Two large studies indicate that inadequate sleep could be contributing to the worldwide increase in cancer diagnoses among people under 50. Cases of early-onset cancer rose nearly 80 percent over three decades, climbing from 1.82 million in 1990 to 3.26 million in 2019. Deaths from the disease in this age group increased by 27 percent. Researchers presented the findings at the American Society of Clinical Oncology meeting in Chicago. The studies, conducted by MD Anderson Cancer Center, reviewed health records of more than 18 million U.S. adults aged 18 to 50. Results showed that individuals with irregular sleep patterns faced greater chances of developing bowel, breast, uterine, or ovarian cancers before age 50. Some participants with insomnia were three times more likely to receive a cancer diagnosis within five years. The authors noted that sleep problems may serve as a modifiable factor in assessing early cancer risk and called for additional study. More than one million people under 50 die from cancer annually, according to data in BMJ Oncology. Outside experts described the results as useful but stressed the need for longer-term research to confirm any causal connection. A clinical lead at Bowel Cancer UK observed that while the disease remains more common after 50, rising cases in younger adults may relate to genetics and lifestyle. A sleep clinic director cautioned that the studies show association rather than direct causation, noting that poor sleep often coincides with other behaviors such as reduced exercise or increased alcohol use that could influence cancer risk. A Cancer Research UK manager said further investigation is required before conclusions can be drawn. In the interim, avoiding tobacco, keeping a healthy weight, and limiting sun exposure remain effective ways to lower overall cancer risk.
