Most cancer cases ’caused by random bad luck’

The majority of cancer cases in adults are caused by bad luck rather than any inherited factors or environmental causes, according to a new study.

Conducted by Johns Hopkins Medicine, the research used a statistical model to measure the proportion of cancer incidence, across numerous tissue types, caused mainly by random mutations that occur when stem cells divide.

It was found that as many as two-thirds of adult cancer cases can be explained primarily by these 'bad luck' mutations occurring in genes that can drive cancer growth, with the remaining third caused by environmental factors and inherited genes.

This means that while changing lifestyle and habits will help to prevent certain cancers, it may not be as effective for others, underlining the importance of early detection.

Dr Bert Vogelstein, professor of oncology at the Johns Hopkins University School of Medicine, said: "Cancer-free longevity in people exposed to cancer-causing agents, such as tobacco, is often attributed to their good genes, but the truth is that most of them simply had good luck."

Despite this, the importance of lifestyle factors in causing cancer cannot be overlooked. A recent Cancer Research UK study attributed more than half a million cancers in the last five years to avoidable lifestyle factors.