Breast Cancer Tops Lung Cancer for No. 1 Diagnosis Worldwide

Breast cancer in women has leap-frogged lung cancer, now accounting for the most cancer diagnoses worldwide – and the situation is likely to get worse in coming decades.

In a report published Feb. 4 in CA: A Cancer Journal for Clinicians, dubbed the “Global Cancer Statistics 2020,” the American Cancer Society (ACS) and International Agency for Research on Cancer (IARC) shared their findings based on data from the Global Cancer Observatory.

Based on their analysis, there were 19.3 million new cancer cases diagnosed in 2020, 2.3 million – 11.7 percent – of which were female breast cancer. In fact, it is now the No. 1 cancer identified in 159 of 185 countries included in the report.

“Overall, the burden of cancer incidence and mortality is rapidly growing worldwide; this reflects both aging and growth of the population, as well as changes in the prevalence and distribution of the main risk factors for cancer, several of which are associated with socioeconomic development,” said the team led by ACS principal scientist Hyuna Sung, Ph.D.

While their assessment determined that female breast cancer is now the most common diagnosis, it is still fifth in line as a cause for cancer mortality. And, it is women in transitioning countries – those moving from centrally planned economies to free-market structures – that are experiencing mortality the most, the team said. The number of women dying from breast cancer in transitioning countries is 17 percent higher than elsewhere, the team pointed out.

The rising incidence level rising in countries where the rate has historically been low, including areas of South America, Africa, and Asia. High-income countries, such as Japan and South Korea, are also being similarly affected. Cultural changes in these areas may have contributed to these increases, the team said.

“Dramatic changes in lifestyle, sociocultural, and built environments brought about by growing economies and an increase in the proportion of women in the industrial workforce have had an impact on the prevalence of breast cancer risk factors – the postponement of childbearing and having fewer children, greater levels of excess body weight and physical inactivity,” the team said, “and have resulted in a convergence toward the risk factor profile of western countries narrowing international gaps in breast cancer morbidity.”

As previously noted, breast cancer mortality rates are higher in transitioning countries even though the incidence rate is 88 percent higher in transitioned countries. Late detection may be responsible, Sung said.

“As the poor outcome in these countries is largely attributable to a late-stage presentation, efforts to promote early detection, followed by timely and appropriate treatment, are urgently needed through the implementation of evidence-based and resource-stratified guidelines,” Sung said.

Unfortunately, the team said, they do not see a turnaround in the future. In fact, over the next two decades, they anticipate the cancer incidence will only grow. In their report, they project that there will be 28.4 million new cancer cases worldwide in 2040 – that is a 47-percent increase from 2020. And, those transitioning countries will also see a higher relative increase compared to those countries that have already transitioned – 64 percent-to-95 percent compared to 32 percent-to-56 percent, respectively.

Consequently, healthcare and medicine must double-down on their cancer prevention efforts in order to stem the tide, the team said.

“The burden of cancer incidence and mortality is rapidly growing worldwide and reflects both aging and growth of the population, as well as changes in the prevalence and distribution of the main risk factors for cancer, several of which are associated with socioeconomic development,” said senior author Freddie Bray, BSc(Hons), MSc, Ph.D., head of the IARC section of cancer surveillance. “Effective and resource-sensitive preventative and curative interventions are pertinent for cancer diagnosis. Tailored integration into health planning can serve to reduce the global burden of cancer and narrow the evidence cancer inequities between transitioning and transitioned countries observed today.”

For more coverage based on industry expert insights and research, subscribe to the Diagnostic Imaging e-Newsletter here.