COVID-19 Pandemic Linked to Divergent Cancer Trends
THE COVID-19 pandemic was associated with distinct, long-term changes in cancer incidence between males and females, according to a population-based study from Manitoba, Canada.
Using a quasi-experimental interrupted time-series design, researchers examined new cancer diagnoses from January 2015 to December 2022, comparing prepandemic and postpandemic trends. The analysis included 36,831 individuals, comprising 16,200 females and 20,631 males, and revealed significant sex-based differences in cancer detection patterns that persisted beyond the initial phase of the pandemic.
Sex Differences in Cancer Incidence After COVID-19
Following the onset of the pandemic, colon cancer incidence dropped by 34% among both sexes between April and September 2020. However, while rates stabilized for males, they continued to decline for females, falling another 22% between late 2021 and 2022. Brain and central nervous system (CNS) cancers declined by 37% among males during 2021–2022 but decreased for females only during late 2020 and early 2021, showing a sharp 77% reduction over that period.
Urinary cancers decreased by 18% for males across the postpandemic window but remained stable for females. Similarly, head and neck cancer incidence dropped by 22% in males during 2020, with no significant change observed in females. By December 2022, males showed cumulative deficits in brain and CNS cancers (31.6%), urinary cancers (18.4%), and an unexpected surplus in endocrine cancers (52.4%), while females experienced the largest ongoing deficit in colon cancer, with nearly one in five cases potentially missed.
Implications for Oncology Practice
These findings suggest that the pandemic’s impact on cancer diagnosis and healthcare access continues to manifest unevenly by sex. The sustained decline in certain cancer types for women may reflect differences in health-seeking behavior, screening disruption, or diagnostic delays, while the variable patterns in men highlight potential differences in disease presentation or care prioritization.
For clinicians, the data reinforce the importance of rebuilding cancer screening programs and addressing sex-specific barriers to diagnosis. Continued surveillance is needed to determine whether these gaps represent temporary disruptions or long-term shifts in cancer incidence and detection.
Reference: Decker KM et al. Measuring the Association Between the COVID-19 Pandemic and Cancer Incidence by Sex Using a Quasi-Experimental Study Design. JCO Clin Cancer Inform. 2025;9:e2400327.
