Comparison of immunochemical and guaiac-based fecal occult blood test in screening and surveillance for advanced colorectal neoplasms: a meta-analysis

Colorectal cancer screening; colonoscopy and biopsy results in people undergoing colonoscopy due to positive fecal occult blood test

Objectives

Screening programs are important for the early detection of colorectal cancer, which is one of the causes of high morbidity and mortality. In this study, we investigated the colonoscopy results, the incidence of adenoma and cancer, and the relationship between test results and cancer in individuals with a positive fecal occult blood test for colorectal cancer screening.

Material and Methods

Within the scope of the colorectal cancer screening program, colonoscopy was requested for individuals aged 50-70 years who applied to our outpatient clinic with a positive fecal occult blood test. The results were collected and analyzed.

Results

The results of the colonoscopy could be obtained in only 237 (56.43%) of the 420 patients who were referred for a colonoscopy because of a positive fecal occult blood test. Colonoscopy results were normal in 15 (6.33%), benign anal disease in 64 (27%), benign colonic disease in 12 (5.06%) and polyp + adenocarcinoma in 146 (61.61%). Pathology results were benign polyp in 37 (15.61%), adenomatous polyp in 86 (36.29%) and adenocarcinoma in 23 (9.71%). Quantitative test results were higher in the adenomatous polyp + adenocarcinoma group and statistically significant (p= 0.03).

Conclusion

Individuals with positive fecal occult blood tests, especially those with high quantitative test results, should be encouraged to have a colonoscopy, and they should be warned about the high probability of adenomatous polyps and colorectal cancer.

Profiling small RNAs in fecal immunochemical tests: is it possible?

Fecal microRNAs represent promising molecules with potential clinical interest as non-invasive diagnostic and prognostic biomarkers. Colorectal cancer (CRC) screening based on the fecal immunochemical test (FIT) is an effective tool for prevention of cancer development. However, due to the poor sensitivity of FIT especially for premalignant lesions, there is a need for implementation of complementary tests. Improving the identification of individuals who would benefit from further investigation with colonoscopy using molecular analysis, such as miRNA profiling of FIT samples, would be ideal due to their widespread use. In the present study, we assessed the feasibility of applying small RNA sequencing to measure human miRNAs in FIT leftover buffer in samples from two European screening populations. We showed robust detection of miRNAs with profiles similar to those obtained from specimens sampled using the established protocol of RNA stabilizing buffers, or in long-term archived samples. Detected miRNAs exhibited differential abundances for CRC, advanced adenoma, and control samples that were consistent for FIT and RNA-stabilizing buffers. Interestingly, the sequencing data also allowed for concomitant evaluation of small RNA-based microbial profiles. We demonstrated that it is possible to explore the human miRNome in FIT leftover samples across populations and envision that the analysis of small RNA biomarkers can complement the FIT in large scale screening settings.

Impact of Various Risk Factors on the Positive Fecal Immunochemical Test for Colorectal Cancer in the Iranian Population

Background: Colorectal cancer (CRC) is the most prevalent cancer with high mortality worldwide. We aimed to evaluate the incidence of CRC based on the positive fecal immunochemical test (FIT) result in the Iranian population. Methods: The present study was conducted on the health assessment data recorded in the SINA (Integrated Health Information System) in 2018 and 2019 from individuals who had participated in the national program, including asymptomatic people aged 50-69 years or had risk factors of CRC such as family or past personal history of CRC as well as symptomatic individuals, for the early detection and prevention of CRC in Mashhad, Iran. Results: The study participants included 140,463 eligible individuals, of whom 8258 (5.88%) and 145 (2.21%) were positive for FIT and diagnosed with colon cancer, respectively. Unfortunately, only 654 people had undergone colonoscopy. Our results indicated that age, fast food intake (≥two units per day), family history of CRC in first or second-degree relatives, some gastrointestinal diseases such as inflammatory bowel disease (IBD) and CRC, as well as bleeding per anus, constipation, abdominal cramp, and losing body weight were associated with increased risk of positive FIT. However, some other factors, including having a hard job, physical activity, and Iranian nationality (compared to non-Iranians), were associated with a low risk of positive FIT screening tests for CRC. Conclusion: A high number of high-risk persons in Mashhad were positive for the FIT test in 2018-2019, and many of them were diagnosed with CRC, according to the colonoscopy results. Therefore, screening is highly recommended as the first step in the early detection of CRC.

Positive Results from the Fecal Immunochemical Test Can Be Related to Dementia: A Nationwide Population-Based Study in South Korea

BACKGROUND

The fecal immunochemical test (FIT) is widely used in screening for colorectal cancer (CRC), but FIT results can be positive for diseases other than CRC.

OBJECTIVE

We investigated the association between positive results of FIT and the incidence of dementia using a nationwide database.

METHODS

FIT-positive participants were collected from a database provided by the Korean National Health Insurance Service.

RESULTS

The incidence of all kinds of dementia was higher in FIT-positive than FIT-negative subjects (p < 0.0001). FIT-positive participants had a higher risk of Alzheimer's disease (AD) (p < 0.0001) and vascular dementia (p = 0.0002), compared to participants with FIT negativity. The risk of all kinds of dementia or AD in FIT-positive participants was higher in younger (age < 65 years) than older participants (p < 0.0001 for all kinds of dementia; p = 0.0002 for AD).

CONCLUSION

FIT positivity was correlated with an increased risk of dementia, especially in participants under 65 years of age. The study suggests that clinicians can consider dementia when FIT-positive participants fail to show any malignancies.

An Assessment of Physicians’ Recommendations for Colorectal Cancer Screening and International Guidelines Awareness and Adherence: Results From a Thai National Survey

Background

Colorectal cancer (CRC) screening uptake is generally low in the Asia Pacific and physicians’ recommendations affect the screening participation.

Objective

The study aimed to assess Thai physicians’ recommendations for CRC screening, and the awareness of and adherence to international guidelines.

Methods

A survey containing questions assessing physicians’ demographic data, screening recommendations, and awareness of the international CRC screening guidelines assessed by clinical vignettes. Independent predictors of physicians’ recommendations for CRC screening were determined by logistic regression analysis.

Results

Five hundred and eighty-sixth of 1,286 (46%) physicians completed the survey, and 58% of them offered CRC screening. The majority of colorectal surgeons (91%) and gastroenterologists (86%) endorsed screening, whereas 35% of primary care physicians recommended screening. The patient’s age was the only factor influencing the physician’s decision to offer CRC screening (OR, 2.75: 95% CI, 1.61–4.67). Colonoscopy was the most recommended modality among specialists, whereas 60% of primary care physicians offered fecal occult blood tests (FOBTs). The guidelines awareness was noted in 81% of participants, with the highest rates among gastroenterologists and colorectal surgeons. Gastroenterologists were more likely to adhere to the guidelines than surgeons, but both recommended shorter interval surveillance colonoscopy than guidelines recommendations in cases of small hyperplastic rectosigmoid polyps.

Conclusions

Recommendations for CRC screening and awareness of guidelines vary among different specialties. A low proportion of primary care physicians recommended screening and colorectal surgeons and gastroenterologists recommended shorter intervals for surveillance of small hyperplastic polyp than suggested by guidelines.

Contribution of Epithelial and Gut Microbiome Inflammatory Biomarkers to the Improvement of Colorectal Cancer Patients’ Stratification

In order to ensure that primary endpoints of clinical studies are attained, the patients’ stratification is an important aspect. Selection criteria include age, gender, and also specific biomarkers, such as inflammation scores. These criteria are not sufficient to achieve a straightforward selection, however, in case of multifactorial diseases, with unknown or partially identified mechanisms, occasionally including host factors, and the microbiome. In these cases, the efficacy of interventions is difficult to predict, and as a result, the selection of subjects is often random. Colorectal cancer (CRC) is a highly heterogeneous disease, with variable clinical features, outcomes, and response to therapy; the CRC onset and progress involves multiple sequential steps with accumulation of genetic alterations, namely, mutations, gene amplification, and epigenetic changes. The gut microbes, either eubiotic or dysbiotic, could influence the CRC evolution through a complex and versatile crosstalk with the intestinal and immune cells, permanently changing the tumor microenvironment. There have been significant advances in the development of personalized approaches for CRC screening, treatment, and potential prevention. Advances in molecular techniques bring new criteria for patients’ stratification—mutational analysis at the time of diagnosis to guide treatment, for example. Gut microbiome has emerged as the main trigger of gut mucosal homeostasis. This may impact cancer susceptibility through maintenance of the epithelial/mucus barrier and production of protective metabolites, such as short-chain fatty acids (SCFAs) via interactions with the hosts’ diet and metabolism. Microbiome dysbiosis leads to the enrichment of cancer-promoting bacterial populations, loss of protective populations or maintaining an inflammatory chronic state, all of which contribute to the development and progression of CRC. Meanwhile, variations in patient responses to anti-cancer immuno- and chemotherapies were also linked to inter-individual differences in intestine microbiomes. The authors aim to highlight the contribution of epithelial and gut microbiome inflammatory biomarkers in the improvement of CRC patients’ stratification towards a personalized approach of early diagnosis and treatment.

[Prevention of gastrointestinal cancer]

Throughout the past decades, considerable progress has been made in the (early) diagnosis and treatment of gastrointestinal cancers. However, the prognosis for advanced stages of gastrointestinal tumors remains limited for many patients and approximately one third of all tumor patients die as a result of gastrointestinal tumors. The prevention and early detection of gastrointestinal tumors is therefore of great importance.For this reason, we summarize the current state of knowledge and recommendations for the primary, secondary and tertiary prevention of esophageal, stomach, pancreas, liver and colorectal cancer in the following.

Public Health: Prevention

Nowadays, colorectal cancer prevention strategies play an essential role in reducing the incidence and mortality of the cases. A well-designed and establishment of the clinical pathway of screening programme needed in all country. Types of screening tools used may vary between the country with the use of FOBT and colonoscopy. The standard guideline related to screening programme such as for high-risk group should be emphasized more as compared to the low-risk group. The uptake of screening for CRC should be highlighted more as the program have showed a significantly reduction of the cases and mortality. The barrier of CRC screening uptake mainly due to poor awareness, discomfort, low physician recommendation, low socioeconomic and improper screening programme. Therefore others prevention strategies beside screening program such as health education and interactive intervention strategies need to be empower.

Population-based organized screening by faecal immunochemical testing and colorectal cancer mortality: a natural experiment

BACKGROUND

Population-based organized screening programmes for colorectal cancer (CRC) are underway worldwide, with many based on the faecal immunochemical test (FIT). No clinical trials assessing FIT compared with no screening are planned, and few studies have assessed the population impact of such programmes.

METHODS

Before 2010, 11 out of 50 Spanish provinces initiated population-based organized screening programmes with FIT for an average-risk population aged 50-69 years. We used a quasi-experimental design across Spanish provinces between 1999 and 2016 to evaluate their impact on population age-standardized mortality and incidence rates due to CRC. Difference-in-differences and synthetic control analyses were performed to test for validation of statistical assumptions and to assess the dynamics of screening-associated changes in outcomes over time.

RESULTS

No differences in outcome trends between exposed (n = 11) and control (n = 36) provinces were observed for up to 7 years preceding the implementation of screening. Relative to controls, exposed provinces experienced a mean increase in age-standardized incidence of 10.08% [95% confidence interval (CI) (5.09, 15.07)] 2 years after implementation, followed by a reduction in age-standardized mortality rates due to CRC of 8.82% [95% CI (3.77, 13.86)] after 7 years. Results were similar for both women and men. No associated changes were observed in adjacent age bands not targeted by screening, nor for 10 other major causes of death in the exposed provinces.

CONCLUSIONS

FIT-based organized screening in Spain was associated with reductions in population colorectal cancer mortality. Further research is warranted in order to assess the replicability and external validity of our findings, and on gender-specific use of FIT in organized screening.

Fecal neopterin level determination: can be a useful screening test for colorectal polyps?

BACKGROUND

Colorectal cancer (CRC) is a leading cause of cancer death worldwide. The main precursor lesion leading to CRC is the adenomatous colorectal polyp (CP). Nowadays, there is no recognized perfect screening test of CP and CRC. Neopterin is an important marker of cellular inflammation. In this study, we aimed to evaluate comparatively immunochromatographic fecal occult blood test (iFOBT) and fecal neopterin levels (FNLs) in patients with CP and controls.

METHODS

One hundred eleven patients diagnosed with CP and 68 individuals with negative colonoscopy were included in the study. iFOBT and FNLs were assessed in patients and controls.

RESULTS

FNLs and iFOBT positivity were significantly higher in patients with CP than in controls (17.15 ± 3.55 µmol/L/g vs. 12.25 ± 2.19 µmol/L/g, P = 0.00 and 46.8% vs. 14.8%, P = 0.00, respectively). FNLs were significantly higher in cases with adenomatous polyps than in hyperplastic polyps (P = 0.002). FNL ≥14.00 µmol/L/g was the best cutoff value to differentiate between patients with CP from controls (P = 0.000). A multiple logistic regression analysis showed that high FNL was positively correlated with presence, number, diameter of CPs, and presence of adenoma (P < 0.005). The sensitivity of high FNL for CP was 81.1%, which was superior to iFOBT positivity (47.7%, P < 0.001).

DISCUSSION

FNL level is significantly increased in CPs. The FNL exhibited increased sensitivity for identifying CP and adenomatous lesions compared with iFOBT. FNL determination could have as a new screening and diagnostic test for CP.

Expression of tumor pyruvate kinase M2 isoform in plasma and stool of patients with colorectal cancer or adenomatous polyps

Background

Tumor pyruvate kinase M2 isoform (tM2-PK), which is an isoform of PK-glycolytic enzyme and appears on the surface of cancerous proliferating cells, has been used as a diagnostic biomarker for colorectal cancer (CRC). The aim of this study was to evaluate the tM2-PK measurement test for the diagnosis of CRCs and adenomatous polyps in plasma and stool samples in an Iranian population.

Methods

In this prospective study, a total of 226 stool and 178 plasma samples were received from patients referred to colonoscopy units. tM2-PK enzyme was measured using two separate ScheBo-Biotech-AG ELISA kits for stool and plasma samples.

Results

According to ROC curves, in the tumor group, at the cut-off value of 4 U/ml, the sensitivity of fecal tM2-PK test was 100% and the specificity was 68%, and in the polyp group, the sensitivity and specificity were 87 and 68%, respectively. For tumor detection in plasma specimens, a cut-off value > 25 U/ml has a sensitivity and specificity of 90.9 and 91.3%, respectively. Similarly, for polyp detection, a cut-off value > 19 U/ml has a sensitivity of 96.3% and the specificity of 85.5%.

Conclusions

Based on our results, a cut-off range of 4.8–8 U/ml and >  8 U/ml could be used to detect polyp and tumor in stool samples, respectively. Similarly, a cut-off range of 19–25 U/ml and > 25 U/ml is recommended in plasma samples, suggesting tM2-PK test as a non-invasive assay to diagnose CRC and adenomatous polyps.

New horizons in iron deficiency anaemia in older adults

Iron deficiency anaemia (IDA) is common in older adults and associated with a range of adverse outcomes. Differentiating iron deficiency from other causes of anaemia is important to ensure appropriate investigations and treatment. It is possible to make the diagnosis reliably using simple blood tests. Clinical evaluation and assessment are required to help determine the underlying cause and to initiate appropriate investigations. IDA in men and post-menopausal females is most commonly due to occult gastrointestinal blood loss until proven otherwise, although there is a spectrum of underlying causative pathologies. Investigation decisions should take account of the wishes of the patient and their competing comorbidities, individualising the approach. Management involves supplementation using oral or intravenous (IV) iron then consideration of treatment of the underlying cause of deficiency. Future research areas are outlined including the role of Hepcidin and serum soluble transferrin receptor measurement, quantitative faecal immunochemical testing, alternative dosing regimens and the potential role of IV iron preparations.

Diagnostic value of fecal B cell activating factor in patients with abdominal discomfort

Fecal calprotectin has successfully been widely recommended as a sensitive biomarker of inflammatory bowel diseases (IBD). Recently, we have identified an excellent new fecal biomarker, B cell activating factor (BAFF), as being as effective as fecal calprotectin for diagnosing intestinal inflammation. In this study, a total of 230 patients with abdominal discomfort were prospectively enrolled and fecal samples were collected within 24 h before the endoscopic examinations. We show that fecal BAFF levels were significantly higher in patients with ulcerative colitis (median = 1549 pg/g, P < 0·0001), Crohn's disease (median = 735 pg/g, P < 0·0001), gastric cancer (median = 267 pg/g, P < 0·0001) and colorectal cancer (median = 533 pg/g, P < 0·0001) than those in healthy groups (median = 61 pg/g), while the values of which in patients with gastric polyps, colorectal polyps, esophagitis/gastritis/duodenitis and peptic ulcer were in the range of healthy individuals (P > 0·05). An optimal cut-off value at 219·5 pg/g of fecal BAFF produced sensitivity, specificity, positive predictive and negative predictive values of 85, 91, 84 and 92%, respectively, for IBD or carcinoma. Our results therefore indicate a potential role for fecal BAFF as a sensitive screening parameter for IBD and gastrointestinal carcinoma, as well a useful tool to select patients with abdominal discomfort for further endoscopic examinations.

A Novel Type of Blood Biomarker: Distinct Changes of Cytokine-Induced STAT Phosphorylation in Blood T Cells Between Colorectal Cancer Patients and Healthy Individuals

Background: Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. Although early diagnosis and treatment is the most successful strategy for improving patient survival, feasible and sensitive blood biomarkers for CRC screening remain elusive. Methods: Sixty-five CRC patients and thirty-three healthy individuals were enrolled. Peripheral blood (PB) and tumor tissues from CRC patients, and PB from healthy individuals were subjected to immunophenotyping and phospho-flow analysis of cytokine-induced phosphorylated STAT (CIPS). Logistic regression was used as a classifier that separates CRC patients from healthy individuals. Results: The proportion of regulatory T cells was increased in PB from CRC patients compared to PB from healthy individuals (p < 0.05). Interestingly, peripheral T cells share several cytokine-induced phosphorylated STAT (CIPS) signatures with T cells from CRC tumor-sites. Additionally, a classifier was made using two signatures distinct between T cells from CRC patients and T cells from healthy individuals. The AUCs (area under curves) of the classifier were 0.88 in initial cohort and 0.94 in the additional validation cohort. Overall AUC was 0.94 with sensitivity of 91% and specificity of 88%. Conclusion: This study highlights that immune cell signatures in peripheral blood could offer a new type of biomarker for CRC screening.

Diagnostic Accuracy of FOBT and Colorectal Cancer Genetic Testing: A Systematic Review & Meta-Analysis

Introduction:

Colorectal cancer (CRC) is the second leading cause of cancer related death in the world after lung cancer. Early detection of CRC leads to improvement in cancer survival rate. In recent years, efforts have been made to discover a non-invasive screening marker of higher sensitivity and specificity. Fecal occult blood testing (FOBT) and genetic testing become alternative modalities to screen CRC in the population other than colonoscopy. The aim of this systematic review and meta-analysis is to determine the diagnostic accuracy, sensitivity and specificity of FOBT and genetic testing as screening tools in colorectal cancer.

Methods:

A literature search of PubMed, ScienceDirect, and Scopus was carried out. The search strategy was restricted to human subjects and studies are published in English. Data on sensitivity and specificity were extracted and pooled. Heterogeneity was assumed at significance level of p < 0.10 and was tested by chi squared. Degree of heterogeneity was quantified using the I² statistic, and values of less than 25% is considered as homogenous. All analyses were performed using the software Meta-Disc.

Results:

A total of eleven studies were suitable for data synthesis and analysis. Five studies were analyzed for the accuracy of genetic testing, the pooled estimate for sensitivity and specificity were 71% (95% CI: 66, 75%) and 95% (95% CI: 93, 97%) respectively. Another group of studies which had been evaluated for the accuracy of FOBT, the pooled sensitivity was 31% (95% CI: 25, 38%) while the pooled specificity was 87% (95% CI: 86, 89%).

Conclusions:

FOBTs is recommended to use as population-based screening tools for colorectal cancer while genetic testing should be focusing on patients with moderate and high risk individuals.

Incidence of faecal occult blood test interval cancers in population-based colorectal cancer screening: a systematic review and meta-analysis

OBJECTIVE

Faecal immunochemical tests (FITs) are replacing guaiac faecal occult blood tests (gFOBTs) for colorectal cancer (CRC) screening. Incidence of interval colorectal cancer (iCRC) following a negative stool test result is not yet known. We aimed to compare incidence of iCRC following a negative FIT or gFOBT.

DESIGN

We searched Ovid Medline, Embase, Cochrane Library, Science Citation Index, PubMed and Google Scholar from inception to 12 December 2017 for citations related to CRC screening based on stool tests. We included studies on FIT or gFOBT iCRC in average-risk screening populations. Main outcome was pooled incidence rate of iCRCs per 100 000 person-years (p-y). Pooled incidence rates were obtained by fitting random-effect Poisson regression models.

RESULTS

We identified 7 426 records and included 29 studies. Meta-analyses comprised data of 6 987 825 subjects with a negative test result, in whom 11 932 screen-detected CRCs and 5 548 gFOBT or FIT iCRCs were documented. Median faecal haemoglobin (Hb) positivity cut-off used was 20 (range 10-200) µg Hb/g faeces in the 17 studies that provided FIT results. Pooled incidence rates of iCRC following FIT and gFOBT were 20 (95% CI 14 to 29; I²=99%) and 34 (95% CI 20 to 57; I²=99%) per 100 000 p-y, respectively. Pooled incidence rate ratio of FIT versus gFOBT iCRC was 0.58 (95% CI 0.32 to 1.07; I²=99%) and 0.36 (95% CI 0.17 to 0.75; I²=10%) in sensitivity analysis. For every FIT iCRC, 2.6 screen-detected CRCs were found (ratio 1:2.6); for gFOBT, the ratio between iCRC and screen-detected CRC was 1:1.2. Age below 60 years and the third screening round were significantly associated with a lower iCRC rate.

CONCLUSION

A negative gFOBT result is associated with a higher iCRC incidence than a negative FIT. This supports the use of FIT over gFOBT as CRC screening tool.

Fecal occult blood test in colorectal cancer screening

Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality worldwide. Cancer screening is known to decrease mortality from CRC. One important test for CRC screening is the fecal occult blood test (FOBT), which includes guaiac FOBT and fecal immunological tests. In this review we discussed the development and application of the FOBT in CRC screening.

Quantitative immunochemical fecal occult blood test for neoplasia in colon cancer screening

OBJECTIVE

To investigate the performance of the quantitative immunochemical fecal occult blood test (qFIT) and to determine the association between the fecal hemoglobin (Hb) level and the location and size of adenomas and the stages of colorectal cancer (CRC).

METHODS

A total of 692 participants were included in the study. Their fecal Hb level was measured using an OC-SENSA MICRO qFIT. The colonoscopy results, including the location, size, and histological features of the adenomas, as well as the relationship between the Hb level and different characteristics were analyzed. Performance of the qFIT at various thresholds of fecal Hb levels was evaluated.

RESULTS

Advanced colorectal neoplasia (ACRN) was identified in 76 patients based on the colonoscopic and pathological examinations. Large adenomas (≥10 mm) had a higher fecal Hb level than small adenomas (<10 mm). Advanced adenomas located on the left side of the colon presented with a higher fecal Hb level than those on the right side (P = 0.022). Stage III-IV CRC patients had a significantly higher Hb level than stage I-II patients (P = 0.013). The sensitivity and specificity of qFIT for ACRN was 51.3% and 86.4%，respectively, with the best cut-off level of 400 ng/mL. The sensitivity and specificity for CRC was 61.0% and 89.1%, with the best cut-off level of 500 ng/mL.

CONCLUSIONS

qFIT has an acceptable sensitivity and specificity for ACRN detection. Furthermore, the qFIT results are associated with the location and size of adenomas as well as the grade of CRC.

Combination of Different Fecal Immunochemical Tests in Colorectal Cancer Screening: Any Gain in Diagnostic Performance?

A variety of fecal immunochemical tests (FITs) are used for colorectal cancer screening. FIT performance could be improved further. It is unclear, whether the combination of different FITs with different analytical characteristics (such as, different antibodies for the detection of fecal hemoglobin) can yield a better diagnostic performance. Fecal samples were obtained from 2042 participants of screening colonoscopy. All participants with advanced neoplasm (AN, colorectal cancer (n = 16) or advanced adenoma (n = 200)) and 300 randomly selected participants without AN were included. Nine quantitative FITs were evaluated simultaneously. Sensitivity and specificity was calculated for single tests (n = 9) and for their pairwise test combinations (n = 36) (requiring either both FITs (P++) or at least one FIT (P+) to be positive for defining a positive test result). Mean age of the participants (n = 516) was 63 (range: 50–79) years and 56% were men. At cutoffs yielding a specificity of 96.7% for single FITs, the median gain in specificity by P++ combination was +1.0%, whereas the median loss in sensitivity for AN was −4.2%. For P+ combination the median gain in sensitivity for AN was +2.8%, at a prize of median loss of −1.0% of specificity. Combinations of different FITs do not yield any relevant gain in diagnostic performance.

FECAL OCCULT BLOOD: A COMPARISON OF CHEMICAL AND IMMUNOCHEMICAL TESTS

BACKGROUND

Colorectal bleeding is a warning sign that may be identified by fecal occult blood testing. A positive fecal occult blood test result requires a subsequent colonoscopy, a costly and invasive examination. Therefore, the use of diagnostic tests with optimal sensitivity and specificity is warranted. In this study, we evaluated four different fecal occult blood tests in 176 patients undergoing colonoscopy and compared their results.

OBJECTIVE

To assess the sensitivity, specificity and predictive values of chemical and immunochemical fecal occult blood tests in patients undergoing colonoscopy and to evaluate the degree of concordance between the tests and colonoscopy.

METHODS

Patients with indications for colonoscopy also underwent fecal occult blood testing by chemical (toluidine test) and immunochemical methods, employing three commercially available kits. Based on the endoscopic findings, the colonoscopy was rated as positive or negative for colorectal bleeding. The degree of concordance between the fecal occult blood tests and the colonoscopy was evaluated by the kappa index.

RESULTS

Forty-four (25%) colonoscopies were categorized as positive for colorectal bleeding. The toluidine test presented lower concordance than the immunochemical tests, which showed moderate concordance with the colonoscopy. The toluidine test had the least sensitivity, specificity, and positive and negative predictive values.

CONCLUSION

The immunochemical fecal occult blood tests showed greater sensitivity, specificity and predictive values in detecting colorectal bleeding. The immunochemical tests had superior indexes of agreement with colonoscopy compared to the toluidine test.

Direct comparison of ten quantitative fecal immunochemical tests for hemoglobin stability in colorectal cancer screening

OBJECTIVES

To systematically investigate and directly compare, for the first time, the sample stability of a large number of quantitative fecal immunochemical tests (FITs) at different storage conditions.

METHODS

Stool samples were obtained from participants of the German screening colonoscopy program between 2005 and 2010. After an initial FIT-based hemoglobin (Hb) measurement, stool samples were kept frozen at -80 °C until analysis. Twenty randomly selected participants with initial measurements ranging from 10 to 100 μg Hb/g feces were included. Ten quantitative FITs were investigated in parallel. A defined stool amount was extracted using each manufacturer's brand-specific fecal sampling device and stored at 5 °C, 20 °C, and 35 °C, respectively. After 1, 4, 5, and 7 days, the samples were analyzed blinded. Median fecal Hb concentrations and positivity rates were calculated.

RESULTS

Mean age of the participants was 67 years (range: 56-80 years) and 60% were male. The most advanced finding at screening colposcopy was advanced adenoma in five and non-advanced adenoma in eight cases. Hyperplastic polyps were found in two participants and five participants were without any findings. At 5 °C storage temperature, almost all FITs showed fairly stable results throughout the 7-day observation period. At 20 °C, most FITs still showed fairly stable results over 4 days, whereas positivity rates significantly declined from day 4 on for most FITs at 35 °C. Major differences regarding the sample stability between FITs were observed.

CONCLUSION

FIT-specific Hb decay according to ambient temperature and time period between sampling and test evaluation requires careful consideration in the design of FIT-based screening programs.

Fecal immunochemical test for hemoglobin in combination with fecal transferrin in colorectal cancer screening

Objective

Fecal transferrin has been suggested as a complementary or even superior marker for early detection of colorectal cancer (CRC) besides fecal hemoglobin. We aimed to evaluate both markers individually and in combination in a large cohort of participants of screening colonoscopy.

Methods

Precolonoscopy stool samples were obtained from participants of screening colonoscopy and frozen at -80℃ until blinded analysis, using a dual-quantitative fecal immunochemical test (FIT) for hemoglobin and transferrin. Sensitivity, specificity and area under the curve (AUC) were calculated for CRC and advanced adenoma (AA).

Results

A total of 1667 participants fulfilled our inclusion criteria. All individuals with advanced neoplasm (AN) (16 CRC, 200 AA) and 300 randomly selected participants without AN were included. Mean age was 63 years and 56% were male. The AUC for CRC and AA was 92% and 68%, respectively, for hemoglobin vs. 79% and 58%, respectively for transferrin. Combination of both markers yielded an AUC for CRC and AA of 92% and 68%, respectively.

Conclusion

FIT for hemoglobin shows better diagnostic performance than FIT for transferrin for the detection of ANs (both proximal and distal neoplasms), and a combination of both markers does not improve the diagnostic performance.

Back-to-back colon capsule endoscopy and optical colonoscopy in colorectal cancer screening individuals

AIM

The aim was to determine the polyp detection rate and per-patient sensitivity for polyps > 9 mm of colon capsule endoscopy (CCE) compared with colonoscopy as well as the diagnostic accuracy of CCE.

METHOD

Individuals who had a positive immunochemical faecal occult blood test during screening had investigator blinded CCE and colonoscopy. Participants underwent repeat endoscopy if significant lesions detected by CCE were considered to have been missed by colonoscopy.

RESULTS

There were 253 participants. The polyp detection rate was significantly higher in CCE compared with colonoscopy (P = 0.02). The per-patient sensitivity for > 9 mm polyps for CCE and colonoscopy was 87% (95% CI: 83-91%) and 88% (95% CI: 84-92%) respectively. In participants with complete CCE and colonoscopy examinations (N = 126), per-patient sensitivity of > 9 mm polyps in CCE (97%; 95% CI: 94-100%) was superior to colonoscopy (89%; 95% CI: 84-94%). A complete capsule endoscopy examination (N = 134) could detect patients with intermediate or greater risk (according to the European guidelines) with an accuracy, sensitivity, specificity and positivity rate of 79%, 93%, 69% and 58% respectively, using a cut-off of at least one polyp > 10 mm or more than two polyps.

CONCLUSION

CCE is superior to colonoscopy in polyp detection rate and per-patient sensitivity to > 9 mm polyps, but only in complete CCE examinations. The rate of incomplete CCE examinations must be improved.

Faecal occult blood screening for colorectal cancer in Serbia: a pilot study

Colorectal cancer (CRC) is becoming a major public health problem in the Republic of Serbia. Organized mass screening has been shown to decrease CRC mortality and even its incidence. The aim of this study was to assess the acceptability of a faecal immunochemical test for haemoglobin proposed by primary care physicians. From August to November 2013, a pilot study for CRC screening was organized in individuals aged 50 to 74 years. The study included 50 primary healthcare centres from all 25 administrative regions of Serbia. A qualitative immunochromatographic faecal immunochemical test for human haemoglobin detection was used. Overall, 50 894 individuals were invited. The participation rate was 67.8 and 3.4% of the tests were positive. Among individuals with a positive test, 69.7% agreed to undergo colonoscopy. The positive predictive value was 27.1% for adenoma and 14.6% for carcinoma. This was the first CRC screening project encompassing approximately one-third of primary healthcare facilities in all regions across the country. It showed a good response of the target population and satisfactory cooperation of the healthcare professionals involved.

Quantitative fecal immunochemical tests for colorectal cancer screening

Fecal immunochemical tests (FITs) for hemoglobin (Hb) are increasingly used for colorectal cancer (CRC) screening. We aimed to review, summarize and compare reported diagnostic performance of various FITs. PubMed and Web of Science were searched from inception to July 24, 2017. Data on diagnostic performance of quantitative FITs, conducted in colonoscopy-controlled average-risk screening populations, were extracted. Summary receiver operating characteristic (ROC) curves were plotted and correlations between thresholds, positivity rates (PRs), sensitivities and specificities were assessed. Seven test brands were investigated across 22 studies. Although reported sensitivities for CRC, advanced adenoma (AA) and any advanced neoplasm (AN) varied widely (ranges: 25-100%, 6-44% and 9-60%, respectively), with specificities for AN ranging from 82% to 99%, the estimates were very close to the respective summary ROC curves whose areas under the curve (95% CI) were 0.905 (0.88-0.94), 0.683 (0.67-0.70) and 0.710 (0.70-0.72) for CRC, AA and AN, respectively. The seemingly large heterogeneity essentially reflected variations in test thresholds (range: 2-82 µg Hb/g feces) and showed moderate correlations with sensitivity (r = -0.49) and specificity (r = 0.60) for AN. By contrast, observed PRs (range: 1-21%) almost perfectly correlated with sensitivity (r = 0.84) and specificity (r = -0.94) for AN. The apparent large heterogeneity in diagnostic performance between various FITs can be almost completely overcome by appropriate threshold adjustments. Instead of simply applying the threshold recommended by the manufacturer, screening programs should adjust the threshold to yield a desired PR which is a very good proxy indicator for the specificity and the subsequent colonoscopy workload.

BCKDK of BCAA Catabolism Cross-talking With the MAPK Pathway Promotes Tumorigenesis of Colorectal Cancer

Branched-chain amino acids catabolism plays an important role in human cancers. Colorectal cancer is the third most commonly diagnosed cancer in males and the second in females, and the new global incidence is over 1.2 million cases. The branched-chain α-keto acid dehydrogenase kinase (BCKDK) is a rate-limiting enzyme in branched-chain amino acids catabolism, which plays an important role in many serious human diseases. Here we investigated that abnormal branched-chain amino acids catabolism in colorectal cancer is a result of the disease process, with no role in disease initiation; BCKDK is widely expressed in colorectal cancer patients, and those patients that express higher levels of BCKDK have shorter survival times than those with lower levels; BCKDK promotes cell transformation or colorectal cancer ex vivo or in vivo. Mechanistically, BCKDK promotes colorectal cancer by enhancing the MAPK signaling pathway through direct MEK phosphorylation, rather than by branched-chain amino acids catabolism. And the process above could be inhibited by a BCKDK inhibitor, phenyl butyrate.

A Highly Predictive Model for Diagnosis of Colorectal Neoplasms Using Plasma MicroRNA: Improving Specificity and Sensitivity

OBJECTIVE

To develop a plasma-based microRNA (miRNA) diagnostic assay specific for colorectal neoplasms, building upon our prior work.

BACKGROUND

Colorectal neoplasms [colorectal cancer (CRC) and colorectal advanced adenoma (CAA)] frequently develop in individuals at ages when other common cancers also occur. Current screening methods lack sensitivity, specificity, and have poor patient compliance.

METHODS

Plasma was screened for 380 miRNAs using microfluidic array technology from a "Training" cohort of 60 patients, (10 each) control, CRC, CAA, breast cancer, pancreatic cancer, and lung cancer. We identified uniquely dysregulated miRNAs specific for colorectal neoplasia (P < 0.05, false discovery rate: 5%, adjusted α = 0.0038). These miRNAs were evaluated using single assays in a "Test" cohort of 120 patients. A mathematical model was developed to predict blinded sample identity in a 150 patient "Validation" cohort using repeat-sub-sampling validation of the testing dataset with 1000 iterations each to assess model detection accuracy.

RESULTS

Seven miRNAs (miR-21, miR-29c, miR-122, miR-192, miR-346, miR-372, and miR-374a) were selected based upon P value, area under the curve (AUC), fold change, and biological plausibility. Area under the curve (±95% confidence interval) for "Test" cohort comparisons were 0.91 (0.85-0.96) between all neoplasia and controls, 0.79 (0.70-0.88) between colorectal neoplasia and other cancers, and 0.98 (0.96-1.0) between CRC and colorectal adenomas. In our "Validation" cohort, our mathematical model predicted blinded sample identity with 69% to 77% accuracy, 67% to 76% accuracy, and 86% to 90% accuracy for each comparison, respectively.

CONCLUSIONS

Our plasma miRNA assay and prediction model differentiate colorectal neoplasia from patients with other neoplasms and from controls with higher sensitivity and specificity compared with current clinical standards.

The Usefulness of a Novel Screening Kit for Colorectal Cancer Using the Immunochromatographic Fecal Tumor M2 Pyruvate Kinase Test

Background/Aims

M2 pyruvate kinase (M2-PK) is an enzyme that is produced in undifferentiated and proliferating tissues. This study aims to evaluate the usefulness of the immunochromatographic M2 pyruvate kinase (iM2-PK) for the screening of colorectal cancer (CRC) and premalignant lesions.

Methods

Healthy volunteers and patients with colorectal neoplasia were enrolled in six academic hospitals in the capital province of Korea. The iM2-PK value was compared with the immunochromatographic fecal occult blood test (iFOBT) and fecal tumor M2-PK enzyme-linked immunosorbent assay (ELISA).

Results

A total of 323 subjects were enrolled. The sensitivity of iM2-PK for CRC was 92.8%, which was superior to iFOBT (47.5%, p<0.0001). For adenomatous lesions, the sensitivity of iM2-PK was 69.4%, which was also superior to iFOBT (12.1%, p<0.001). Compared with M2-PK ELISA, iM2-PK exhibited significantly enhanced sensitivity for CRC (97.5% vs 80.0%, p=0.0289). The sensitivity of iM2-PK was higher in advanced stages of CRC compared with cancers confined to the mucosa and submucosa (p<0.05). However, lymph node metastasis had no influence on the sensitivity of iM2-PK.

Conclusions

The iM2-PK exhibited increased sensitivity for identifying CRC and adenomatous lesions compared with iFOBT. Given its rapid results and convenience, CRC screening using iM2-PK is promising.

Role of Raman spectroscopy and surface enhanced Raman spectroscopy in colorectal cancer

Colorectal cancer (CRC) is the fourth most common cancer in the United Kingdom and is the second largest cause of cancer related death in the United Kingdom after lung cancer. Currently in the United Kingdom there is not a diagnostic test that has sufficient differentiation between patients with cancer and those without cancer so the current referral system relies on symptomatic presentation in a primary care setting. Raman spectroscopy and surface enhanced Raman spectroscopy (SERS) are forms of vibrational spectroscopy that offer a non-destructive method to gain molecular information about biological samples. The techniques offer a wide range of applications from in vivo or in vitro diagnostics using endoscopic probes, to the use of micro-spectrometers for analysis of biofluids. The techniques have the potential to detect molecular changes prior to any morphological changes occurring in the tissue and therefore could offer many possibilities to aid the detection of CRC. The purpose of this review is to look at the current state of diagnostic technology in the United Kingdom. The development of Raman spectroscopy and SERS in clinical applications relation for CRC will then be discussed. Finally, future areas of research of Raman/SERS as a clinical tool for the diagnosis of CRC are also discussed.

Cost-Effectiveness between Double and Single Fecal Immunochemical Test(s) in a Mass Colorectal Cancer Screening

This study investigated the cost-effectiveness between double and single Fecal Immunochemical Test(s) (FIT) in a mass CRC screening. A two-stage sequential screening was conducted. FIT was used as a primary screening test and recommended twice by an interval of one week at the first screening stage. We defined the first-time FIT as FIT1 and the second-time FIT as FIT2. If either FIT1 or FIT2 was positive (+), then a colonoscopy was recommended at the second stage. Costs were recorded and analyzed. A total of 24,419 participants completed either FIT1 or FIT2. The detection rate of advanced neoplasm was 19.2% among both FIT1+ and FIT2+, especially high among men with age ≥55 (27.4%). About 15.4% CRC, 18.9% advanced neoplasm, and 29.9% adenoma missed by FIT1 were detected by FIT2 alone. Average cost was $2,935 for double FITs and $2,121 for FIT1 to detect each CRC and $901 for double FITs and $680 for FIT1 to detect each advanced neoplasm. Double FITs are overall more cost-effective, having significantly higher positive and detection rates with an acceptable higher cost, than single FIT. Double FITs should be encouraged for the first screening in a mass CRC screening, especially in economically and medically underserved populations/areas/countries.

European Code against Cancer, 4th Edition: Cancer screening

In order to update the previous version of the European Code against Cancer and formulate evidence-based recommendations, a systematic search of the literature was performed according to the methodology agreed by the Code Working Groups. Based on the review, the 4th edition of the European Code against Cancer recommends: "Take part in organized cancer screening programmes for: Bowel cancer (men and women); Breast cancer (women); Cervical cancer (women)." Organized screening programs are preferable because they provide better conditions to ensure that the Guidelines for Quality Assurance in Screening are followed in order to achieve the greatest benefit with the least harm. Screening is recommended only for those cancers where a demonstrated life-saving effect substantially outweighs the potential harm of examining very large numbers of people who may otherwise never have, or suffer from, these cancers, and when an adequate quality of the screening is achieved. EU citizens are recommended to participate in cancer screening each time an invitation from the national or regional screening program is received and after having read the information materials provided and carefully considered the potential benefits and harms of screening. Screening programs in the European Union vary with respect to the age groups invited and to the interval between invitations, depending on each country's cancer burden, local resources, and the type of screening test used For colorectal cancer, most programs in the EU invite men and women starting at the age of 50-60 years, and from then on every 2 years if the screening test is the guaiac-based fecal occult blood test or fecal immunochemical test, or every 10 years or more if the screening test is flexible sigmoidoscopy or total colonoscopy. Most programs continue sending invitations to screening up to the age of 70-75 years. For breast cancer, most programs in the EU invite women starting at the age of 50 years, and not before the age of 40 years, and from then on every 2 years until the age of 70-75 years. For cervical cancer, if cytology (Pap) testing is used for screening, most programs in the EU invite women starting at the age of 25-30 years and from then on every 3 or 5 years. If human papillomavirus testing is used for screening, most women are invited starting at the age of 35 years (usually not before age 30 years) and from then on every 5 years or more. Irrespective of the test used, women continue participating in screening until the age of 60 or 65 years, and continue beyond this age unless the most recent test results are normal.

SEPT9: A Specific Circulating Biomarker for Colorectal Cancer

SEPT9 gene methylation has been implicated as a biomarker for colorectal cancer (CRC) for more than 10 years and has been used clinically for more than 6 years. Studies have proven it to be an accurate, reliable, fast, and convenient method for CRC. In this chapter, we will first provide the background on the role of septin9 protein and the theoretical basis of the SEPT9 gene methylation assay. We will then focus on the performance of SEPT9 gene methylation assay for CRC early detection and screening by analyzing the data obtained in clinical trials and comparing its performance with other methods or markers. Finally, we will discuss the future applications of the assay in monitoring cancer recurrence, evaluating surgery, chemotherapy, and predicting long-term survival. We hope this chapter can provide a full overview of the theoretical basis, development, validation, and clinical applications of the SEPT9 assay for both basic science researchers and clinical practitioners.

Detection of colorectal cancer by DNA methylation biomarker SEPT9: past, present and future

Colorectal cancer has become the third most common cancer in the world. Early diagnosis and treatment can significantly reduce colorectal cancer mortality. The current routinely used fecal-based screening methods do not provide satisfactory sensitivity. Although colonoscopy provides macroscopic diagnosis, the compliance is low due to its inconvenience and complications. Hence, the development of new screening methods is needed urgently. Peripheral blood SEPT9 gene methylation assay has become a potential option with promising future for early detection and screening of colorectal cancer. It is shown to be convenient, reliable with good compliance by several clinical trials. This article will review the theoretical foundation and development of the assay, focusing on its clinical trials, comparing it with other screening methods and discussing its future applications.

Performance of a second-generation methylated SEPT9 test in detecting colorectal neoplasm

BACKGROUND AND AIM

Screening and early detection reduces mortality due to colorectal cancer (CRC). Methylated Septin 9 (SEPT9) is a new blood-based biomarker for CRC. We evaluated the performance of the second-generation SEPT9 assay for the detection of colorectal neoplasm, and compared it with fecal immunochemical test (FIT).

METHODS

A total of 135 patients with CRC, 169 with adenomatous polyps, 81 with hyperplastic polyps, and 91 healthy controls were included. The clinical status of all subjects was verified by colonoscopy. In all patients, peripheral blood samples were taken for SEPT9 testing using Epi proColon 2.0 test. For 177 patients, both SEPT9 and FIT were performed.

RESULTS

The sensitivity and specificity of SEPT9 for CRC were 74.8% (95% confidence interval [CI]: 67.0-81.6%) and 87.4% (vs non-CRC, 95% CI: 83.5-90.6%), respectively. SEPT9 was positive in 66.7% of stage I, 82.6% of stage II, 84.1% of stage III, and 100% of stage IV CRCs. The sensitivity of SEPT9 for advanced adenomas was 27.4% (95% CI: 18.7-37.6%). The sensitivity and specificity of FIT for CRC was 58.0% (95% CI: 46.1-69.2%) and 82.4% (95% CI: 74.4-88.7%), respectively. SEPT9 showed better performance in CRC detection than FIT, but similar among advanced adenomas.

CONCLUSIONS

With improved performance characteristics in detecting CRC, the second-generation SEPT9 assay could play an important role in CRC screening and early detection.

A systematic review and meta-analysis of the diagnostic accuracy of pyruvate kinase M2 isoenzymatic assay in diagnosing colorectal cancer

BACKGROUND

Screening programmes exist in many countries for colorectal cancer. In recent years, there has been a drive for a non-invasive screening marker of higher sensitivity and specificity. Stool-based pyruvate kinase isoenzyme M2 (M2-PK) is one such biomarker under investigation. The aim of this systematic review and meta-analysis is to determine the diagnostic accuracy, sensitivity and specificity of M2-PK as a screening tool in colorectal cancer.

METHODS

A literature search of Ovid Medline, EMBASE and Google Scholar was carried out. The search strategy was restricted to human subjects and studies published in English. Data on sensitivity and specificity were extracted and pooled. Statistical analysis was conducted using summary receiver operating characteristic (SROC) curve methodology.

RESULTS

A total of eight studies were suitable for data synthesis and analysis. Our analysis showed a pooled sensitivity and specificity for M2-PK to be 79% (CI 73%-83%) and 80% (CI 73%-86%), respectively. The accuracy of M2-PK was 0.85(0.82-0.88).

CONCLUSION

Faecal M2-PK assay has a relatively good sensitivity and specificity and high accuracy for screening colorectal cancer.

How can screening colonoscopy be optimized?

Since the implementation of screening programmes, both the incidence and mortality of colorectal cancer have been decreasing. The choice of the preferred screening tool, however, is divergent and the adherence to screening programmes in most countries is still low. Cancer detection tests such as the guaiac faecal occult blood test (gFOBT) and the immunohistochemical FOBT (iFOBT) achieve higher acceptance than endoscopy. The sensitivity and specificity of iFOBT are higher than those of gFOBT, but gFOBT is cheaper and easier to perform. Endoscopic screening, which represents cancer prevention tests, has higher sensitivity for premalignant lesions than gFOBT and iFOBT and enables diagnosis and therapy in one single procedure. Since screening colonoscopy and sigmoidoscopy are invasive procedures with potentially severe adverse events, the highest possible quality must be provided. High-tech equipment, experience, training, quality control programmes, excellent bowel preparation and low adverse event rates are pivotal. Alternative screening tools such as CT colonography, barium enema CT and multitarget stool DNA tests have not been established as routine screening tools to date.

Role of faecal occult bloods in the diagnosis of iron deficiency anaemia

OBJECTIVE

To determine whether faecal occult blood (FOB) testing in patients with iron deficiency anaemia (IDA) can predict the presence of gastrointestinal cancer.

DESIGN

Cohort study.

SETTINGS

Single secondary care hospital UK.

PATIENTS

All individuals aged 20 years and older referred for the investigation for IDA.

INTERVENTIONS

Data was collected from all the patients regarding haemoglobin (Hb), mean corpuscular volume, age, sex, symptomatology and medication. All patients had FOB tests using laboratory guaiac and haemocell methods, and then underwent gastroscopy and colonoscopy.

MAIN OUTCOME MEASURES

Accuracy, sensitivity and specificity of FOBs for identifying cancer in the upper or lower gastrointestinal tract.

RESULTS

In total, 292 patients completed the study; 37 patients were diagnosed with carcinoma (colon 34, gastro-oesophageal 3). Using an optimal combination of lab guiaic and haemocell test resulted in just one colorectal cancer being missed, a sensitivity of 97%, specificity of 49% and negative predictive value of 99%. The test was less effective for upper gastrointestinal cancer, with 2/3 tumours missed by the tests.

CONCLUSIONS

Patients who have negative FOB tests are very unlikely to have a colorectal cancer, and the benefits to further colonic investigation is limited. This should be carefully considered in patients with significant comorbidities, where the risks of investigation may outweigh the benefits.

Prospective evaluation of methylated SEPT9 in plasma for detection of asymptomatic colorectal cancer

BACKGROUND

As screening methods for colorectal cancer (CRC) are limited by uptake and adherence, further options are sought. A blood test might increase both, but none has yet been tested in a screening setting.

OBJECTIVE

We prospectively assessed the accuracy of circulating methylated SEPT9 DNA (mSEPT9) for detecting CRC in a screening population.

DESIGN

Asymptomatic individuals ≥50 years old scheduled for screening colonoscopy at 32 US and German clinics voluntarily gave blood plasma samples before colon preparation. Using a commercially available assay, three independent blinded laboratories assayed plasma DNA of all CRC cases and a stratified random sample of other subjects in duplicate real time PCRs. The primary outcomes measures were standardised for overall sensitivity and specificity estimates.

RESULTS

7941 men (45%) and women (55%), mean age 60 years, enrolled. Results from 53 CRC cases and from 1457 subjects without CRC yielded a standardised sensitivity of 48.2% (95% CI 32.4% to 63.6%; crude rate 50.9%); for CRC stages I-IV, values were 35.0%, 63.0%, 46.0% and 77.4%, respectively. Specificity was 91.5% (95% CI 89.7% to 93.1%; crude rate 91.4%). Sensitivity for advanced adenomas was low (11.2%).

CONCLUSIONS

Our study using the blood based mSEPT9 test showed that CRC signal in blood can be detected in asymptomatic average risk individuals undergoing screening. However, the utility of the test for population screening for CRC will require improved sensitivity for detection of early cancers and advanced adenomas.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00855348.

Immunochemical faecal occult blood tests in primary care and the risk of delay in the diagnosis of colorectal cancer

OBJECTIVE

To evaluate the value, risks, and shortcomings of immunochemical faecal occult blood tests (iFOBTs) in the diagnosis of colorectal cancer (CRC) and adenomas with high-grade dysplasia (HGD) in patients initially presenting to primary care.

DESIGN

A retrospective population-based study.

SETTING AND SUBJECTS

All 495 cases of CRC and adenomas with HGD diagnosed in the county of Jämtland, Sweden from 2005 to 2009.

RESULTS

Of 495 patients 323 (65%) initially presented to primary care. IFOBTs were performed in 215 of 323 (67%) patients. The sensitivity of iFOBT for CRC and adenomas with HGD was 88% (83% when patients with a history of rectal bleeding were excluded). Of 34 patients with anaemia found en passant, 10 had negative iFOBTs. Time to diagnosis was longer for patients with negative iFOBTs (p < 0.0005).

CONCLUSION

IFOBT might be helpful in selecting which patients to refer for colonoscopy. However, iFOBT has a limited sensitivity as a diagnostic test for CRC and adenomas with HGD. Relying only on iFOBT for colonoscopy referral could delay diagnosis, especially for patients with anaemia found en passant.

Validity of fecal occult blood test in the national cancer screening program, Korea

AIM

The aims of the current study were to assess the validity of the fecal occult blood test (FOBT) in an organized screening setting in Korea and to determine factors associated with FOBT validity, such as screening round, age group, and anatomical location of the cancer.

METHODS

Study participants were those who were 50 years and older who received an FOBT through the National Cancer Screening Program between 2004 and 2007. Colorectal cancer diagnoses were ascertained through linkage with the Korean National Cancer Incidence Database. The positivity rate, colorectal cancer detection rate, interval cancer rate, sensitivity, specificity, and positive predictive value of the FOBT were calculated.

RESULTS

A total of 2,193,093 tests were included in the analysis. Overall, the sensitivity of the FOBT for colorectal cancer was 59.7% for the first round and 56.1% for the subsequent round. Sensitivity was highest for distal colon cancer (65.9%) in the first round, and for rectal cancer (58.4%) for the subsequent round. The sensitivity and positive predictive value of the FOBT generally improved between 2004 and 2008.

CONCLUSIONS

The FOBT showed reasonable validity in an organized screening setting, and the validity of the FOBT varied by screening round, anatomical location, and screening year.

Screening and Primary prevention of Colorectal Cancer: a Review of sex-specific and site-specific differences

Background

Colorectal cancer (CRC) is the second commonest cancer in England. Incidence rates for colorectal adenomas and advanced colorectal neoplasia are higher in men than in women of all age groups. The male-to-female ratio for CRC incidence rates differs for different parts of the large bowel.

Objective

To summarize the current evidence on colorectal screening and prevention, focussing on potential differences in benefits between sexes and colorectal sites.

Methods

(i), We reviewed the evidence from randomized controlled trials (RCTs) of the impact of different screening approaches on CRC incidence and mortality, overall, for each sex separately, and for subsites of the large bowel. (ii) We reviewed studies comparing detection parameters for faecal immunochemical tests for haemoglobin (FIT) with guaiac FOBt (gFOBt). (iii) The role of aspirin in CRC prevention in the general population was reviewed using evidence from RCTs, with specific emphasis on the differences observed between sexes and lesion site.

Results

(i) Our intention-to-treat random-effects meta-analysis showed that once-only flexible sigmoidoscopy (FS) screening performed on average-risk individuals aged 55 + decreased CRC incidence by 18% and mortality by 28%, but sex-specific results were lacking. (ii) Modern quantitative FIT were superior to qualitative gFOBt in average-risk population screening in their ability to discriminate between individuals with and without colorectal neoplasia. Some recent FIT studies suggest varying operating characteristics in men and women. (iii) Evidence of an effect of aspirin on the incidence of CRC (in particular, proximal disease) in both sexes aged 40 and over at average-risk of CRC is emerging.

Conclusions

We encourage researchers of CRC screening and prevention to publish their results by sex where possible. Pilot studies should be undertaken before implementation of quantitative FIT in a national screening programme to establish the appropriate threshold. Finally, individual risk assessment for CRC and non-CRC events, will be necessary to make an informed decision on whether a patient should receive aspirin chemoprevention.

Comparison of the performance of guaiac-based and two immunochemical fecal occult blood tests for identifying advanced colorectal neoplasia in Taiwan

OBJECTIVES

We aimed to evaluate the performance of fecal occult blood tests (FOBT) for the screening of colorectal cancer (CRC).

METHODS

We selected participants from a medical center in Taiwan, China from November 2009 to June 2011. All participants underwent screening colonoscopy and were asked to provide their stool samples for qualitative immunochemical FOBT (qlFIT), quantitative immunochemical FOBT (qnFIT) and the guaiac-based FOBT(GT). The receiver operating characteristic curve was utilized to determine the optimal cut-off value of qnFIT. We measured the detection ability of the FOBT for colonic polypoid lesions.

RESULTS

In all, 699 participants were enrolled in this study. For qnFIT, we found increased levels of fecal hemoglobin in participants with polyps ≥10 mm (251.0 ng/mL), villous-containing adenomas (98.7 ng/mL) and advanced adenomas (187.9 ng/mL). The optimal cut-off value for qnFIT was 25 ng/mL for detecting advanced colorectal neoplasms (ACRN). All three FOBT had a similar but low estimate in detecting small and tubular adenomatous polyps. The qnFIT had a better detection ability for large adenomas (positive likelihood ratio [PLR], 5.6 vs 3.1 vs 0.3) and adenomas with villous-components (PLR 3.7 vs 3.3 vs 0.3) than qlFIT and GT. For the ACRN group, qnFIT also showed the best screening ability with a sensitivity of 56.8%, accuracy of 86.7% and PLR 5.0.

CONCLUSIONS

Both qnFIT and qlFIT perform better than GT in detecting advanced adenomas and CRC in the Taiwanese population.

Tumor markers in colorectal cancer, gastric cancer and gastrointestinal stromal cancers: European group on tumor markers 2014 guidelines update

Biomarkers currently play an important role in the detection and management of patients with several different types of gastrointestinal cancer, especially colorectal, gastric, gastro-oesophageal junction (GOJ) adenocarcinomas and gastrointestinal stromal tumors (GISTs). The aim of this article is to provide updated and evidence-based guidelines for the use of biomarkers in the different gastrointestinal malignancies. Recommended biomarkers for colorectal cancer include an immunochemical-based fecal occult blood test in screening asymptomatic subjects ≥50 years of age for neoplasia, serial CEA levels in postoperative surveillance of stage II and III patients who may be candidates for surgical resection or systemic therapy in the event of distant metastasis occurring, K-RAS mutation status for identifying patients with advanced disease likely to benefit from anti-EGFR therapeutic antibodies and microsatellite instability testing as a first-line screen for subjects with Lynch syndrome. In advanced gastric or GOJ cancers, measurement of HER2 is recommended in selecting patients for treatment with trastuzumab. For patients with suspected GIST, determination of KIT protein should be used as a diagnostic aid, while KIT mutational analysis may be used for treatment planning in patients with diagnosed GISTs.

Evaluation of fecal immunochemical tests for colorectal cancer screening

BACKGROUND

Colorectal cancer (CRC) screening reduces the mortality due to CRC. It is important for health care providers to be aware of the variation in the products available for CRC screening.

PURPOSE

The purpose of this study was to summarize the accuracy of results of individual fecal immunochemical test (FIT) products across pathology proficiency testing programs.

METHODS

Secondary data analysis of proficiency testing programs' FIT results.

RESULTS

Four of 7 proficiency testing program's FIT evaluations were obtained for a 2-year period. Fourteen unique FIT brands were evaluated by at least 1 of the 4 proficiency testing programs. Five of the products performed similarly with sensitivities ranging from 98.1% to 98.8% and specificities from 98.1% to 99.6%. Ninety-three percent of the FIT tests completed were manual Clinical Laboratory Improvement Amendments-waived FITs.

CONCLUSIONS

About two thirds of the commonly used FIT products performed acceptably on spiked samples of human hemoglobin. However, some had low sensitivity and specificity and probably should not be used for population-based or other screening. Further investigation to determine appropriate, reliable products for fecal occult blood testing is warranted.

[Korean guidelines for colorectal cancer screening and polyp detection]

Colorectal cancer is the second most common cancer in males and the fourth most common in females in Korea. Since the most of colorectal cancer occur through the prolonged transformation of adenomas into carcinomas, early detection and removal of colorectal adenomas are one of the most effective methods to prevent colorectal cancer. Considering the increasing incidence of colorectal cancer and polyps in Korea, it is very important to establish Korean guideline for colorectal cancer screening and polyp detection. Korean Multi-Society Take Force developed the guidelines with evidence-based methods. Parts of the statements drawn by systematic reviews and meta-analyses. Herein we discussed the epidemiology of colorectal cancers and adenomas in Korea, optimal screening methods for colorectal cancer, and detection for adenomas including fecal occult blood tests, radiologic tests, and endoscopic examinations.

Serum M2-pyruvate kinase: A promising non-invasive biomarker for colorectal cancer mass screening

AIM: To explore the value of serum M2-pyruvate kinase (M2-PK) in colorectal cancer (CRC) mass screening.

METHODS: We conducted a molecular epidemiology study in Hangzhou, China, from year 2006 to year 2008. Serum samples were collected from 93 CRC, 41 advanced adenomas, 137 adenomas, 47 non-adenomatous polyps, and 158 normal participants in a community setting. Serum M2-PK and carcinoembryonic antigen (CEA) were measured using Enzyme-linked immunosorbent assay. SPSS 16.0 software was used to perform data analysis. Area under the receiver operating characteristic curve (AUC), sensitivity, and specificities were estimated for serum M2-PK in diagnosis of colorectal lesions and compared with CEA.

RESULTS: Average serum M2-PK value among 158 normal people was 2.96 U/mL and not affected by gender (P = 0.47) or age (P = 0.59). Average serum M2-PK (U/mL) was 14.75 among stage III and 13.10 among stage I and II CRC patients, about 4 times higher than that among normal people. Average serum M2-PK was 8.58, 6.70, 5.13 and 2.51 U/mL among advanced adenoma, adenomas, non-adenomatous polyps, and inflammatory bowel disease patients, respectively. AUC for serum M2-PK was greater than that for CEA among all colorectal lesions. AUC for serum M2-PK was 0.89 (0.84, 0.94) (95% confidence interval), higher than that for CEA [0.70 (0.62-0.79)] in CRC stage I and II, 0.89 (0.84-0.94) vs 0.73 (0.63-0.83) in CRC stage III, 0.81 (0.74-0.86) vs 0.63 (0.53 - 0.73) in advanced adenomas, 0.69 (0.64-0.76) vs 0.54 (0.47-0.60) in adenomas, and 0.69 (0.62-0.78) vs 0.58 (0.48-0.68) in non-adenomatous polyps. The diagnostic sensitivity for all colorectal lesions increased with decrease in the cut-off value of serum M2-PK. The diagnostic sensitivity (%) of serum M2-PK was 100.00 for CRC, 95.12 advanced adenoma, 82.48 adenoma, and 82.98 non-adenomatous polyp. There were no CRC cases missed and 40.51% of unnecessary colonoscopies were avoided when the cut-off value was 2.00 U/mL.

CONCLUSION: Serum M2-PK can be used as a primary screening test in CRC mass screening. It may be a promising non-invasive biomarker for CRC early detection.

Korean guidelines for colorectal cancer screening and polyp detection

Now colorectal cancer is the second most common cancer in males and the fourth most common cancer in females in Korea. Since most of colorectal cancers occur after the prolonged transformation of adenomas into carcinomas, early detection and removal of colorectal adenomas are one of the most effective methods to prevent colorectal cancer. Considering the increasing incidence of colorectal cancer and polyps in Korea, it is very important to establish Korean guideline for colorectal cancer screening and polyp detection. The guideline was developed by the Korean Multi-Society Take Force and we tried to establish the guideline by evidence-based methods. Parts of the statements were draw by systematic reviews and meta-analyses. Herein we discussed epidemiology of colorectal cancers and adenomas in Korea and optimal methods for screening of colorectal cancer and detection of adenomas including fecal occult blood tests, radiologic tests, and endoscopic examinations.