The COVID-19 pandemic has placed an unprecedented burden on the healthcare system, disrupting routine care including breast cancer screening. We used data from 2392 women without a history of breast cancer enrolled in the Boston Mammography Cohort Study (BMCS) to investigate whether subgroups defined by age, race, or family history of breast cancer: 1) experienced greater declines in screening or diagnostic imaging during the lockdown;or 2) had slower rebound during reopening. In this interrupted time series analysis, we used Poisson regression with robust standard errors to model expected monthly rates of breast cancer screening and diagnostic imaging from January 2019 through December 2020. We defined the pre-COVID-19 period as January 1, 2019, to February 29, 2020;the lockdown period as March 1 to May 30, 2020;and the reopening period as June 1 to December 31, 2020. We examined changes in trends overall and tested for the difference in trends by age (<50 vs ≤50), race (white vs non-white), and first-degree family history of breast cancer (yes or no). The mean monthly rate of breast cancer screening in the BMCS cohort was 45 per 1000 people during the pre-COVID-19 period, 7 per 1000 people during the lockdown period, and 50 per 1000 people during the reopening period. The mean monthly rate of breast cancer diagnostic imaging was 6 per 1000 people during the pre-COVID-19 period, 3 per 1000 people during the lockdown period, and 6 per 1000 people during the reopening period. During the pre-COVID-19 period, those who are age 50 or older had 5.3% higher monthly trend in breast cancer screening rates (p=0.005) and 9.8% higher monthly trend in diagnostic imaging rates (p=0.0389). During the lockdown period, those who were age 50 or older had a lower monthly trend in breast cancer screening rates compared to those who were younger than 50 (p<0.0001), while those who were white and those with family history have higher monthly trends of breast cancer screening rates compared to their respective counterparts (p<0.0001). During the reopening phase, those who are age 50 or older have 18.5% lower monthly trend in breast cancer screening rates in comparison to those who are younger than 50 (p=0.0008) and those who were white have 36.2% higher monthly trend in breast cancer diagnostic procedure rates in comparison to those who are non-white (p=0.018). Overall, we observed a significant decline in breast cancer screening rates with the advent of the COVID-19 pandemic. For the most part, screening and diagnostic imaging rates during the reopening phase equaled or exceeded those of the pre-COVID-19 period. However, the rate of return to screening was lower in women age 50 or older and the rebound in diagnostic imaging was lower in nonwhite women. Careful attention must be paid as the COVID-19 recovery continues to ensure equitable resumption of care. Future work will examine other factors including insurance status, breast cancer risk scores, and geographic location.
Impact of age, race, and family history on COVID-19 related changes in breast cancer screening among the Boston Mammography Cohort Study