Studies spotlight COVID-disrupted breast-cancer screening, cancer treatment delays or stoppage

Empty mammography machine

Olga Volodina / iStock

Three new studies delve into patterns of breast-cancer screening and follow-up during the COVID-19 pandemic, rates of care continuity among patients with cancer and COVID-19, and the characteristics of those most likely to discontinue treatment. 

Screening dropped 81% in first pandemic months

For the first study, Pennsylvania State University at Hersey researchers analyzed the electronic health records of nearly 1.2 million women eligible for breast cancer screening at multiple US healthcare systems from January 1, 2017, to February 28, 2022. The team assessed monthly screening volumes and compared the rate of adherence to follow-up screening 2 years later during the COVID-19 pandemic versus prepandemic.

The average patient age was 54.8 years, 50.3% were White, 12.9% were Black, and 7.2% were Hispanic. Common underlying medical conditions were high blood pressure (17.9%), high cholesterol levels (14.3%), diabetes (7.6%), depression (6.9%), and hypothyroidism (6.6%).

"The COVID-19 pandemic led to a decline in the number of people seeking health care services, including breast cancer screening, as many screening programs were temporarily suspended because of concerns about exposure to the virus and the burden on the health care system," the researchers wrote.

The findings were published yesterday in the Annals of Family Medicine.

The monthly breast cancer screening volume among the 1,186,669 eligible women fell 80.6% from February to April 2020 and then returned to nearly prepandemic levels by June 2020. But the rate of follow-up screening declined from 78.9% before the pandemic to 77.7% after the emergence of SARS-CoV-2.

The COVID-19 pandemic had a transient negative effect on breast cancer screening overall and a prolonged negative effect on follow-up screening.

Lower adherence to follow-up screening was seen throughout the pandemic (odds ratio [OR], 0.86), especially among women aged 65 and older and those of non-Hispanic other race (Asian, American Indian, Alaska Native, Native Hawaiian, and other Pacific Islander; OR, 0.71).

"The COVID-19 pandemic had a transient negative effect on breast cancer screening overall and a prolonged negative effect on follow-up screening," the study authors wrote. "It also exacerbated gaps in adherence to follow-up screening, especially among certain vulnerable groups, requiring innovative strategies to address potential health disparities in primary care."

The researchers said that understanding the chronic conditions and social determinants that affect breast cancer screening adherence during the pandemic, as well as age and racial health disparities, is important.

"Decisions for postponing cancer screening could be due to numerous uncertainties of older adults regarding their health conditions and fear of COVID-19 infection, especially among older women," they wrote. "Such delays could result in late-stage diagnoses and worse health outcomes for patients at high risk of morbidity and mortality."

Socioeconomic factors may have at least partly led to the racial disparities observed in the study. 

"Compared with White women, women of other races were more likely to be unemployed and uninsured because of the economic downturn caused by the pandemic, preventing them from accessing essential preventive care services and follow-up," the researchers said. "Future research is needed to further understand the underlying social determinants that drive the current gap and disparities, and how the disruption in health services could exacerbate the gaps through these factors."

Racial disparities in treatment disruption rates 

For the second study, published in JAMA Network Open, a team led by researchers from the Lee Moffitt Cancer Center and Research Institute in Tampa, Florida, studied rates of care continuity among patients who had cancer and were diagnosed as having COVID-19 during their cancer-treatment planning from April 2020 to September 2022.

Treatment delay or discontinuation (TDD) was defined as any cancer treatment postponed for more than 2 weeks or cancelled with no plans to reschedule.

Of the 4,054 patients included in the study, 3.5% were American Indian or Alaska Native, 4.3% were Asian, 12.8% were Black, 11.6% were Hispanic, 67.8% were White, 59.3% were women, 35.1% were aged 50 to 64 years, and 47.7% were 65 or older. The patients were scheduled to receive chemotherapy (90.8%), radiation therapy (9.4%), surgery (5.4%), or transplant (0.7%). 

A total 1,853 patients (45.7%) experienced TDD at 69 US cancer-care centers. Racial disparities in TDD varied by pandemic wave. Black (third-wave adjusted prevalence ratio [aPR], 1.56) and Hispanic cancer patients with COVID-19 (third-wave aPR, 1.35) were more likely to experience TDD than their White peers in the first year of the pandemic. By 2022, Asian patients (aPR, 1.51) had greater odds of TDD than their White counterparts, while American Indian or Alaska Native patients had lower odds (aPR, 0.37).

"Due to the delays or cancellations in cancer treatment observed in this study, downstream inequities in cancer outcomes among minoritized racial and ethnic groups may occur in the future and may differ across race and ethnicity due to differential impacts based on case surge during the pandemic," the authors wrote.

Treatment stoppage rates higher among Asians

A third study by the authors of the second study examined the characteristics of patients diagnosed as having cancer and COVID-19 who discontinued cancer treatment.

The study, also published in JAMA Network Open, included 3,812 patients, 82% of whom were 50 years or older, 60% were women, 68% were White, 12% were Hispanic, and 86% had at least two chronic conditions. Most (90.6%) were scheduled to receive chemotherapy, while 9.5% were to receive radiation, 5.7% surgery, and 0.8% transplant or cellular therapy.

Our findings suggest long-term consequences of cancer treatment cancellations should be monitored to identify any potential exacerbations in inequities in cancer outcomes due to the COVID-19 pandemic.

The overall rate of treatment discontinuation (TD) was 5.3%. Asian patients were much more likely than White patients to experience TD (aPR, 1.62). Clinical risk factors for TD were higher among patients with a higher Eastern Cooperative Oncology Group score (tolerance for therapy; aPR, 2.61) or a diagnosis of gastrointestinal cancer (aPR, 2.13). 

Severe COVID-19 infections were tied to a higher likelihood of cancer TD, while TD was less likely among those with stable cancer at COVID-19 diagnosis than those with advancing cancer (aPR, 0.51). "This may suggest that patients already engaged in care were able to continue treatment," the authors said.

TD was more likely early in the pandemic, perhaps because of factors such as the nonavailability of COVID-19 vaccines and healthcare system responses when little was known about the newly emerged virus, the researchers said.

They added that the higher TD rate among Asian cancer patients could have been due to language barriers that interfered with the ability to use telehealth services among older Asian patients and Asians' higher rate of hospitalization and COVID-19 death compared with White patients.

"Nonetheless, our findings suggest long-term consequences of cancer treatment cancellations should be monitored to identify any potential exacerbations in inequities in cancer outcomes due to the COVID-19 pandemic," they concluded.

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