A cancer patient holds the IV tubes during chemotherapy.
Cancer: The facts
01:00 - Source: CNN
CNN  — 

Breast cancer in women has surpassed lung cancer as the most commonly diagnosed cancer in the world, according to a new report.

The paper, published in the CA: A Cancer Journal for Clinicians on Thursday, estimates that there were about 2.3 million new cases of female breast cancer last year, making up 11.7% of all new cancer cases. Meanwhile, lung cancer made up 11.4% of total cases diagnosed, according to the new report.

Until now, lung cancer had been the most diagnosed in previous reports covering the last two decades, said Hyuna Sung, principal scientist and cancer epidemiologist at the American Cancer Society, who was an author of the paper.

“The change of the rank signals the epidemiologic transition of cancers,” Sung told CNN. “That was quite surprising news for us.”

Breast cancer leads in cases, lung cancer leads in deaths

There were 2.3 million new cases of breast cancer and 2.2 million new cases of lung cancer in 2020, according to the new report.

In 2018, the most recent year with available data, lung cancer was in the lead – there were 2,088,849 new cases of breast cancer and 2,093,876 new cases of lung cancer at that time.

Sung said in an email to CNN on Thursday that there has been an increase in breast cancer awareness, but mammogram screenings may not explain the full rise of beast cancer diagnoses over time.

“The increasing trend of breast cancer is likely to reflect the increase in the prevalence of breast cancer risk factors such as excess body weight, physical inactivity, alcohol consumption, postponement of childbearing, fewer childbirths, and less breastfeeding,” Sung said.

Researchers from the American Cancer Society in Atlanta and the International Agency for Research on Cancer in France wrote in the report that lung cancer still ranked as the leading cause of cancer death among both men and women combined, with an estimated 1.8 million deaths, making up 18% of all cancer deaths.

Lung cancer was the leading cause of cancer deaths among men, making up 21.5% of men’s cancer deaths. Whereas, breast cancer was the leading cause of cancer death among women at 15.5%.

‘The burden of cancer … is rapidly growing worldwide’

The report is based on cancer incidence and mortality data from the International Agency for Research on Cancer. Overall, the data suggest that there were an estimated 19.3 million new cases and 10 million cancer deaths worldwide in 2020.