Cancer rates are climbing around the world, but the latest wave of research reveals a troubling shift: younger adults are increasingly being diagnosed with cancers once thought to be the preserve of older generations. Meanwhile, some nations, like Lebanon, are experiencing an unprecedented surge in both cancer incidence and mortality, prompting urgent calls for action from public health experts and lawmakers alike. The complex web of causes—ranging from lifestyle changes and rising obesity to air pollution and tobacco use—demands a multi-pronged approach to prevention, detection, and care.
According to a sweeping study published in the Annals of Internal Medicine, cancer incidence data from 42 countries across five continents between 2003 and 2017 paints a stark picture. Researchers focused on 13 cancer types and found a rise in thyroid, breast, colorectal, kidney, endometrial, and leukemia cases among adults aged 20 to 49. More than three-quarters of the countries included in the study reported increasing rates among this younger cohort. Thyroid cancer led the pack, with a median annual growth rate of 3.57%, followed by kidney cancer at 2.21% and endometrial cancer at 1.66%. Colorectal cancer, a much-discussed early-onset cancer, rose by 1.45% per year among younger adults. In nearly 70% of countries studied, new cancer diagnoses grew faster in younger adults than in older populations, signaling a concerning shift in disease patterns that is strongly associated with rising obesity levels.
What’s fueling this surge? The researchers point to several culprits. Rising obesity rates, dietary changes, and antibiotic use may all be at play, influencing hormone levels, inflammation, and metabolic function. "Obesity is strongly linked to endometrial, kidney, and colorectal cancers due to effects on hormone regulation, chronic inflammation, and metabolic processes," the study notes. Diet changes—including high consumption of processed foods, added sugars, and low fiber intake—contribute to weight gain and increased cancer risk, while sedentary lifestyles further compound the danger. Even frequent antibiotic use, which can alter the gut microbiome, may play a role in cancer susceptibility.
Despite these rising numbers among younger adults, older populations still carry the greatest cancer burden. In the United States in 2022, for example, approximately 50,000 women under 50 were diagnosed with breast cancer, compared to over 210,000 women aged 50 and above. The researchers stress that while early-onset cancers are increasingly recognized, prevention and treatment efforts must continue to prioritize older adults, who still bear the highest overall burden. Clinical priorities should include specialized treatment strategies and supportive care for younger patients, alongside healthy lifestyle promotion and screening for all age groups.
Breast cancer, in particular, is under the microscope. A new study published in Cancer, the journal of the American Cancer Society, reveals that rates of one subtype—invasive lobular carcinoma (ILC)—have been rising in the United States more than three times faster than those of all other breast cancers combined over the past decade. The study analyzed national data from 2012 to 2021 and found that rates of ILC increased by about 2.8% each year, while rates of all other breast cancers rose by about 0.8% a year. ILC is the second most common type of breast cancer, accounting for 10% to 15% of all new breast cancer diagnoses in the US, with about 47,500 cases diagnosed annually.
ILC presents unique diagnostic challenges. As Dr. Leana Wen, an emergency physician and expert for CNN, explains: "This type of tumor tends to grow in a way that doesn’t change the breast’s structure as much as other cancers. Instead of forming a defined mass, the cancer cells spread through the tissue in thin strands that appear more like normal breast tissue on imaging." As a result, mammograms may show only subtle changes, or sometimes none at all, and women may be less likely to feel a distinct lump during a self-exam. Additional imaging such as breast ultrasound and MRI can help, especially for women at higher risk, but mammography remains the standard screening tool for most.
The rise in ILC is not uniform across all groups. The steepest increase was seen among Asian American and Pacific Islander women, with about a 4.4% annual increase. Age is also a significant risk factor—about 70% of new ILC cases were diagnosed in women aged 60 and older, and the median age at diagnosis is 66. Several factors may be driving this increase, including changes in hormone exposure, rising obesity and alcohol use, and shifts in childbearing and menopause patterns. Improved diagnosis and greater awareness may also be leading to more accurate identification, as some lobular cancers may have been misclassified in the past.
Treatment for ILC is similar to other breast cancers and may include surgery, radiation, hormonal therapy, chemotherapy, and newer targeted drugs. However, ILC may be more resistant to treatment in advanced stages and tends to carry a poorer prognosis once it has spread. "Some risk factors can’t be changed, such as age or family history, but many lifestyle choices can make a difference," Dr. Wen advises. Quitting smoking, limiting alcohol, maintaining a healthy weight, and staying physically active all help lower the risk of breast cancer. Regular screening and knowing what’s normal for your breasts are key for early detection.
While the global rise in cancer is cause for concern, nowhere is the crisis more acute than in Lebanon. According to a global survey published in The Lancet and reported by NPR, Lebanon is experiencing the fastest increase in cancer incidence and mortality worldwide. New cancer cases have increased by 162% from 1990 to 2023, and cancer-related deaths by 80% over the same period. In 2023, Lebanon saw 233.5 new cancer cases per 100,000 people.
Ali Mokdad, chief strategy officer of population health at the University of Washington and co-author of the survey, points to several factors behind Lebanon’s alarming rise. Air pollution from diesel generators and smoky tailpipes, poor enforcement of vehicle emission laws, and overuse of agricultural chemicals all contribute. But by far the biggest risk factor is smoking. "There is no more taboo about smoking," Mokdad told NPR. "Everybody smokes. Kids smoke in front of their parents." The lack of public health campaigns warning against the dangers of smoking or secondhand smoke only exacerbates the problem. As a result, lung cancer rates have jumped nationwide, along with increases in leukemia, pancreatic, and liver cancers.
Screening and early detection could help, but health education remains a challenge. While screening is available, most people don’t know to seek it out. Mokdad has called on Lebanon’s government to improve health screening, ban smoking in public spaces, and launch aggressive anti-tobacco campaigns. Lawmakers have begun to take notice, but as Inaya Ezzeddine, a member of parliament and physician, told NPR, "It’s a journey. It’s not something that we can implement overnight because it has to do with a lot of sectors." Meanwhile, individuals like 57-year-old Najah Mourda, who has lost several loved ones to cancer, hope for change but struggle to quit smoking themselves.
With cancer cases and deaths predicted to continue rising worldwide through at least 2050, especially in low- and middle-income countries, the need for coordinated action is urgent. Addressing obesity, promoting healthier lifestyles, improving air quality, and strengthening public health campaigns could all help stem the tide. The stakes, as these studies and personal stories make clear, could not be higher.
