Efectiveness of population based colorectal cancer screening programebin shifing cancer stage to earlier disease

of population-based colorectal cancer screening iew ed Effectiveness programme in shifting cancer stage to earlier disease Chi-Ching Law a, Connie H.N Wong b, Patrick S.K Chong c, Oscar W.K Mang b,*, Albert W.H Lam c, Michelle M.Y Chak c, Rachel S.P Lee b, Keziah a pe er re v N.T Yip c, Kam-Hung Wong a,b, Rita K.W Ho c Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong, China b Hong Kong Cancer Registry, Hospital Authority, Hong Kong, China c Department of Health, Hong Kong, China * Corresponding author at: Hong Kong Cancer Registry, Hospital Authority, Hong Kong ot E-mail address: mangwk@ha.org.hk (Oscar W.K Mang) Word count of Abstract: 249 Pr ep rin tn Word count of manuscript: 2,996 This preprint research paper has not been peer reviewed Electronic copy available at: https://ssrn.com/abstract=4005927 iew ed ABSTRACT Background: This is the first evaluation study to assess the demographic characteristics of the colorectal cancer (CRC) cases detected in the prevalent round of the population-based Colorectal Cancer Screening Programme (CRCSP) in Hong Kong and to explore the effectiveness of the programme on the stage distribution of CRC pe er re v Methods: This study covered the period between 28 September 2016 and 31 December 2018 Information on CRC diagnosis, age and stage at diagnosis were retrieved and reviewed by the Hong Kong Cancer Registry (HKCaR) The CRC detection rate among participants of the CRCSP and incidence rate among the Hong Kong general population were calculated respectively, along with the odds ratio (OR) to measure the strength of association and quantify the effect of CRCSP on stage shift Results: The CRC detection rate among participants of the CRCSP during the ot study period was 736.0/100,000, whereas the overall CRC incidence rate among general population of similar age groups was 393.7/100,000 The OR tn of 3.91 at stage I dropped to 0.54 at stage IV for all ages and both sexes Meanwhile, the OR dropped from 2.24 to 1.62 with increasing age rin Conclusion: The present study has demonstrated the initial impact of the CRCSP on shifting the stage at diagnosis towards earlier stage The benefit of ep stage-shift was similar for all ages from 60 to 77 in both sexes and seems to increase with younger age Given the stage-dependent survival outcomes, this stage-shift could lead to a reduction in CRC-associated mortality in Hong Kong Pr in future This preprint research paper has not been peer reviewed Electronic copy available at: https://ssrn.com/abstract=4005927 Colorectal cancer Population-based screening programme Staging Pr ep rin tn ot pe er re v Sex/gender difference iew ed Keywords: This preprint research paper has not been peer reviewed Electronic copy available at: https://ssrn.com/abstract=4005927 iew ed Introduction Colorectal cancer (CRC) is a major public health problem The Global Burden of Disease Study showed that the incidence of CRC increased greatly from 0.83 million in 1990 to 1.83 million in 2017 [1] In Hong Kong, CRC has become the commonest cancer and the second ‘cancer killer’ According to the Hong Kong Cancer Registry, the number of CRC new cases increased from pe er re v 2,022 in 1990 to 5,634 in 2018, accounting for 16.6% of all new cancer cases diagnosed in 2018 Meanwhile, the number of deaths attributed to CRC also increased from 889 in 1990 to 2,314 in 2018, accounting for 15.9% of all cancer deaths in 2018 [2] Population-based CRC screening programmes have been introduced in many countries [3, 4] Colorectal cancer screening aims to mitigate the risk of CRC mortality through detection of cancer at earlier stages, and to reduce the tn adenomatous polyp ot incidence and mortality of CRC through detection and removal of precancerous The stage of CRC at diagnosis has a major impact on 5-year survival rates rin Overall survival is more favorable in patients detected by screening colonoscopy when compared to patients detected after the appearance of ep clinical symptoms [5] Studies evaluating the CRC screening programmes in Western populations have consistently shown the phenomenon of stage shift Pr towards earlier stage in CRC cases detected in screening as compared with those non-screening diagnosed cases [3, 6] Moreover, studies have demonstrated that screening programmes could lead to reduce incidence and This preprint research paper has not been peer reviewed Electronic copy available at: https://ssrn.com/abstract=4005927 iew ed mortality of CRC [7, 8] In Hong Kong, a government-subsidised, population-based Colorectal Cancer Screening Programme (CRCSP) has been launched by the Department of Health (DH) since September 2016 Participants first receive a Faecal Immunochemical Test (FIT), and a colonoscopy will be arranged if the FIT result pe er re v is positive Participants with negative FIT result will receive FIT re-screening every two years until the age of 75 [9] The present study aimed to assess the demographic characteristics of the CRC cases detected in the prevalent round of the CRCSP in Hong Kong and to evaluate the impact of the programme on the stage distribution of CRC 2.1 Study population ot Material and methods tn This was a retrospective cohort study covering the period between 28 September 2016 and 31 December 2018 In this period, the CRCSP was initiated in different phases: start from September 2016 for Hong Kong rin residents born in the years 1946 to 1948, in 2017 for residents born in the years 1946 to 1955, and in 2018 for residents born in the years 1942 to 1957 The ep cohort consisted of de-identified tabular data extracted from DH, which included all participants who enrolled the CRCSP with interpreted FIT results in the Pr corresponding periods As of the end of December 2018, over 115,000 Hong Kong residents enrolled the CRCSP Of those FIT-positive participants who were subsequently diagnosed with CRC, information on CRC diagnosis, date This preprint research paper has not been peer reviewed Electronic copy available at: https://ssrn.com/abstract=4005927 Kong Cancer Registry (HKCaR) iew ed and stage of disease at diagnosis were retrieved and reviewed by the Hong Individuals who participated and detected to have CRC in the CRCSP were compared with those in the rest of the target population The population at risk information was obtained from the Hong Kong Census and Statistics pe er re v Department and was used to calculate the CRC incidence rate [10] Annual counts of the population data by sex and corresponding single years of age (in aged 68–70 in 2016; aged 62–68 in 2017; and aged 61–62 and 73–76 in 2018) were selected as the target population Eligible persons who did not enroll in the CRCSP were classified as non-screened individuals All CRC cases diagnosed outside the CRCSP would be matched with the relevant birth cohorts by the HKCaR within the same period of time as “HKCaR cohort” The demographic data and stage at diagnosis of the two cohorts were evaluated ot based on the database of the HKCaR tn Cancer stage classification of the CRC was based on the 7th edition of the American Joint Committee on Cancer (AJCC) staging system [11] The stages rin at diagnosis were categorised as stage 0, I, II, III, and IV The stage at diagnosis was classified as “unknown” if there was inadequate available information for ep cancer staging Pr 2.2 Statistical analyses Data analyses for this study were performed using SPSS version 26 for Window (IBM Corporation) Proportion of age at diagnosis and cancer stage This preprint research paper has not been peer reviewed Electronic copy available at: https://ssrn.com/abstract=4005927 iew ed distribution between CRCSP-detected and HKCaR cohort, and further stratified by gender would be compared with the Chi-square (χ2) test All statistical tests were two-sided and a p-value less than 0.05 was considered statistically significant Age-specific CRC detection rates were calculated for each of the populations: participants of CRCSP and the rest of the target population of Hong Kong, along with the odds ratio (OR) of CRC among participants of the pe er re v CRCSP compared with those not yet participated with 95% confidence intervals (CIs) to measure the strength of association CRC detection per 100,000 and OR with 95% CIs of CRC at different stages would be likewise calculated for CRCSP-detected and HKCaR cohorts in order to quantify the effect of CRCSP on stage shift All results were then stratified by age group and gender Results From September 2016 to December 2018, a total of 1,217,800 Hong Kong ot residents were eligible for inclusion into the CRCSP As of 31 December 2018, a total of 115,223 Hong Kong residents participated in the CRCSP with tn interpreted FIT results, constituting around 9.5% of the target population The ratio of men to women on CRCSP participants was 1:1.2 As the programme rin commenced in late September 2016, there were some participants who were due for the second round of FIT screening starting from end September 2018 ep Among 848 participants detected with CRC by the programme, 17 participants were detected in the second round Compared with the rest of the target Pr population, there were 4,341 CRC patients detected within the same period of time, after matching with relevant birth cohorts The demographic characteristics of the two groups are summarised in Table This preprint research paper has not been peer reviewed Electronic copy available at: https://ssrn.com/abstract=4005927 iew ed For those individuals participated in the CRCSP, the CRC detection rate during the study period was 736.0/100,000, whereas the overall CRC incidence rate was 393.7/100,000 for not participated individuals (Table 1) The male-to- female ratio of CRC detected from the CRCSP and from the HKCaR cohort was 1.8:1 and 1.7:1, respectively More men were detected with CRC even though pe er re v more women participated the programme Regarding the distribution of cancer stage, it was observed that earlier stages (stage to II) were identified from the CRCSP-detected cohort (61.0%), comparing to those from the HKCaR cohort (41.5%) In particular, 33.8% of CRC detected in the CRCSP belonged to stage I compared with 16.2% in the HKCaR cohort Besides, more advanced stage (stage IV) was found in HKCaR ot cohort (23.3%) than in the CRCSP-detected cohort (6.7%) Table summarises the distribution of stage at diagnosis between men tn and women Both men and women in the CRCSP-detected cohort were significantly more likely to be diagnosed with earlier stages (stage to II) than rin in the HKCaR cohort (men: 59.3% vs 44.3%, p