The detection of interval colorectal cancers following screening by fecal immunochemical test may predict worse outcomes and prompt ethical concerns: a 6-year population-based cohort study in a full district

Role of demographics in noninvasive testing for colorectal cancer screening: do targeted cut-off values improve detection?

BACKGROUND

Fecal immunochemical test (FIT) is a yearly alternative colorectal screening modality for average risk individuals unwilling or unable to undergo invasive colorectal cancer (CRC) screening due to cost and accessibility. This study aimed to determine whether FIT should be interpreted within the context of patient demographics and medical history.

METHODS

Patients >50 years old who had a FIT followed by colonoscopy within 1 year were analyzed based on age, race, BMI, social and medical comorbidities. False positive (FP) and false negative (FN) FIT results within each patient demographic and medical history variable were determined by comparing with the gold standard of colonoscopy using χ2 analysis.

RESULTS

One thousand twenty-five patients were reviewed. 21.8% of FIT results were positive. Factors which differed in positive FIT rates were age (P=0.003), smoking (P<0.001), alcohol (P=0.001), and hypertension (P<0.001). The difference in rates of FP and FN FIT outcomes among each variable underwent further subanalysis. The FP was 66.8% and the FN rate was 12.8%. Higher FN outcomes were noted in those above 70, males and smokers, though the result was only statistically significant for males (P=0.009). Females were observed to have higher FP rates (P=0.019).

CONCLUSIONS

Females had higher FP FIT rates compared to males, indicating that sex may influence FIT outcomes and should be accounted for when interpreting FIT results. This information can be utilized to identify populations at higher risk of FP or FN FIT results to target CRC screening. Additionally, recalculating the FP and FN rates for each variable may help determine new FIT targets.

Optimizing the colorectal cancer screening programme using faecal immunochemical test (FIT) in Flanders, Belgium from the “interval cancer” perspective

Background

Interval cancer (IC) is a critical issue in colorectal cancer (CRC) screening. We identified factors associated with ICs after faecal immunochemical test (FIT) screening and explored the impact of lowering FIT cut-off or shortening screening interval on FIT-ICs in Flanders.

Methods

FIT participants diagnosed with a CRC during 2013–2018 were included. Factors associated with FIT-ICs were identified using logistic regression. Distributions of FIT results among FIT-ICs were examined.

Results

In total, 10,122 screen-detected CRCs and 1534 FIT-ICs were included (FIT-IC proportion of 13%). FIT-ICs occurred more frequently in women (OR 1.58 [95% CI 1.41–1.76]) and ages 70–74 (OR 1.35 [1.14–1.59]). FIT-ICs were more often right-sided (OR 3.53 [2.98–4.20]), advanced stage (stage IV: OR 7.15 [5.76–8.88]), and high grade (poorly/undifferentiated: OR 2.57 [2.08–3.18]). The majority (83–92%) of FIT-ICs would still be missed if FIT cut-off was lowered from 15 to 10 µg Hb/g or screening interval was shortened from 2 to 1 year.

Conclusions

FIT-ICs were more common in women, older age, right-sided location, advanced stage and high grade. In Flanders, lowering FIT cut-off (to 10 µg Hb/g) or shortening screening interval (to 1 year) would have a minimal impact on FIT-ICs.

Future incidence and mortality of colorectal carcinoma in the United States: an updated overview of risk factors and preventative measures

According to the Global Cancer Observatory (GLOBOCAN) 2020, colorectal carcinoma (CRC) was the second leading cause of cancer death globally. Current literature utilizes reported databases such as Surveillance, Epidemiology, and End Results (SEER) to better understand the epidemiology of CRC. The global cancer observatory’s “Cancer Tomorrow” data visualization tools was used to predict the future incidence and mortality of colorectal cancers until 2030 as a guided tool to look over ways to reduce incidence by controlling risk factors of CRC. The total number of CRC is expected to rise by 2030, with a percent change of 17.3%. The expected percent change in colon cancer is more than rectal cancer (19.8% vs. 11.6%). The estimated number of deaths secondary to CRC is expected to increase in 2030, an estimated percent change of 22.2%. The incidence and mortality rate was higher in men vs. women; however, the gap seems to be closing on trend analysis. Major risk factors for CRC include familial syndromes, family history, race, gender, obesity, diet, alcohol, and smoking. Risk can be reduced by exercise and dietary changes, fiber intake, vitamin D, calcium, and minerals. Individualized screening based on age, gender, and additional risk factors could be an option that needs further comparative data to propose a definitive benefit over established screening guidelines.

Positive impact of a faecal-based screening programme on colorectal cancer mortality risk

INTRODUCTION

The effectiveness of colorectal cancer (CRC) screening programs is directly related to participation and the number of interval CRCs. The objective was to analyse specific-mortality in a cohort of individuals invited to a CRC screening program according to type of CRC diagnosis (screen-detected cancers, interval cancers, and cancers among the non-uptake group).

MATERIAL AND METHODS

Retrospective cohort that included invitees aged 50-69 years of a CRC screening program (target population of 85,000 people) in Catalonia (Spain) from 2000-2015 with mortality follow-up until 2020. A screen-detected CRC was a cancer diagnosed after a positive faecal occult blood test (guaiac or immunochemical); an interval cancer was a cancer diagnosed after a negative test result and before the next invitation to the program (≤24 months); a non-uptake cancer was a cancer in subjects who declined screening.

RESULTS

A total of 624 people were diagnosed with CRC (n = 265 screen-detected, n = 103 interval cancers, n = 256 non-uptake). In the multivariate analysis, we observed a 74% increase in mortality rate in the group with interval CRC compared to screen-detected CRC adjusted for age, sex, location and stage (HR: 1.74%, 95% CI:1.08-2.82, P = 0.02). These differences were found even when we restricted for advanced-cancers participants. In the stratified analysis for type of faecal occult blood test, a lower mortality rate was only observed among FIT screen-detected CRCs.

CONCLUSION

CRC screening with the FIT was associated with a significant reduction in CRC mortality.

Occurrence and characteristics of faecal immunochemical screen-detected cancers vs non-screen-detected cancers: Results from a Flemish colorectal cancer screening programme

BACKGROUND

Colorectal cancer (CRC) and its precursor lesions are detected at an early stage by CRC screening programmes, which reduce CRC-related mortality. An important quality indicator for CRC screening is the occurrence of interval CRC (IC) between screening rounds. Currently there is no guideline regarding acceptable levels of ICs in CRC screening programmes, and ICs reported in prior work vary considerably.

METHODS

This study describes the occurrence of screen-detected (SD) CRC and non-screen-detected CRC within the population-based CRC screening programme of Flanders, stratified by multiple variables such as sex, age, tumour location and tumour stage between October 2013 and July 2017. In addition, faecal immunochemical test (FIT) IC proportions over the sum of SD-CRCs and FIT-ICs are calculated, together with FIT sensitivity and programme sensitivity to display the effectiveness of detecting CRC by the screening programme.

RESULTS

Of 1,212,354 FIT participants, 4094 were diagnosed with SD-CRC, whereas 772 participants were diagnosed with CRC between FIT-screening rounds. Significant associations were shown between people not being SD for CRC and women, older individuals, right-sided tumour location and more advanced tumour stage. Furthermore, a clear distinction was shown between the right-sided and the left-sided colorectum concerning all above-mentioned variables and distributions of tumour stages.

CONCLUSION

The Flemish FIT-interval CRC proportion of 15.9% was within the limits of previously published results. In addition, calculations show that the effectiveness of the screening programme is dependent on tumour location, suggesting that future research should report results stratified by location.