A major US study has revealed a nearly 18% increase in stage 4 breast cancer diagnoses over the past decade, with the steepest rises among women under 40. The research, published in JAMA Network Open, analyzed data from 761,471 breast cancer patients between 2010 and 2021, finding that 43,934 had stage 4 cancer at diagnosis. The rate of stage 4 diagnoses increased from 9.5 cases per 100,000 women in 2010 to 11.2 per 100,000 in 2021.

The 3.1% annual rise among women under 40

Researchers found that women under 40 saw a 3.1% annual increase in stage 4 breast cancer diagnoses , nearly three times the overall rate.. This trend is particularly alarming as breast cancer is traditionally more common in older patients. the study also highlighted a rapid rise in triple-negative tumours, one of the deadliest and hardest-to-treat forms of the disease, which kills nine in 10 patients once diagnosed at stage 4.

Possible factors behind the surge

Several possible factors may be contributing to the increase in stage 4 breast cancer diagnoses. According to the study, these include later pregnancies, rising obesity rates, and exposure to endocrine-disrupting chemicals found in plastics . Breast cancer experts have urged more research into the causes of the rise, warning that much about the trend remains unknown.

Triple-negative breast cancers rise by 2.7% annually

The study also found that triple-negative breast cancers rose by an average of 2.7% annually. This form of breast cancer is particularly aggressive and difficult to treat, making the rise in diagnoses even more concerning. The researchers emphasized the need for further investigation into the underlying causes of this trend.

Men also see a 3.7% annual increase in stage 4 diagnoses

While men account for only a small percentage of breast cancer cases, the study found that stage 4 diagnoses in men rose by 3.7% annually between 2010 and 2021 .. Overall, stage 4 diagnoses rose from 5.6% of all breast cancer cases in 2010 to 6% in 2021. This increase highlights the need for greater awareness and research into breast cancer in men.