Trends and projections of cause-specific premature mortality in Australia to 2044: a statistical modelling study.

Background: Long-term projections of premature mortality (defined as deaths age <75 years) help to inform decisions about public health priorities. This study aimed to project premature mortality rates in Australia to 2044, and to estimate numbers of deaths and potential years of life lost (PYLL) due to premature mortality overall and for 59 causes. Methods: We examined the past trends in premature mortality rates using Australian mortality data by sex, 5-year age group and 5-year calendar period up to 2019. Cigarette smoking exposure data (1945-2019) were included to project lung cancer mortality. Age-period-cohort or generalised linear models were developed and validated for each cause to project premature mortality rates to 2044. Findings: Over the 25-year period from 1990-1994 to 2015-2019, there was a 44.4% decrease in the overall age-standardised premature mortality rate. This decline is expected to continue, from 162.4 deaths/100,000 population in 2015-2019 to 141.7/100,000 in 2040-2044 (12.7% decrease). Despite declining rates, total numbers of premature deaths are projected to increase by 22.8%, rising from 272,815 deaths in 2015-2019 to 334,894 deaths in 2040-2044. This is expected to result in 1.58 million premature deaths over the 25-year period 2020-2044, accounting for 24.5 million PYLL. Of the high-level cause categories, cancer is projected to remain the most common cause of premature death in Australia by 2044, followed by cardiovascular disease, external causes (including injury, poisoning, and suicide), and respiratory diseases. Interpretation: Despite continuously declining overall premature mortality rates, the total number of premature deaths in Australia is projected to remain substantial, and cancer will continue to be the leading cause. These projections can inform the targeting of public health efforts and can serve as benchmarks against which to measure the impact of future interventions. They emphasise the ongoing importance of accelerating the prevention, early detection, and treatment of key health conditions. Funding: No funding was provided for this study.

Fifty-year forecasts of daily smoking prevalence: can Australia reach 5% by 2030?

OBJECTIVE: To compare 50-year forecasts of Australian tobacco smoking rates in relation to trends in smoking initiation and cessation and in relation to a national target of ≤5% adult daily prevalence by 2030. METHODS: A compartmental model of Australian population daily smoking, calibrated to the observed smoking status of 229 523 participants aged 20-99 years in 26 surveys (1962-2016) by age, sex and birth year (1910-1996), estimated smoking prevalence to 2066 using Australian Bureau of Statistics 50-year population predictions. Prevalence forecasts were compared across scenarios in which smoking initiation and cessation trends from 2017 were continued, kept constant or reversed. RESULTS: At the end of the observation period in 2016, model-estimated daily smoking prevalence was 13.7% (90% equal-tailed interval (EI) 13.4%-14.0%). When smoking initiation and cessation rates were held constant, daily smoking prevalence reached 5.2% (90% EI 4.9%-5.5%) after 50 years, in 2066. When initiation and cessation rates continued their trajectory downwards and upwards, respectively, daily smoking prevalence reached 5% by 2039 (90% EI 2037-2041). The greatest progress towards the 5% goal came from eliminating initiation among younger cohorts, with the target met by 2037 (90% EI 2036-2038) in the most optimistic scenario. Conversely, if initiation and cessation rates reversed to 2007 levels, estimated prevalence was 9.1% (90% EI 8.8%-9.4%) in 2066. CONCLUSION: A 5% adult daily smoking prevalence target cannot be achieved by the year 2030 based on current trends. Urgent investment in concerted strategies that prevent smoking initiation and facilitate cessation is necessary to achieve 5% prevalence by 2030.

Cancer incidence and mortality in Australia from 2020 to 2044 and an exploratory analysis of the potential effect of treatment delays during the COVID-19 pandemic: a statistical modelling study.

BACKGROUND: Long-term projections of cancer incidence and mortality estimate the future burden of cancer in a population, and can be of great use in informing the planning of health services and the management of resources. We aimed to estimate incidence and mortality rates and numbers of new cases and deaths up until 2044 for all cancers combined and for 21 individual cancer types in Australia. We also illustrate the potential effect of treatment delays due to the COVID-19 pandemic on future colorectal cancer mortality rates. METHODS: In this statistical modelling study, cancer incidence and mortality rates in Australia from 2020 to 2044 were projected based on data up to 2017 and 2019, respectively. Cigarette smoking exposure (1945-2019), participation rates in the breast cancer screening programme (1996-2019), and prostate-specific antigen testing rates (1994-2020) were included where relevant. The baseline projection model using an age-period-cohort model or generalised linear model for each cancer type was selected based on model fit statistics and validation with pre-COVID-19 observed data. To assess the impact of treatment delays during the COVID-19 pandemic on colorectal cancer mortality, we obtained data on incidence, survival, prevalence, and cancer treatment for colorectal cancer from different authorities. The relative risks of death due to system-caused treatment delays were derived from a published systematic review. Numbers of excess colorectal cancer deaths were estimated using the relative risk of death per week of treatment delay and different durations of delay under a number of hypothetical scenarios. FINDINGS: Projections indicate that in the absence of the COVID-19 pandemic effects, the age-standardised incidence rate for all cancers combined for males would decline over 2020-44, and for females the incidence rate would be relatively stable in Australia. The mortality rates for all cancers combined for both males and females are expected to continuously decline during 2020-44. The total number of new cases are projected to increase by 47·4% (95% uncertainty interval [UI] 35·2-61·3) for males, from 380 306 in 2015-19 to 560 744 (95% UI 514 244-613 356) in 2040-44, and by 54·4% (95% UI 40·2-70·5) for females, from 313 263 in 2015-19 to 483 527 (95% UI 439 069-534 090) in 2040-44. The number of cancer deaths are projected to increase by 36·4% (95% UI 15·3-63·9) for males, from 132 440 in 2015-19 to 180 663 (95% UI 152 719-217 126) in 2040-44, and by 36·6% (95% UI 15·8-64·1) for females, from 102 103 in 2015-19 to 139 482 (95% UI 118 186-167 527) in 2040-44, due to population ageing and growth. The example COVID-19 pandemic scenario of a 6-month health-care system disruption with 16-week treatment delays for colorectal cancer patients could result in 460 (95% UI 338-595) additional deaths and 437 (95% UI 314-570) deaths occurring earlier than expected in 2020-44. INTERPRETATION: These projections can inform health service planning for cancer care and treatment in Australia. Despite the continuous decline in cancer mortality rates, and the decline or plateau in incidence rates, our projections suggest an overall 51% increase in the number of new cancer cases and a 36% increase in the number of cancer deaths over the 25-year projection period. This means that continued efforts to increase screening uptake and to control risk factors, including smoking exposure, obesity, physical inactivity, alcohol use, and infections, must remain public health priorities. FUNDING: Partly funded by Cancer Council Australia.

Projections of smoking-related cancer mortality in Australia to 2044.

BACKGROUND: While many high-income countries including Australia have successfully implemented a range of tobacco control policies, smoking remains the leading preventable cause of cancer death in Australia. We have projected Australian mortality rates for cancer types, which have been shown to have an established relationship with cigarette smoking and estimated numbers of cancer deaths attributable to smoking to 2044. METHODS: Cancer types were grouped according to the proportion of cases currently caused by smoking: 8%-30% and >30%. For each group, an age-period- cohort model or generalised linear model with cigarette smoking exposure as a covariate was selected based on the model fit statistics and validation using observed data. The smoking-attributable fraction (SAF) was calculated for each smoking-related cancer using Australian smoking prevalence data and published relative risks. RESULTS: Despite the decreasing mortality rates projected for the period 2015-2019 to 2040-2044 for both men and women, the overall number of smoking-related cancer deaths is estimated to increase by 28.7% for men and 35.8% for women: from 138 707 (77 839 men and 60 868 women) in 2015-2019 to 182 819 (100 153 men and 82 666 women) in 2040-2044. Over the period 2020-2044, there will be 254 583 cancer deaths (173 943 men and 80 640 women) directly attributable to smoking, with lung, larynx, oesophagus and oral (comprising lip, oral cavity and pharynx) cancers having the largest SAFs. INTERPRETATION: Cigarette smoking will cause over 250 000 cancer deaths in Australia from 2020 to 2044. Continued efforts in tobacco control remain a public health priority, even in countries where smoking prevalence has substantially declined.

Changes in prostate cancer incidence, mortality and survival in relation to prostate specific antigen testing in New South Wales, Australia.

BACKGROUND: To examine changes in prostate cancer incidence and mortality rates, and 5-year relative survival, in relation to changes in the rate of prostate specific antigen (PSA) screening tests and the use of radical prostatectomy (RP) in the Australian population. METHODS: Prostate cancer stage-specific incidence rates, 5-year relative survival and mortality rates were estimated using New South Wales Cancer Registry data. PSA screening test rates and RP/Incidence ratios were estimated from Medicare Benefits Schedule claims data. We used multiple imputation to impute stage for cases with "unknown" stage at diagnosis. Annual percentage changes (APC) in rates were estimated using Joinpoint regression. RESULTS: Trends in the age-standardized incidence rates for localized disease largely mirrored the trends in PSA screening test rates, with a substantial 'spike' in the rates occurring in 1994, followed by a second 'spike' in 2008, and then a significant decrease from 2008 to 2015 (APC -6.7, 95% CI -8.2, -5.1). Increasing trends in incidence rates were observed for regional stage from the early 2000s, while decreasing or stable trends were observed for distant stage since 1993. The overall RP/Incidence ratio increased from 1998 to 2003 (APC 9.6, 95% CI 3.8, 15.6), then remained relatively stable to 2015. The overall 5-year relative survival for prostate cancer increased from 58.4% (95% CI: 55.0-61.7%) in 1981-1985 to 91.3% (95% CI: 90.5-92.1%) in 2011-2015. Prostate cancer mortality rates decreased from 1990 onwards (1990-2006: APC -1.7, 95% CI -2.1, -1.2; 2006-2017: APC -3.8, 95% CI -4.4, -3.1). CONCLUSIONS: Overall, there was a decrease in the incidence rate of localized prostate cancer after 2008, an increase in survival over time and a decrease in the mortality rate since the 1990s. This seems to indicate that the more conservative use of PSA screening tests in clinical practice since 2008 has not had a negative impact on population-wide prostate cancer outcomes.

Changes in cancer incidence and mortality in Australia over the period 1996-2015.

OBJECTIVE: A previous Australian study compared the observed numbers of cancer cases and deaths in 2007 with the expected numbers based on 1987 rates. This study examines the impact of cancer rate changes over the 20-year period 1996-2015, for people aged under 75 years. RESULTS: The overall age-standardised cancer incidence rate increased from 350.7 in 1995 to 364.4 per 100,000 in 2015. Over the period 1996-2015, there were 29,226 (2.0%) more cases (males: 5940, 0.7%; females: 23,286, 3.7%) than expected numbers based on 1995 rates. Smaller numbers of cases were observed compared to those expected for cancers of the lung for males and colorectum, and cancers with unknown primary. Larger numbers of cases were observed compared to those expected for cancers of the prostate, thyroid and female breast. The overall age-standardised cancer mortality rate decreased from 125.6 in 1995 to 84.3 per 100,000 in 2015. During 1996 to 2015 there were 106,903 (- 20.6%) fewer cancer deaths (males: - 69,007, - 22.6%; females: - 37,896, - 17.9%) than expected based on the 1995 mortality rates. Smaller numbers of deaths were observed compared to those expected for cancers of the lung, colorectum and female breast, and more cancer deaths were observed for liver cancer.

Lung cancer mortality in Australia in the twenty-first century: How many lives can be saved with effective tobacco control?

OBJECTIVES: To estimate the number of past and future lung cancer deaths that have already been averted by tobacco control initiatives in Australia, and to estimate the number of additional deaths averted under various smoking scenarios. METHODS: We predicted lung cancer mortality rates and case numbers to 2100 using a previously validated generalized linear model based on age, birth cohort and population cigarette smoking exposure. We estimated the impact of various tobacco control scenarios: 'actual tobacco control' (incorporating the aggregate effect of past and current taxation, plain packaging, mass media campaigns and other initiatives) and scenarios where 10%, 5% and 0% smoking prevalence was achieved by 2025, all of which were compared to a counterfactual scenario with the highest historical smoking consumption level continuing into the future as if no tobacco control initiatives had been implemented. RESULTS: Without tobacco control, there would have been an estimated 392,116 lung cancer deaths over the period 1956-2015; of these 20% (78,925 deaths; 75,839 males, 3086 females) have been averted due to tobacco control. However, if past and current measures continue to have the expected effect, an estimated 1.9 million deaths (1,579,515 males, 320,856 females; 67% of future lung cancer deaths) will be averted in 2016-2100. If smoking prevalence is reduced to 10%, 5% or 0% by 2025, an additional 97,432, 208,714 or 360,557 deaths could be averted from 2016 to 2100, respectively. CONCLUSION: Tobacco control in Australia has had a dramatic impact on the number of people dying from lung cancer. Several hundred thousand more lung cancer deaths could be averted over the course of the century if close-to-zero smoking prevalence could be achieved in the next decade.