The number of individuals suffering from cancer globally is expected to rise by 77 percent to 35 million by mid-century with behaviors like alcohol consumption, unhealthy diet, and poor physical activity contributing to the increase.
“This rise in projected cancer cases by 2050 is solely due to the aging and growth of the population, assuming current incidence rates remain unchanged,” said Dr. Hyuna Sung, senior principal scientist at the American Cancer Society (ACS) and co-author of the study.
“Notably, the prevalence of major risk factors such as consumption of unhealthy diet, physical inactivity, heavy alcohol consumption, and cigarette smoking are increasing in many parts of the world and will likely exacerbate the future burden of cancer barring any large scale interventions.”
With 2.5 million new cases, and accounting for one in eight cancers globally or 12.4 percent of all cancers, lung cancer was the most frequently diagnosed cancer in 2022. This was followed by female breast cancer which made up 11.6 percent of global incidents, colorectum cancer at 9.6 percent, prostate at 7.3 percent, and stomach at 4.9 percent.
The leading cause of cancer death was also lung cancer, accounting for 1.8 million or 18.7 percent of all cancer deaths. This was followed by colorectal cancer at 9.3 percent, liver cancer at 7.8 percent, breast cancer at 6.9 percent, and stomach cancer at 6.8 percent.
The study attributed tobacco use as the “principal cause” of lung cancer, stating that the disease can “largely be prevented through effective tobacco control policies and regulations.”
“Elimination of tobacco use alone could prevent 1 in 4 cancer deaths or approximately 2.6 million cancer deaths annually,” said Dr. Ahmedin Jemal, senior vice president of surveillance & health equity science at ACS and senior author of the study.
“With more than half of cancer deaths worldwide being potentially preventable, prevention offers the most cost-effective and sustainable strategy for cancer control.”
Among women, breast cancer was seen most frequently, both in terms of number of cases and deaths. Among men, it was lung cancer.
Breast cancer accounted for almost one in four disease cases and one in six cancer deaths among women globally, with the highest incidence rates seen in France, Australia/New Zealand, Northern America, and Northern Europe. In these regions, incidence rates were four times higher than in South-Central Asia and Middle Africa.
The study suggested that “a reduction in excess body weight and alcohol consumption and increasing physical activity and breastfeeding may have an impact in reducing breast cancer incidence.”
Overall, almost half of all cancer cases, 49.2 percent, occurred in Asia. The region also accounted for 56.1 percent of global cancer deaths. Since Asia makes up 59.2 percent of the world’s population, cancer cases and deaths are nearly proportional to their population.
However, “Europe has a disproportionately higher cancer incidence and mortality burden, given that the continent has one-fifth of the global cancer cases (22.4 percent) and cancer deaths (20.4 percent) yet less than 10 percent of the global population (9.6 percent),” the study noted.
Authors declared no financial support from any organization for the work, and no influencing relationships that could have affected the submitted study.
Cancer in the US
The ACS estimates a little over two million new cancer cases to be diagnosed in the United States this year. The number of cancer deaths is estimated to be 611,720, which is roughly 1,680 deaths per day. Cancer is the “second most common cause of death in the U.S., exceeded only by heart disease,” it points out.ACS notes that a “substantial proportion” of cancers can be prevented. “At least 42 percent of newly diagnosed cancers in the U.S.—about 840,000 cases in 2024—are potentially avoidable, including the 19 percent of cancers caused by smoking and at least 18 percent caused by a combination of excess body weight, alcohol consumption, poor nutrition, and physical inactivity.”
Some of the over five million skin cancer cases diagnosed annually in the United States can be prevented when people protect their skin from excessive sun exposure and avoid using indoor tanning devices, it said.
“Certain cancers caused by infectious agents, such as human papillomavirus (HPV), hepatitis B virus (HBV), hepatitis C virus (HCV), and Helicobacter pylori (H. pylori), could be prevented through behavioral changes, vaccination to prevent infection, or by treating the infection.”
The virus, Kaposi sarcoma-associated herpesvirus (KSHV), was found to have activated a specific pathway responsible for how cells multiply and grow. The researchers used breast cancer drugs to reduce virus replication and decrease the size of existing tumors in preclinical models.
“Our findings have significant implications: viruses cause between 10 [percent] to 20 [percent] of cancers worldwide, a number that is constantly increasing as new discoveries are made,” said Jun Zhao from the Cleveland Clinic Florida Research and Innovation Center.
“Treating virus-induced cancers with standard cancer therapies can help shrink tumors that are already there, but it doesn’t fix the underlying problem of the virus … Understanding how pathogens transform a healthy cell into a cancer cell uncovers exploitable vulnerabilities and allows us to make and repurpose existing drugs that can effectively treat virus-associated malignancies.”
ACS pointed out that timely screening can prevent cancers like cervical and colorectal cancers by detecting precancers that can be removed.
Similarly, “screening can also reduce mortality for these cancers and for cancers of the breast, lung (among people with a history of heavy smoking), and prostate by detecting cancer early when treatment is often less intensive and more successful.”
