Incidence of Colorectal, Lung, and Breast Cancers May Be Rising Due to COVID-19–Related Screening Delays

Get Permission

Delays in cancer screenings during the COVID-19 pandemic may have resulted in lower reported incidences of colorectal, lung, and breast cancers, reflecting potentially high rates of undiagnosed cancer and later-stage diagnoses, according to a new study published by Romatoski et al in the Journal of the American College of Surgeons. The findings demonstrated that there may be a significant increase in cancer cases that could have been caught earlier with screenings, placing an increased burden on an already strained health-care system.


“These are all cancers that have very profound incidences in our patient population across the United States. They are much better managed and often curable when found early, and devastating when caught late. In addition, these are all screening tests that were likely put off during COVID-19 because they require patients to come into the hospital setting,” explained senior study author Teviah E. Sachs, MD, MPH, FACS, Associate Professor of Surgery at the Boston University Chobanian & Avedisian School of Medicine and Chief of the Section of Surgical Oncology at the Boston Medical Center. “While the medical system as a whole experienced an incredible burden from the COVID-19 pandemic, now we’re going to see a much different burden present itself due to delays in cancer screening. With this study, we sought to illustrate with data how we could forecast these likely future trends related to screenable cancer incidence,” he added.

Study Methods and Results

In the new study, investigators analyzed the data of 1,066,138 patients with colorectal cancer, 1,707,395 patients with lung cancer, and 2,200,505 patients with breast cancer to develop a predictive statistical model. The investigators used data from the National Cancer Database to quantify missed diagnoses of colorectal, lung, and breast cancers by comparing the observed cancer incidence rates in 2020 with the prepandemic rates from 2010 to 2019. The investigators emphasized that their findings added to the growing body of scientific research revealing how pandemic-related disruptions may have constrained cancer care. To adjust for cancer cases not included in the database, the investigators standardized the data to the U.S. population using Census data.

Significant differences between the observed cancer rates in 2020 compared with the historical data from 2010 to 2019 were discovered for all three types of cancer—where the observed incidence of colorectal cancer decreased by 18.6%, the incidence of lung cancer decreased by 18.1%, and the incidence of breast cancer decreased by 14.6%.

“The incidence for all these cancers decreased, but there’s no reason to believe that cancer incidence dropped during the pandemic in 2020. The data we observed is not likely due to decreasing incidence rates, but I think more likely reflective of missing cancer diagnoses,” stressed first study author Kelsey S. Romatoski, MD, a general surgery resident at the Boston Medical Center. “These missed diagnoses are likely going to lead to delays in treatment and upstaging of disease in the coming years,” she underscored.

In addition, missed diagnoses appeared to disproportionately affect certain sociodemographic populations—including non-White and Hispanic patients and those treated in the Northeast and West United States.


“For these vulnerable patients, it’s especially important that they stay up to date on their screenings so we can detect these missed cancers,” Dr. Romatoski noted.

“The data in this paper [are] an important reminder for practitioners to encourage patients who have delayed their recommended cancer screenings to get screened now. [W]e encourage patients to ask their primary care physicians about recommended cancer screenings. It’s imperative that screenings put off due to the pandemic aren’t delayed any longer,” Dr. Sachs concluded.

Disclosure: The research in this study was supported by the Health Resources Services Administration’s National Research Service Award. For full disclosures of the study authors, visit

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.