-quality surgery.

Background. Patients with chemotherapy refractory metastatic colorectal cancer and KRAS mutations have no effective treatment option. The present study evaluated the efficacy of temsirolimus in chemotherapy refractory mCRC with KRAS mutations. Furthermore, we wanted to investigate if resistance to temsirolimus could be reversed by the addition of irinotecan. Finally, we analyzed pre-treatment blood samples for KRAS mutations to investigate the association between quantitative measures of KRAS mutated alleles and clinical outcome. Material and methods. Patients received weekly temsirolimus 25 mg until progression. Thereafter patients were treated with combination therapy comprising biweekly irinotecan 180 mg/m(2) and weekly temsirolimus. A polymerase chain reaction method was used to quantify the KRAS mutated alleles in plasma (pKRAS). Results. Sixty-four patients were included. Treatment was well tolerated. Thirty-eight percent achieved stable disease on monotherapy and 63% on combination therapy. Four and eight patients had a minimal response, respectively. Median overall survival was 160 days. Median time to progression was 45 and 84 days, respectively. The concordance between KRAS status in tumor and plasma was 82%. All patients with tumor reduction had low levels of pKRAS. Patients with high pKRAS had a 77% risk of early progression on monotherapy compared to 43% in patients with lower levels. Multivariate survival analysis confirmed that pKRAS was a strong prognostic factor. Conclusion. Temsirolimus has limited efficacy in chemotherapy resistant KRAS mutant disease, but plasma KRAS quantification is a strong predictor of outcome.

The aim of this study was to describe the dynamics of HIF-1α, GLUT-1, Bcl-2 and Ki-67 during chemoradiotherapy (CRT) of rectal cancer, and to investigate the fluctuation of these biomarkers in relation to pathological response to CRT. The study included 86 patients with rectal adenocarcinoma receiving preoperative CRT (>50.4 Gy and Uracil/Tegafur). Immunohistological expressions of HIF-1α, GLUT-1, Bcl-2 and Ki-67 were investigated in biopsies taken before treatment, after 2, 4 and 6 weeks of CRT and in specimens from the operation. Decreasing expressions of HIF-1α, Bcl-2 and Ki-67 were observed during CRT, whereas GLUT-1 overall was unchanged. No significant changes of the markers were observed in the interval between CRT and surgery. A significant association was observed between the presence of residual carcinoma after 6 weeks of treatment and pathological response to CRT, but no association was seen between the fluctuations of any of the markers and response to CRT. This unique material containing specimens before, after and during CRT for rectal cancer demonstrated biological dynamics in HIF-1α, Bcl-2 and Ki-67, but not GLUT-1, expression during CRT, and a significant association was seen between the presence of residual carcinoma after 6 weeks of treatment and pathological response to CRT.

The aim of this study was to investigate the predictive impact of polymorphisms in the HIF-1α gene on the response to chemoradiotherapy (CRT) in rectal cancer. This study included two cohorts of patients with locally advanced rectal cancer receiving long-course CRT. The HIF-1α C1772T (rs11549465), G1790A (rs11549467) and c(*)191T>C (rs2057482) polymorphisms were investigated in the test cohort (n=65), and HIF-1α c(*)191T>C was analysed in the validation cohort (n=198). No correlations were identified between the polymorphisms and clinicopathological factors. The HIF-1α C1772T and HIF-1α G1790A polymorphisms demonstrated no correlation with tumour response to CRT in the test cohort. The HIF-1α c(*)191T>C CC genotype was marginally associated with a higher rate of complete tumour response (P=0.05) in the test cohort, while the HIF-1α c(*)191T>C CC genotype was associated with a poor tumour response (P=0.03) in the validation cohort. In conclusion, these results suggest that HIF-1α polymorphisms have no value as predictors of response to neoadjuvant CRT in rectal cancer. The results of the HIF-1α c(*)191T>C in two cohorts differ and emphasise the importance of biomarker validation.

The aim of the present study was to investigate hypoxia-inducible factor 1α (HIF-1α) and glucose transporter-1 (GLUT-1) expressions as predictors of response and survival after chemoradiotherapy in pretreatment biopsy specimens from patients with rectal cancer.The immunohistological expressions of HIF-1α and GLUT-1 were investigated in pretreatment biopsies from 86 patients with rectal cancer receiving long course preoperative chemoradiotherapy. The immunohistological stainings were scored semi-quantitatively (percentage of stained cells and staining intensity), and an immunoreactive score was calculated. The response to the chemoradiotherapy was assessed by the Mandard Tumour Regression Grade system (TRG).No association was found between HIF-1α or GLUT-1 and clinicopathological variables. HIF-1α and GLUT-1 expression had no predictive impact regarding response to chemoradiotherapy measured by TRG and was not associated with overall survival.The present study did not suggest any predictive or prognostic value of pretreatment HIF-1α or GLUT-1 expression in patients with rectal cancer treated with preoperative chemoradiotherapy.

Clinical Aspects of Hypoxia-inducible Factors in Colorectal Cancer Birgitte Mayland Havelund1,4 MD, Karen-Lise Garm Spindler1,4 MD, PhD, Flemming Brandt Sørensen2,4 MD, DMSc, Ivan Brandslund3 MD, DMSc, Anders Jakobsen1,4 MD, DMSc.1Department of Oncology, 2Pathology and 3Biochemistry, Vejle Hospital, Vejle, Denmark4Institute of Regional Health Services Research, University of Southern Denmark, Odense DenmarkBackgroundPrognostic and predictive markers are needed for individualizing the treatment of colorectal cancer. Hypoxia-inducible factor 1α (HIF-1α) is a transcription-inducing factor which activates transcription of numerous genes associated with angiogenesis, ATP-metabolism, cell-proliferation, glycolysis and apoptosis. HIF-1α is over expressed in many malignant tumors and is reported to play an important role in tumor invasion and progression. The aim of this Ph.D. project is to investigate the predictive and prognostic value of HIF-1α in colorectal cancer.Materials and MethodsThe project is divided into 3 substudies:1. Biological and methodological aspects. The expression of HIF-1α measured by immunohistochemistry in paraffin embedded tissue is related to single nucleotide polymorphism (SNP), neoangiogenesis and other markers. The role of preanalytic treatment of the tissue including peroperative ischemia is investigated in biopsies taken preoperatively with momentarily fixation compared to the resected rectal tumor. Tumor heterogeneity is explored in biopsies taken according to a standardized scheme.2. The prognostic value of HIF-1α is investigated by SNP analysis and HIF-1α expression in tissue from 300 patients operated for colorectal cancer and the results is validated in a prospectively population of 200 patients.3. The predictive value of HIF-1α will be investigated in patients with locally advanced rectal cancer, treated with preoperative chemoradiation (CRT).Preliminary ResultsExpression of HIF-1α has been investigated in diagnostic biopsies from 58 rectal tumors who received preoperative long-course CRT. An association was found between major response to CRT as measured by tumor regression grade (TRG) and strong intensity of the nuclear HIF-1α staining of tumor cells (p=0,04), the same applied to staining of >10% of the cancer stromal cells (p=0,03). Conclusion:Results are hypothesis generating and need to be validated.

Introduction Tumour hypoxia is well-established phenomenon in solid tumours and is an important factor in relation to radioresistance. Visualising hypoxia by positron emission tomography (PET) is attractive because it is a non-invasive method, and leaves an option to measure hypoxia consecutively during treatment. 18F-Flouroazomycinarabinofuranoside (18F-FAZA) has attractive pharmacokinetic properties. In experimental models 18F-FAZA is accumulated in hypoxic tumour cells and rapidly cleared from non-hypoxic tissues. Only few studies are available of 18F-FAZA PET/CT scans of human tumours and none of these include patients with rectal cancer. The aim of this study was to investigate the feasibility of 18F-FAZA PET/CT in patients with locally advanced rectal cancer. Methods The study included 14 patients with locally advanced rectal cancer (cT3-T4, cN1-2, cM0, CRM Results The rectal tumours had a median value (range) of SUVmax 2.06 (1.23-2.99) and SUVmean 1.31 (0.72-2.04). 18F-FAZA uptake (SUVmax and SUVmean) was significantly higher in the rectal tumours compared with both muscle (p Conclusion F-FAZA PET/CT imaging is feasible in patients with rectal cancer visualising hypoxia but scattered activity from the urinary bladder should be taken into consideration.