Factors associated with interval colorectal cancer after negative FIT: Results of two screening rounds in the Dutch FIT-based CRC screening program

Interval cancer risk after the upper age limit of screening has been reached: Informing risk stratification in FIT-based colorectal cancer screening

Upper age limits are currently fixed for all fecal immunochemical test (FIT)-based colorectal cancer (CRC) screening programs. A risk-stratified upper age limit may be beneficial. Therefore, we assessed differences in interval CRC risk among individuals who had reached the upper age limit of screening (75 years). Individuals with a negative FIT (<47 μg Hb/g feces) in the final round of the Dutch CRC screening program were selected from the national screening database and linked to the national cancer registry to identify CRCs diagnosed within 24 months (interval CRCs). Survival analyses assessed whether sex and last fecal hemoglobin (f-Hb) concentration were associated with interval CRC risk. A multivariable logistic regression assessed whether sex, last f-Hb concentration and screening round were associated with stage distribution (early vs. late). Last f-Hb concentrations were considered detectable when they were >0 μg Hb/g feces. Among 305,761 individuals with a complete follow-up (24 months), 661 were diagnosed with interval CRC (21.6 per 10,000 negative FITs). Individuals with detectable f-Hb (15%) were 5 times more likely to be diagnosed with interval CRC than those without (HR 4.87, 95%CI: 4.19-5.65). Moreover, their cancers were more often detected at a late stage compared to individuals without detectable f-Hb (OR 1.45, 95%CI: 1.06-2.01). Our results show that interval CRC risk among individuals aged ≥75 differs substantially by last f-Hb concentration, indicating a uniform age to stop screening is suboptimal. Future research, taking into account multiple screening rounds and FIT results, should determine the optimal risk-stratified screening strategy.

Fecal Hemoglobin Levels in Prior Negative Screening and Detection of Colorectal Neoplasia: A Dose-Response Meta-Analysis

BACKGROUND & AIMS

Prior studies have shown that individuals with fecal hemoglobin (f-Hb) concentrations just below the positivity cutoff have an increased colorectal cancer risk compared with those with no or low f-Hb. Understanding the dose-response association between f-Hb in a prior screening round and the detection of colorectal neoplasia is crucial for tailoring risk-based screening recommendations.

METHODS

We searched the literature to identify studies reporting the association between f-Hb in prior screening round and colorectal neoplasia detection in an average-risk population. Analysis involved a 2-stage approach using log-log regression models to assess dose-response relationships across studies, with effect sizes pooled using a random effects model. Heterogeneity was assessed by excluding individual studies in sensitivity analyses. Subgroup analyses examined variations in effects by outcome definitions and detection methods.

RESULTS

This systematic review and meta-analysis included 13 studies with 4,493,672 individuals. All studies demonstrated a positive association between f-Hb in prior screenings and colorectal neoplasia detection. Pooled analysis revealed that individuals with f-Hb concentrations of 5, 10, 20, and 40 μg/g had a 3-, 5-, 8-, and 13-fold higher risk of colorectal neoplasia, respectively, compared with individuals with 0 μg/g. Although significant heterogeneity (I2 = 97.5%, P < .001) was observed, sensitivity analyses confirmed the consistency of findings. Subgroup analyses indicated that f-Hb concentrations from previous negative tests were especially predictive of advanced neoplasia in subsequent screenings.

CONCLUSIONS

Our findings suggest that the risk of detecting colorectal neoplasia increases with prior f-Hb concentrations in negative tests, supporting the development of risk-stratified screening strategies based on these concentrations.

Insights Into Colorectal Cancer Screening: A Multidatabase Cohort Study of Over 1.5 Million Taiwanese

INTRODUCTION

Colorectal cancer (CRC) remains a significant public health concern. This study aims to provide a comprehensive understanding of the effectiveness of fecal immunochemical test (FIT) screening on CRC incidence and mortality, leveraging the scale of over 1.5 million randomly selected Taiwanese and more than 11.7 million person-years of follow-up.

METHODS

This prospective cohort study merges data from 3 robust Taiwanese health databases: the CRC screening program, cancer registration, and death registration databases. Incidence and mortality rates of CRC were calculated based on age, sex, urbanization, and past screening status. Cox proportional hazard models were used to assess the association between screening statuses and CRC incidence or mortality, adjusting for age, sex, and urbanization levels. Statistical analysis of the data was conducted in 2021-2022.

RESULTS

FIT screening was associated with a 33% reduction in CRC incidence and a 47% reduction in mortality. The study identified a dose-response relationship between the fecal hemoglobin concentration (f-HbC) levels and CRC risk. Participants with consistent FIT-negative results had significantly reduced CRC incidence and mortality risks, while those with one or more positive FIT results faced increased risks. Notably, compliance with follow-up examinations after a positive FIT significantly lowered mortality risk.

CONCLUSIONS

This large-scale study validates the efficacy of FIT screening in reducing CRC incidence and mortality. It offers a nuanced understanding of how various screening statuses impact CRC risks, thus providing valuable insights for public health strategies aimed at CRC prevention.

Real-world data evaluating Guy's rapid diagnostic clinic as an alternate pathway for patients with FIT levels below 10

OBJECTIVE

To analyse the effectiveness of rapid diagnostic clinics (RDCs) as an alternative pathway for patients with concerning symptoms and a faecal immunochemical test (FIT) result <10. Our primary endpoint was rate of colorectal cancer (CRC) detection. Second endpoints were rates of other cancers and gastrointestinal (GI) serious benign conditions. Finally, we analysed the specific pathway followed by FIT <10 patients with cancer at Guy's and St Thomas NHS Foundation Trust (GSTT) RDC.

DESIGN

A retrospective and prospective cohort study.

SETTING

GSTT RDC, one of England's largest single-centre RDCs. Sociodemographic and clinical characteristics of FIT <10 patients were analysed descriptively.

PARTICIPANTS

Patients with an FIT result <10, seen at GSTT RDC between 1 January 2020 and 5 May 2023.

RESULTS

A total of 1299 patients with an FIT<10 were seen at GSTT RDC between January 2020 and May 2023. Of these, 66% (n=861) reported weight loss, 62% (n=805) pain, 37% (n=481) fatigue, 34% (n=444) were anaemic and 23% (n=301) had nausea and vomiting. Among these patients, 7% (n=88) received a cancer diagnosis, 36% (n=462) were identified as having a serious benign condition. Within the patients with cancer, 9% (n=8) were diagnosed with CRC. Among patients with serious benign conditions, 7% (n=31) were referred to colorectal, hepatopancreatobiliary, or upper GI specialists.

CONCLUSION

This study demonstrates the effectiveness of RDCs as an alternate pathway for FIT <10 patients with ongoing clinical concerns. These results contribute to enhancing patient care and optimising resource allocation within the healthcare system.

Interval Cancer in Population-Based Colorectal Screening Programmes: Incidence and Characteristics of Tumours

The objective of this study is to evaluate interval cancer (IC) in colorectal cancer (CRC) screening, which is CRC diagnosed in an individual after having received a negative faecal occult blood test and before the next invitation to participate in screening. A follow-up study was conducted on a cohort of participants in the first three screening rounds of four colorectal cancer screening programmes in Spain, n = 664,993. A total of 321 ICs and 2120 screen-detected cancers (SCs) were found. The IC and SC rates were calculated for each guaiac (gFOBT) or immunochemical (FIT) test. A Cox regression model was used to estimate the hazard ratios (HR) of IC risk factors. A nested case-control study was carried out to compare IC and SC tumour characteristics. The IC rate was 1.16‱ with the gFOBT and 0.35‱ with the FIT. Men and people aged 60-69 showed an increased probability of IC (HR = 1.81 and HR = 1.95, respectively). There was a decreased probability of IC in individuals who regularly participated in screening, HR = 0.62 (0.47-0.82). IC risk gradually rose as the amount of Hb detected in the FIT increased. IC tumours were in more advanced stages and of a larger size than SC tumours, and they were mostly located in the cecum. These results may play a key role in future strategies for screening programmes, reducing IC incidence.

Improved use of faecal immunochemical tests for haemoglobin in the Scottish bowel screening programme

OBJECTIVES

This study aimed to develop a risk-scoring model in the Scottish Bowel Screening Programme incorporating faecal haemoglobin concentration with other risk factors for colorectal cancer.

METHODS

Data were collected for all individuals invited to participate in the Scottish Bowel Screening Programme between November 2017 and March 2018 including faecal haemoglobin concentration, age, sex, National Health Service Board, socioeconomic status, and screening history. Linkage with The Scottish Cancer Registry identified all screening participants diagnosed with colorectal cancer. Logistic regression was performed to identify which factors demonstrated significant association with colorectal cancer and could be used in the development of a risk-scoring model.

RESULTS

Of 232,076 screening participants, 427 had colorectal cancer: 286 diagnosed following a screening colonoscopy and 141 arising after a negative screening test result giving an interval cancer proportion of 33.0%. Only faecal haemoglobin concentration and age showed a statistically significant association with colorectal cancer. Interval cancer proportion increased with age and was higher in women (38.1%) than men (27.5%). If positivity in women were mirrored in men at each age quintile interval cancer proportion would still have remained higher in women (33.2%). Moreover, an additional 1201 colonoscopies would be required to detect 11 colorectal cancers.

CONCLUSIONS

Development of a risk scoring model using early data from the Scottish Bowel Screening Programme was not feasible due to most variables showing insignificant association with colorectal cancer. Tailoring the faecal haemoglobin concentration threshold according to age could help to diminish some of the disparity in interval cancer proportion between women and men. Strategies to achieve sex equality using faecal haemoglobin concentration thresholds depend considerably on which variable is selected for equivalency and this requires further exploration.

Interval colorectal cancers after negative faecal immunochemical test in the New Zealand Bowel Screening Pilot

OBJECTIVE

Evaluate the diagnostic performance of faecal immunochemical test (FIT), identify risk factors for FIT-interval colorectal cancers (FIT-IC) and describe long-term outcomes of participants with colorectal cancers (CRC) in the New Zealand Bowel Screening Pilot (BSP).

DESIGN

From 2012 to 2017, the BSP offered eligible individuals, aged 50-74 years, biennial screening using a quantitative FIT with positivity threshold of 15 µg haemoglobin (Hb)/g faeces. Retrospective review of prospectively maintained data extracted from the BSP Register and New Zealand Cancer Registry identified any CRC reported in participants who returned a definitive FIT result. Further details were obtained from hospital records. FIT-ICs were primary CRC diagnosed within 24 months of a negative FIT. Factors associated with FIT-ICs were identified using logistic regression.

RESULTS

Of 387 215 individuals invited, 57.4% participated with 6.1% returning positive FIT results. Final analysis included 520 CRC, of which 111 (21.3%) met FIT-IC definition. Overall FIT sensitivity for CRC was 78.7% (95% CI=74.9% to 82.1%), specificity was 94.1% (95% CI=94.0% to 94.2%). In 78 (70.3%) participants with FIT-IC, faecal Hb was reported as undetectable. There were no significant associations between FIT-IC and age, sex, ethnicity and deprivation. FIT-ICs were significantly associated with proximal tumour location, late stage at diagnosis, high-grade tumour differentiation and subsequent round screens. Median follow-up time was 74 (2-124) months. FIT-IC had significantly poorer overall survival.

CONCLUSION

FIT sensitivity in BSP compared favourably to published data. FIT-ICs were more likely to be proximal tumours with poor long-term outcomes. Further lowering of FIT threshold would have minimal impact on FIT-IC.

Personalised colorectal cancer screening strategies: Information needs of the target population

Prior faecal Hemoglobin (f-Hb) concentrations of a negative fecal immunochemical test (FIT) can be used for risk stratification in colorectal cancer (CRC) screening. Individuals with higher f-Hb concentrations may benefit from a shorter screening interval (1 year), whereas individuals with undetectable f-Hb concentrations could benefit from a longer screening interval (3 year). Individuals' views on personalised CRC screening and information needed to make a well-informed decision is unknown. We conducted three semi-structured focus groups among individuals eligible for CRC screening (i.e. men and women aged 55 to 75) in the Netherlands. Thematic analysis was used to analyse participants' information need on personalised CRC screening strategies. Fourteen individuals took part. The majority were positive about CRC screening and indicated that they would participate in personalised CRC screening. The rationale for a longer interval among those at lowest risk was, however, unclear for many. The preferred information on individual risk was variable: ranging from full information to only information on the personalised strategy without mentioning the risk. It was not possible to address everyone's need with a single approach. Additional communications, e.g. public media campaigns, billboards, videos on social media, were also suggested as necessary. This study showed that preferences on receiving information on individual CRC risk varied substantially and no consensus was reached. Introducing a personalised screening programme will require careful communication, particularly around the rationale for the strategy, and a layered approach to deliver information.

Socioeconomic inequalities in interval colorectal cancer are explained by differences in faecal haemoglobin concentration and age: a register-based cohort study

OBJECTIVE

To estimate the risk of interval colorectal cancer (CRC) in faecal immunochemical test (FIT) negative screening participants according to socioeconomic status.

DESIGN

In this register-based study, first round FIT negative (<20 µg hb/g faeces) screening participants (biennial FIT, citizens aged 50-74) were followed to estimate interval CRC risk. Multivariate Cox proportional hazard regression models estimated HRs based on socioeconomic status defined by educational level and income. Models were adjusted for age, sex and FIT concentration.

RESULTS

We identified 829 (0.7‰) interval CRC in 1 160 902 individuals. Interval CRC was more common in lower socioeconomic strata with 0.7‰ for medium-long higher education compared with 1.0‰ for elementary school and 0.4‰ in the highest income quartile compared with 1.2‰ in the lowest. These differences did not translate into significant differences in HR in the multivariate analysis, as they were explained by FIT concentration and age. HR for interval CRC was 7.09 (95% CI) for FIT concentrations 11.9-19.8 µg hb/g faeces, and 3.37 (95% CI) for FIT between 7.2 and 11.8 compared with those <7.2. The HR rose with increasing age ranging from 2.06 (95% CI 1.45 to 2.93) to 7.60 (95% CI 5.63 to 10.25) compared with those under 55 years.

CONCLUSION

Interval CRC risk increased with decreasing income, heavily influenced by lower income individuals more often being older and having increased FIT concentrations. Individualising screening interval based on age and FIT result, may decrease interval CRC rates, reduce the social gradient and thereby increase the screening efficiency.