By now, you’ve probably come to terms with the fact that smokers are far more likely to develop lung cancer than non-smokers. But a study has found that the nicotine in cigarettes can cause that cancer to spread to the brain.
Scientists from Wake Forest University, in North Carolina found that the percentage of lung cancer patients who also develop brain metastasis is dramatically high.
They analysed 281 lung cancer patients in the US and found a significantly higher incidence of brain cancer among cigarette smokers.
The researchers were curious to find out what caused this relationship, so they analysed tumours from deceased patients and found large amounts of immune cells called M2 microglia.
These create and release chemicals which are capable of enhancing tumour growth.
In lab experiments on mice, the team from Wake Forest University then discovered that the nicotine encourages the formation of these microglia.
Removing the offending microglia from the brains of living mice prevented nicotine from inducing brain metastasis and enhanced the survival of mice with lung cancer.
It is believed nicotine which is found in cigarettes but is not in itself carcinogenic — is not only highly addictive but could be responsible for spreading the cancer.
A a result, scientists urge lung cancer patients who are habitual smokers to not only quit smoking, but instead go cold turkey and ditch nicotine altogether.
Once cancer spreads to the brain, the average life expectancy for patients is less than six months.