Workers inspect the quality of N95 masks on the production line at United States Mask in Fort Worth, Texas, on Feb. 5, 2021. (COOPER NEILL, New York Times/The Minnesota Star Tribune)

The damage from COVID-19 lockdowns continues to appear, and another example is an increase in more lethal cancers. A new study in the Lancet finds that patients were more likely to be diagnosed with advanced cancer in 2020 following delays and disruptions in non-COVID health care.

Researchers from the American Cancer Society compared the change in the stage of new cancer diagnoses in the U.S. in 2019 vs. 2020. Early in the pandemic, routine health care was disrupted as hospitals prepared for a surge of COVID patients that didn't materialize in most places. States also suspended "elective" care, including cancer screenings.

While most physician offices reopened in summer 2020, many faced a backlog of patients, which delayed screenings, exams and treatment. Some patients also delayed doctors' visits for symptoms that may have been caused by undiagnosed cancers because they were afraid of catching COVID.

As a result, patients were 5.4% less likely to be diagnosed with a stage 1 cancer and 7.4% more likely to be diagnosed with a stage 4 cancer in 2020 than in 2019, according to the Lancet study. The biggest relative increase for stage 4 disease occurred for liver (13%), stomach (13%), prostate (14%) and thyroid (19%) cancers.

The study also notes that "due to safety concerns, guidelines often recommended postponing elective outpatient procedures for patients deemed to have less aggressive disease, and most endoscopy centres mandated patients to have COVID-19 tests before procedures after their re-opening," which "might have created additional obstacles for patients."

Survival rates are much higher when cancers are caught early, and they can often be treated without chemotherapy and radiation. The five-year survival rate for stage 1 prostate cancer is nearly 100% compared with 32% if the disease has spread to other areas of the body.

The impact of late diagnoses is evident in more cancer deaths. Age-adjusted cancer mortality increased 1.7% in 2021 after falling 17% between 2009 and 2020. Cancer deaths were 2.8% higher during the first six months of this year than in the same period in 2021.

This is more evidence that the lockdown enthusiasts Americans mistakenly trusted during COVID lost sight of the costs in lost livelihoods, learning and lives.