Critical research gaps and recommendations to inform research prioritisation for more effective prevention and improved outcomes in colorectal cancer

Reshaping the critical role of surgeons in oncology research

Surgery remains a mainstay in the treatment of most solid cancers. Surgeons have always engaged in various forms of high-quality cancer research to optimize outcomes for their patients, for example, contributing to clinical research and outcomes research as well as health education and public health policy. Over the past decade, however, concerns have been raised about a global decline in the number of surgeons performing basic science research alongside clinical activity - so-called surgeon scientists. Herein, we describe some of the unique obstacles faced by contemporary trainee and practising surgeons engaged in research, as well as providing a perspective on the implications of the diminishing prominence of the surgeon scientist. Finally, we offer some thoughts on potential strategies and future directions for surgical engagement in oncology research to increase the number of research-active surgeons.

The association and diagnostic value of red blood cell distribution width in colorectal cancer

Red blood cell distribution width (RDW) is associated with several diseases. However, the diagnostic value of RDW and its related factors remain unclear in colorectal cancer (CRC).This single-center retrospective study evaluated 211 Chinese CRC patients and 103 healthy controls. The association of RDW with the clinical parameters of CRC, as well as its correlations with carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) were analyzed. The diagnostic value of RDW alone or combined with CEA and CA19-9 was evaluated using receiver operating characteristic curve analysis. A meta-analysis was also performed to combine our data with previously published data to enhance our findings.In the CRC patients, RDW was clearly elevated and was significantly associated with CRC tumor location, histological type, T status (but not N or M status), and clinical stage. However, RDW was not significantly correlated with CEA or CA19-9 levels. Using RDW to diagnose CRC provided a sensitivity of 53.1% and specificity of 77.7%. The diagnostic accuracy of RDW was enhanced by combining RDW with CEA and CA19-9 levels. We identified 5 previous studies with 633 CRC patients and 1050 controls, which were combined with our cases and controls. The meta-analysis revealed an overall sensitivity of 69%, specificity of 70%, and an area under the curve of 0.74.In CRC cases, RDW was associated with tumor location, histological type, T status, and clinical stage. Furthermore, RDW had a moderate value for diagnosing CRC and might be useful in this setting.

General practitioners' awareness of the recommendations for faecal immunochemical tests (FITs) for suspected lower gastrointestinal cancers: a national survey

OBJECTIVES

In July 2017, UK National Institute for Health and Care Excellence (NICE) published a diagnostic guidance (DG30) recommending the use of faecal immunochemical tests (FITs) for symptomatic patients who do not meet the urgent referral pathway for suspected colorectal cancer (CRC). We assessed general practitioners' (GP) awareness of DG30 in primary care 6 months after its publication.

DESIGN AND SETTING

Cross-sectional online survey of GPs hosted by an English panel of Primary health care professionals.

PARTICIPANTS

In December 2017, 1024 GPs registered on an online panel (M3) based in England took part in an online survey.

OUTCOMES AND VARIABLES

We investigated a number of factors including previous experience of using FIT and guaiac faecal occult blood tests (FOBTs), the number of urgent referrals for CRC that GPs have made in the last year and their sociodemographic and professional characteristics that could be associated with their self-reported awareness of the FIT diagnostic guidance.

RESULTS

Of the 1024 GPs who completed the survey, 432 (42.2%) were aware of the current recommendation but only 102 (10%) had used it to guide their referrals. Awareness was lowest in North West England compared with London (30.5% vs 44.9%; adjusted OR: 0.55, 95% CI 0.33 to 0.92). Awareness of the FIT guidance was positively associated with test usage after the NICE update (adjusted OR: 13.00, 95% CI 6.87 to 24.61) and having specialist training (adjusted OR: 1.48, 95% CI 1.05 to 2.08). The number of urgent referrals, the previous use of FOBt, GPs' age and gender, work experience and practice size (both in terms of the number of GPs or patients at the practice) were not associated with awareness.

CONCLUSIONS

Less than half of GPs in this survey recognised the current guidance on the use of FIT. Self-reported awareness was not systematically related to demographic of professional characteristics.

Precision immunoprofiling by image analysis and artificial intelligence

Clinical success of immunotherapy is driving the need for new prognostic and predictive assays to inform patient selection and stratification. This requirement can be met by a combination of computational pathology and artificial intelligence. Here, we critically assess computational approaches supporting the development of a standardized methodology in the assessment of immune-oncology biomarkers, such as PD-L1 and immune cell infiltrates. We examine immunoprofiling through spatial analysis of tumor-immune cell interactions and multiplexing technologies as a predictor of patient response to cancer treatment. Further, we discuss how integrated bioinformatics can enable the amalgamation of complex morphological phenotypes with the multiomics datasets that drive precision medicine. We provide an outline to machine learning (ML) and artificial intelligence tools and illustrate fields of application in immune-oncology, such as pattern-recognition in large and complex datasets and deep learning approaches for survival analysis. Synergies of surgical pathology and computational analyses are expected to improve patient stratification in immuno-oncology. We propose that future clinical demands will be best met by (1) dedicated research at the interface of pathology and bioinformatics, supported by professional societies, and (2) the integration of data sciences and digital image analysis in the professional education of pathologists.

Colorectal cancer and adenoma screening using urinary volatile organic compound (VOC) detection: early results from a single-centre bowel screening population (UK BCSP)

BACKGROUND

The United Kingdom (UK) bowel cancer screening programme has reduced mortality from colorectal cancer (CRC), but poor uptake with stool-based tests and lack of specificity of faecal occult blood testing (FOBT), has prompted investigation for a more suitable screening test. The aim of this study was to investigate the feasibility of a urinary volatile organic compounds (VOC)-based screening tool for CRC.

METHODS

The urine from FOBT-positive patients was analysed using field asymmetric ion mobility spectrometry (FAIMS) and gas chromatography coupled with ion mobility spectrometry (GC-IMS). Data were analysed using a machine learning algorithm to calculate the test accuracy for correct classification of CRC against adenomas and other gastrointestinal pathology.

RESULTS

One hundred and sixty-three patients were enrolled in the study. Test accuracy was high for differentiating CRC from control: area under the curve (AUC) 0.98 (95% CI 0.93-1) and 0.82 (95% CI 0.67-0.97) using FAIMS and GC-IMS respectively. Correct classification of CRC from adenoma was high with AUC range 0.83-0.92 (95% CI 0.43-1.0). Classification of adenoma from control was poor with AUC range 0.54-0.61 (95% CI 0.47-0.75) using both analytical modalities.

CONCLUSIONS

CRC was correctly distinguished from adenomas or no bowel pathology using urinary VOC markers, within the bowel screening population. This pilot study demonstrates the potential of this method for CRC detection, with higher test uptake and superior sensitivity than FOBT. In addition, this is the first application of GC-IMS in CRC detection which has shown high test accuracy and usability.

Essential Research Priorities in Renal Cancer: A Modified Delphi Consensus Statement

BACKGROUND

Identification of clear and focused research priorities is crucial to drive research forward.

OBJECTIVE

To identify research priorities in renal cell carcinoma (RCC) through a multidisciplinary collaboration between clinicians, researchers, and patients.

DESIGN, SETTING, AND PARTICIPANTS

In phase I, 44 RCC experts provided 24 literature reviews within their field, summarising research gaps (RGs). Three expert discussion meetings and patient interviews were performed, and 39 potential RGs were identified. In phase II, experts (N=82) scored these gaps on a nine-point scale (1-3: not important; 4-6: important; 7-9: critical) through a multistep Delphi process involving three online surveys and two further consensus meetings. The surveys aimed to reach a consensus, defined as ≥70% agreement by experts.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Three iterations of the Delphi survey were performed. The results obtained after the third Delphi survey were distributed amongst the RCC experts and patient representatives for final feedback.

RESULTS AND LIMITATIONS

In the first Delphi survey, the response rate was 56% (46/82), increasing to 67% (55/82) and 71% (58/82) in the second and third iterations, respectively. Survey respondents included 45.7% urologists, 37.0% oncologists, 8.7% radiologists, and 8.6% other specialists (pathologists, health economists, geneticist, and scientists). The process resulted in the identification of 14 crucial RGs, across a broad range of RCC themes. Key themes included further research into systemic therapies for RCC and management strategies that maximise quality of life, especially in patient groups that are "difficult to treat" and have rarer RCC subtypes. Two crucial RGs relate to biomarkers and novel imaging approaches for both localised and metastatic disease, to enable prognostic risk stratification and individualise patient management. Study participants were from a UK and European setting; therefore, we acknowledge that the RGs identified represent European priorities.

CONCLUSIONS

These RGs will facilitate international collaboration towards a concerted attempt to improve patients' survival and quality of life.

PATIENT SUMMARY

We formed a collaboration between researchers, clinicians, and patients to identify research priorities in kidney cancer. We identified 14 priorities that will improve patient outcomes by focusing on research efforts.

Risk factors for advanced colorectal neoplasms in the proximal colon in 6218 subjects undergoing complete colonoscopy

BACKGROUND AND AIM

Proximal migration of colonic lesion has been observed; however, risk factors of lesions in the proximal colon remain uncertain. This study aimed to investigate risk factors of lesions in the proximal colon.

METHODS

Consecutive subjects with complete colonoscopy were included. The primary outcome was risk factors associated with advanced neoplasm (AN) and serrated lesion in the proximal colon. Age, gender, first-degree relative (FDR) with colorectal cancer (CRC), smoking, alcohol consumption, body mass index, hypertension, diabetes, ischemic heart disease, and the use of aspirin, non-steroidal anti-inflammatory drug, and anticoagulants were fitted into a regression model, with reference to subjects without colonic finding. Results were measured by odds ratio (OR) with 95% confidence interval (CI).

RESULTS

Among 6218 subjects (mean age 56.65 ± 6.15 years; 46.8% male), 352 (5.7%) had AN; 809 (13.0%) had serrated lesions, and 3648 (58.7%) had no colonic finding. There were 148 (2.4%) and 235 (3.8%) subjects having AN and serrated lesion in the proximal colon. Age ≥ 50 (OR: 13.30; 95% CI: 1.85-95.76), male gender (OR: 1.82; 95% CI: 1.26-2.62), FDR with CRC (OR: 2.12; 95% CI: 1.43-3.15), and hypertension (OR: 1.86; 95% CI: 1.30-2.68) were associated with AN in the proximal colon. Age ≥ 50 (OR: 5.72; 95% CI: 2.10-15.53), male gender (OR: 1.54; 95% CI: 1.15-2.05), and smoking (OR: 1.85; 95% CI: 1.23-2.79) increased risk of serrated lesions in the proximal colon.

CONCLUSION

Age ≥ 50 and male gender were associated with both proximally located AN and serrated lesion; FDR with CRC and hypertension increased the risk of proximal AN, while ever smoking increased the risk of proximal serrated lesion. FDR with CRC was not associated with serrated lesion.

Whole-colon investigation vs. flexible sigmoidoscopy for suspected colorectal cancer based on presenting symptoms and signs: a multicentre cohort study

BACKGROUND

Patients with suspected colorectal cancer (CRC) usually undergo colonoscopy. Flexible sigmoidoscopy (FS) may be preferred if proximal cancer risk is low. We investigated which patients could undergo FS alone.

METHODS

Cohort study of 7375 patients (≥55 years) referred with suspected CRC to 21 English hospitals (2004-2007), followed using hospital records and cancer registries. We calculated yields and number of needed whole-colon examinations (NNE) to diagnose one cancer by symptoms/signs and subsite. We considered narrow (haemoglobin <11 g/dL men; <10 g/dL women) and broad (<13 g/dL men; <12 g/dL women) anaemia definitions and iron-deficiency anaemia (IDA).

RESULTS

One hundred and twenty-seven proximal and 429 distal CRCs were diagnosed. A broad anaemia definition identified 80% of proximal cancers; a narrow definition with IDA identified 39%. In patients with broad definition anaemia and/or abdominal mass, proximal cancer yield and NNE were 4.8% (97/2022) and 21. In patients without broad definition anaemia and/or abdominal mass, with rectal bleeding or increased stool frequency (41% of cohort), proximal cancer yield and NNE were 0.4% (13/3031) and 234.

CONCLUSION

Most proximal cancers are accompanied by broad definition anaemia. In patients without broad definition anaemia and/or abdominal mass, with rectal bleeding or increased stool frequency, proximal cancer is rare and FS should suffice.

Ginsenoside Rg5 overcomes chemotherapeutic multidrug resistance mediated by ABCB1 transporter: in vitro and in vivo study

Background

Multidrug resistance (MDR) to chemotherapy drugs remains a major challenge in clinical cancer treatment. Here we investigated whether and how ginsenoside Rg5 overcomes the MDR mediated by ABCB1 transporter in vitro and in vivo.

Methods

Cytotoxicity and colon formation as well as the intracellular accumulation of ABCB1 substrates were carried out in MDR cancer cells A2780/T and A549/T for evaluating the reversal effects of Rg5. The expressions of ABCB1 and Nrf2/AKT pathway were determined by Western blotting. An A549/T cell xenograft model was established to investigate the MDR reversal activity of Rg5 in vivo.

Results

Rg5 significantly reversed ABCB1-mediated MDR by increasing the intracellular accumulation of ABCB1 substrates without altering protein expression of ABCB1. Moreover, Rg5 activated ABCB1 ATPase and reduced verapamil-stimulated ATPase activity, suggesting a high affinity of Rg5 to ABCB1 binding site which was further demonstrated by molecular docking analysis. In addition, co-treatment of Rg5 and docetaxel (TXT) suppressed the expression of Nrf2 and phosphorylation of AKT, indicating that sensitizing effect of Rg5 associated with AKT/Nrf2 pathway. In nude mice bearing A549/T tumor, Rg5 and TXT treatment significantly suppressed the growth of drug-resistant tumors without increase in toxicity when compared to TXT given alone at same dose.

Conclusion

Therefore, combination therapy of Rg5 and chemotherapy drugs is a strategy for the adjuvant chemotherapy, which encourages further pharmacokinetic and clinical studies.

Exploring the effect of a lifestyle intervention on cancer risk: 43-year follow-up of the randomized Oslo diet and antismoking study

BACKGROUND/OBJECTIVES

The Oslo diet and antismoking study showed that counselling for a healthy lifestyle reduced lifelong coronary mortality in high-risk men. We explored whether the same counselling reduced also cancer risk.

METHODS

The study randomly allocated males at high coronary risk to either a 5-year intervention for lifestyle changes (cholesterol-lowering dietary changes, weight loss and stopping smoking) or a control group (1 : 1) in 1972/73. We explored the incidence and mortality of all cancers and cancer forms related to smoking, BMI or diet up to 43 years after randomization.

RESULTS

A total of 595 men in the intervention and 621 in the control group were included. At inclusion median age was 45 years, 588 (48.4%) subjects were overweight (BMI > 25 kg m-2 ) and 925 (76.1%) current smokers. The intervention did not reduce the risk of cancer after 43 years (adjusted hazard ratio (HR) 0.96, 95% confidence interval (CI) 0.80-1.15). In the first 25 years of follow-up, among the 1088 (89.5%) men who were overweight/obese and/or smokers, the intervention reduced the incidence of those cancer forms related to smoking, BMI or diet (including carcinoma of the respiratory, digestive and urinary tracts; adjusted HR 0.69; 95% CI 0.49-0.99). The intervention had no significant effect on incidence beyond 25 years, or on mortality.

CONCLUSIONS

The 5-year counselling for a healthy lifestyle did not reduce the overall cancer risk in the very long term. However, in the first 25 years, the counselling reduced the risk of relevant cancer types in overweight/obese subjects and smokers.

Circulating tumor DNA in patients with colorectal adenomas: assessment of detectability and genetic heterogeneity

Improving early detection of colorectal cancer (CRC) is a key public health priority as adenomas and stage I cancer can be treated with minimally invasive procedures. Population screening strategies based on detection of occult blood in the feces have contributed to enhance detection rates of localized disease, but new approaches based on genetic analyses able to increase specificity and sensitivity could provide additional advantages compared to current screening methodologies. Recently, circulating cell-free DNA (cfDNA) has received much attention as a cancer biomarker for its ability to monitor the progression of advanced disease, predict tumor recurrence and reflect the complex genetic heterogeneity of cancers. Here, we tested whether analysis of cfDNA is a viable tool to enhance detection of colon adenomas. To address this, we assessed a cohort of patients with adenomas and healthy controls using droplet digital PCR (ddPCR) and mutation-specific assays targeted to trunk mutations. Additionally, we performed multiregional, targeted next-generation sequencing (NGS) of adenomas and unmasked extensive heterogeneity, affecting known drivers such as APC, KRAS and mismatch repair (MMR) genes. However, tumor-related mutations were undetectable in patients' plasma. Finally, we employed a preclinical mouse model of Apc-driven intestinal adenomas and confirmed the inability to identify tumor-related alterations via cfDNA, despite the enhanced disease burden displayed by this experimental cancer model. Therefore, we conclude that benign colon lesions display extensive genetic heterogeneity, that they are not prone to release DNA into the circulation and are unlikely to be reliably detected with liquid biopsies, at least with the current technologies.

Activation of p53 by costunolide blocks glutaminolysis and inhibits proliferation in human colorectal cancer cells

Colorectal cancer is a leading cause of cancer-related death. Glutaminolysis has been suggested as a therapeutic target for cancer. Costunolide is a natural sesquiterpene lactone showing potent antitumor activity. Our studies were aimed at evaluating how costunolide affected glutaminolysis leading to proliferation inhibition in human colorectal cancer cells. Costunolide suppressed viability and proliferation of HCT116 cells concentration-dependently, but did not apparently affect human intestinal epithelial cells. Costunolide at 20 μM reduced viability and proliferation of HCT116 cells time-dependently. Costunolide also repressed phosphorylation of mTOR and its downstream kinases p70S6K and 4E-BP1. Examinations of glutaminolysis metabolites showed that costunolide increased intracellular glutamine levels, but decreased intracellular levels of glutamate, α-ketoglutarate (α-KG), and ATP in HCT116 cells, suggesting costunolide blockade of glutaminolysis. Furthermore, costunolide inhibited promoter activity of glutaminase 1 (GLS1), the first rate-limiting enzyme in glutaminolysis, and reduced mRNA and protein expression of GLS1 in HCT116 cells, The GLS1 inhibitor BPTES, similar to costunolide, significantly reduced intracellular levels of α-KG and ATP and inhibited proliferation in HCT116 cells. Finally, costunolide increased phosphorylation and nuclear translocation of p53 in HCT116 cells. Both p53 inhibitor pifithrin-α and p53 siRNA significantly rescued costunolide suppression of GLS1 promoter activity and expression in HCT116 cells. These data in aggregate suggested that activation of p53 was required for costunolide inhibition of GLS1 resulting in blockade of glutaminolysis and inhibition of proliferation in colorectal cancer cells, which was a novel mechanism underlying the antitumor activity of costunolide against colorectal cancer.

Mapping the European cancer research landscape: An evidence base for national and Pan-European research and funding

BACKGROUND

Cancer research is among the most active biomedical research domains for the European Union (EU). However, little quantitative empirical evidence is available to guide the decisions on the choice of disease site to study, specific research domain focus or allocation of research resources. To inform national/supranational cancer research policy, high-resolution intelligence is needed.

METHODS

We performed a bibliometric analysis of European cancer research papers in the Web of Science from 2002 to 2013 to quantify research activity in each of the 28 EU Member States, along with Iceland, Norway and Switzerland (EUR31), which cancer sites/research domains they addressed, and their sources of financial support (2009-2013).

FINDINGS

Cancer research papers from EUR31 correlated well with national Gross Domestic Products (r² = 0.94). However, certain cancer sites (lung, oesophagus and pancreas) were under-researched relative to their disease burden, whereas central nervous system and blood cancers were more generously supported than their burden would warrant. An analysis of research domains indicated a paucity of research on radiotherapy (5%), palliative care (1.2%) and quality of life (0.5%). European cancer research funding in 2012-2013 amounted to ∼€7.6 billion and came from diverse sources, especially in western Europe/Scandinavia, where in nine countries the charitable sector outspent the government but not in Eastern Europe where charitable research funding barely exists.

INTERPRETATION

Several countries need to increase their cancer research outputs substantially, and/or alter their research portfolios to better match their growing (and changing) cancer burden. More co-ordination among funding agencies is required, so that resources can be attuned to align activities to research gaps and perceived clinical needs. In Eastern Europe, the charitable funding sector needs to be developed, so that both public and patient advocacy can have an active role in research.

A high-throughput serum Raman spectroscopy platform and methodology for colorectal cancer diagnostics

Translating Raman spectroscopy for colorectal cancer diagnosis with a focus on high-throughput design, inter-user variability and sample handling considerations.