Pandemic restrictions corresponded with a big drop in diagnoses of breast, colorectal and prostate cancers in addition to melanoma, in keeping with a latest Alberta study published in CMAJ (Canadian Medical Association Journal) https://www.cmaj.ca/lookup/doi/10.1503/cmaj.221512.

“The sweeping and unprecedented measures enacted in the beginning of the COVID-19 pandemic in Alberta had an inevitable impact on cancer care,” writes Dr. Darren Brenner, an epidemiologist in Calgary, Alberta, and associate professor on the University of Calgary’s Cumming School of Medicine, with coauthors. “Regardless that treatment and urgent surgeries for cancers were prioritized when other procedures were delayed or cancelled, preventive and diagnostic services were greatly reduced.”

The study compared survival rates for 3 groups of patients diagnosed between (1) Jan. 16, 2018, and Mar. 15, 2019; (2) Mar. 16, 2019, and Mar. 15, 2020; and (3) Mar. 16 and Dec. 15, 2020. The researchers divided the third period right into a “state of emergency” (SOE) phase (Mar. 16 to June 15, 2020) and post-SOE phase (June 16 to Dec. 15, 2020).

Researchers saw large reductions within the number of recent diagnoses for some cancer types through the SOE period, with a drop of 43% (melanoma), 36% (colorectal and prostate) and 33% (breast). Within the post-SOE phase, diagnoses increased 9%, 8% and 10% monthly, respectively. Other cancers, resembling bladder, kidney, lung and cervical, didn’t show decreases in diagnoses during that period.

“Our findings that early-stage breast and colorectal cancer had the most important decrease in diagnoses suggest that a discount in screening services through the first wave of pandemic-related restrictions in Alberta resulted in asymptomatic individuals receiving a diagnosis later than they might have otherwise,” write the authors. “These results highlight the importance of screening services in reducing late-stage cancer diagnoses.”

Patients with colorectal cancer and non-Hodgkin lymphoma diagnosed through the pandemic period in 2020 had poorer 1-year survival than those diagnosed in 2018.

By December 2020, the speed of diagnoses had returned to a level more consistent with pre-SOE levels.

The findings are consistent with studies from the UK, United States, the Netherlands, Germany, Japan and other parts of Canada. In Ontario, there was a 34% drop in latest cancer diagnoses in April 2020, and Manitoba had a 23% reduction in the identical period. An estimated 15% reduction in Quebec occurred in the primary yr of the pandemic.

Cancer care must develop into more efficient and increase capability to scale back long-term effects of the pandemic on cancer outcomes, the authors conclude.

Source:

Canadian Medical Association Journal

Journal reference:

Heer, E., et al. (2023) Impact of the COVID-19 pandemic on cancer diagnoses, stage and survival in Alberta. Canadian Medical Association Journal. doi.org/10.1503/cmaj.221512.