Findings add to growing efforts to explain why cancer rates are increasing among younger adults worldwide

Poor sleep may be fuelling the global rise in under-50s being diagnosed with cancer, two large studies suggest.

The number of younger people diagnosed with the disease has risen by almost 80% in three decades. Worldwide cases of early-onset cancer increased from 1.82m in 1990 to 3.26m in 2019, while cancer deaths among people in their 40s, 30s or younger rose by 27%.