A clinical decision support system optimising adjuvant chemotherapy for colorectal cancers by integrating deep learning and pathological staging markers: a development and validation study.

BACKGROUND: The DoMore-v1-CRC marker was recently developed using deep learning and conventional haematoxylin and eosin-stained tissue sections, and was observed to outperform established molecular and morphological markers of patient outcome after primary colorectal cancer resection. The aim of the present study was to develop a clinical decision support system based on DoMore-v1-CRC and pathological staging markers to facilitate individualised selection of adjuvant treatment. METHODS: We estimated cancer-specific survival in subgroups formed by pathological tumour stage (pT<4 or pT4), pathological nodal stage (pN0, pN1, or pN2), number of lymph nodes sampled (≤12 or >12) if not pN2, and DoMore-v1-CRC classification (good, uncertain, or poor prognosis) in 997 patients with stage II or III colorectal cancer considered to have no residual tumour (R0) from two community-based cohorts in Norway and the UK, and used these data to define three risk groups. An external cohort of 1075 patients with stage II or III R0 colorectal cancer from the QUASAR 2 trial was used for validation; these patients were treated with single-agent capecitabine. The proposed risk stratification system was evaluated using Cox regression analysis. We similarly evaluated a risk stratification system intended to reflect current guidelines and clinical practice. The primary outcome was cancer-specific survival. FINDINGS: The new risk stratification system provided a hazard ratio of 10·71 (95% CI 6·39-17·93; p<0·0001) for high-risk versus low-risk patients and 3·06 (1·73-5·42; p=0·0001) for intermediate versus low risk in the primary analysis of the validation cohort. Estimated 3-year cancer-specific survival was 97·2% (95% CI 95·1-98·4; n=445 [41%]) for the low-risk group, 94·8% (91·7-96·7; n=339 [32%]) for the intermediate-risk group, and 77·6% (72·1-82·1; n=291 [27%]) for the high-risk group. The guideline-based risk grouping was observed to be less prognostic and informative (the low-risk group comprised only 142 [13%] of the 1075 patients). INTERPRETATION: Integrating DoMore-v1-CRC and pathological staging markers provided a clinical decision support system that risk stratifies more accurately than its constituent elements, and identifies substantially more patients with stage II and III colorectal cancer with similarly good prognosis as the low-risk group in current guidelines. Avoiding adjuvant chemotherapy in these patients might be safe, and could reduce morbidity, mortality, and treatment costs. FUNDING: The Research Council of Norway.

Spatial analysis and CD25-expression identify regulatory T cells as predictors of a poor prognosis in colorectal cancer.

Regulatory T cells (Tregs) are a heterogeneous cell population that can either suppress or stimulate immune responses. Tumor-infiltrating Tregs are associated with an adverse outcome from most cancer types, but have generally been found to be associated with a good prognosis in colorectal cancer (CRC). We investigated the prognostic heterogeneity of Tregs in CRC by co-expression patterns and spatial analyses with diverse T cell markers, using multiplex fluorescence immunohistochemistry and digital image analysis in two consecutive series of primary CRCs (total n = 1720). Treg infiltration in tumors, scored as FOXP3+ or CD4+/CD25+/FOXP3+ (triple-positive) cells, was strongly correlated to the overall amount of CD3+ and CD8+ T cells, and consequently associated with a favorable 5-year relapse-free survival rate among patients with stage I-III CRC who underwent complete tumor resection. However, high relative expression of the activation marker CD25 in triple-positive Tregs was independently associated with an adverse outcome in a multivariable model incorporating clinicopathological and known molecular prognostic markers (hazard ratio = 1.35, p = 0.028). Furthermore, spatial marker analysis based on Voronoi diagrams and permutation testing of cellular neighborhoods revealed a statistically significant proximity between Tregs and CD8+-cells in 18% of patients, and this was independently associated with a poor survival (multivariable hazard ratio = 1.36, p = 0.017). These results show prognostic heterogeneity of different Treg populations in primary CRC, and highlight the importance of multi-marker and spatial analyses for accurate immunophenotyping of tumors in relation to patient outcome.

Deep learning for prediction of colorectal cancer outcome: a discovery and validation study.

BACKGROUND: Improved markers of prognosis are needed to stratify patients with early-stage colorectal cancer to refine selection of adjuvant therapy. The aim of the present study was to develop a biomarker of patient outcome after primary colorectal cancer resection by directly analysing scanned conventional haematoxylin and eosin stained sections using deep learning. METHODS: More than 12 000 000 image tiles from patients with a distinctly good or poor disease outcome from four cohorts were used to train a total of ten convolutional neural networks, purpose-built for classifying supersized heterogeneous images. A prognostic biomarker integrating the ten networks was determined using patients with a non-distinct outcome. The marker was tested on 920 patients with slides prepared in the UK, and then independently validated according to a predefined protocol in 1122 patients treated with single-agent capecitabine using slides prepared in Norway. All cohorts included only patients with resectable tumours, and a formalin-fixed, paraffin-embedded tumour tissue block available for analysis. The primary outcome was cancer-specific survival. FINDINGS: 828 patients from four cohorts had a distinct outcome and were used as a training cohort to obtain clear ground truth. 1645 patients had a non-distinct outcome and were used for tuning. The biomarker provided a hazard ratio for poor versus good prognosis of 3·84 (95% CI 2·72-5·43; p<0·0001) in the primary analysis of the validation cohort, and 3·04 (2·07-4·47; p<0·0001) after adjusting for established prognostic markers significant in univariable analyses of the same cohort, which were pN stage, pT stage, lymphatic invasion, and venous vascular invasion. INTERPRETATION: A clinically useful prognostic marker was developed using deep learning allied to digital scanning of conventional haematoxylin and eosin stained tumour tissue sections. The assay has been extensively evaluated in large, independent patient populations, correlates with and outperforms established molecular and morphological prognostic markers, and gives consistent results across tumour and nodal stage. The biomarker stratified stage II and III patients into sufficiently distinct prognostic groups that potentially could be used to guide selection of adjuvant treatment by avoiding therapy in very low risk groups and identifying patients who would benefit from more intensive treatment regimes. FUNDING: The Research Council of Norway.

Increased sensitivity to SMAC mimetic LCL161 identified by longitudinal ex vivo pharmacogenomics of recurrent, KRAS mutated rectal cancer liver metastases.

Tumor heterogeneity is a primary cause of treatment failure. However, changes in drug sensitivity over time are not well mapped in cancer. Patient-derived organoids (PDOs) may predict clinical drug responses ex vivo and offer an opportunity to evaluate novel treatment strategies in a personalized fashion. Here we have evaluated spatio-temporal functional and molecular dynamics of five PDO models established after hepatic re-resections and neoadjuvant combination chemotherapies in a patient with microsatellite stable and KRAS mutated metastatic rectal cancer. Histopathological differentiation phenotypes of the PDOs corresponded with the liver metastases, and ex vivo drug sensitivities generally reflected clinical responses and selection pressure, assessed in comparison to a reference data set of PDOs from metastatic colorectal cancers. PDOs from the initial versus the two recurrent metastatic settings showed heterogeneous cell morphologies, protein marker expression, and drug sensitivities. Exploratory analyses of a drug screen library of 33 investigational anticancer agents showed the strongest ex vivo sensitivity to the SMAC mimetic LCL161 in PDOs of recurrent disease compared to those of the initial metastasis. Functional analyses confirmed target inhibition and apoptosis induction in the LCL161 sensitive PDOs from the recurrent metastases. Gene expression analyses indicated an association between LCL161 sensitivity and tumor necrosis factor alpha signaling and RIPK1 gene expression. In conclusion, LCL161 was identified as a possible experimental therapy of a metastatic rectal cancer that relapsed after hepatic resection and standard systemic treatment.

Treatment outcomes and prognostic factors after chemoradiotherapy for anal cancer.

BACKGROUND: Squamous cell carcinoma of the anus (SCCA) is a rare malignancy with rising incidence, associated with human papilloma virus (HPV). Chemoradiotherapy (CRT) is the preferred treatment. The purpose was to investigate treatment failure, survival and prognostic factors after CRT. MATERIAL AND METHODS: In this prospective observational study from a large regional centre, 141 patients were included from 2013 to 2017, and 132 were eligible for analysis. The main inclusion criteria were SCCA, planned radiotherapy, and performance status (ECOG) ≤2. Patient characteristics, disease stage, treatment, and treatment response were prospectively registered. Disease-free survival (DFS), overall survival (OS), and locoregional treatment failure after CRT were analysed. Hazard ratios (HRs) were estimated with Cox`s proportional hazards model. RESULTS: Median follow-up was 54 (range 6-71) months. Eighteen patients (14%) had treatment failures after CRT; of these 10 (8%) had residual tumour, and 8 (6%) relapse as first failure. The first treatment failure was locoregional (11 patients), distant (5 patients), and both (2 patients). Salvage abdomino-perineal resection was performed in 10 patients, 2 had resections of metastases, and 3 both. DFS was 85% at 3 years and 78% at 5 years. OS was 93% at 3 years and 86% at 5 years. In analyses adjusted for age and gender, HPV negative tumours (HR 2.5, p = 0.024), N3 disease (HR 2.6, p = 0.024), and tumour size ≥4 cm (HR 2.4, p = 0.038) were negative prognostic factors for DFS. CONCLUSION: State-of-the-art chemoradiotherapy for SCCA resulted in excellent outcomes, and improved survival compared with previous national data, with <15% treatment failures and a 3-year DFS of >80%.

Digital image analysis of multiplex fluorescence IHC in colorectal cancer recognizes the prognostic value of CDX2 and its negative correlation with SOX2.

Flourescence-based multiplex immunohistochemistry (mIHC) combined with multispectral imaging and digital image analysis (DIA) is a quantitative high-resolution method for determination of protein expression in tissue. We applied this method for five biomarkers (CDX2, SOX2, SOX9, E-cadherin, and ß-catenin) using tissue microarrays of a Norwegian unselected series of primary colorectal cancer. The data were compared with previously obtained chromogenic IHC data of the same tissue cores, visually assessed by the Allred method. We found comparable results between the methods, although confirmed that DIA offered improved resolution to differentiate cases with high and low protein expression. However, we experienced inherent challenges with digital image analysis of membrane staining, which was better assessed visually. DIA and mIHC enabled quantitative analysis of biomarker coexpression on the same tissue section at the single-cell level, revealing a strong negative correlation between the differentiation markers CDX2 and SOX2. Both methods confirmed known prognostic associations for CDX2, but DIA improved data visualization and detection of clinicopathological and biological associations. In summary, mIHC combined with DIA is an efficient and reliable method to evaluate protein expression in tissue, here shown to recapitulate and improve detection of known clinicopathological and survival associations for the emerging biomarker CDX2, and is therefore a candidate approach to standardize CDX2 detection in pathology laboratories.

Alternative splicing expands the prognostic impact of KRAS in microsatellite stable primary colorectal cancer.

KRAS mutation is a well-known marker for poor response to targeted treatment and patient prognosis in microsatellite stable (MSS) colorectal cancer (CRC). However, variation in clinical outcomes among patients wild-type for KRAS underlines that this is not a homogeneous population. Here, we evaluated the prognostic impact of KRAS alternative splicing in relation to mutation status in a single-hospital series of primary MSS CRCs (N = 258). Using splicing-sensitive microarrays and RNA sequencing, the relative expression of KRAS-4A versus KRAS-4B transcript variants was confirmed to be down-regulated in CRC compared to normal colonic mucosa (N = 41; p ≤ 0.001). This was independent of mutation status, however, gene set enrichment analysis revealed that the effect of splicing on KRAS signaling was specific to the KRAS wild-type subgroup, in which low relative KRAS-4A expression was associated with a higher level of KRAS signaling (p = 0.005). In concordance, the prognostic value of KRAS splicing was also dependent on mutation status, and for patients with Stage I-III KRAS wild-type MSS CRC, low relative KRAS-4A expression was associated with inferior overall survival (HR: 2.36, 95% CI: 1.07-5.18, p = 0.033), a result not found in mutant cases (pinteraction = 0.026). The prognostic association in the wild-type subgroup was independent of clinicopathological factors, including cancer stage in multivariable analysis (HR: 2.68, 95% CI: 1.18-6.09, p = 0.018). This suggests that KRAS has prognostic value beyond mutation status in MSS CRC, and highlights the importance of molecular heterogeneity in the clinically relevant KRAS wild-type subgroup.

Tumour-infiltrating CD8+ lymphocytes and colorectal cancer recurrence by tumour and nodal stage.

BACKGROUND: Intratumoural T-cell infiltrate intensity cortes wrelaith clinical outcome in stage II/III colorectal cancer (CRC). We aimed to determine whether this association varies across this heterogeneous group. METHODS: We performed a pooled analysis of 1804 CRCs from the QUASAR2 and VICTOR trials. Intratumoural CD8+ and CD3+ densities were quantified by immunohistochemistry in tissue microarray (TMA) cores, and their association with clinical outcome analysed by Cox regression. We validated our results using publicly available gene expression data in a pooled analysis of 1375 CRCs from seven independent series. RESULTS: In QUASAR2, intratumoural CD8+ was a stronger predictor of CRC recurrence than CD3+ and showed similar discriminative ability to both markers in combination. Pooled multivariable analysis of both trials showed increasing CD8+ density was associated with reduced recurrence risk independent of confounders including DNA mismatch repair deficiency, POLE mutation and chromosomal instability (multivariable hazard ratio [HR] for each two-fold increase = 0.92, 95%CI = 0.87-0.97, P = 3.6 × 10-3). This association was not uniform across risk strata defined by tumour and nodal stage: absent in low-risk (pT3,N0) cases (HR = 1.03, 95%CI = 0.87-1.21, P = 0.75), modest in intermediate-risk (pT4,N0 or pT1-3,N1-2) cases (HR = 0.92, 95%CI = 0.86-1.0, P = 0.046) and strong in high-risk (pT4,N1-2) cases (HR = 0.87, 95%CI = 0.79-0.97, P = 9.4 × 10-3); PINTERACTION = 0.090. Analysis of tumour CD8A expression in the independent validation cohort revealed similar variation in prognostic value across risk strata (PINTERACTION = 0.048). CONCLUSIONS: The prognostic value of intratumoural CD8+ cell infiltration in stage II/III CRC varies across tumour and nodal risk strata.

Correction: Tumour-infiltrating CD8+ lymphocytes and colorectal cancer recurrence by tumour and nodal stage.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Chromatin organisation and cancer prognosis: a pan-cancer study.

BACKGROUND: Chromatin organisation affects gene expression and regional mutation frequencies and contributes to carcinogenesis. Aberrant organisation of DNA has been correlated with cancer prognosis in analyses of the chromatin component of tumour cell nuclei using image texture analysis. As yet, the methodology has not been sufficiently validated to permit its clinical application. We aimed to define and validate a novel prognostic biomarker for the automatic detection of heterogeneous chromatin organisation. METHODS: Machine learning algorithms analysed the chromatin organisation in 461 000 images of tumour cell nuclei stained for DNA from 390 patients (discovery cohort) treated for stage I or II colorectal cancer at the Aker University Hospital (Oslo, Norway). The resulting marker of chromatin heterogeneity, termed Nucleotyping, was subsequently independently validated in six patient cohorts: 442 patients with stage I or II colorectal cancer in the Gloucester Colorectal Cancer Study (UK); 391 patients with stage II colorectal cancer in the QUASAR 2 trial; 246 patients with stage I ovarian carcinoma; 354 patients with uterine sarcoma; 307 patients with prostate carcinoma; and 791 patients with endometrial carcinoma. The primary outcome was cancer-specific survival. FINDINGS: In all patient cohorts, patients with chromatin heterogeneous tumours had worse cancer-specific survival than patients with chromatin homogeneous tumours (univariable analysis hazard ratio [HR] 1·7, 95% CI 1·2-2·5, in the discovery cohort; 1·8, 1·0-3·0, in the Gloucester validation cohort; 2·2, 1·1-4·5, in the QUASAR 2 validation cohort; 3·1, 1·9-5·0, in the ovarian carcinoma cohort; 2·5, 1·8-3·4, in the uterine sarcoma cohort; 2·3, 1·2-4·6, in the prostate carcinoma cohort; and 4·3, 2·8-6·8, in the endometrial carcinoma cohort). After adjusting for established prognostic patient characteristics in multivariable analyses, Nucleotyping was prognostic in all cohorts except for the prostate carcinoma cohort (HR 1·7, 95% CI 1·1-2·5, in the discovery cohort; 1·9, 1·1-3·2, in the Gloucester validation cohort; 2·6, 1·2-5·6, in the QUASAR 2 cohort; 1·8, 1·1-3·0, for ovarian carcinoma; 1·6, 1·0-2·4, for uterine sarcoma; 1·43, 0·68-2·99, for prostate carcinoma; and 1·9, 1·1-3·1, for endometrial carcinoma). Chromatin heterogeneity was a significant predictor of cancer-specific survival in microsatellite unstable (HR 2·9, 95% CI 1·0-8·4) and microsatellite stable (1·8, 1·2-2·7) stage II colorectal cancer, but microsatellite instability was not a significant predictor of outcome in chromatin homogeneous (1·3, 0·7-2·4) or chromatin heterogeneous (0·8, 0·3-2·0) stage II colorectal cancer. INTERPRETATION: The consistent prognostic prediction of Nucleotyping in different biological and technical circumstances suggests that the marker of chromatin heterogeneity can be reliably assessed in routine clinical practice and could be used to objectively assist decision making in a range of clinical settings. An immediate application would be to identify high-risk patients with stage II colorectal cancer who might have greater absolute benefit from adjuvant chemotherapy. Clinical trials are warranted to evaluate the survival benefit and cost-effectiveness of using Nucleotyping to guide treatment decisions in multiple clinical settings. FUNDING: The Research Council of Norway, the South-Eastern Norway Regional Health Authority, the National Institute for Health Research, and the Wellcome Trust.

Surgical options and trends in treating rectal prolapse: long-term results in a 19-year follow-up study.

PURPOSE: Many different operations have been proposed for treating rectal prolapse, with varying recurrence rates and functional outcome. The main purpose of this study was to assess long-term results of surgery for prolapse of the rectum. METHODS: We carried out a retrospective study to evaluate changing trends in surgical strategies and outcome in all patients treated in our hospital over 19 years. RESULTS: Ninety-three patients were operated and 30 (32%) experienced recurrence of external prolapse during a median (range) follow-up time of 82 (2-231) months. There were 37 reoperations for recurrence, bringing the total number of operations to 130. From 1998 to 2010, laparoscopic posterior suture rectopexy was the preferred abdominal procedure with Delorme's operation as the perineal alternative. Observed recurrence rates were 15/49 (31%) and 8/15 (53%) during a median observation time of 84 and 9 months, respectively. From 2011 to 2017, these procedures were replaced by ventral mesh rectopexy and Altemeier's rectosigmoidectomy. The observed recurrence rate for ventral mesh rectopexy was 3/22 (14%) during a median observation time of 29 months. The 30-day mortality rate was 3% and complication rate 14%. CONCLUSIONS: The recurrence rates were high after all procedures, with no significant difference between posterior suture rectopexy and ventral mesh rectopexy, but the short observation time for the latter procedure is a limitation of the study. Both procedures had low complication rates, and ventral mesh rectopexy had no mortality.

CpG island methylator phenotype identifies high risk patients among microsatellite stable BRAF mutated colorectal cancers.

The prognostic value of CpG island methylator phenotype (CIMP) in colorectal cancer remains unsettled. We aimed to assess the prognostic value of this phenotype analyzing a total of 1126 tumor samples obtained from two Norwegian consecutive colorectal cancer series. CIMP status was determined by analyzing the 5-markers CAGNA1G, IGF2, NEUROG1, RUNX3 and SOCS1 by quantitative methylation specific PCR (qMSP). The effect of CIMP on time to recurrence (TTR) and overall survival (OS) were determined by uni- and multivariate analyses. Subgroup analyses were conducted according to MSI and BRAF mutation status, disease stage, and also age at time of diagnosis (<60, 60-74, ≥75 years). Patients with CIMP positive tumors demonstrated significantly shorter TTR and worse OS compared to those with CIMP negative tumors (multivariate hazard ratio [95% CI] 1.86 [1.31-2.63] and 1.89 [1.34-2.65], respectively). In stratified analyses, CIMP tumors showed significantly worse outcome among patients with microsatellite stable (MSS, P < 0.001), and MSS BRAF mutated tumors (P < 0.001), a finding that persisted in patients with stage II, III or IV disease, and that remained significant in multivariate analysis (P < 0.01). Consistent results were found for all three age groups. To conclude, CIMP is significantly associated with inferior outcome for colorectal cancer patients, and can stratify the poor prognostic patients with MSS BRAF mutated tumors.

Portrait of the PI3K/AKT pathway in colorectal cancer.

PI3K/AKT signaling leads to reduced apoptosis, stimulates cell growth and increases proliferation. Under normal conditions, PI3K/AKT activation is tightly controlled and dependent on both extracellular growth signals and the availability of amino acids and glucose. Genetic aberrations leading to PI3K/AKT hyper-activation are observed at considerable frequency in all major nodes in most tumors. In colorectal cancer the most commonly observed pathway changes are IGF2 overexpression, PIK3CA mutations and PTEN mutations and deletions. Combined, these alterations are found in about 40% of large bowel tumors. In addition, but not mutually exclusive to these, KRAS mutations are observed at a similar frequency. There are however additional, less frequent and more poorly understood events that may also push the PI3K/AKT pathway into overdrive and thus promote malignant growth. Here we discuss aberrations of components at the genetic, epigenetic, transcriptional, post-transcriptional, translational and post-translational level where perturbations may drive excessive PI3K/AKT signaling. Integrating multiple molecular levels will advance our understanding of this cancer critical circuit and more importantly, improve our ability to pharmacologically target the pathway in view of clonal development, tumor heterogeneity and drug resistance mechanisms. In this review, we revisit the PI3K/AKT pathway cancer susceptibility syndromes, summarize the known aberrations at the different regulatory levels and the prognostic and predictive values of these alterations in colorectal cancer.

National Early Rectal Cancer Treatment Revisited.

BACKGROUND: Treatment of early stage rectal cancer has excellent oncological results. To reduce treatment-related mortality and morbidity and improve functional results, a focus on local resections is increasingly important. OBJECTIVE: The purpose of this study was to compare outcomes after transanal endoscopic microsurgery and total mesorectal excision for early stage rectal cancer (T1 + T2) in Norway. DESIGN: This was an observational study based on prospective data from the Norwegian Colorectal Cancer Registry. SETTINGS: The study was conducted as a national, population-based study. PATIENTS: All 543 patients with T1 and 1593 patients with T2 rectal cancer without distant metastases that was treated by transanal endoscopic microsurgery or total mesorectal excision without radiochemotherapy during 2000-2009 were included. MAIN OUTCOME MEASURES: The primary outcomes were 5-year relative survival and 5-year local recurrence rate. RESULTS: Among 543 patients with T1 cancer, the 5-year overall survival rate was 65.3% after transanal endoscopic microsurgery versus 81.5% after total mesorectal excision (p = 0.012). Adjusted for age and sex there was no excess mortality for transanal endoscopic microsurgery (HR = 1.28 (95% CI, 0.8-1.9); p = 0.22). The 5-year relative survival rate was 96.8% after transanal endoscopic microsurgery versus 98.2% after total mesorectal excision (p = 0.603), and the 5-year local recurrence rate was 14.5% versus 1.4% (p < 0.001). Among 1593 patients with T2 cancer, 5-year overall survival was 42.1% versus 76.1% (p < 0.001), 5-year relative survival was 65.4% versus 93.9% (p < 0.001), and 5 year local recurrence rate was 11.4% versus 4.4% in the 2 groups. LIMITATIONS: The study is limited by its observational design and that the 2 groups were different according to patient and tumor characteristics. Another limitation was the low number of transanal endoscopic microsurgery procedures. CONCLUSIONS: Transanal endoscopic microsurgery had comparable 5-year relative survival to total mesorectal excision in T1 rectal cancer but inferior 5-year relative survival in T2 rectal cancer. Transanal endoscopic microsurgery was associated with higher local recurrence rates for both T1 and T2 tumors.

The novel colorectal cancer biomarkers CDO1, ZSCAN18 and ZNF331 are frequently methylated across gastrointestinal cancers.

We have previously shown that gastrointestinal cancers display similar epigenetic aberrations. In a recent study, we identified frequently methylated genes for cholangiocarcinoma (CDO1, DCLK1, SFRP1 and ZSCAN18), where one of these genes, DCLK1, was also confirmed to be highly methylated in colorectal cancer. The aim of the present study was to determine whether these four genes, in addition to one gene found to be methylated in colon cancer cell lines (ZNF331), are commonly methylated across gastrointestinal malignancies, as well as explore their role as potential biomarkers. Quantitative methylation specific PCR (qMSP) of colorectal cancer (n=164) and normal colorectal mucosa (n=106) samples showed that all genes were frequently methylated in colorectal cancer (71-92%) with little or no methylation in normal mucosa (0-3%). Methylation of minimum two of these five genes identified 95% of the tumors with a specificity of 98%, and an area under the receiver operating characteristics curve (AUC) of 0.98. For gastric (n=25) and pancreatic (n=20) cancer, the same panel detected 92% and 90% of the tumors, respectively. Seventy-four cancer cell lines were further analyzed by qMSP and real time RT-PCR. In addition to the previously reported DCLK1, a high negative correlation between promoter DNA methylation and gene expression was observed for CDO1, ZNF331 and ZSCAN18. In conclusion, the high methylation frequency of these genes in colorectal- as well as in gastric-, pancreatic- and bile duct cancer confirmed an epigenetic similarity between gastrointestinal cancer types, and simultaneously demonstrated their potential as biomarkers, particularly for colorectal cancer detection.

Nationwide improvement of rectal cancer treatment outcomes in Norway, 1993-2010.

BACKGROUND: The Norwegian Rectal Cancer Project was initated in 1993 with the aims of improving surgery, decreasing local recurrence rates, improving survival, and establishing a national rectal cancer registry. Here we present results from the Norwegian Colorectal Cancer Registry (NCCR) from 1993 to 2010. MATERIAL AND METHODS: A total of 15 193 patients were diagnosed with rectal cancer in Norway 1993-2010, and were registered with clinical data regarding diagnosis, treatment, locoregional recurrences and distant metastases. Of these, 10 796 with non-metastatic disease underwent tumour resection. The results were stratified into five time periods, and the treatment outcomes were compared. Recurrence rates are presented for the 9785 patients who underwent curative major resection (R0/R1). RESULTS: Among all 15 193 patients, relative five-year survival increased from 54.1% in 1993-1997 to 63.4% in 2007-2010 (p < 0.001). Among the 10 796 patients with stage I-III disease who underwent tumour resection, from 1993-1997 to 2007-2010, relative five-year survival improved from 71.2% to 80.6% (p < 0.001). An increasing proportion of these patients underwent surgery at large-volume hospitals; and 30- and 100-day mortality rates, respectively, decreased from 3.0% to 1.4% (p < 0.001) and from 5.1% to 3.0% (p < 0.011). Use of preoperative chemoradiotherapy increased from 6.5% in 1993 to 39.0% in 2010 (p < 0.001). Estimated local recurrence rate after major resection (R0/R1) decreased from 14.5% in 1993-1997 to 5.0% in 2007-2009 (p < 0.001), and distant recurrence rate decreased from 26.0% to 20.2% (p < 0.001). CONCLUSION: Long-term outcomes from a national population-based rectal cancer registry are presented. Improvements in rectal cancer treatment have led to decreased recurrence rates of 5% and increased survival on a national level.

A novel transcript, VNN1-AB, as a biomarker for colorectal cancer.

Colorectal cancer is a global health challenge with high incidence rate and mortality. The patients' prognosis is strongly associated with disease stage and currently there is a need for improved prognostic and predictive biomarkers. In this study, novel colorectal cancer-specific transcript structures were nominated from whole transcriptome sequencing of seven colorectal cancer cell lines, two primary colorectal carcinomas with corresponding normal colonic mucosa and 16 normal tissues. The nominated transcripts were combined with gene level outlier expression analyses in a cohort of 505 colorectal cancers to identify biomarkers with capacity to stratify colorectal cancer subgroups. The transcriptome sequencing data and outlier expression analysis revealed 11 novel colorectal cancer-specific exon-exon junctions, of which 3 were located in the gene VNN1. The junctions within VNN1 were further characterized using rapid amplification of cDNA ends (RACE) and the prevalence of the subsequently characterized novel transcript, VNN1-AB, was investigated by real-time RT-PCR in 291 samples of miscellaneous origins. VNN1-AB was not present in any of the 43 normal colorectal tissue samples investigated, but in 5 of the 6 polyps, and 102 of the 136 (75%) colorectal cancers. We have identified a novel transcript of the VNN1 gene, with an organ-confined complete specificity for colorectal neoplasia.

Frailty is an independent predictor of survival in older patients with colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is prevalent in the older population. Geriatric assessment (GA) has previously been found to predict treatment tolerance and postoperative complications in older cancer patients. The aim of this study was to explore whether GA also predicts 1-year and 5-year survival after CRC surgery in older patients and to compare the predictive power of GA with that of established prognostic factors such as TNM classification of malignant tumors (TNM) stage and age. MATERIALS AND METHODS: A cohort of 178 CRC patients aged 70 and older were followed prospectively. All patients went through elective surgery, and GA was performed presurgery. The GA resulted in patients being divided into two groups: frail or nonfrail. All patients were followed for 5 years or until death. Data were analyzed by Kaplan-Meier plots and the Cox proportional hazards model. RESULTS: Seventy-six patients (43%) were frail, and one hundred and two (57%) were nonfrail. Twenty-three patients (13%) died during the first year after surgery. One-year survival was 80% in the frail group and 92% in the nonfrail group. Five-year survival was significantly lower in frail (24%) than nonfrail patients (66%), and this difference was apparent both within the stratums of TNM stages 0-II and TNM stage III. In multivariable analysis adjusting for TNM stage, age, and sex, frailty was an independent prognostic factor for survival. CONCLUSION: A GA-based frailty assessment predicts 1-year and 5-year survival in older patients after surgery for CRC. In localized and regional disease, the impact of frailty upon 5-year survival is comparable with that of TNM stage.

B7-H3 expression in colorectal cancer: associations with clinicopathological parameters and patient outcome.

BACKGROUND: We have previously reported overexpression of the immunoregulatory protein B7-H3 in colorectal cancer and that nuclear expression predicted poor outcome in colon cancer patients. The present study was performed to examine the prognostic role of B7-H3 in an independent colorectal cancer cohort. METHODS: Using tissue microarrays from 731 colorectal cancer patients, tumour B7-H3 expression was assessed by immunohistochemistry. Associations with clinicopathological parameters and patient outcome were investigated. RESULTS: Nuclear expression of B7-H3 in cancer cells was present in 27% of the samples in the total study cohort, while cytoplasmic/membrane and stromal expression was seen in 86% and 77% of the samples, respectively. Nuclear B7-H3 had no prognostic relevance in the complete outcome cohort, neither in colon cancer patients. However, nuclear B7-H3 was significantly associated with reduced recurrence-free survival in TNM stage I colorectal cancer patients. CONCLUSIONS: Overexpression of B7-H3 in colorectal cancer was confirmed, but in contrast to previous results, nuclear B7-H3 was not a strong prognostic biomarker in this cohort. The discrepancy might be related to the use of single-core tissue microarrays for detection of the heterogeneously expressed B7-H3, and the role of B7-H3 in colorectal cancer still needs further examination.

Hospital use and cancer treatment by age and socioeconomic status in the last year of life: A Norwegian population-based study of patients dying of cancer.

INTRODUCTION: Cancer is the leading cause of death in Norway. In this nationwide study we describe the number and causes of hospital admissions and treatment in the final year of life for patients who died of cancer, as well as the associations to age and socioeconomic status (SES). MATERIALS AND METHODS: From nationwide registries covering 2010-2014, we identified all patients who were diagnosed with cancer 12-60 months before death and had cancer as their reported cause of death. We examined the number of overnight hospital stays, causes of admission, and treatment (chemotherapy, radiotherapy, surgical procedures) offered during the last year of life by individual (age, sex, comorbidity), cancer (type, stage, months since diagnosis), and socioeconomic variables (co-residential status, income, education). RESULTS: The analytical sample included 17,669 patients; 8,247 (47%) were female, mean age was 71.7 years (standard deviation 13.7). At diagnosis, 31% had metastatic disease, while 29% had an intermediate or high comorbidity burden. Altogether, 94% were hospitalized during their final year, 82% at least twice, and 33% six times or more. Patients spent a median of 23 days in hospital (interquartile range 11-41), and altogether 38% died there. Younger age, bladder and ovarian cancer, not living alone, and higher income were associated with having ≥6 hospitalizations. Cancer-related diagnoses were the main causes of hospitalizations (65%), followed by infections (11%). Around 51% had ≥1 chemotherapy episode, with large variations according to patient age and SES; patients who were younger, did not live alone, had high education, and high income received more chemotherapy. Radiotherapy was received by 15% and declined with age, and the variation according to SES characteristics was minor. Of the 12,940 patients with a cancer type where surgery is a main treatment modality, only 835 (6%) underwent surgical procedures for their primary tumor in the last year of life. DISCUSSION: Most patients who die of cancer are hospitalized multiple times during the last year of life. Hospitalizations and treatment decline with advancing age. Living alone and having low income is associated with fewer hospitalizations and less chemotherapy treatment. Whether this indicates over- or undertreatment across various groups warrants further exploration.