Dataset Information

Trends in breast cancer incidence in Hong Kong between 1973 and 1999: an age-period-cohort analysis.

ABSTRACT: Hong Kong has the highest breast cancer incidence in Asia and studying secular changes in its rates may lead to hypotheses regarding disease aetiology and also predictions of future trends for China. We examined statistics from the Hong Kong Cancer Registry based on 26 566 cases of invasive breast cancer from 1973 to 1999. The trends in breast cancer incidence were studied using log-linear longitudinal models. We further analysed the independent effects of chronological age, time period and birth cohort on incidence trends using age-period-cohort modelling. The average annual per cent change of the age-standardised incidence was 3.6% during 1973-1999. Age-period-cohort modelling indicated the incidence development was predominantly a cohort effect, where the rise in relative risk was seemingly linear in successive birth cohorts, showing a 2-3-fold difference when comparing women born in the 1960's with those born around 1900. Our results suggest that direct and indirect consequences of westernisation may have been responsible for most of the observed increase in breast cancer incidence. As China moves towards a more westernised way of life, we can expect an emerging epidemic of breast cancer as Hong Kong's experience has demonstrated.

SUBMITTER: Leung GM

PROVIDER: S-EPMC2364319 | biostudies-other | 2002 Oct

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:ObjectivesPrevalence of multimorbidity has been increasing worldwide. While population ageing undoubtedly contributes, secular trends have seldom been decomposed into age, period and cohort effects to investigate intergenerational differences. This study examines the birth cohort effect on morbidity burden and multimorbidity in Hong Kong community.DesignSex-specific age-period-cohort analysis with repeated cross-sectional surveys.SettingA territory-wide population survey database.Participants69 636 adults aged 35 or above who participated in the surveys in 1999, 2001, 2005 or 2008.Main outcome measuresMorbidity burden was operationalised as number of chronic conditions from a list of 14, while multimorbidity was defined as a dichotomous status of whether participants had two or more conditions.ResultsFor both sexes, there was an upward inflection (positive change) of risk of increased morbidity burden starting from cohort 1955-1959. For men born after 1945-1954, there was a trend of lower risk (relative risk=0.63, 95% CI 0.50 to 0.80 for 1950-1954 vs 1935-1939) which continued through subsequent cohorts but with no further declines. In women, there had been a gradual increase of risk, although only significant for cohort 1970-1974 (relative risk=1.90, 95% CI 1.08 to 1.34 vs 1935-1939). Similar results were found for dichotomous multimorbidity status.ConclusionsThe trend of lower risk starting from men born in 1945-1954 may be due to a persistent decline in smoking rates since the 1980s. On the other hand, the childhood obesity epidemic starting from the late 1950s coincided with the observed upward inflection of risk for both sexes, that is, notably more drastic increase of risk in women and the levelling-off of the decline of risk in men. These findings highlight that the cohort effects on morbidity burden and multimorbidity may be sex-specific and contextual. By examining such effects in different world populations, localised sex-specific and generation-specific risk factors can be identified to inform policy-making.

Project description:BACKGROUND:There is very limited data on the time trend of diabetes incidence in Asia. Using population-level data, we report the secular trend of the incidence of type 1 and type 2 diabetes in Hong Kong between 2002 and 2015. METHODS AND FINDINGS:The Hong Kong Diabetes Surveillance Database hosts clinical information on people with diabetes receiving care under the Hong Kong Hospital Authority, a statutory body that governs all public hospitals and clinics. Sex-specific incidence rates were standardised to the age structure of the World Health Organization population. Joinpoint regression analysis was used to describe incidence trends. A total of 562,022 cases of incident diabetes (type 1 diabetes [n = 2,426]: mean age at diagnosis is 32.5 years, 48.4% men; type 2 diabetes [n = 559,596]: mean age at diagnosis is 61.8 years, 51.9% men) were included. Among people aged <20 years, incidence of both type 1 and type 2 diabetes increased. For type 1 diabetes, the incidence increased from 3.5 (95% CI 2.2-4.9) to 5.3 (95% CI 3.4-7.1) per 100,000 person-years (average annual percentage change [AAPC] 3.6% [95% CI 0.2-7.1], p < 0.05) in boys and from 4.3 (95% CI 2.7-5.8) to 6.4 (95% CI 4.3-8.4) per 100,000 person-years (AAPC 4.7% [95% CI 1.7-7.7], p < 0.05] in girls; for type 2 diabetes, the incidence increased from 4.6 (95% CI 3.2-6.0) to 7.5 (95% CI 5.5-9.6) per 100,000 person-years (AAPC 5.9% [95% CI 3.4-8.5], p < 0.05) in boys and from 5.9 (95% CI 4.3-7.6) to 8.5 (95% CI 6.2-10.8) per 100,000 person-years (AAPC 4.8% [95% CI 2.7-7.0], p < 0.05) in girls. In people aged 20 to <40 years, incidence of type 1 diabetes remained stable, but incidence of type 2 diabetes increased over time from 75.4 (95% CI 70.1-80.7) to 110.8 (95% CI 104.1-117.5) per 100,000 person-years (AAPC 4.2% [95% CI 3.1-5.3], p < 0.05) in men and from 45.0 (95% CI 41.4-48.6) to 62.1 (95% CI 57.8-66.3) per 100,000 person-years (AAPC 3.3% [95% CI 2.3-4.2], p < 0.05) in women. In people aged 40 to <60 years, incidence of type 2 diabetes increased until 2011/2012 and then flattened. In people aged ≥60 years, incidence was stable in men and declined in women after 2011. No trend was identified in the incidence of type 1 diabetes in people aged ≥20 years. The present study is limited by its reliance on electronic medical records for identification of people with diabetes, which may result in incomplete capture of diabetes cases. The differentiation of type 1 and type 2 diabetes was based on an algorithm subject to potential misclassification. CONCLUSIONS:There was an increase in incidence of type 2 diabetes in people aged <40 years and stabilisation in people aged ≥40 years. Incidence of type 1 diabetes continued to climb in people aged <20 years but remained constant in other age groups.

Dataset Information

Trends in breast cancer incidence in Hong Kong between 1973 and 1999: an age-period-cohort analysis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets