Cancer survival statistics
People diagnosed with cancer during 2018 to 2020

About this release

This release by Public Health Scotland (PHS) describes the impact of the COVID-19 pandemic on cancer survival statistics for Scotland. Standard measures of survival were calculated for patients diagnosed between 2018 to 2020 with follow-up to the end of 2021. Data are presented for all cancers combined (excluding non‑melanoma skin cancer), and five specific sites: lung, female breast, colorectal, prostate and cervical. Two analyses are presented: a comparison of 2020 against 2018-19; and an analysis of a series of quarterly diagnosis cohorts for 2018-2020.

Main points

• COVID-19 led to substantial under-diagnosis of cancers in 2020, with an 8% reduction in diagnoses for all cancers, and larger falls for earlier stage cancers (Cancer Incidence in Scotland 2020). Consequently, the 2020 cohort was a smaller cohort with a higher proportion of more advanced cancers compared with pre-pandemic years.
• Cancer survival in Scotland has generally improved over the last few decades, however, survival estimates were generally lower for the cohort diagnosed with cancer in 2020 (e.g. one-year survival: 67.5% in 2020 vs 71.1% in 2018-19 for all cancers combined).
• For the cohort diagnosed in 2020 compared with 2018-19, one-year survival estimates:
  • were significantly lower for colorectal cancer (by 6 percentage points) and prostate cancer (by 1.8 percentage points);
  • appeared to be lower for lung cancer (by 3 percentage points) and cervical cancer (by 4 percentage points), but these differences were not statistically significant and may be due to chance;
  • were unchanged for (female) breast cancer.
• For the quarterly cohort diagnosed at the start of the pandemic (Q2 2020) compared with pre-pandemic (Q1 2020), one-year survival estimates:
  • were significantly lower for colorectal cancer (by 13 percentage points), breast cancer (by 4 percentage points) and all cancers combined (by 9 percentage points);
  • appeared to be lower for lung (by 9 percentage points) and prostate cancer (by 2 percentage points), but these differences were not statistically significant, and may be due to chance. The small number of cervical cancers in each quarter makes it difficult to interpret any changes in survival.
• For the cohorts diagnosed in Q3 and Q4 2020, one-year overall survival estimates appeared generally higher than in the Q2 2020 cohort, perhaps suggesting the start of a gradual return to pre-pandemic trends.
• Interpretation of the changes in survival for those diagnosed early in the pandemic is challenging due to both direct and indirect consequences of the pandemic. These include:
  • under-diagnosis of cancer in 2020 (Cancer Incidence in Scotland 2020);
  • larger falls in early-stage diagnoses for some cancer sites, particularly those with screening programmes, which were paused during the pandemic;
  • people dying of COVID-19 who otherwise may have been diagnosed with cancer;
  • delays in diagnosis and treatment, due to infection control measures.
• Lower survival estimates for the cohort diagnosed in 2020 therefore likely reflect both under-diagnosis of early-stage cancers and delayed diagnosis/treatment.
• It is reassuring that survival estimates for quarterly cohorts began to return to pre-pandemic trend in late 2020. However, there may still be 'missing' patients who will be diagnosed later than they would have been had the pandemic not occurred, perhaps with more progressed cancer and poorer outcomes.
• Although it is unclear whether patients diagnosed in 2020 had poorer survival than they would have done had the pandemic not occurred, these statistics underscore the substantial impact of the pandemic on cancer services in Scotland.
• Further research is required to assess whether there is any evidence for lower-than-normal survival in those patients who were diagnosed during the pandemic.

Background

Previous releases of this publication have reported survival estimates for a larger number of cancer sites, using five-year diagnosis cohorts (e.g. 2015-19), with estimates of survival at 1, 5 and 10 years after diagnosis. In this release, a different approach was needed to assess the impact of the COVID-19 pandemic on cancer survival, such as shorter periods of diagnosis and estimation of shorter-term outcomes (up to 1 year).