Cancer incidence, stage shift and survival during the 2020 COVID‐19 pandemic: A population‐based study in Belgium

• Published in: International journal of cancer 2024-10, Vol.155 (7), p.1212-1224
• Main Authors: Peacock, Hanna M., Van Meensel, Mira, Van Gool, Bart, Silversmit, Geert, Dekoninck, Kris, Brierley, James D., Van Eycken, Liesbet
• Format: Article
• Language: English
• Subjects: Adult; Aged; Belgium - epidemiology; Bladder cancer; Breast cancer; Cancer; cancer incidence; Cervical cancer; Colorectal cancer; Colorectal carcinoma; COVID-19; COVID-19 - epidemiology; COVID-19 - mortality; Fallopian tube; Female; Head & neck cancer; Humans; Incidence; Lung cancer; Male; Medical diagnosis; Medical prognosis; Medical screening; Middle Aged; Neoplasm Staging; Neoplasms - epidemiology; Neoplasms - mortality; Ovarian cancer; Pandemics; Population decline; Population studies; Population-based studies; Prostate; Prostate cancer; Registries; relative survival; SARS-CoV-2; stage distribution; stage shift; Survival; Survival analysis; Tumors
• ISSN: 0020-7136; 1097-0215; 1097-0215
• DOI: 10.1002/ijc.35001

The COVID‐19 pandemic was associated with a profound decline in cancer diagnoses in 2020 in Belgium. Disruption in diagnostic and screening services and patient reluctance to visit health facilities led to fewer new cases and concerns that cancers may be diagnosed at more advanced stages and hence have poorer prognosis. Using data from mandatory cancer registration covering all of Belgium, we predicted cancer incidence, stage distribution and 1‐year relative survival for 2020 using a Poisson count model over the preceding years, extrapolated to 2020 for 11 common cancer types. We compared these expected values to the observed values in 2020 to specifically quantify the impact of the COVID‐19 pandemic, accounting for background trends. A significantly lower incidence was observed for cervical, prostate, head and neck, colorectal, bladder and breast cancer, with limited or no recovery of diagnoses in the second half of 2020 for these cancer types. Changes in stage distribution were observed for cervical, prostate, bladder and ovarian and fallopian tube tumours. Generally, changes in stage distribution mainly represented decline in early‐stage than in late‐stage tumours. One‐year relative survival was lower than predicted for lung cancer and colorectal cancer. Stage shifts are hypothesised to result from alterations in access to diagnosis, potentially due to prioritisation of symptomatic patients, and patient reluctance to contact a physician. Since there were over 5000 fewer cancer diagnoses than expected by the end of 2020, it is critical to monitor incidence, stage distribution and survival for these cancers in the coming years. What's new? Cancer diagnoses declined in Belgium in 2020, following the onset of the COVID‐19 pandemic. An ageing population and migration, however, suggest that the actual pandemic impact on cancer trends in Belgium is underestimated. This study assessed cancer incidence, stage distribution and survival during the COVID‐19 pandemic using cancer registry data in Belgium. By the end of 2020, the number of expected cancer diagnoses was found to have declined by more than 5000. Incidence of early‐stage cancers was reduced, and shifts in stage distribution were observed. Whether stage shifts are associated with delayed diagnosis during the pandemic warrants further investigation.