Risk Scoring Systems for Predicting the Presence of Colorectal Neoplasia by Fecal Immunochemical Test Results in Chinese Population

Age, frequency, and strategy optimization for organized colorectal cancer screening: a decision analysis conducted in China for the years 2023-2038

BACKGROUND

The colorectal cancer mortality rate in China has exceeded that in many developing countries and is expected to further increase owing to multiple factors, including the aging population. However, the optimal policy for colorectal cancer screening is unknown.

METHODS

We synthesized the most up-to-date data using a 12-state Markov model populated with a cohort of Chinese men and women born during 1949-1988, and evaluated 16 conventional and 40 risk-tailored schemes for colorectal cancer screening, considering possible combinations of age (starting at 40 + years and ending at 75 years), frequency, and strategy (standard colonoscopy, fecal immunochemical testing with colonoscopy if positive, or risk-tailored). We projected the incidence and mortality of CRC, cost, and quality-adjusted life years for 2023-2038; and performed incremental cost-effectiveness, probability acceptability, and sensitivity analyses to identify the optimal scheme and the factors affecting this choice.

RESULTS

By 2038, all standard colonoscopy, colonoscopy following fecal immunochemical testing, and risk-tailored schemes were effective in reshaping China's colorectal cancer trajectory, with relative reductions in colorectal cancer incidence and mortality rates of up to 34% and 33.7%, respectively, versus no screening. Two standard colonoscopy, one colonoscopy following fecal immunochemical testing, and four risk-tailored schemes were efficient using a starting age of 40 years. Among these options, a risk-tailored scheme (standard colonoscopy every 5 years for high-risk and annual fecal immunochemical testing screening for moderate-to-low-risk) had a high probability (31.1%) of being optimal (with ≥ 40% uptake for a high-risk population, in particular), given China's present per capita gross domestic product, and would yield the highest gain in quality-adjusted life years in 17 of 31 provinces.

CONCLUSIONS

Our findings suggest the commencement of colorectal cancer screening at 40 years of age in China, and that risk-tailored and some conventional schemes would be effective and cost-efficient. These findings should be valuable for policy-making regarding cancer control and resource allocation.

Population-based screening for colorectal cancer in Wuhan, China

Fecal DNA test has emerged as a non-invasive alternative for colorectal cancer (CRC) screening in average-risk population. However, there is currently insufficient evidence in China to demonstrate the effectiveness of population-based CRC screening using fecal DNA based test. Here, a large-scale real-world study for CRC screening was implemented in Wuhan, Hubei province, China. A total of 98,683 subjects aged between 45 and 60 years were screened by a fecal DNA test (ColoTect®) which detected methylation status of SDC2, ADHFE1, and PPP2R5C. Participants who tested positive were advised to receive diagnostic colonoscopy. 4449 (4.5%) subjects tested positive for fecal DNA test, and 3200 (71.9%) underwent colonoscopy. Among these, 2347 (73.3%) had abnormal colonoscopy findings, of which 1330 (56.7%) subjects received pathological diagnosis. Detection rates for CRC and advanced precancerous lesions were 1.3% and 2.3%, respectively. Detection rates for nonadvanced adenomas and polyps were 14.0% and 21.6%, respectively. 28.0% of all colonoscopies showed colorectal neoplasm but lack pathological diagnosis. 6.1% showed other abnormalities such as enteritis. In conclusion, preliminary real-world evidence suggested that fecal DNA tests had promising diagnostic yield in population-based CRC screening.

Clinical trial registration

https://www.chictr.org.cn/showproj.html?proj=192838, identifier ChiCTR2300070520.

Diagnostic accuracy of risk assessment and fecal immunochemical test in colorectal cancer screening: Results from a population-based program and meta-analysis

BACKGROUND

Fecal immunochemical test (FIT) is a commonly used initial test for colorectal cancer (CRC) screening. Parallel use of FIT with risk assessment (RA) could improve the detection of non-bleeding lesions, but at the expense of compromising sensitivity. In this study, we evaluated the accuracy of FIT and/or RA in the Shanghai CRC screening program, and systematically reviewed the relevant evaluations worldwide.

METHODS

RA and 2-specimen FIT were used in parallel in the Shanghai screening program, followed by a colonoscopy among those with positive results. Sensitivity, specificity, detection rate of CRC, positive predictive value (PPV), and other measures with their 95% confident intervals were calculated for each type of tests and several assumed combined tests. We further searched PubMed, Embase, Web of Science, and Cochrane Library for relevant studies published in English up to January 5, 2022.

RESULTS

By the end of 2019, a total of 1,901,360 participants of the screening program completed 3,045,108 tests, with 1,901,360 first-time tests and 1,143,748 subsequent tests. Parallel use of RA and 2-specimen FIT achieved a sensitivity of 0.78 (0.77-0.80), a specificity of 0.78 (0.78-0.78), PPV of 0.89% (0.86-0.92), and a detection rate of 1.99 (1.93-2.05) for CRC per 1000 among participants enrolled in the first screening round, and performed similarly among those who participated for several times. A meta-analysis of 103 published observational studies demonstrated a higher sensitivity [0.76 (0.36, 0.94)] but a much lower specificity [0.59 (0.28, 0.85)] of parallel use of RA and FIT for detecting CRC in average-risk populations than in our subjects. One-specimen FIT, the most commonly used initial test, had a pooled specificity comparable to the Shanghai screening program (0.92 vs. 0.91), but a much higher pooled sensitivity (0.76 vs. 0.57).

CONCLUSION

Our results indicate the limitation of FIT only as an initial screening test for CRC in Chinese populations, and highlight the higher sensitivity of parallel use of RA and FIT. Attempts should be made to optimize RA to improve effectiveness of screening in the populations.