Breast cancer remains the most commonly diagnosed cancer among women worldwide, and global cases are projected to surpass 3.5 million by 2050, according to a new study published in The Lancet Oncology.
While high-income countries have seen significant progress—nearly a 30% decline in breast cancer mortality between 1990 and 2023 due to decades of investment in screening, early detection, and treatment—the trend in low-income nations is alarming. In these regions, deaths from breast cancer have nearly doubled over the same period.
The study analyzed breast cancer trends across 204 countries and territories over more than three decades, highlighting a widening gap between survival outcomes in wealthier and poorer nations.
“There were improvements in mortality rates over time in higher-income settings, but there were real inequities in progress and increasing mortality in some lower-income settings,” said Dr. Lisa Force, senior author of the study and assistant professor at the University of Washington School of Medicine’s Institute for Health Metrics and Evaluation.
In 2023, an estimated 2.3 million women were diagnosed with breast cancer globally, resulting in 764,000 deaths. Nearly one in four cancers diagnosed in women worldwide that year was breast cancer.
While age-adjusted mortality dropped by nearly 30% in high-income nations, it rose by roughly 99% in low-income countries, with diagnosis rates in these regions increasing by 147% over the same period. Sub-Saharan Africa faces particularly dire outcomes, with mortality rates in central and western regions more than double the global average—approximately 35 deaths per 100,000 people annually after adjusting for age.
“People’s outcomes from cancer depend on what country they live in,” said Dr. Kamal Menghrajani, an oncologist at Massachusetts General Hospital. “And that shouldn’t be the case.”
Infrastructure Gap Drives Mortality
Experts attribute the disparity to insufficient cancer care infrastructure in low-income countries. Screening and awareness alone are not enough, as treatment options remain limited.
“Treating breast cancer requires a carefully coordinated system including surgery, radiation therapy, and chemotherapy or targeted treatments,” said Menghrajani. “In low-income countries, people are being left behind—they may detect cancer, but lack access to optimal care.”
In sub-Saharan Africa, only about half of countries offered external beam radiotherapy by 2020, and none had adequate capacity for their populations. Where radiation therapy is unavailable, mastectomy is often the default, but without postoperative care or systemic treatments, its effectiveness is limited.
Cost further compounds the problem. A standard course of trastuzumab, a targeted therapy for a common breast cancer subtype, combined with chemotherapy, can cost the equivalent of a decade’s average income in some low-income countries.
Addressing these gaps requires both political will and investment in strategies that span the entire cancer care continuum, Dr. Force said. She emphasized that services must be accessible, affordable, and integrated with broader noncommunicable disease efforts.
The World Health Organization’s Global Breast Cancer Initiative recommends three pillars to reduce mortality: early identification of cancer, timely diagnosis after symptom onset, and access to comprehensive treatment. Without a meaningful global approach, many countries may fall short of the initiative’s target of a 2.5% annual reduction in mortality worldwide.
Disparities Persist Even in Wealthy Nations
The study also highlights inequalities within high-income countries. In the United States, Black women have a breast cancer mortality rate 40% higher than White women despite the availability of advanced treatment infrastructure. Factors contributing to this include delayed diagnoses, gaps in treatment access, and biases in care delivery.
“Disparities within countries often mirror those seen globally,” Dr. Force said. “Later-stage diagnoses generally lead to poorer outcomes.”
Reducing Risk and Early Detection
While systemic improvements are essential, individuals can take steps to reduce their breast cancer risk. Lifestyle adjustments, including limiting red meat consumption, avoiding tobacco, maintaining a healthy weight, moderating alcohol intake, controlling blood sugar, and staying physically active, can help—but most breast cancer causes are not lifestyle-related.
Screening remains critical. The U.S. Preventive Services Task Force recommends women undergo mammograms every two years from age 40 to 74. Self-exams are no longer standard guidance due to their limited effectiveness in detecting cancer early. However, women should monitor for any new lumps, masses, or changes in breast shape or skin and seek medical evaluation when needed.
“For the majority of women in the U.S., breast cancer is diagnosed on mammography,” said Menghrajani. “Keeping up with recommended screening is the most effective step people can take.”
