Participation in a government-subsidised colorectal cancer screening programme for asymptomatic individuals in Hong Kong

1Background

Colorectal cancer (CRC) is the second most common cancer and the second leading cause of cancer death among men and women globally. In 2020, the age-standardized incidence and mortality rates for CRC were 19.5 and 9.0 per 100,000 individuals, respectively [1] . CRC can be prevented or detected early through screening. A guaiac faecal occult blood test (gFOBT) or a faecal immunochemical test (FIT) for haemoglobin, sigmoidoscopy and colonoscopy are procedures that are recommended to aid screening. Adults between the ages of 50 and 75 years are recommended to undergo a gFOBT/FIT annually or biennially, a sigmoidoscopy once every 5 years, or colonoscopy once every 10 years [2] . Previous work has shown that individuals who had their CRC detected by gFOBT screening had higher five-year survival than those who did not [3] .

Despite the effectiveness of CRC screening, rates of uptake vary across countries and regions. According to Chan et al. [4] , the percentage of adults aged 50–75 years in Singapore who had been screened for colorectal cancer using the gFOBT, sigmoidoscopy or colonoscopy was 49.0% [4] . A previous study on Chinese individuals in Hong Kong who were of a similar age group (aged 50 years or above) documented lower rates of uptake for gFOBT and colonoscopies, at 19% and 12%, respectively [5] . Among this population, common reasons for not undergoing screening included thinking that the screening was unnecessary, lacking a doctor’s recommendation and lacking knowledge about the tests available [5] . Apart from these factors, the higher uptake rate among the population in Singapore compared with that in the population in Hong Kong could be attributed to the former’s implementation of a population-based colorectal cancer control programme since 2011 [4] . In order to encourage more individuals to undergo CRC screenings, a CRC screening programme (CRCSP) was piloted in Hong Kong in 2016. The CRCSP subsidises the costs of obtaining a FIT for asymptomatic individuals who are aged 50–75 years in private health clinics. Under the CRCSP, participants should first meet a primary care doctor in the clinic and be assessed for eligibility. They then sign a consent form and receive an FIT kit for stool specimen collection. A subsidised follow-up colonoscopy is arranged whenever a positive result is obtained [6] . Those who obtain a negative FIT result repeat the FIT every 2 years. In the pilot programme, an initial participation rate of 8.3% was observed. Among 66,697 participants, 8724 (13.1%) of them obtained a positive FIT. Further, 7203 of them underwent a colonoscopy, and 68.9% of them were found to have adenoma [6] . In view of the success of the pilot programme in identifying these precancerous lesions, the programme was later adopted in 2018 and fully implemented in 2020.

This report presents the results of analysis of the participation rate in the CRCSP in Hong Kong among Chinese individuals aged from 50–75 years. The report also identifies individuals’ reasons for not joining the CRCSP for a FIT.