Cancer staging data

About this release

This release by Public Health Scotland (PHS) presents data examining the impact of COVID-19 on cancer staging distributions, with the focus of the report being on the 2022 data in comparison with the most recent pre-pandemic data (2018 and 2019). For each cancer type, a chi squared test of association was performed to identify any association between stage distribution and 'year' (pre-pandemic vs 2022). A p-value <0.05 suggests a significant association and that there has been a change in the stage distribution.

Main points

• In 2022 there were 4,644 patients diagnosed with breast cancer, 3,833 patients diagnosed with colorectal cancer and 4,851 patients diagnosed with lung cancer.
• Breast and colorectal cancer diagnoses increased in late 2020 and into 2021 and 2022, reaching levels that exceeded 2018-2019. Lung cancer diagnoses also increased following Quarter 2 of 2020, however they have not quite reached pre-pandemic levels (based on 2018-2019 average).

• There has been a significant stage shift (p=0.009) for breast cancer since the pandemic. This was largely driven by an increase in stage 3 diagnoses (8.4% in 2022 vs 6.6% in 2018-2019). This stage shift was more apparent for patients resident in the least deprived areas of Scotland.
• There was no evidence of an overall stage shift for colorectal cancer in 2022 when compared with the pre-pandemic stage distribution (p=0.07). However, the inequality gap in stage 1 narrowed between the least and most deprived areas from 5.9 percentage points pre-pandemic to 2.4 percentage points in 2022.
• There has been a significant stage shift (p<0.001) for lung cancer since the pandemic. This was driven by an increase in early-stage (stage 1 and 2) diagnoses (29.2% in 2022 vs 26.5% in 2018-2019) and a decrease in diagnoses with unknown stage (4.6% in 2022 vs 6.0% in 2018-2019).

Background

The staging data provided use the Quality Performance Indicator (QPI) audit information, rather than the Scottish Cancer Registry. Therefore, these data are not directly comparable to PHS's cancer incidence publication and are subject to change in future publications, as submissions may be updated to reflect a more accurate and complete set of data from NHS Boards.