COVID-19 may have lower-than-expected long-term impact on breast cancer mortality
Disruptions in breast cancer care during the COVID-19 pandemic may have a small long-term cumulative impact on breast cancer mortality in the U.S., according to study findings published in Journal of the National Cancer Institute.
“The COVID-19 pandemic disrupted breast cancer care in the United States dramatically, especially during the first few months of the pandemic. Mammography screenings and symptomatic detections decreased more than 80% during the initial months. Similarly, chemotherapy treatments were reduced or delayed,” Oguzhan Alagoz, PhD, Procter & Gamble Bascom professor in the department of engineering at University of Wisconsin-Madison, told Healio. “Screenings and many other components of breast cancer care returned to normal levels by the end of the summer, but there is still a deficit in total number of exams compared with pre-pandemic years. We know that early diagnosis and screening save lives, and there was a lot of concern about whether the deficit in care would have any long-term impacts.”
In May 2020, Alagoz and colleagues performed an initial analysis for a commentary by NCI Director Norman E. “Ned” Sharpless, MD, published in Science. Modeling results reported in that commentary showed almost 10,000 excess deaths due to breast and colorectal cancer could occur by 2030 as a result of COVID-19-related disruptions in screening and care.
“Once we had additional data on the effect of the pandemic on breast cancer control activities, by September 2020, we wanted to update our initial analysis and provide more accurate projections of the long-term effect of pandemic-related disruptions on breast cancer deaths,” Alagoz said.
Investigators estimated the effect of COVID-19 on breast cancer mortality among all U.S. women aged 30 to 84 years between 2020 and 2030. They used three Cancer Intervention and Surveillance Modeling Network breast cancer models to project the impact of reductions in mammography screening use, delays in symptomatic cancer diagnosis and decreased use of chemotherapy among women with early-stage breast cancer during the first 6 months of the pandemic, with a return to pre-pandemic patterns after that time.
Researchers additionally performed sensitivity analyses to determine the effect of key model parameters that included the duration of the impact of the pandemic.
The models projected that by 2030, there will be 950 (range, 860-1,297) cumulative excess breast cancer deaths associated with reduced screening, 1,314 (266-1,325) deaths associated with delays in diagnosis of symptomatic cases and 151 (146-207) deaths associated with decreased chemotherapy use among women with hormone receptor-positive, early-stage breast cancer.
Overall, researchers estimated that 2,487 (range, 1,713-2,575) excess breast cancer deaths may occur, for a 0.52% (range, 0.36-0.56) cumulative increase compared with expected breast cancer deaths by 2030 had there been no disruptions due to the pandemic.
Results of sensitivity analyses additionally showed that if the modeled pandemic effects on screening, symptomatic diagnosis and chemotherapy extended for 1 year, the breast cancer mortality impact would be nearly doubled.
“[Although] there are many reports on the short-term impact of disruptions due to the COVID-19 pandemic on breast cancer control activities in the U.S., this study provides a 10-year prediction of the impact of such disruptions on breast cancer deaths,” Alagoz said. “We are now closely watching the effect of the pandemic on breast cancer care. As more data become available, we may do a follow-up study to the present one.”
For more information:
Oguzhan Alagoz, PhD, can be reached at University of Wisconsin-Madison, 3242 Mechanical Engineering Building, 1513 University Ave., Madison WI 53706; email:firstname.lastname@example.org.