Physician-office vs home uptake of colorectal cancer screening using FOBT/FIT among screening-eligible US adults

A proteomic classifier panel for early screening of colorectal cancer: a case control study

BACKGROUND

Diagnosis of colorectal cancer (CRC) during early stages can greatly improve patient outcome. Although technical advances in the field of genomics and proteomics have identified a number of candidate biomarkers for non-invasive screening and diagnosis, developing more sensitive and specific methods with improved cost-effectiveness and patient compliance has tremendous potential to help combat the disease.

METHODS

We enrolled three cohorts of 479 subjects, including 226 CRC cases, 197 healthy controls, and 56 advanced precancerous lesions (APC). In the discovery cohort, we used quantitative mass spectrometry to measure the expression profile of plasma proteins and applied machine-learning to select candidate proteins. We then developed a targeted mass spectrometry assay to measure plasma concentrations of seven proteins and a logistic regression classifier to distinguish CRC from healthy subjects. The classifier was further validated using two independent cohorts.

RESULTS

The seven-protein panel consisted of leucine rich alpha-2-glycoprotein 1 (LRG1), complement C9 (C9), insulin-like growth factor binding protein 2 (IGFBP2), carnosine dipeptidase 1 (CNDP1), inter-alpha-trypsin inhibitor heavy chain 3 (ITIH3), serpin family A member 1 (SERPINA1), and alpha-1-acid glycoprotein 1 (ORM1). The panel classified CRC and healthy subjects with high accuracy, since the area under curve (AUC) of the training and testing cohort reached 0.954 and 0.958. The AUC of the two independent validation cohorts was 0.905 and 0.909. In one validation cohort, the panel had an overall sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 89.9%, 81.8%, 89.2%, and 82.9%, respectively. In another blinded validation cohort, the panel classified CRC from healthy subjects with a sensitivity of 81.5%, specificity of 97.9%, and overall accuracy of 92.0%. Finally, the panel was able to detect APC with a sensitivity of 49%.

CONCLUSIONS

This seven-protein classifier is a clear improvement compared to previously published blood-based protein biomarkers for detecting early-stage CRC, and is of translational potential to develop into a clinically useful assay.

IgM and IgA augmented autoantibody signatures improve early-stage detection of colorectal cancer prior to nodal and distant spread

Objectives

Tumor‐associated autoantibodies (AAbs) in individuals with cancer can precede clinical diagnosis by several months to years. The objective of this study was to determine whether the primary immune response in form of IgM and gut mucosa‐associated IgA can aid IgG AAbs in the detection of early‐stage colorectal cancer (CRC).

Methods

We developed a novel protein array comprising 492 antigens seropositive in CRC. The array was used to profile IgG, IgM and IgA antibody signatures in 99 CRC patients and 99 sex‐ and age‐matched non‐cancer controls. A receiver operating curve (ROC), Kaplan–Meier survival analysis and univariate and multivariate Cox regression analyses were conducted.

Results

We identified a panel of 16 multi‐isotype AAbs with a cumulative sensitivity of 91% and specificity of 74% (AUC 0.90, 95% CI: 0.850–0.940) across all CRC stages. IgM and IgG isotypes were conversely associated with disease stage with IgM contributing significantly to improved stage I and II sensitivity of 96% at 78% specificity (AUC 0.928, 95% CI: 0.884–0.973). A single identified IgA AAb reached an overall sensitivity of 5% at 99% specificity (AUC 0.520, 95% CI: 0.440–0.601) balanced across all CRC stages. Kaplan–Meier analysis revealed that se33‐1 (ZNF638) IgG AAbs were associated with reduced 5‐year overall survival (log‐rank test, P = 0.012), whereas cumulative IgM isotype signatures were associated with improved 5‐year overall survival (log‐rank test, P = 0.024).

Conclusion

IgM AAbs are associated with early‐stage colorectal cancer. Combining IgG, IgM and IgA AAbs is a novel strategy to improve early diagnosis of cancers.

Metabolic profiling analysis for clinical urine of colorectal cancer

AIM

To demonstrate the little-known metabolic changes and pathways in patients with colorectal cancer (CRC).

METHODS

We used gas chromatography time-of-flight mass spectrometry (GC-TOF/MS) to perform metabolic profiling of urine samples from 163 consecutive patients with CRC and 111 healthy controls without history of gastrointestinal tumors. The metabolic profiles were assayed using multivariate statistical analysis and one-way analysis of variance, and further analyzed to identify potential marker metabolites related to CRC. The GC-TOF/MS-derived models showed clear discriminations in metabolic profiles between the CRC group and healthy control group.

RESULTS

We demonstrated that 15 metabolites contributed to the differences. Among them, eleven metabolites were significantly upregulated, while other four metabolites were downregulated in the urine samples of CRC patients compared with healthy controls. Pathway analysis revealed changes in energy metabolism of patients with CRC, which are reflected in the upregulation of glycolysis and amino acid metabolism and the downregulation of lipid metabolism. Our study revealed the metabolic profile of urine from CRC patients and indicated that GC-TOF/MS-based methods can distinguish CRC from healthy controls.

CONCLUSION

GC-TOF/MS-based metabolomics has the potential to be developed into a novel, non-invasive, and painless clinical tool for CRC diagnosis, and may contribute to an improved understanding of disease mechanisms.

Early colorectal cancer detection-Current and evolving challenges in evidence, guidelines, policy, and practices

The understanding at the beginning of the last century that colorectal cancer began as a localized disease that progressed and became systemic, and that most colorectal cancer arose from adenomatous polyps gave rise to aggressive attempts at curative treatment and eventually attempts to detect advanced lesions before they progressed to invasive disease. In the last four decades, steadily greater uptake of screening has led to reductions in colorectal cancer incidence and mortality. However, the fullest potential of screening is not being met due to the lack of organized screening, where a systems approach could lead to higher rates of screening of average and high risk groups, higher quality screening, and prompt followup of adults with positive screening tests. ABSTRACT: Since the beginning of the 20th century, there has been a general understanding that colorectal cancer is a clonal disease that progresses from a localized stage with a favorable prognosis through progressively more advanced stages which have progressively worse prognosis. That understanding led first to determined efforts to detect and treat early stage symptomatic disease, and then to detect pre-symptomatic colorectal cancer and precursor lesions, where there was hope that the natural history of the disease could be arrested and the incidence and premature mortality of colorectal cancer averted. Toward the end of the last century, guidelines for colorectal cancer screening, growth in the number of technical options for screening, and a steady increase in the proportion of the adult population who attended screening contributed to the beginning of a significant decline in colorectal cancer incidence and mortality. Despite this progress, colorectal cancer remains the third leading cause of death among men and women in the United States. Screening for early detection of precursor lesions and localized cancer offers the single most productive opportunity to further reduce the burden of disease, and yet nearly four in five deaths from colorectal cancer are associated with having never been screened, not recently screened, or not followed up for an abnormal screening test. This simple observation is a call to action in all communities to apply existing knowledge to fulfill the potential to prevent avertable incidence and mortality.

A 5-year evaluation of using stool-based test for opportunistic colorectal cancer screening in primary health institutions across Malaysia

INTRODUCTION

The immunochemical fecal occult blood test (iFOBT) has been widely used for opportunistic colorectal cancer (CRC) screening in average-risk individuals seeking care from public health clinics in Malaysia. This study provides a 5-year outcome evaluation of such a practice.

METHODS

The findings for a few outcome indicators, ranging from the iFOBT uptake to the CRC and polyp detection rates, were generated from the data contributed by 583 public health clinics between 2014 and 2018. The trends in their changes were also evaluated.

RESULTS

The iFOBT uptake constantly increased over the years (p < 0.001), totaling 2.29 % (n = 127,957) as at 2018. Nearly 10 % (n = 11,872) of the individuals screened had a positive test result. Of those who underwent colonoscopy (n = 6,491), 4.04 % (n = 262) and 13.93 % (n = 904) were found to have CRC and polyps, respectively.

CONCLUSION

An uptrend in the CRC screening uptake was witnessed following the introduction of the iFOBT in public health clinics.

Risk-Adapted Cutoffs in Colorectal Cancer Screening by Fecal Immunochemical Tests

INTRODUCTION

Fecal immunochemical tests (FITs) for hemoglobin are increasingly used in colorectal cancer (CRC) screening. The use of uniform positivity thresholds (cutoffs) within screening populations is expected to imply lower positive predictive values (PPVs) and higher numbers of colonoscopies needed (numbers needed to scope [NNSs]) to detect advanced neoplasms among screening participants at lower risk compared with those at higher risk. We aimed to assess such variation and its potential implications in a large screening cohort.

METHODS

A quantitative FIT (FOB Gold; Sentinel Diagnostics, Milan, Italy) was conducted in fecal samples collected by 4,332 participants of screening colonoscopy before bowel preparation. Participants were classified into 3 risk groups (low, medium, and high) by tertiles of a previously derived risk-factor-based risk score. We determined the variation of PPVs and NNSs for detecting advanced neoplasms (i.e., CRC or advanced adenoma) when using the same FIT cutoffs and variation of FIT cutoffs that would yield uniform PPVs across risk groups.

RESULTS

When a fixed FIT cutoff of 10 μg/g was used, the PPV increased from 23.3% to 41.8% from the low- to the high-risk group, with NNS decreasing from 4.3 to 2.4 (P < 0.001). Similar variations of PPVs and NNSs across risk groups were observed at higher FIT cutoffs. When risk group-specific cutoffs were defined to achieve fixed PPVs of 25%, 30%, and 35% across all risk groups, cutoffs varied from 5.3 to 11.4, 6.5 to 18.7, and 7.5 to 31.0 μg hemoglobin/g feces, respectively, between high- and low-risk groups (P < 0.05 for all differences).

DISCUSSION

Using risk-adapted cutoffs may help to achieve target levels of PPV and NNS and might be an option to consider for personalized FIT-based CRC screening.

Physician-office vs home uptake of colorectal cancer screening using FOBT/FIT among screening-eligible US adults

Background

Guidelines of the American Cancer Society and US Preventive Services Task Force specify that colorectal cancer (CRC) screening using guaiac‐based fecal occult blood test (FOBT)/fecal immunochemical test (FIT) should be done at home. We therefore examined the prevalence and correlates of CRC screening using FOBT/FIT in physicians' office vs at home.

Methods

Analysis of 9493 respondents 50‐75 years old from the Cancer Control Supplement of the 2015 National Health Interview Survey was conducted. Weighted multivariable logistic regression was used to identify the determinants of in‐office vs home use of FOBT/FIT for CRC screening.

Results

Of the overall sample of screening‐eligible adults (n = 9403), only 937 (10.4%) respondents underwent CRC screening using FOBT/FIT within the past year; among this screening population, 279 (28.3%) respondents were screened in‐office. We found that sociodemographic factors alone, not CRC risk factors, determined whether FOBT/FIT would be used in‐office or at home. Hispanics had greater odds of being screened in‐office using FOBT/FIT (aOR: 2.04; 95% CI: 1.05‐3.99). Compared with those 50‐59 years old, respondents 70‐75 years old were less likely to be screened in‐office using FOBT/FIT (aOR: 0.44, 95% CI: 0.25‐0.79). Similarly, individuals residing in the Western region of the country had lower odds of in‐office FOBT/FIT (aOR: 0.26; 95% CI: 0.11‐0.58).

Conclusion

Amid low overall uptake rates of FOBT/FIT in the United States, in‐physician office testing is high, indicative of a missed opportunity for effective screening and poor adherence of physicians to national guidelines. Sociodemographic factors are determinants of uptake of FOBT/FIT at home or in‐office and should be considered in designing interventions aimed at providers and the general population.

Amid low overall uptake rates of FOBT/FIT in the United States, in‐physician office testing is high, indicative of a missed opportunity for effective screening and poor adherence of physicians to national guidelines.