Interval post-colonoscopy colorectal cancer following a negative colonoscopy in a fecal immunochemical test-based screening program

BACKGROUND

 In the Dutch colorectal (CRC) screening program, fecal immunochemical test (FIT)-positive individuals are referred for colonoscopy. If no relevant findings are detected at colonoscopy, individuals are reinvited for FIT screening after 10 years. We aimed to assess CRC risk after a negative colonoscopy in FIT-positive individuals.

METHODS

 In this cross-sectional cohort study, data were extracted from the Dutch national screening information system. Participants with a positive FIT followed by a negative colonoscopy between 2014 and 2018 were included. A negative colonoscopy was defined as a colonoscopy during which no more than one nonvillous, nonproximal adenoma < 10 mm or serrated polyp < 10 mm was found. The main outcome was interval post-colonoscopy CRC (iPCCRC) risk. iPCCRC risk was reviewed against the risk of interval CRC after a negative FIT (FIT IC) with a 2-year screening interval.

RESULTS

 35 052 FIT-positive participants had a negative colonoscopy and 24 iPCCRCs were diagnosed, resulting in an iPCCRC risk of 6.85 (95 %CI 4.60-10.19) per 10 000 individuals after a median follow-up of 1.4 years. After 2.5 years of follow-up, age-adjusted iPCCRC risk was approximately equal to FIT IC risk at 2 years.

CONCLUSION

 Risk of iPCCRC within a FIT-based CRC screening program was low during the first years after colonos-copy but, after 2.5 years, was the same as the risk in FIT-negative individuals at 2 years, when they are reinvited for screening. Colonoscopy quality may therefore require further improvement and FIT screening interval may need to be reduced after negative colonoscopy.

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

The interval colorectal cancer (CRC) rate after negative fecal immunochemical testing (FIT) is an important quality indicator of CRC screening programs. We analyzed the outcomes of two rounds of the FIT-based CRC screening program in the Netherlands, using data from individuals who participated in FIT-screening from 2014 to 2017. Data of individuals with one prior negative FIT (first round) or two prior negative FITs (first and second round) were included. Outcomes included the incidence of interval CRC in FIT-negative participants (<47 μg Hb/g feces [μg/g]), FIT-sensitivity, and the probability of detecting an interval CRC by fecal hemoglobin concentration (f-Hb). FIT-sensitivity was estimated using the detection method and the proportional incidence method (based on expected CRC incidence). Logistic regression analysis was performed to estimate whether f-Hb affects probability of detecting interval CRC, adjusted for sex- and age-differences. Incidence of interval CRC was 10.4 per 10 000 participants after the first and 9.6 after the second screening round. FIT-sensitivity based on the detection method was 84.4% (95%CI 83.8-85.0) in the first and 73.5% (95% CI 71.8-75.2) in the second screening round. The proportional incidence method resulted in a FIT-sensitivity of 76.4% (95%CI 73.3-79.6) in the first and 79.1% (95%CI 73.7-85.3) in the second screening round. After one negative FIT, participants with f-Hb just below the cut-off (>40-46.9 μg/g) had a higher probability of detecting an interval CRC (OR 16.9; 95%CI: 14.0-20.4) than had participants with unmeasurable f-Hb (0-2.6 μg/g). After two screening rounds, the odds ratio for interval CRC was 12.0 (95%CI: 7.8-17.6) for participants with f-Hb just below the cut-off compared with participants with unmeasurable f-Hb. After both screening rounds, the Dutch CRC screening program had a low incidence of interval CRC and an associated high FIT-sensitivity. Our findings suggest there is a potential for further optimizing CRC screening programs with the use of risk-stratified CRC screening based on prior f-Hb.

Colonoscopy-Related Mortality in a Fecal Immunochemical Test-Based Colorectal Cancer Screening Program

BACKGROUND & AIMS

Many countries have introduced colorectal cancer (CRC) screening programs with fecal immunochemical tests (FITs), and follow-up colonoscopies for individuals with a positive FIT result. In order to make an informed decision to participate, individuals must be informed about the benefits and harms of FIT-based screening and subsequent colonoscopy. Colonoscopy-related fatal complications in FIT-based screening are understudied. We aimed to estimate the colonoscopy-related mortality in a national FIT-based CRC screening program.

METHODS

Colonoscopy-related mortality within 30 days after colonoscopy was assessed by analysis of data from national endoscopy complication databases in the Netherlands, determining the excess 30-day rate of death in FIT-positive individuals undergoing colonoscopy vs FIT-negative individuals (based on data from the national screening database), and determining the rate of likely colonoscopy-related deaths based on registered causes of death by the Statistics Netherlands.

RESULTS

Between October 2013 and December 2017, 172,797 participants underwent colonoscopy after a positive result from a FIT in the Dutch national CRC screening program; 13,848 participants received a diagnosis of CRC. The reported fatal complication rate was 0.23 per 10,000 FIT-positive participants (or 1 per 43,199; 95% CI, 0.090 - 0.60) undergoing colonoscopy, whereas this was 0.91 per 10,000 FIT-positive participants (or 1 per 10,961; 95% CI, 0.44 - 1.38) according to the excess death rate. Likely colonoscopy-related causes of death were reported in 0.86 per 10,000 FIT-positive participants (or 1 per 11,236; 95% CI, 0.48 - 1.63) who underwent colonoscopy, of which 50% considered cardiovascular events.

CONCLUSIONS

Colonoscopy-related mortality within the Dutch FIT-based CRC screening program was estimated to range from 0.23 to 0.91 per 10,000 FIT-positive participants undergoing colonoscopy. These findings indicate underreporting of fatal complications in registries and a noteworthy incidence of fatal cardiovascular adverse events that requires further investigation. Nevertheless, the harm of FIT-based CRC screening is vastly outweighed by the benefits.

Incidence of Interval Colorectal Cancer After Negative Results From First-Round Fecal Immunochemical Screening Tests, by Cutoff Value and Participant Sex and Age

BACKGROUND & AIMS

We evaluated the incidence of interval cancers between the first and second rounds of colorectal cancer (CRC) screening with the FOB-Gold fecal immunochemical test (FIT), and the effects of different cutoff values and patient sex and age.

METHODS

We collected data from participants in a population-based CRC screening program in the Netherlands who had a negative result from a first-round of FIT screening. We calculated the cumulative incidence of interval cancer after a negative result from a FIT and the sensitivity of the FIT for detection of CRC at a low (15 μg Hb/g feces) and high (47 μg Hb/g feces) cutoff value.

RESULTS

Among the 485,112 participants with a negative result from a FIT, 544 interval cancers were detected; 126 were in the 111,800 participants with negative results from a FIT with the low cutoff value and 418 were in the 373,312 FIT participants with negative results from a FIT with the high cutoff value. The mean age of participants tested with the low cutoff value was 72.0 years and the mean age of participants tested the high cutoff value was 66.7 years. The age-adjusted 2-year cumulative incidence of interval cancer after a negative result from a FIT were 9.5 per 10,000 persons at the low cutoff value vs 13.8 per 10,000 persons at the high cutoff value (P < .005). The age-adjusted sensitivity of the FIT for CRC were 90.5% for the low cutoff value vs 82.9% for the high cutoff (P < .0001). The FIT identified men with CRC with 87.4% sensitivity and women with CRC with 82.6% sensitivity (P < .001).

CONCLUSIONS

In an analysis of data from a FIT population-based screening program in the Netherlands, we found that incidence of interval CRC after a negative result from a FIT to be low. Although the sensitivity of detection of CRC decreased with a higher FIT cutoff value, it remained above 80%.

The second round of the Dutch colorectal cancer screening program: Impact of an increased fecal immunochemical test cut-off level on yield of screening

The Dutch colorectal cancer (CRC) screening program started in 2014, inviting the target population biennially to perform a fecal immunochemical test (FIT). We obtained prospectively collected data from the national screening information‐system to present the results of the second round (2016) and evaluate the impact of increasing the FIT cut‐off halfway through the first round from 15 to 47 μg Hb/g feces on outcomes in the second round. Second round screening was done with a 47 μg Hb/g feces FIT cut‐off. Participants were classified based on first round participation status as either FIT (15,47) or FIT (47,47) participants, and previous nonparticipants. In total, 348,891 (75.9%) out of 459,740 invitees participated in the second round. Participation rates were 93.4% among previous participants and 21.0% among previous non‐participants. FIT(47,47) participants had a significantly higher detection rate of AN (15.3 vs. 10.4 per 1,000 participants) compared to FIT(15,47) participants in the second round, while their cumulative detection rate of AN over two rounds was significantly lower (45.6 vs. 52.6 per 1,000 participants). Our results showed that participation in the Dutch CRC screening program was consistently high and that second round detection rates depended on the first round FIT cut‐off. The cumulative detection over two rounds was higher among FIT(15,47) participants. These findings suggest that a substantial part of, but not all the missed findings in the first round due to the increased FIT cut‐off were detected in the subsequent round.

What's new?

In 2014, the Netherlands implemented colorectal cancer (CRC) screening based on non‐invasive fecal immunochemical testing (FIT), which offers a practical approach for population‐based CRC detection. In the Dutch program's first round, to match local resources, FIT cut‐off was increased, resulting in reduced positivity rates and reduced colonoscopy referrals, at the cost of missing advanced neoplasias. The current study shows that many of these missed advanced neoplasias were detected in subsequent screening, suggesting that increased FIT cut‐off had marginal impact on screening outcome. The findings could benefit other CRC screening programs in establishing effective FIT cut‐offs.

Change in incidence, characteristics and management of colorectal neuroendocrine tumours in the Netherlands in the last decade

BACKGROUND

Neuroendocrine tumours (NETs) are rare. However, a rising incidence has been reported over the past decades. For colorectal NETs, this is presumably caused by an increased awareness of colorectal diseases and colonoscopic procedures. This study aims to analyse the change in incidence of colorectal NETs, characteristics and management and evaluate the proportion of colorectal NETs detected in a national colorectal cancer (CRC) screening programme.

METHODS

Histopathological reports on colorectal well-differentiated NETs detected between 2006 and 2016 were collected from the Dutch pathology database (PALGA) containing nationwide histo- and cytopathology reports of all pathology laboratories in the Netherlands.

RESULTS

Colorectal NETs were detected in 1055 individuals. Increasing incidence rates were observed from 0.36 per 100,000 inhabitants in 2006 to 0.75 per 100,000 inhabitants in 2011 (p value < 0.001), remaining stable afterward. Most NETs were grade I (73.5%) and detected in the rectum (76.4%). The majority (88.2%) were detected by colonoscopy, and the final intervention depended significantly on primary location of the tumour; 94.6% of rectal NETs were endoscopically removed, whereas 61.0% of colonic NETs were removed by surgery. There was an increase in local excision both of rectal and colonic NETs over the years instead of radical resection. Screening for CRC started in 2014 and contributed by detecting 32% of the diagnosed colorectal NETs within the invited age group, of which 94.6% were detected at an early stage.

CONCLUSION

The incidence of reported colorectal NETs in the Netherlands doubled over the last decade. The Dutch CRC screening programme had a clear contribution to colorectal NETs incidence among its target population. A shift to more local management of detected lesions was observed over time.