Background
The COVID-19 pandemic been associated with a decline in cancer diagnoses in Europe, America, New Zealand, and Australia. Recovery has been variable and impacted by underlying community COVID-19 infection rates, service delivery disruption, and restrictions on movement of people. In Victoria, cancer diagnoses declined by 7% in 2020 and by 4.3% in 2021. We analysed preliminary incidence data for the further six-month period to 30 June 2022.
Methods
New cancer diagnoses to 2019 were available to predict the number of new diagnoses up to July 2022. The latest historical period during which standardised incidence rate was linear was used, by tumour stream. Expected and observed counts were compared for the breast, lung, colorectal cancer and melanoma, and reported by age, sex, remoteness and area based socio-economic position. Cases identified through death certificate only (DCO) were excluded as DCOs were not yet processed for 2022.
Results
After the initial reduction following the first COVID-19 lockdown (Q2 2020), it took ~6 months to return to expected numbers for some tumour steams (breast, colorectal). No clear ‘catch-up’ in diagnoses was seen following the initial dip in early 2020. Instead, in the first half of 2022, a substantial reduction in diagnoses was observed (colorectal -21% (95% CI: -19%, -23%), lung -12% (-11%, -14%), melanoma -10% (-8%, -13%), breast -5% (-3%, -7%)). Reductions were seen in both males and females, and were generally larger in the more elderly age groups.
Conclusions
Over the first half of 2022, a second reduction in diagnoses was seen which coincided with a burst in COVID-19 infections after restrictions were lifted. The observed reduction in diagnoses compared to expected is concerning and signals a need for ongoing media campaigns and targeted interventions to encourage Victorians to seek medical advice if concerned and resume routine health checks.