Rates of Newly Diagnosed Cancer Among U.S. Patients During the First Full Year of the COVID-19 Pandemic

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In a study of Quest Diagnostics data reported as a research letter in JAMA Network Open, Kaufman et al found significant decreases in monthly new cancer diagnoses during the first full year of the COVID-19 pandemic compared with the prepandemic period.

As stated by the investigators, “We previously reported a substantial decline in new cancer [cases] diagnosed early in the COVID-19 pandemic in the United States. During the period from March 1 to April 18, 2020, weekly cases fell 46.4% (from 4,310 to 2,310) for six cancer [types] combined, with significant declines for each type. This was expected, given recommendations to conserve health-care resources to address the initial set of patients with COVID-19. Medical practices have since reopened, but patient concerns remain. This study updates the analysis through March 2021.”

Study Details

The study included U.S. patients who received testing at Quest Diagnostics for any cause from January 2018 through March 2021 for which ordering physicians assigned diagnosis codes associated with eight cancer types: female breast, colorectal, lung, pancreatic, cervical, gastric, esophageal, and prostate cancers. A cancer diagnosis during 2019 to 2021 was considered new if patients had no prior entries for the same cancer. Monthly trends in newly diagnosed cancers were evaluated for four periods: prepandemic (January 2019 to February 2020), and pandemic periods 1 (March to May 2020), 2 (June to October 2020), and 3 (November 2020 to March 2021).

Key Findings

The study included a total of 799,496 patients, with 453,712 (56.7%) included in the prepandemic period, 68,246 (8.5%) in pandemic period 1, 146,518 (18.3%) in period 2, and 131,020 (16.4%) in period 3.

During the prepandemic period, the mean monthly number of patients with newly diagnosed cancer was highest for prostate (13,214), followed by breast (9,583), colorectal (4,101), lung (3,015), pancreatic (1,177), cervical (493), gastric (415), and esophageal (409) cancers.

During pandemic period 1, the mean monthly number of new diagnoses decreased significantly by 29.8% (from 32,407 to 22,748) for the eight cancers combined. Reductions in mean monthly new diagnoses were significant for each of the cancers, ranging from 21.2% for pancreatic cancer (from 1,177 to 927; P = .03) to 36.1% for breast cancer (from 9,583 to 6,122; P = .01).

During pandemic period 2, the mean monthly number of new diagnoses decreased by 9% (from 32,407 to 29,304) for the eight cancers combined. No statistically significant reductions were observed overall or for any of the eight individual cancers, except prostate cancer.

During pandemic period 3, the mean monthly number of new diagnoses decreased significantly by 19.1% (from 32,407 to 26,204) for the eight cancers combined. Significant reductions were observed for each of the eight cancers, although the magnitudes of reduction were smaller than in pandemic period 1.

The investigators stated, “Our results indicate a significant decline in newly identified patients with eight common types of cancer in the first and third pandemic periods (winter months) but not in the second period (summer months)…. Because the number of newly identified patients with cancer in the third pandemic period did not exceed the prepandemic value, as would be expected if patients with delayed care returned for care, many cancers may remain undiagnosed. The impact of delayed diagnosis may vary with the type of cancer and the extent of delay but could lead to presentation at more advanced stages, with potentially poorer clinical outcomes. Our findings call for planning to address the consequences of delayed diagnoses, including strengthened clinical telehealth offerings supporting patient-clinician interactions.”

Harvey W. Kaufman, MD, of Quest Diagnostics, Secaucus, NJ, is the corresponding author for the JAMA Network Open article.

Disclosure: For full disclosures of the study authors, visit