Most people think that only older people get lung cancer although it has been reported in people as young as 20 years old. The average age at diagnosis is indeed 70 years but that is only an average. 10% of lung cancers occur in people under 55, and 1.5% occurs in people under 35. These percentages may look small, but in Singapore context where around 1500 people are diagnosed with lung cancer every year, this means 150 patients under 55 and 23 patients under 35 every year.
Young women are affected more by the disease than young men. When lung cancer affects younger people, it tends to present in an advanced stage with most presenting with stage 4 disease. Delay in diagnosis is considered to be the main reason for this as doctors don’t generally suspect it in a young person. Reliance on chest X-ray is another reason for the delay in the diagnosis as chest X-ray often misses lung cancer.
In addition, young people with lung cancer are more likely to be non-smokers than smokers, a profile which again dampens the sense of suspicion because everyone thinks that only smokers get lung cancer. According to research 70% of patients who get lung cancer at a young age are never smokers.
So what is the reason? Genetic abnormalities are thought to be the reason. For example, ROS1 mutations and ALK rearrangements are more common in the lung cancer of young people and are almost always associated with aggressive disease. About 60% of young people with lung cancer will have these and other genetic mutations. Having a first degree relative with a lung cancer increase the risk of having lung cancer by 50% compared to no family history.
Despite all this, the good thing is that the outcome seems to be better in young people with lung cancer as they are able to tolerate aggressive cancer therapies better than the older people. The five-year survival rate of people 18 to 35 with lung cancer is 53.3% for all stages compared to 16% five-year survival rate seen in the older population.
What can you do? If you are young and wondering whether you may be having lung cancer, relax. Without a personal history of cancer, or a family history of lung cancer it is less likely to have lung cancer. Stay away from the known cause of lung cancer that is smoking and maintain a healthy exercise and sleep routine. If you do have a personal or family history of cancer, seek advise from a lung specialist.