NEW DELHI: More than 55,000 expected cancer cases were not diagnosed across seven high-income countries during the first nine months of the COVID-19 pandemic in 2020 due to lockdowns or widespread disruption of cancer diagnostic services, said a new Lancet study.
The study, which for the first time examined the impact of COVID-19 pandemic on population-wide cancer diagnoses in 18 jurisdictions across seven countries, found that 16% of expected cancer diagnoses were missing between April and December 2020.
The study from the International Agency for Research on Cancer (IARC), a specialised cancer agency of the World Health Organisation (WHO) and the International Cancer Benchmarking Partnership found that the largest decreases were observed for prostate cancer (24%), female breast cancer (18%), and skin melanoma (18%).
Lung cancer and ovarian cancer were less affected, said the study published in The Lancet Oncology.
The researchers examined trends in seven common cancer types between 2015 and 2020 to compare the number of cancers diagnosed during the COVID-19 pandemic with the number expected based on pre-pandemic trends.
The study analysed population-based cancer registry data on 2.6 million patients across Australia, Canada, Denmark, Ireland, New Zealand, Norway, and the UK.
“This study offers a unique opportunity to assess the impact of the COVID-19 pandemic on cancer incidence and stage at diagnosis using nationwide data on patients living with cancer, and to learn from those countries where disruptions were more limited,” says Dr Eileen Morgan, a scientist in the Cancer Surveillance Branch at IARC and the lead author of the study.
“By comparing experiences across countries, the study provides valuable insights that inform future health system planning, strengthen resilience, and improve preparedness.”
The most significant reductions occurred during the first months of lockdowns, from April to July 2020, when access to health services was most restricted.
Some of the steepest decreases in diagnoses were observed in the UK and Ireland, whereas in Norway and New Zealand there were comparatively smaller disruptions and a faster recovery to expected diagnosis levels.
The researchers suggest that the differences between countries may reflect variations in health system resilience, public health responses and communication, access to primary care, and the continuity of cancer screening and diagnostic services during the pandemic.
Temporary suspension of screening programmes and reduced access to general practice appointments are believed to have contributed to the decrease in diagnoses, particularly for breast cancer, colorectal cancer, prostate cancer, and skin cancer.
Fear of contracting COVID-19 may also have discouraged people from seeking medical attention for early symptoms.
Despite the sharp reduction in diagnoses, the study found relatively limited evidence of an immediate shift towards diagnoses of more advanced-stage cancers during 2020.
However, the researchers caution that the long-term consequences remain uncertain and that continued monitoring is essential to determine whether delayed diagnoses will affect cancer outcomes and survival in the years ahead.
The researchers said ongoing surveillance is essential to determine whether these missing cancer cases were diagnosed later and whether long-term outcomes are affected.
“A more detailed understanding of why some health systems were better able to withstand the pressures of the COVID-19 pandemic could provide valuable lessons for future crisis preparedness,” said Dr Isabelle Soerjomataram, the Deputy Head of the Cancer Surveillance Branch at IARC and the senior author of the study.
“These findings also offer important insights for governments and policy-makers seeking to strengthen cancer care systems and maintain continuity of care during future crises.”
The authors say that the findings underscore the importance of maintaining cancer services during future public health emergencies and strengthening health system preparedness to minimise disruption to diagnosis and treatment and maintain the lived experience of people with cancer.
