Reply to screening for colorectal cancer in Taiwan and France: Does the fecal immunochemical test (FIT) fit?
Journal
Cancer
Journal Volume
121
Journal Issue
24
Pages
4442-4443
Date Issued
2015
Author(s)
Abstract
We appreciate the commentary written by Dr. Braillon, which raises several important issues pertinent to a population-based colorectal cancer (CRC) screening program. The first enquiry pertains to why a screening program was implemented so late in Taiwan given the existing clinical evidence regarding the guaiac fecal occult blood test (gFOBT). When implementing a population-screening program, there are several aspects that need to be prudently considered. First, a population-based, organized services screening program for FOBT not only involves stool sampling but also clinical verification and the diagnostic process, treatment and therapies, and follow-up. Accordingly, constructing infrastructure such as the methods of invitation to screening, collection of stool samples, referral system, diagnostic workup, screening database, cancer registry, and death registry is mandatory. To test these practical and clinical aspects, a pilot community-based screening program was used from 1999 to 2003 to evaluate the feasibility of a screening program using the fecal immunochemical test (FIT)1 and to determine its optimal cutoff.2 Moreover, the legal aspect through legislation is also crucial for providing information concerning the follow-up of ascertaining clinically detected cancers (such as interval cancers and cancers from nonparticipants) that plays a key role in the evaluation of a population-based cancer screening program. In Taiwan, after the Cancer Control Act was enacted in 2003, the comprehensiveness and good quality of the cancer registry database could then be achieved. The second enquiry is regarding the significance of CRC mortality reduction. In addition to the 62% reduction in CRC mortality noted for screened subjects compared with unscreened subjects, we also provided the adjusted figure of a 10% reduction in mortality given 21.4% coverage compared with the scenario in the absence of screening (ie, the uninvited rather than the unscreened). Despite a mere 10% reduction in mortality, it was still statistically significant (95% confidence interval, 6%-16%) given the small coverage of the initial screening program. To project the effectiveness of reducing mortality with expanded coverage, a significant 36% reduction in mortality would be achieved at a 60% screening rate and 30% repeat screening rate.3 Regarding the uptake of screening, the information concerning the availability of this screening program was publicized through the media, CRC awareness campaigns, and an outreach screening service unit launched in each municipality (partially by telephone or letter invitation), and therefore we could not ascertain the real uptake of FIT. This accounts for why only the screening rate was reported. Third, our choosing FIT as the primary screening tool was based on several reasons. The advantages of using FIT over gFOBT have been well addressed in previous literature.4 It is highly automated and enables high-throughput analysis, and is specific for lower gastrointestinal bleeding. A previous head-to-head comparison trial demonstrated that FIT has comparable specificity but superior sensitivity for early cancers and advanced adenoma compared with gFOBT.5 Moreover, it has been shown that public acceptance of FIT was 12% to 13% higher compared with gFOBT.6 To our knowledge to date, although there is still a lack of trials comparing FIT and gFOBT in terms of reducing CRC-related mortality in an average-risk population, the results of a simulation study demonstrated that effectiveness in reducing CRC death is superior with FIT than with gFOBT.7 A recent study from Italy demonstrated a reduction in CRC mortality in regions in which screening with FIT was adopted compared with others, which is consistent with the results we obtained.8 Collectively, it is highly anticipated that FIT can achieve a greater effectiveness compared with gFOBT if the coverage rate is enhanced and the cohort is followed for an equivalent long period of time. With regard to the higher detection of CRC in men compared with women, this finding is the result of different disease prevalence rates in the target population, which is consistent with the findings from other programs and also comparable to the well-established evidence that males have a higher incidence rate than females.9 Finally, we agree that attention should be paid to every step of the screening program. In the Taiwanese program, we have monitored the entire screening process with a central screening database through various indicators and linkage to the national death and cancer registry so as to evaluate the long-term outcome. Last but not least, we should identify any barriers for public participation such that we can maximize the effectiveness of this population-based, organized service screening program. No specific funding was disclosed. The authors made no disclosures. Han-Mo Chiu, MD, PhD Department of Internal Medicine College of Medicine National Taiwan University Taipei, Taiwan Hsiu-Hsi Chen, PhD Graduate Institute of Epidemiology and Prevention Medicine College of Public Health National Taiwan University Taipei, Taiwan
SDGs
Publisher
John Wiley and Sons Inc.
Type
letter