A predictive model combining fecal calgranulin B and fecal occult blood tests can improve the diagnosis of colorectal cancer. PLoS One. 2014;9:e106182. [PMID: 25188229 DOI: 10.1371/journal.pone.0106182]

Cross-sectional risk models using quantitative fecal hemoglobin in colorectal cancer screening: a systematic review

INTRODUCTION

Fecal Immunochemical Testing (FIT) is a central tool in colorectal cancer (CRC) screening. To improve the selection of individuals for colonoscopy, risk models combining FIT with additional CRC risk factors have been developed. This systematic review aims to provide an overview of the current noninvasive FIT-based risk models for CRC screening to facilitate future implementation.

METHODS

We performed a systematic literature search for risk models that combined quantitative fecal hemoglobin with clinical data or noninvasive biomarkers and that were intended for CRC screening. Risk of bias was assessed using the PROBAST tool.

RESULTS

Twenty risk models reported across 29 publications were included. The overall risk of bias was high. In studies that compared risk models to FIT, 11/12 (92%) risk models had a significantly higher c-statistic than FIT only. 16/20 risk models (80%) had not been externally validated and only one model has been implemented so far.

CONCLUSION

FIT-based risk models have the potential to improve the yield of CRC screening. Unfortunately, all included publications had a high risk of bias and most risk models have not yet been externally validated. The prospect of improved CRC screening with risk models should encourage more rigorous evaluation in existing screening programs.

Fecal Immunochemical Tests Detect Screening Participants with Multiple Advanced Adenomas Better than T1 Colorectal Cancers

BACKGROUND

Fecal immunochemical tests (FITs) are widely used for colorectal cancer (CRC) screening. The detection of early-stage cancer and advanced adenoma (AA), the most important premalignant lesion, is highly relevant to reducing CRC-related deaths. We aimed to assess sensitivity for the detection of CRC and AA stratified by tumor stage; number; size; histology of AA; and by location, age, sex, and body mass index (BMI).

METHODS

Participants of screening colonoscopy (n = 2043) and newly diagnosed CRC patients (n = 184) provided a stool sample before bowel preparation or CRC surgery. Fecal hemoglobin concentration was determined in parallel by nine different quantitative FITs among 94 CRC patients, 200 AA cases, and 300 participants free of advanced neoplasm. Sensitivities were calculated at original cutoffs and at adjusted cutoffs, yielding 93% specificity among all FITs.

RESULTS

At adjusted cutoffs, UICC stage I cancers yielded consistently lower sensitivities (range: 62-68%) compared to stage II-IV cancers (range: 73-89%). An even stronger gradient was observed according to T status, with substantially lower sensitivities for T1 (range: 39-57%) than for T2-T4 cancers (range: 71-100%). Sensitivities for the detection of participants with multiple AAs ranged from 55% to 64% and were by up to 25% points higher than sensitivities for T1 cancers.

CONCLUSIONS

FITs detect stage I cancers and especially T1 cancers at substantially lower sensitivities than more advanced cancer stages. Participants with multiple AAs were detected with slightly lower sensitivities than stage I cancers and with even higher sensitivities than T1 cancers. Further research should focus on improving the detection of early-stage cancers.

Stage-Specific Sensitivity of Fecal Immunochemical Tests for Detecting Colorectal Cancer: Systematic Review and Meta-Analysis

OBJECTIVE

Fecal immunochemical tests (FITs) detect the majority of colorectal cancers (CRCs), but evidence for variation in sensitivity according to the CRC stage is sparse and has not yet been systematically synthesized. Thus, our objective was to systematically review and summarize evidence on the stage-specific sensitivity of FITs.

METHODS

We screened PubMed, Web of Science, Embase, and the Cochrane Library from inception to June 14, 2019, for English-language articles reporting on the stage-specific sensitivity of FIT for CRC detection using colonoscopy as a reference standard. Studies reporting stage-specific sensitivities and the specificity of FIT for CRC detection were included. Summary estimates of sensitivity according to the CRC stage and study setting (screening cohorts, symptomatic/diagnostic cohorts, and case-control studies) were derived from bivariate meta-analysis.

RESULTS

Forty-four studies (92,447 participants including 3,034 CRC cases) were included. Pooled stage-specific sensitivities were overall very similar but suffered from high levels of imprecision because of small case numbers when calculated separately for screening cohorts, symptomatic/diagnostic cohorts, and case-control studies. Pooled sensitivities (95% confidence intervals) for all studies combined were 73% (65%-79%) for stage-I-CRCs and 80% (74%-84%), 82% (77%-87%), and 79% (70%-86%) for the detection of CRC stages II, III, and IV, respectively. Even substantially larger variation was seen in sensitivity by T-stage, with summary estimates ranging from 40% (21%-64%) for T1 to 83% (68%-91%) for T3-CRC.

DISCUSSION

Although FITs detect 4 of 5 CRCs at stages II-IV, the substantially lower sensitivity for stage-I-CRC and, in particular, T1 CRC indicates both need and potential for further improvement in performance for the early detection of CRC.

Fecal calprotectin and colorectal cancer

Fecal calprotectin (FC) is a bioactive protein secreted by inflammatory cells in the intestine, having anti-microbial and anti-infection activities. The content of FC reflects the inflammatory state of the intestine, and its role in inflammatory bowel disease has been translated into clinical practice. In recent years, the application of FC in colorectal cancer (CRC) has been increasing. Previous research results show that FC can be used to screen colorectal cancer and differentiate it from other intestinal diseases, and the concentration of FC may be related to the stage, location, and resectability of CRC. However, its role still needs to be further clarified through high-quality, large-sample research. This paper reviews the application of FC in colorectal cancer.

Diagnostic Accuracy Of Fecal Occult Blood Tests For Detecting Proximal Versus Distal Colorectal Neoplasia: A Systematic Review And Meta-Analysis

Objective

We conducted a systematic review and meta-analysis aimed at evaluating the differences of diagnostic performance of fecal occult blood tests (FOBTs) in detecting advanced colorectal neoplasms located in the proximal versus distal colorectum.

Methods

PubMed, Embase, Cochrane Library, and Web of Science were searched for eligible articles published before August 17, 2018. Two independent reviewers conducted study assessment and data extraction. Diagnosis-related indicators of FOBT for detecting proximal and distal colorectal neoplasms were summarized, and further stratified by the type of FOBT (guaiac-based FOBT (gFOBT) and immunochemical FOBT (iFOBT)). Pooled sensitivities and specificities were calculated using a random effect model. Summary receiver operating characteristic curves were plotted and area under the curves were calculated.

Results

Overall, 31 studies meeting the inclusion criteria were included in this review. For gFOBT, we found no site-specific difference (proximally vs distally located) of pooled sensitivities observed in the colorectal cancer (CRC), advanced adenomas, and advanced neoplasms groups. As for iFOBT, pooled sensitivities for detecting CRC located in the distal colon/rectum were comparable with that in the proximal colon (proximal vs distal, 0.67, 95% CI 0.62-0.72 vs 0.72, 95% CI 0.68-0.75), while higher pooled sensitivities for detecting advanced adenomas and advanced neoplasms located in the distal colon/rectum than for detecting those in the proximal colon were observed for iFOBT with the values of 0.24 (95% CI 0.22-0.25) vs 0.32 (95% CI 0.30-0.34) and 0.25 (95% CI 0.23-0.28) vs 0.38 (95% CI 0.36-0.40), respectively. Summary receiver operating characteristic curve analyses showed similar patterns for both types of FOBT regarding the diagnostic accuracy for detecting colorectal neoplasms according to the anatomical sites of the colorectum.

Conclusion

iFOBT had higher sensitivity for detecting advanced adenomas and advanced neoplasia located in the distal colon/rectum than that for those in the proximal colon.

Diagnostic accuracy of one or two faecal haemoglobin and calprotectin measurements in patients with suspected colorectal cancer

BACKGROUND

The role of faecal biomarkers in patients at 'high risk' of colorectal cancer (CRC) is not yet defined. Pre-analytical factors, such as heterogeneity of biomarker distribution within faeces, may influence their optimisation in clinical practice. We undertook to determine whether repeat or combined biomarker testing improves diagnostic accuracy for CRC or clinically significant disease.

METHODS

Patients referred with suspected CRC provided two separate faecal samples each for faecal immunochemical testing (FIT) and faecal calprotectin (FC) prior to investigation. Diagnostic accuracy of FIT and FC were evaluated based on final diagnoses.

RESULTS

Five hundred fifteen patients completed a full colorectal evaluation. The optimal cut-off for CRC using a single FIT was ≥12 µgHb/g faeces (84.6% sensitivity, 88.5% specificity). For two FIT, the cut-off was ≥43 µgHb/g faeces if either and ≥2 µgHb/g faeces if both were positive. There was no advantage in their diagnostic accuracy compared with a single FIT. FC had a lower diagnostic accuracy for CRC than FIT, which was not improved by repeat FC. No benefit was identified with FIT-FC combined. For CRC, significant adenomatous polyps and organic enteric disease combined, FIT and FC performed similarly to each other but were poorer predictors (AUC 0.677 and 0.660). There was no uplift in diagnostic accuracy when the tests were repeated or combined.

CONCLUSION

This study supports using a single FIT at a cut-off close to that recommended by NICE DG30 to improve diagnostic accuracy for 'two-week wait' patients referred with suspected CRC.

Identification of calgranulin B interacting proteins and network analysis in gastrointestinal cancer cells

Calgranulin B is known to be involved in tumor development, but the underlying molecular mechanism is not clear. To gain insight into possible roles of calgranulin B, we screened for calgranulin B-interacting molecules in the SNU-484 gastric cancer and the SNU-81 colon cancer cells. Calgranulin B-interacting partners were identified by yeast two-hybrid and functional information was obtained by computational analysis. Most of the calgranulin B-interacting partners were involved in metabolic and cellular processes, and found to have molecular function of binding and catalytic activities. Interestingly, 46 molecules in the network of the calgranulin B-interacting proteins are known to be associated with cancer and FKBP2 was found to interact with calgranulin B in both SNU-484 and SNU-81 cells. Polyubiquitin-C encoded by UBC, which exhibited an interaction with calgranulin B, has been associated with various molecules of the extracellular space and plasma membrane identified in our screening, including Na-K-Cl cotransporter 1 and dystonin in SNU-484 cells, and ATPase subunit beta-1 in SNU-81 cells. Our data provide novel insight into the roles of calgranulin B of gastrointestinal cancer cells, and offer new clues suggesting calgranulin B acts as an effector molecule through which the cell can communicate with the tumor microenvironment via polyubiquitin-C.

Proteins that interact with calgranulin B in the human colon cancer cell line HCT-116

Calgranulin B is released from immune cells and can be internalized into colon cancer cells to prevent proliferation. The present study aimed to identify proteins that interact with calgranulin B to suppress the proliferation of colon cancer cells, and to obtain information on the underlying anti-tumor mechanism(s) of calgranulin B. Calgranulin B expression was induced in colon cancer cell line HCT-116 by infection with calgranulin B-FLAG expressing lentivirus, and it led to a significant suppression of cell proliferation. Proteins that interacted with calgranulin B were obtained by immunoprecipitation using whole homogenate of lentivirus-infected HCT-116 cells which expressing calgranulin B-FLAG, and identified using liquid chromatography-mass spectrometry/mass spectrometry analysis. A total of 454 proteins were identified that potentially interact with calgranulin B, and most identified proteins were associated with RNA processing, post-transcriptional modifications and the EIF2 signaling pathway. Direct interaction of calgranulin B with flotillin-1, dynein intermediate chain 1, and CD59 glycoprotein has been confirmed, and the molecules N-myc proto-oncogene protein, rapamycin-insensitive companion of mTOR, and myc proto-oncogene protein were shown to regulate calgranulin B-interacting proteins. Our results provide new insight and useful information to explain the possible mechanism(s) underlying the role of calgranulin B as an anti-tumor effector in colon cancer cells.

Faecal calprotectin in patients with suspected colorectal cancer: a diagnostic accuracy study

BACKGROUND

NICE guidance exists for the use of faecal calprotectin (FC) when irritable bowel syndrome or inflammatory bowel disease are suspected. Often, however, colorectal cancer is considered within the differential. Should FC have a high diagnostic accuracy for colorectal cancer, it may be applicable as a primary care screening test for all patients with lower gastrointestinal symptoms.

AIM

To determine the negative and positive predictive value (NPV/PPV) of FC in patients referred from primary care with suspected colorectal cancer.

DESIGN AND SETTING

A diagnostic accuracy study conducted at a single secondary care site

METHOD

Consenting patients referred with suspected colorectal cancer within the '2-week wait' pathway provided a stool sample for FC prior to investigation. FC levels were reconciled with end diagnoses: cancer, adenomatous polyps ≥10 mm, and all enteric organic disease.

RESULTS

A total of 654 patients completed the evaluation; median age 69 years, female 56%. The NPV for colorectal cancer was 98.6% and 97.2% when including polyps ≥10 mm. The PPV for all organic enteric disease was 32.7%. The diagnostic yield for cancer based on clinical suspicion was 6.3%. By altering the FC cut-off to fix the NPV at 97.0%, the PPV for cancer increased from 8.7% to 13.3%.

CONCLUSION

FC has a high NPV for colorectal cancer and significant polyps in patients with suspected cancer. In total, 27.8% of patients had a normal FC and could safely have been spared a '2-week wait' referral. The addition of FC testing into the current symptom-based assessment has the potential to increase colorectal cancer detection rate yet be clinically and cost effective.

Fecal Immunochemical Tests Combined With Other Stool Tests for Colorectal Cancer and Advanced Adenoma Detection: A Systematic Review

OBJECTIVES

Despite moderate to high detection rates of fecal immunochemical tests (FITs) of colorectal cancer (CRC), detection of adenomas remains limited. Further stool tests exist, which are not used in routine practice, such as DNA or RNA markers and protein markers. We aimed at systematically investigating and summarizing evidence for diagnostic performance of combinations of FIT with other stool tests compared with FIT alone in early detection of CRC and its precursors.

METHODS

We systematically reviewed studies that evaluated FITs in combination with other stool tests and compared measures of diagnostic accuracy with and without additional stool tests. PubMed and Web of Science were searched from inception to May 2015. Reference lists of eligible studies were also screened. Two reviewers extracted data independently.

RESULTS

Some of the reports on DNA, RNA, or tissue tests, including tests based on DNA mutations, methylation, and integrity in selected genes as well as microRNA expression, showed some improvements of diagnostic test accuracy. In contrast, so far assessed stool protein markers did generally not lead to substantial improvements in performance of FIT when added to the latter. Many marker combinations were reported only in one study each, and few studies were conducted in a true screening setting.

CONCLUSIONS

Several stool markers show potential to improve performance of FITs. However, the results require confirmation in further studies, which should also evaluate the costs and cost-effectiveness of combined screening strategies.

Systematic review with meta-analysis: faecal occult blood tests show lower colorectal cancer detection rates in the proximal colon in colonoscopy-verified diagnostic studies

BACKGROUND

The performance of faecal occult blood tests (FOBTs) to screen proximally located colorectal cancer (CRC) has produced inconsistent results.

AIM

To assess in a meta-analysis, the diagnostic accuracy of FOBTs for relative detection of CRC according to anatomical location of CRC.

METHODS

Diagnostic studies including both symptomatic and asymptomatic cohorts assessing performance of FOBTs for CRC were searched from MEDINE and EMBASE. Primary outcome was accuracy of FOBTs according to the anatomical location of CRC. Bivariate random-effects model was used. Subgroup analyses were performed to evaluate test performance of guaiac-based FOBT (gFOBT) and immunochemical-based FOBT (iFOBT).

RESULTS

Thirteen studies, with 17 cohorts, reporting performance of FOBT were included; a total of 26 342 patients (mean age 58.9 years; 58.1% male) underwent both colonoscopy and FOBT. Pooled sensitivity, specificity, positive likelihood ratio and negative likelihood ratio of FOBTs for CRC detection in the proximal colon were 71.2% (95% CI 61.3-79.4%), 93.6% (95% CI 90.7-95.7%), 11.1 (95% CI 7.8-15.8) and 0.3 (95% CI 0.2-0.4) respectively. Corresponding findings for CRC detection in distal colon were 80.1% (95% CI 70.9-87.0%), 93.6% (95% CI 90.7-95.7%), 12.6 (95% CI 8.8-18.1) and 0.2 (95% CI 0.1-0.3). The area-under-curve for FOBT detection for proximal and distal CRC were 90% vs. 94% (P = 0.0143). Both gFOBT and iFOBT showed significantly lower sensitivity but comparable specificity for the detection of proximally located CRC compared with distal CRC.

CONCLUSION

Faecal occult blood tests, both guaiac- and immunochemical-based, show better diagnostic performance for the relative detection of colorectal cancer in the distal colon than in the proximal bowel.

Fecal calprotectin for diagnosis of digestive system diseases

Calprotectin is a 36 kDa calcium- and zinc-binding protein that belongs to the S100 family. Calprotectin shows an excellent stability in feces and appears to be superior to conventional fecal markers. Fecal calprotectin concentrations closely correlate with the fecal excretion of in-labelled leukocytes. In addition, fecal calprotectin has an overall high specificity. Therefore, it could be a useful marker for diagnosis of intestinal diseases. In this review we summarize the structure, physical and chemical characteristics of fecal calprotectin and analyze the relationship between calprotectin and intestinal diseases.