Fecal occult blood test for colorectal cancer screening

Faecal microRNAs as a non-invasive tool in the diagnosis of colonic adenomas and colorectal cancer: A meta-analysis

MicroRNAs (miRNAs) are proposed as potential biomarkers for the diagnosis of numerous diseases. Here, we performed a meta-analysis to evaluate the utility of faecal miRNAs as a non-invasive tool in colorectal cancer (CRC) screening. A systematic literature search, according to predetermined criteria, in five databases identified 17 research articles including 6475, 783 and 5569 faecal-based miRNA tests in CRC, adenoma patients and healthy individuals, respectively. Sensitivity, specificity, positive/negative likelihood and diagnostic odds ratios, area under curve (AUC), summary receiver operator characteristic (sROC) curves, association of individual or combinations of miRNAs to cancer stage and location, subgroup, meta-regression and Deeks' funnel plot asymmetry analyses were employed. Pooled miRNAs for CRC had an AUC of 0.811, with a sensitivity of 58.8% (95% confidence interval [CI]: 51.7-65.5%) and specificity of 84.8% (95% CI: 81.1-87.8%), whilst for colonic adenoma, it was 0.747, 57.3% (95% CI: 40.8-72.3%) and 76.1% (95% CI: 66.1-89.4%), respectively. The most reliable individual miRNA was miR-21, with an AUC of 0.843, sensitivity of 59.3% (95% CI: 26.3-85.6%) and specificity of 85.6% (95% CI: 72.2-93.2%). Paired stage analysis showed a better diagnostic accuracy in late stage CRC and sensitivity higher in distal than proximal CRC. In conclusion, faecal miR-21, miR-92a and their combination are promising non-invasive biomarkers for faecal-based CRC screening.

Accuracy of self-checked fecal occult blood testing for colorectal cancer in Thai patients

PURPOSE

Colorectal cancer (CRC) screening with fecal occult blood testing (FOBT) has been associated with a reduction in CRC incidence and CRC-related mortality. However, a conventional FOBT requires stool collection and handling, which may be inconvenient for participants. The EZ-DetectTM (Siam Pharmaceutical Thailand) is a FDA-approved chromogen-substrate based FOBT which is basically a self-checked FOBT (no stool handling required). This study aimed to evaluate the accuracy of EZ-Detect for CRC detection.

METHODS

This prospective study was conducted in the Faculty of Medicine, Siriraj Hospital, Bangkok, Thailand between November 2013 and May 2014. Some 96 patients with histologically-proven CRC and 101 patients with normal colonoscopic findings were invited to perform self-checked FOBT according to the manufacturer's instructions. RESULTS were compared with endoscopic and pathologic findings. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for CRC detection were calculated.

RESULTS

The present study revealed the sensitivity, specificity, PPV and NPV of this self-checked FOBT for CRC detection to be 41% (95% CI: 31-51), 97% (95% CI: 92-99), 93% (95% CI: 81-98) and 63% (95% CI: 55-70), respectively. The overall accuracy of the self-checked FOBT for identifying CRC was 70%. The sensitivity for CRC detection based on 7th AJCC staging was 29% for stage I, 32% for stage II and 50% for stage III/IV (P=0.19). The sensitivity was 33% for proximal colon and 42% for distal colon and rectal cancer (P=0.76). Notably, none of nine infiltrative lesions gave a positive FOBT.

CONCLUSIONS

The self-checked FOBT had an acceptable accuracy of CRC detection except for infiltrative tumors. This home-administrated or 'DIY' do-it-yourself FOBT could be considered as one non-invasive and convenient tool for CRC screening.

Use of the Analysis of the Volatile Faecal Metabolome in Screening for Colorectal Cancer

Diagnosis of colorectal cancer is an invasive and expensive colonoscopy, which is usually carried out after a positive screening test. Unfortunately, existing screening tests lack specificity and sensitivity, hence many unnecessary colonoscopies are performed. Here we report on a potential new screening test for colorectal cancer based on the analysis of volatile organic compounds (VOCs) in the headspace of faecal samples. Faecal samples were obtained from subjects who had a positive faecal occult blood sample (FOBT). Subjects subsequently had colonoscopies performed to classify them into low risk (non-cancer) and high risk (colorectal cancer) groups. Volatile organic compounds were analysed by selected ion flow tube mass spectrometry (SIFT-MS) and then data were analysed using both univariate and multivariate statistical methods. Ions most likely from hydrogen sulphide, dimethyl sulphide and dimethyl disulphide are statistically significantly higher in samples from high risk rather than low risk subjects. Results using multivariate methods show that the test gives a correct classification of 75% with 78% specificity and 72% sensitivity on FOBT positive samples, offering a potentially effective alternative to FOBT.

Biomarkers: refining diagnosis and expediting drug development - reality, aspiration and the role of open innovation

In the last decade, there have been intensive efforts to invent, qualify and use novel biomarkers as a means to improve success rates in drug discovery and development. The biomarkers field is maturing and this article considers whether these research efforts have brought about the expected benefits. The characteristics of a clinically useful biomarker are described and the impact this area of research has had is evaluated by reviewing a few, key examples of emerging biomarkers. There is evidence that the impact has been genuine and is increasing in both the drug and the diagnostic discovery and development processes. Beneficial impact on patient health outcomes seems relatively limited thus far, with the greatest impact in oncology (again, both in terms of novel drugs and in terms of more refined diagnoses and therefore more individualized treatment). However, the momentum of research would indicate that patient benefits are likely to increase substantially and to broaden across multiple therapeutic areas. Even though this research was originally driven by a desire to improve the drug discovery and development process, and was therefore funded with this aim in mind, it seems likely that the largest impact may actually come from more refined diagnosis. Refined diagnosis will facilitate both better allocation of healthcare resources and the use of treatment regimens which are optimized for the individual patient. This article also briefly reviews emerging technological approaches and how they relate to the challenges inherent in biomarker discovery and validation, and discusses the role of public/private partnerships in innovative biomarker research.

Epigenomic analysis of aberrantly methylated genes in colorectal cancer identifies genes commonly affected by epigenetic alterations

BACKGROUND

Determination of the profile of genes that are commonly methylated aberrantly in colorectal cancer (CRC) will have substantial value for diagnostic and therapeutic applications. However, there is limited knowledge of the DNA methylation pattern in CRC.

MATERIALS AND METHODS

We analyzed the methylation profile of 27,578 CpG sites spanning more than 14,000 genes in CRC and in the adjacent normal mucosa with bead-chip array-based technology.

RESULTS

We identified 621 CpG sites located in promoter regions and CpG islands that were greatly hypermethylated in CRC compared to normal mucosa. The genes on chromosome 18 showed promoter hypermethylation most frequently. According to gene ontology analysis, the most common biologically relevant class of genes affected by methylation was the class associated with the cadherin signaling pathway. Compared to the genome-wide expression array, mRNA expression was more likely to be downregulated in the genes demonstrating promoter hypermethylation, even though this was not statistically significant. We validated ten CpG sites that were hypermethylated (ADHFE1, BOLL, SLC6A15, ADAMTS5, TFPI2, EYA4, NPY, TWIST1, LAMA1, GAS7) and 2 CpG sites showing hypomethylation (MAEL, SFT2D3) in CRC compared to the normal mucosa in the array studies using pyrosequencing. The methylation status measured by pyrosequencing was consistent with the methylation array data.

CONCLUSIONS

Methylation profiling based on bead-chip arrays is an effective method for screening aberrantly methylated genes in CRC. In addition, we identified novel methylated genes that are candidate diagnostic or prognostic markers for CRC.

Effectiveness of the immunofecal occult blood test for colorectal cancer screening in a large population

BACKGROUND

Guaiac tests are the most widely used tests to detect colorectal cancer (CRC). However, their sensitivity is relatively low and results may be affected by various factors. Immunofecal occult blood test (IFOBT) is specific for human hemoglobin and does not require dietary restrictions.

AIMS

The aim of this study was to evaluate the effectiveness of IFOBT for the screening of precancerous lesions and CRC.

METHODS

From July 2006 to June 2007, IFOBT was performed on 5,919 adults who received periodic health examinations in our hospital. The positive cases were examined by colonoscopy and a double-contrast barium enema. Diagnosis was confirmed by histopathological analysis.

RESULTS

Positive IFOBT was detected in 314 of 5,919 cases (5.30%). Further examinations were made in 264 IFOBT-positive cases. Of these, 116 cases with colorectal cancer (16 cases) or precancerous lesions (94 cases with colorectal adenomatous polyps and 6 cases with active ulcerative colitis) were detected. The total detection rate of CRC and precancerous lesions was 43.94% (116/264). TNM classification of 16 CRC cases was as follows: TNM I in eight cases (50.00%), TNM II in seven cases (43.75%) and TNM III in one case (6.25%), indicating IFOBT can detect CRC in the early stages.

CONCLUSION

Regular IFOBT can detect precancerous lesions and CRC in early stages and can thus reduce mortality from CRC.

Identification of endothelial cell-specific molecule-1 as a potential serum marker for colorectal cancer

No ideal serum markers for screening colorectal cancer (CRC) have been identified. The aim of this study was to determine the usefulness of endothelial cell-specific molecule-1 (ESM-1) as a serum marker for CRC. Illumina microarray was carried out to search CRC-related biomarkers. cDNA microarray detected that ESM-1 was one of the overexpressed genes in CRC. Overexpression of ESM-1 mRNA was confirmed in tissues of CRC by RT-PCR and real-time PCR. Immunohistochemical staining showed strong expression of ESM-1 in the cytoplasm of tumor cells. Overexpression of ESM-1 in human serum with CRC was found by Western blot analysis. For quantitative analysis of ESM-1 in serum, we determined the ESM-1 levels in serum specimens using an ELISA kit. We showed that the ESM-1 levels in the serum of patients with CRC were significantly elevated (70.1 ± 29.7 pg/mL) compared to healthy subjects (29.7 ± 14.9 pg/mL). The accuracy, sensitivity, and specificity of ESM-1 for CRC were 0.94, 99%, and 73%, respectively, by receiver operating characteristics curve analysis. The positive predictive value and negative predictive value were 63% and 95%, respectively. The likelihood ratios of a positive or negative test result were 73 and 0.27, respectively. When analyzed with a Cox regression model, a higher serum ESM-1 level (≥76.0 pg/mL) was correlated with poor prognosis. This study suggests that expression of ESM-1 is increased in tissue and serum of CRC patients and that ESM-1 can be used as a potential serum marker for the early detection of CRC.

Derivation and validation of a risk-factor model for detection of oral potentially malignant disorders in populations with high prevalence

BACKGROUND

Oral and pharyngeal cancers constitute the sixth most common type of cancer globally, with high morbidity and mortality. In many countries, most cases of oral cancer arise from long-standing, pre-existing lesions, yet advanced malignancies prevail. A new approach to early detection is needed. We aimed to validate a model for screening so that only high-risk individuals receive the clinical examination.

METHODS

A community-based case-control study (n=1029) in rural Sri Lanka assessed risk factors and markers for oral potentially malignant disorders (OPMD) by administering a questionnaire followed by an oral examination. We then developed a model based on age, socioeconomic status and habits of betel-quid chewing, alcohol drinking and tobacco smoking, with weightings based on odds ratios from the multiple logistic regression. A total, single score was calculated per individual. Standard receiver-operator characteristic curves were plotted for the total score and presence of OPMD. The model was validated on a new sample of 410 subjects in a different community.

RESULTS

A score of 12.0 produced optimal sensitivity (95.5%), specificity (75.9%), false-positive rate (24.0%), false-negative rate (4.5%), positive predictive value (35.9%) and negative predictive value (99.2%).

CONCLUSION

This model is suitable for detection of OPMD and oral cancer in high-risk communities, for example, in Asia, the Pacific and the global diaspora therefrom. A combined risk-factor score of 12.0 was optimal for participation in oral cancer/OPMD screening in Sri Lanka. The model, or local adaptations, should have wide applicability.

A comparison of the acceptance of immunochemical faecal occult blood test and colonoscopy in colorectal cancer screening: a prospective study among Chinese

BACKGROUND

Preferences to choose immunochemical faecal occult blood test (FIT) and colonoscopy as colorectal cancer (CRC) screening modalities among asymptomatic Chinese subjects remain unknown.

AIM

To evaluate the preference of choosing colonoscopy vs. FIT among CRC screening participants.

METHODS

From a community-based CRC screening programme for asymptomatic Hong Kong Chinese aged 50-70 years, participants attended standardized educational sessions and chose the options of annual FIT for 5 years or direct colonoscopy once. Factors associated with choosing colonoscopy were evaluated by multivariate regression analysis.

RESULTS

Among 3430 participants [mean age 56.8 years (s.d. 5.0); female 55.1%, male 44.9%], 51.3% chose colonoscopy and 48.7% chose FIT. Older participants (65-70 years) were less likely to choose colonoscopy [adjusted odds ratio (aOR) 0.731, P = 0.041]. Subjects who chose colonoscopy were those disagreed screening would lead to discomfort (aOR 1.356, P < 0.001), had relatives or friends who had CRC (first degree relatives aOR 1.679, P < 0.001; second degree relatives aOR 1.304, P = 0.019; friends or others aOR 1.252, P = 0.026) and those who self-perceived their health as poor (aOR 1.529, P = 0.025).

CONCLUSIONS

Faecal occult blood test and direct colonoscopy were equally preferable to Chinese. Colonoscopy was preferred among the younger subjects, those with positive family history of CRC and self-perceived poor health status.

The public prefers fecal occult blood test over colonoscopy for colorectal cancer screening

The acceptability of colorectal cancer (CRC) screening tests to the population influences adherence. Population preferences between fecal occult blood test (FOBT) and colonoscopy for CRC screening were examined by previous test experience. The study population was a random sample of 413 members of Israel's largest Health Maintenance Organization (HMO) aged 48-68 years. In a telephone interview, an explanation was provided regarding FOBT and colonoscopy. Participants were asked which they preferred and their degree (1-6) of agreement with each of eight test characteristics. Overall Attitude Scores toward FOBT and colonoscopy were compared. Predictors of colonoscopy preference and of refusal to undergo screening were examined using a logistic regression model. FOBT was preferred as a screening test by 70.2% of the participants, colonoscopy by 9.3%, 7.4% were indecisive, and 13.1% were not interested in screening. FOBT and colonoscopy similarly scored highly as life saving (5.2 vs. 5.1, respectively), with colonoscopy scoring significantly higher as time consuming (3.8 vs. 1.3, P<0.0001), disturbing (4.6 vs. 1.8, P<0.0001), painful (4.1 vs. 1.0, P<0.0001), annoying (4.8 vs. 1.9, P<0.0001), and involving risk (3.2 vs. 1.0, P<0.0001). In a logistic multivariate analysis, preference of colonoscopy was associated with the perception of being at CRC risk [odds ratio (OR): 3.1 (95% confidence interval (CI): 1.3-7.6)], with more positive attitude scores towards this test [OR: 2.2 (95% CI: 1.6-3.0)], and with a more negative one toward FOBT [OR: 0.4 (95% CI: 0.3-0.7)]. Target population preferences for CRC screening supports a policy of FOBT screening for an average risk population and colonoscopy for high-risk individuals.

Positive rate comparison between immunological and chemical methods of fecal occult blood test in upper digestive tract bleeding

AIM: To compare the positive rates of immune fecal occult blood test (IFOBT) and chemical fecal occult blood test (CFOBT) in screening upper digestive tract bleeding.

METHODS: A total of 206 consecutive patients who suffered upper digestive tract bleeding and underwent endoscopic examination in our hospital were chosen from July 2006 to March 2007. CFOBT (using o-toluidine) and IFOBT were used to detect fecal occult blood positive rate in the same fecal specimen, and comparison was made between the two methods. The positive rates were also analyzed combined with the clinical data.

RESULTS: The results of IFOBT and CFOBT were not associated with anatomic sites in esophageal and gastric cancer, but associated with the invasion depth in gastric cancer, and they were positively correlated with the largest diameter of gastric cancer (IFOBT: r = 0.30, P = 0.02; CFOBT: r = 0.20, P = 0.04). Meanwhile, IFOBT result showed a positive correlation with the largest diameter of esophageal cancer (r = 0.38, P = 0.01). The positive rate of CFOBT was superior to that of squamous cell carcinoma (SCC) antigen detection in esophageal cancer patients (47.43% vs 20.45%, P < 0.05), and the positive rates of both methods were higher than those of CA125, CEA and CA199 detection. CFOBT was superior to IFOBT in detecting gastric cancer, esophageal cancer, reflux esophagitis and peptic ulcer (50.88% vs 35.09%; 47.73% vs 29.55%; 18.00% vs 6.00%; 60.00% vs 41.82%; all P < 0.05). The total positive rate of IFOBT was lower than that of CFOBT in detecting upper digestive tract bleeding.

CONCLUSION: The IFOBT is not suitable for screening upper digestive tract diseases, but relatively specific for lower digestive tract bleeding.

Oral vinorelbine: role in the management of metastatic breast cancer

The treatment of advanced breast cancer is continually evolving, with the aim of improving the quality and duration of remission and, in some instances, survival. In this setting, the importance of quality of life cannot be underestimated, and growing attention is being paid to treatment convenience and compliance. New anticancer agents have improved efficacy, but for many of them, toxicity often remains a problem. Vinorelbine seems to represent both an active and a well tolerated treatment for metastatic breast cancer. In particular, the oral formulation has similar efficacy to that of the injectable formulation and has demonstrated generally favourable tolerability, with a high degree of acceptance by both patients and physicians. The availability of this and other novel, well tolerated and effective treatments provides greater potential to tailor treatment to meet individual patient needs and, therefore, also provide the potential to improve patient outcomes. Preliminary data suggest that oral vinorelbine may permit continued, effective chemotherapy when further parenteral therapy with more intensive and more toxic agents is considered inappropriate. Early findings also suggest that oral vinorelbine, when administered together with another new oral agent, capecitabine, may be a valid choice in metastatic breast cancer treatment. Furthermore, vinorelbine plus the monoclonal antibody trastuzumab, with or without oral capecitabine, appears to be another regimen that may be worthy of additional study in patients with human epidermal growth factor-2 positive advanced breast cancer.

Randomized phase II trial of the efficacy and safety of trastuzumab combined with docetaxel in patients with human epidermal growth factor receptor 2-positive metastatic breast cancer administered as first-line treatment: the M77001 study group

PURPOSE

This randomized, multicenter trial compared first-line trastuzumab plus docetaxel versus docetaxel alone in patients with human epidermal growth factor receptor 2 (HER2) -positive metastatic breast cancer (MBC).

PATIENTS AND METHODS

Patients were randomly assigned to six cycles of docetaxel 100 mg/m2 every 3 weeks, with or without trastuzumab 4 mg/kg loading dose followed by 2 mg/kg weekly until disease progression.

RESULTS

A total of 186 patients received at least one dose of the study drug. Trastuzumab plus docetaxel was significantly superior to docetaxel alone in terms of overall response rate (61% v 34%; P = .0002), overall survival (median, 31.2 v 22.7 months; P = .0325), time to disease progression (median, 11.7 v 6.1 months; P = .0001), time to treatment failure (median, 9.8 v 5.3 months; P = .0001), and duration of response (median, 11.7 v 5.7 months; P = .009). There was little difference in the number and severity of adverse events between the arms. Grade 3 to 4 neutropenia was seen more commonly with the combination (32%) than with docetaxel alone (22%), and there was a slightly higher incidence of febrile neutropenia in the combination arm (23% v 17%). One patient in the combination arm experienced symptomatic heart failure (1%). Another patient experienced symptomatic heart failure 5 months after discontinuation of trastuzumab because of disease progression, while being treated with an investigational anthracycline for 4 months.

CONCLUSION

Trastuzumab combined with docetaxel is superior to docetaxel alone as first-line treatment of patients with HER2-positive MBC in terms of overall survival, response rate, response duration, time to progression, and time to treatment failure, with little additional toxicity.

Detection of colorectal cancer by a quantitative fluorescence determination of DNA amplification in stool

DNA amplification of exfoliated cells in stool represents an inexpensive and rapid test, but has only 50% to 60% sensitivity. A new quantitative method, called fluorescence long DNA, was developed and validated in our laboratory on stool obtained from 86 patients with primary colorectal cancer and from 62 healthy individuals. It consists of the amplification of stool DNA with fluorescence primers and the quantification of the amplification using a standard curve. Results are arbitrarily expressed in nanograms. The potential of the new method compared to the conventional approach was analyzed in a subgroup of 94 individuals (56 patients and 38 healthy volunteers). In the present series, DNA amplification analysis showed a specificity of 97% and a sensitivity of only 50%. Conversely, fluorescence DNA evaluation, using the best cutoff of 25 ng, showed a sensitivity of about 76% and a specificity of 93%. Similar sensitivity was observed regardless of Dukes stage, tumor location, and size, thus also permitting the detection of early-stage tumors. The present study seems to indicate that quantitative fluorescence DNA determination in stool successfully identifies colorectal cancer patients with a sensitivity comparable, if not superior, to that of multiple gene analysis but at a lower cost and in a shorter time.

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Fecal multiple molecular tests to detect colorectal cancer in stool

BACKGROUND & AIMS

Evaluation of molecular alterations in fecal DNA is a potential, noninvasive, alternative tool for the detection of colorectal cancer. We analyzed a large panel of molecular alterations involved in tumor transformation and progression to define their single diagnostic contribution in terms of sensitivity, cost, and time required to carry out the different tests.

METHODS

DNA was analyzed in stool from 38 healthy individuals and in paired stools and primary lesions from 56 patients with colorectal cancer. p53 exons 5-8, K-ras exons 1-2, four fragments of adenomatous polyposis coli (APC) exon 15, and 5 microsatellite loci were analyzed. Moreover, DNA amplification was evaluated for 4 exons of both p53 and APC.

RESULTS

K-ras (34%) and p53 (34%) mutations were the most frequent alterations in tumors, followed by microsatellite instability (13%) and APC mutations (13%). The most frequent event in stool was DNA amplification (51%), followed by alterations of K-ras (11%), p53 and microsatellite instability (6%), and APC (2%). K-ras and p53 gene mutations increased the capacity of DNA amplification to detect tumor cells by 8%.

CONCLUSIONS

K-ras and p53 gene mutations were the most frequent alterations observed in stool from patients with colorectal cancer, but DNA amplification was even more frequent, being present in more than half of patients. If these preliminary results are confirmed in a prospective study on a larger case series, this approach could be used for noninvasive colon cancer diagnosis in screening programs.