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.

Tobacco smoking changes during the first pre-vaccination phases of the COVID-19 pandemic: A systematic review and meta-analysis.

Background: Globally, tobacco smoking remains the largest preventable cause of premature death. The COVID-19 pandemic has forced nations to take unprecedented measures, including 'lockdowns' that might impact tobacco smoking behaviour. We performed a systematic review and meta-analyses to assess smoking behaviour changes during the early pre-vaccination phases of the COVID-19 pandemic in 2020. Methods: We searched Medline/Embase/PsycINFO/BioRxiv/MedRxiv/SSRN databases (January-November 2020) for published and pre-print articles that reported specific smoking behaviour changes or intentions after the onset of the COVID-19 pandemic. We used random-effects models to pool prevalence ratios comparing the prevalence of smoking during and before the pandemic, and the prevalence of smoking behaviour changes during the pandemic. The PROSPERO registration number for this systematic review was CRD42020206383. Findings: 31 studies were included in meta-analyses, with smoking data for 269,164 participants across 24 countries. The proportion of people smoking during the pandemic was lower than that before, with a pooled prevalence ratio of 0·87 (95%CI:0·79-0·97). Among people who smoke, 21% (95%CI:14-30%) smoked less, 27% (95%CI:22-32%) smoked more, 50% (95%CI:41%-58%) had unchanged smoking and 4% (95%CI:1-9%) reported quitting smoking. Among people who did not smoke, 2% (95%CI:1-3%) started smoking during the pandemic. Heterogeneity was high in all meta-analyses and so the pooled estimates should be interpreted with caution (I2 >91% and p-heterogeneity<0·001). Almost all studies were at high risk of bias due to use of non-representative samples, non-response bias, and utilisation of non-validated questions. Interpretation: Smoking behaviour changes during the first phases of the COVID-19 pandemic in 2020 were highly mixed. Meta-analyses indicated that there was a relative reduction in overall smoking prevalence during the pandemic, while similar proportions of people who smoke smoked more or smoked less, although heterogeneity was high. Implementation of evidence-based tobacco control policies and programs, including tobacco cessation services, have an important role in ensuring that the COVID-19 pandemic does not exacerbate the smoking pandemic and associated adverse health outcomes. Funding: No specific funding was received for this study.

Impact of COVID-19 Pandemic on Cancer-Related Hospitalizations in Brazil.

BACKGROUND: Alongside the SARS-CoV-2 (COVID-19) pandemic, Brazil also faces an ongoing rise in cancer burden. In 2020, there were approximately 592 000 new cancer cases and 260 000 cancer deaths. Considering the heterogeneities across Brazil, this study aimed to estimate the impact of the COVID-19 pandemic on cancer-related hospital admissions at a national and regional level. METHODS: The national, regional, and state-specific monthly average of cancer-related hospital admission rates per 100 000 inhabitants and 95% confidence intervals (95% CIs) were calculated from March to July (2019: pre-COVID-19; and 2020: COVID-19 period). Thematic maps were constructed to compare the rates between periods and regions. RESULTS: Cancer-related hospital admissions were reduced by 26% and 28% for clinical and surgical purposes, respectively. In Brazil, the average hospitalization rates decreased from 13.9 in 2019 to 10.2 in 2020 per 100,000 inhabitants, representing a rate difference of -3.7 (per 100,000 inhabitants; 95% CI: -3.9 to -3.5) for cancer-related (clinical) hospital admissions. Surgical hospital admissions showed a rate decline of -5.8 per 100,000 (95% CI: -6.0 to -5.5). The reduction in cancer-related admissions for the surgical procedure varies across regions ranging between -2.2 and -10.8 per 100 000 inhabitants, with the most significant decrease observed in the south and southeastern Brazil. CONCLUSIONS: We observed a substantial decrease in cancer-related hospital admissions during the COVID-19 pandemic with marked differences across regions. Delays in treatment may negatively impact cancer survival in the future; hence, cancer control strategies to mitigate the impact are needed.