Trends in cancer incidence in Singapore over the last two decades.

10554 Background: Singapore has witnessed a significant rise in cancer incidence over recent decades. The most rapid increase in age-specific incidence of cancer was observed among younger age group in recent years. Gaining insight into the factors driving this trend is essential for developing prevention strategies. Methods: This population-based study analysed 268,189 cancer cases diagnosed between 2000 and 2021 from the Singapore Cancer Registry via the TRUST platform (https://trustplatform.sg/). Cases diagnosed in 2020 and 2021 were subsequently excluded from the trend analysis due to potential COVID-19 effects. We first examined the temporal trend of age-standardized incidence rate and estimated average annual percentage changes (AAPC) using Joinpoint regression analysis. Decomposition analysis was performed to assess the increase in cancer cases attributable to changes in population age structure, population size, and cancer risk due to epidemiological factors. We conducted an Age-Period-Cohort analysis to estimate the net drift, local drift, and the cohort- and period-specific incidence rate ratio (IRR). These analyses were repeated for the four most common cancers in Singapore: breast, colorectal, lung and prostate cancer. Results: Over the 22-year period, the number of cancer cases nearly doubled for both men and women. The age-standardized incidence rate rose from 200.77 per 100,000 to 246.43 per 100,000 for women and remained stable at 235.30 per 100,000 for men. The AAPC was 0.92% (0.73%-1.15%) for women and 0.13% (-0.01%- 0.30%) for men, and was the largest for female breast and prostate cancer. Decomposition analysis showed that aging population was the primary driver for an overall increase in cancer cases, whereas change in cancer risk had the highest impact for breast cancer, prostate cancer and lung cancer in men. The Age-Period-Cohort analysis revealed significant period and birth cohort effects with a net drift of 1.17% (0.90% - 1.43%) for women and 0.78% (0.54% - 1.05%) for men. For breast cancer, both birth cohort and period effects showed an increasing trend [IRRcohort1990vs1950 = 1.47 (0.98-2.22), IRRperiod2015vs2000 = 1.24 (1.17-1.31)]. A similar trend was observed for prostate cancer [IRRcohort1970vs1935 = 3.42(1.83-6.38), IRRperiod2015vs2000 = 1.74(1.59-1.92)]. In contrast, a decreasing trend was noted for lung cancer in men [IRRcohort1970vs1945= 0.65(0.48-0.87), IRRperiod2015vs2000 = 0.76 (0.70-0.82)]. Conclusions: The rising cancer incidence in Singapore is multifactorial, with demographic factors, particularly an ageing population, playing a significant role. Our analysis revealed important temporal patterns and a notable rise in cancer risk for breast and prostate cancers, likely influenced by shifts in environmental and lifestyle factors, and cancer screening. These insights should be used to inform and guide future public health policies aimed at addressing modifiable risk factors.