Home 5 Clinical Diagnostic Insider 5 Lost Ground: Cancer Screening in the COVID-19 Era

Lost Ground: Cancer Screening in the COVID-19 Era

by | Jan 2, 2024 | Clinical Diagnostic Insider, Testing Trends-dtet, Top of the News-dtet

A pandemic-related drop in cancer diagnoses could spell long-term trouble for patients and providers.

Each year, four major health organizations—the American Cancer Society, the Centers for Disease Control and Prevention, the National Cancer Institute, and the North American Association of Central Cancer Registries—collaborate to release the Annual Report to the Nation on the Status of Cancer, an overview of trends, statistics, outcomes, and hot topics for the disease. This year’s report included good news on multiple fronts, with mortality rates on the decline over the past five years for 11 of the 19 most common cancers in men and 14 of the 20 most common in women.1 Overall death rates  for male and female patients declined by 2.3 percent and 1.9 percent, respectively, along with decreases of 1.5 percent per year in children and 0.9 percent per year in young adults.

But not all of the news is good—with the COVID-19 pandemic came a drop in cancer diagnoses, which is likely to have knock-on effects on rates of treatment success, recurrence, and mortality. The 2023 report included a special focus on the pandemic’s effect on cancer diagnosis rates,2 comparing 2020’s predicted rates (based on trends from the preceding five years) with the year’s actual numbers. The result? A significant shortfall in diagnoses across six major primary cancer sites, with a corresponding decrease in relevant pathology report volume.3

The story in statistics

The six cancer sites examined in the report included colorectal, breast (in women only), lung, pancreas, prostate, and thyroid cancers. A month-by-month examination of the ratio of observed to expected diagnoses (O/E ratio) reveals that, although case rates were at or above expected levels through January and February of 2020, they experienced a rapid drop in March and especially April, only returning to approximately expected levels in the latter half of the year (see Figure 1).

Figure 1. O/E ratio of cancers at six major primary sites throughout 2020. Charts recreated from the National Cancer Institute’s Surveillance, Epidemiology, and End Results Program (2023).4

The annual report also examined the numbers of pathology reports submitted to participating cancer registries, using an artificial intelligence (AI) algorithm to group reports by month of collection, primary tumor site, histology, and report type. The number of biopsy reports each month correlated closely with the absolute number of new diagnoses, showing a rapid drop in April 2020 and a return to near previous levels in the second half of the year. But despite this apparent recovery, overall new cancer diagnoses in 2020 remained significantly below expected rates in almost all primary sites—though thyroid cancer diagnosis in men and pancreatic cancer diagnosis in all genders ultimately fell within expected ranges for the year. Additional analysis revealed that incidence rates also fell for cancer types not examined in the report, such as leukemia, lymphoma, and melanoma (see Figure 2).

Figure 2. Percent change in incidence rate by cancer type from 2019 to 2020. Data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results Program (2023).5

The report also broke down cancer diagnoses by stage at diagnosis, showing that the diagnosis rates for advanced cancers were closer to expected values than those for in situ and localized cases—likely a result of the reduction in screening procedures,6 in-person medical visits,7 nonessential surgeries,8 and investigations of minor or nonspecific symptoms9 during pandemic lockdowns.

Implications for the lab

A reduction in cancer diagnoses may spell trouble for patients and providers alike. “We are deeply concerned about the implications of delayed diagnosis, which is typically associated with more aggressive disease and worse outcomes,” American Cancer Society CEO Karen E. Knudsen, MBA, PhD, told journalists.10 “It is imperative to ensure that we make up for lost ground on finding cancers early and thereby maximize opportunities for effective treatment and survival.”

For labs, this has meant a rapid post-lockdown increase in the demand for services, especially those related to screening and early detection.11 With work-life balance stress and burnout prevalent even before the pandemic in all clinical laboratory professions,12–14 rising workloads and ongoing workforce shortages can threaten service provision and place throughput and turnaround time targets at risk. To address these issues, the American Society for Clinical Pathology proposed a blueprint for action that includes promoting laboratory careers, expanding and refining training and recruitment efforts, and increasing diversity and inclusivity in the clinical lab.15 Technology can also support laboratorians in coping with rising demand, with options ranging from remote reporting software to AI-based diagnostic support. As digital solutions become more widespread, gains in quality and efficiency may help offset the workload issues labs face.

The long-term outlook

Missed opportunities for early detection in 2020 and beyond may threaten recent progress against cancer and increase the number of late-stage diagnoses—a trend already emerging in lung,16 breast,17 and colorectal18 cancers. In addition, over half of patients already diagnosed had treatments missed or delayed during lockdowns;19 others hesitated to seek cancer-related care due to fear of contracting COVID-19.20 These disruptions to diagnosis and disease management have affected patients’ treatment options, raised the likelihood of adverse outcomes, and increased cancer-associated healthcare costs. The backlog may take years to clear21 and cause significant loss of life in the long term.22

But hope remains—in no small part thanks to laboratories. The rapid development and approval of novel vaccines during the pandemic has led to technological and regulatory advancements that could herald new approaches to cancer prevention and treatment. (In fact, the viral vector technology used to create the Oxford–AstraZeneca COVID-19 vaccine is now under investigation in cancer immunotherapy.23) Labs are working to reduce backlogs and alleviate delays in diagnosis and treatment, using new tools and techniques to decrease turnaround times and deliver personalized care. Combining innovations in cancer screening and detection with growing recruitment and training efforts could offer a path to recovery and restore previous gains made in cancer prevention, treatment, and survival.


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