Fecal Immunochemical Test: The World's Colorectal Cancer Screening Test

Unsatisfactory Fecal Immunochemical Tests for Colorectal Cancer Screening: Prevalence, Reasons, and Subsequent Testing

BACKGROUND

Fecal immunochemical test (FIT) is an effective colorectal cancer screening modality. Little is known about prevalence, reasons, and testing after unsatisfactory FIT, or a FIT that cannot be processed by the laboratory due to inadequate stool specimen or incomplete labeling.

METHODS

Our retrospective cohort study examined unsatisfactory FIT among average-risk individuals aged 50-74 years in a large, integrated, safety-net health system who completed an index FIT from 2010 to 2019. We determined prevalence of unsatisfactory FIT and categorized reasons hierarchically. We used multivariable logistic regression models to identify factors associated with: (i) unsatisfactory FIT; and (ii) subsequent testing within 15 months of the unsatisfactory FIT.

RESULTS

Of 56,980 individuals completing an index FIT, 10.2% had an unsatisfactory FIT. Reasons included inadequate specimen (51%), incomplete labeling (27%), old specimen (13%), and broken/leaking container (8%). Unsatisfactory FIT was associated with being male [OR, 1.10; confidence interval (CI), 1.03-1.16], Black (OR, 1.46; CI, 1.33-1.61), Spanish speaking (OR, 1.12; CI, 1.01-1.24), on Medicaid (OR, 1.42; CI, 1.28-1.58), and received FIT by mail (OR, 2.66; CI, 2.35-3.01). Among those with an unsatisfactory FIT, fewer than half (41%) completed a subsequent test within 15 months (median, 4.4 months). Adults aged 50-54 years (OR, 1.16; CI, 1.01-1.39) and those who received FIT by mail (OR, 1.92; CI, 1.49-2.09) were more likely to complete a subsequent test.

CONCLUSIONS

One in ten returned a FIT that could not be processed, mostly due to patient-related reasons. Fewer than half completed a subsequent test after unsatisfactory FIT.

IMPACT

Screening programs should address these breakdowns such as specimen collection and labeling to improve real-world effectiveness. See related In the Spotlight, p. 183.

Overview and countermeasures of cancer burden in China

Cancer is one of the leading causes of human death worldwide. Treatment of cancer exhausts significant medical resources, and the morbidity and mortality caused by cancer is a huge social burden. Cancer has therefore become a serious economic and social problem shared globally. As an increasingly prevalent disease in China, cancer is a huge challenge for the country's healthcare system. Based on recent data published in the Journal of the National Cancer Center on cancer incidence and mortality in China in 2016, we analyzed the current trends in cancer incidence and changes in cancer mortality and survival rate in China. And also, we examined several key risk factors for cancer pathogenesis and discussed potential countermeasures for cancer prevention and treatment in China.

Implementation of an organized colorectal cancer screening program through quantitative fecal immunochemical test followed by colonoscopy in an urban low-income community: Guidance and strategies

Fecal Immunochemical Test (FIT) followed by a colonoscopy is an efficacious strategy to improve the adenoma detection rate and Colorectal Cancer (CRC). There is no organized national screening program for CRC in Brazil. The aim of this research was to describe the implementation of an organized screening program for CRC through FIT followed by colonoscopy, in an urban low-income community of São Paulo city. The endpoints of the study were: FIT participation rate, FIT positivity rate, colonoscopy compliance rate, Positive Predictive Values (PPV) for adenoma and CRC, and the rate of complications. From May 2016 to October 2019, asymptomatic individuals, 50-75 years old, received a free kit to perform the FIT. Positive FIT (≥ 50 ng/mL) individuals were referred to colonoscopy. 10,057 individuals returned the stool sample for analysis, of which (98.2%) 9,881 were valid. Women represented 64.8% of the participants. 55.3% of individuals did not complete elementary school. Positive FIT was 7.8% (776/9881). The colonoscopy compliance rate was 68.9% (535/776). There were no major colonoscopy complications. Adenoma were detected in 63.2% (332/525) of individuals. Advanced adenomatous lesions were found in 31.4% (165/525). CRC was diagnosed in 5.9% (31/525), characterized as adenocarcinoma: in situ in 3.2% (1/31), intramucosal in 29% (9/31), and invasive in 67.7% (21/31). Endoscopic treatment with curative intent for CRC was performed in 45.2% (14/31) of the cases. Therefore, in an urban low-income community, an organized CRC screening using FIT followed by colonoscopy ensued a high participation rate, and high predictive positive value for both, adenoma and CRC.

Salivary and fecal microbiota: potential new biomarkers for early screening of colorectal polyps

Objective

Gut microbiota plays an important role in colorectal cancer (CRC) pathogenesis through microbes and their metabolites, while oral pathogens are the major components of CRC-associated microbes. Multiple studies have identified gut and fecal microbiome-derived biomarkers for precursors lesions of CRC detection. However, few studies have used salivary samples to predict colorectal polyps. Therefore, in order to find new noninvasive colorectal polyp biomarkers, we searched into the differences in fecal and salivary microbiota between patients with colorectal polyps and healthy controls.

Methods

In this case-control study, we collected salivary and fecal samples from 33 patients with colorectal polyps (CP) and 22 healthy controls (HC) between May 2021 and November 2022. All samples were sequenced using full-length 16S rRNA sequencing and compared with the Nucleotide Sequence Database. The salivary and fecal microbiota signature of colorectal polyps was established by alpha and beta diversity, Linear discriminant analysis Effect Size (LEfSe) and random forest model analysis. In addition, the possibility of microbiota in identifying colorectal polyps was assessed by Receiver Operating Characteristic Curve (ROC).

Results

In comparison to the HC group, the CP group's microbial diversity increased in saliva and decreased in feces (p < 0.05), but there was no significantly difference in microbiota richness (p > 0.05). The principal coordinate analysis revealed significant differences in β-diversity of salivary and fecal microbiota between the CP and HC groups. Moreover, LEfSe analysis at the species level identified Porphyromonas gingivalis, Fusobacterium nucleatum, Leptotrichia wadei, Prevotella intermedia, and Megasphaera micronuciformis as the major contributors to the salivary microbiota, and Ruminococcus gnavus, Bacteroides ovatus, Parabacteroides distasonis, Citrobacter freundii, and Clostridium symbiosum to the fecal microbiota of patients with polyps. Salivary and fecal bacterial biomarkers showed Area Under ROC Curve of 0.8167 and 0.8051, respectively, which determined the potential of diagnostic markers in distinguishing patients with colorectal polyps from controls, and it increased to 0.8217 when salivary and fecal biomarkers were combined.

Conclusion

The composition and diversity of the salivary and fecal microbiota were significantly different in colorectal polyp patients compared to healthy controls, with an increased abundance of harmful bacteria and a decreased abundance of beneficial bacteria. A promising non-invasive tool for the detection of colorectal polyps can be provided by potential biomarkers based on the microbiota of the saliva and feces.

Uptake patterns and predictors of colorectal cancer screening among adults resident in Spain: A population-based study from 2017 to 2020

Background

Although population screening has improved the early diagnosis of colorectal cancer (CRC), most cases are diagnosed in symptomatic patients. This study aimed to estimate the prevalence and evolution over time of uptake patterns to fecal immunochemical test (FIT) as a screening test for CRC among individuals aged 50-69 in Spain, and to determine the predictive factors for uptake patterns to this type of screening based on sociodemographic, health, and lifestyle characteristics.

Methods

A cross-sectional study with 14,163 individuals from the 2017 Spanish National Health Survey and the 2020 European Health Survey was performed, including as the main variable uptake pattern to FIT screening within the last 2 years, with which we analyzed sociodemographic factors, health status and lifestyle habits.

Results

38.01% of participants had undergone FIT in the previous 2 years, and from 2017 to 2020, a significant increase in the uptake rate for CRC was observed (2017: 32.35%, 2020: 43.92%, p < 0.001). The positive predictors to FIT uptake pattern included factors such as being between 57 and 69 years, having a higher educational level or a higher social class, having at least one chronic illness, frequent contact with the primary care physician, alcohol consumption and physical activity, while immigration and smoking habit were negative predictors.

Conclusion

In Spain, although the evolution of FIT uptake pattern over time is positive, the prevalence of FIT uptake is still low (38.01%), not reaching the level considered as acceptable in the European guidelines. Moreover, there are disparities in CRC screening uptake among individuals.

Real‐world application of a fast stool DNA test for colorectal cancer screening in primary screening positive population

BACKGROUND

Stool DNA test has been emerged as an effective noninvasive method for colorectal cancer (CRC) screening, but the real-world performance of stool DNA test in Chinese population has rarely been reported.

METHODS

A total of 36,527 subjects were recruited in Haining City from January 2021 to December 2021. Participants underwent primary screening by taking both two-samples fecal immunochemical tests (FITs) and high-risk factor questionnaire (HRFQ), and those who tested either positive by FITs or evaluated to be high risk by HRFQ were recommended to undertake subsequent stool DNA test and colonoscopy.

RESULTS

Of 36,527 participants, 34,778 (95%) completed both HRFQ and FITs, 9947 (29%) showed positive results during primary screening, and the colonoscopy compliance rate was 49%. Of primary screening positives, 8733 (88%) completed stool sample collections, and colonoscopy results from 4293 eligible participants were used for analyzing the performance of stool DNA test. The sensitivities for detecting CRC and advanced adenomas (AA) were 100% (95% CI: 60-100%) and 40% (95% CI: 34-46%), and the area under curve (AUC) was 0.961 (95% CI:0.954-0.967) and 0.625 (95% CI: 0.609-0.641), respectively. The specificity of stool DNA test was 84% (95% CI: 82-85%). The false-positive rate for stool DNA test is about 10% less than that of primary screening.

CONCLUSION

Stool DNA test is a cost-effective and promising alternative strategy for CRC screening in China.

MicroRNA-based signature for diagnosis and prognosis of colorectal cancer using residuum of fecal immunochemical test

BACKGROUND

Colorectal cancer (CRC) is still among the most lethal and prevalent malignancies in the world. Despite continuous efforts, the diagnosis and prognosis of CRC have never been satisfying, especially the non-invasive assays.

METHODS

Our study comprised three independent cohorts of 835 qualified stool samples. From 46 literature-identified miRNA candidates, four miRNA ratios were selected and developed into a miRNA-based signature after applied to the training and test sets. The clinical performances of this signature were further evaluated in the prospective cohorts.

RESULTS

Four miRNA ratios with significant alterations and the highest discriminating power between the CRC and control groups in the training set were successfully validated in the test set. In the training dataset, combining these four miRNA ratios using a logistic regression model improved the area under the curve value to 0.821 and obtained a sensitivity of 73.6% and specificity of 78.9%. This miRNA signature showed consistent performances in the other two sample cohorts, with the highest sensitivity of 85.7% in the prospective cohort. Additionally, the higher miRNA signature was associated with worse disease-free survival (hazard ratio = 2.27) and overall survival (hazard ratio = 1.83) of CRC patients. For fecal immunochemical test (FIT)-positive populations, the positive predictive value for CRC detection in miRNA-positive subjects was 3.43-fold higher in the prospective cohort, compared to FIT alone.

CONCLUSION

This stool miRNA signature is highly associated with poor outcome of CRC and can be added to FIT tests to help identify the most at-risk group to receive prompt colonoscopy examination.