Investigators may have identified a decrease in newly diagnosed breast cancer cases during the first year of the COVID-19 pandemic, according to a recent study published by Fefferman et al in Cancer Medicine. The findings highlight that breast cancer was not immune to pandemic-related stressors and may also have implications for how physicians and policymakers address issues related to the diagnostic delays that occurred during the COVID-19 pandemic.
Background
Previous studies have described the distinct impact of the COVID-19 pandemic on cancer care. However, little is currently known about how the pandemic disrupted breast cancer.
Study Methods and Results
In the recent study, the investigators analyzed data from the American College of Surgeons (ACS) National Cancer Database—which captures approximately 74% of all newly diagnosed cancers in the United States. They also used the U.S. Census data to determine the number of women and men in the general population over the course of the study period. In total, they examined 1.5 million patients with stage 0 to IV breast cancer across 1,328 Commission on Cancer sites.
The investigators discovered a 15% to 20% decline in the rate of breast cancer diagnoses reported to the Commission on Cancer in 2020 compared with in 2019. Although the decreased rate of diagnoses was seen in both female and male patients as well as across nearly all age groups, races, and ethnicities, the declines were most significant among female patients between the ages of 50 and 59 (17.4%). The investigators cited two potential factors contributing to decreased breast cancer diagnoses among these patient groups: patients older than 50, including those between 60 and 69, may be more likely to be affected by breast cancer compared with younger patients; and older female patients may be more likely to undergo screening mammograms and therefore may be more susceptible to the screening delays that occurred during the COVID-19 pandemic.
Additionally, Hispanic female patients experienced the greatest decline in breast cancer diagnoses from 2019 to 2020 among all races and ethnicities (18.4%). This was consistent with other disparities that Hispanic patients faced during the COVID-19 pandemic, including higher incidence and mortality rates for COVID-19 infections.
Geographically, female patients receiving care in the Western and mid-Atlantic regions of the United States experienced the largest declines in 2020, reflecting the adverse effects of the COVID-19 pandemic in California, Washington State, New York, and mid-Atlantic states during the study period.
Although comprising less than 1% of the breast cancer cases reported during the first year of the COVID-19 pandemic, the number of breast cancer diagnoses in male patients in 2020 declined by 20% compared with in 2019.
The investigators indicated the reasons behind the decreased rates of breast cancer diagnoses were likely multifactorial, representing screening restrictions that occurred in the early months of the COVID-19 pandemic, when stay-at-home orders were implemented in several states as well as the fear of exposure that may have influenced patients to delay care for breast cancer symptoms. Other factors such as unemployment may have discouraged some patients from receiving care even after pandemic restrictions were lifted.
Conclusions
“There are so many unknowns. For example, in the next 5 to 10 years, are we going to see worse survival rates or higher recurrence rates because patients weren’t getting their screening mammograms or coming in to be evaluated? We just don’t know,” emphasized senior study author Katharine Yao, MD, FACS, Chair of the National Accreditation Program for Breast Cancers at the ACS, Vice Chair of Research in the Department of Surgery at NorthShore University, and a breast surgeon. “I think what’s notable is the drop in breast cancer diagnoses was consistent across all regions of the country, all age groups, and all different races. It was not an isolated event. The results of this study tell us that during the [COVID-19] pandemic, patients weren’t coming in for evaluation of breast findings and for screening mammograms, and that’s very likely why we saw fewer cancers diagnosed in 2020,” she noted.
The investigators underscored that further research may be needed to determine when breast cancer case numbers will return to baseline levels as well as the full consequences of delayed diagnosis and care—particularly among patients and geographic areas that were most severely affected by the pandemic.
“I think it’s important to have [these] data as a baseline, so we can look at future data and compare [them] to what happened in the past. To know that, we need to know where we started, and that’s what this study really presents: a starting point. Looking at years after 2020, we’ll gain a more complete picture and can start to see where the trends lie,” Dr. Yao concluded.
Disclosure: For full disclosures of the study authors, visit onlinelibrary.wiley.com.
