Lung cancer can lie dormant for more than 20 years before turning deadly, helping explain why a disease that kills more than 1.5 million a year worldwide is so persistent and difficult to treat, scientists said on Thursday.
Two papers detailing the evolution of lung cancer reveal how after an initial disease-causing genetic fault — often due to smoking — tumor cells quietly develop numerous new mutations, making different parts of the same tumor genetically unique.
By the time patients are sick enough to be diagnosed with cancer, their tumors will have developed down multiple evolutionary pathways, making it extremely hard for any one targeted medicine to have an effect.
The findings show the pressing need to detect lung cancer before it has shape-shifted into multiple malignant clones.
"What we've not been able to understand before is why this is really the emperor of all cancers and one of the hardest diseases to treat," said Charles Swanton, an author on one of the papers from Cancer Research UK’s London Research Institute.
"Previously, we didn't know how heterogeneous these early-stage lung cancers were."
Lung cancer is the world's deadliest cancer, killing an estimated 4,300 people a day, according to the World Health Organization. Around 85% of patients have non-small cell lung cancer (NSCLC), the type analyzed in the two studies.
To get a clearer understanding of the disease, the two groups of British and American scientists looked at genetic variability in different regions of lung tumors removed during surgery and worked out how genetic faults had developed over time.
What they found was an extremely long latency period between early mutations and clinical symptoms, which finally appeared after new, additional faults triggered rapid disease growth.
In the case of some ex-smokers, the initial genetic faults that started their cancer dated back to the time they were smoking cigarettes two decades earlier. But these faults became less important over time and more recent mutations were caused by a new process controlled by a protein called APOBEC.
The research was published in the journal Science.
Source:
http://www.nydailynews.com/life-style/health/lung-cancer-lie-hidden-20-years-study-article-1.1970079
Two papers detailing the evolution of lung cancer reveal how after an initial disease-causing genetic fault — often due to smoking — tumor cells quietly develop numerous new mutations, making different parts of the same tumor genetically unique.
By the time patients are sick enough to be diagnosed with cancer, their tumors will have developed down multiple evolutionary pathways, making it extremely hard for any one targeted medicine to have an effect.
The findings show the pressing need to detect lung cancer before it has shape-shifted into multiple malignant clones.
"What we've not been able to understand before is why this is really the emperor of all cancers and one of the hardest diseases to treat," said Charles Swanton, an author on one of the papers from Cancer Research UK’s London Research Institute.
"Previously, we didn't know how heterogeneous these early-stage lung cancers were."
Lung cancer is the world's deadliest cancer, killing an estimated 4,300 people a day, according to the World Health Organization. Around 85% of patients have non-small cell lung cancer (NSCLC), the type analyzed in the two studies.
To get a clearer understanding of the disease, the two groups of British and American scientists looked at genetic variability in different regions of lung tumors removed during surgery and worked out how genetic faults had developed over time.
What they found was an extremely long latency period between early mutations and clinical symptoms, which finally appeared after new, additional faults triggered rapid disease growth.
In the case of some ex-smokers, the initial genetic faults that started their cancer dated back to the time they were smoking cigarettes two decades earlier. But these faults became less important over time and more recent mutations were caused by a new process controlled by a protein called APOBEC.
The research was published in the journal Science.
Source:
http://www.nydailynews.com/life-style/health/lung-cancer-lie-hidden-20-years-study-article-1.1970079
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