Lung cancer can stay hidden for over 20 years

Lung cancers can lie dormant for over 20 years before suddenly turning into an aggressive form of the disease, according to a study published Thursday in the U.S. journal Science.

The study, led by researchers at the Cancer Research U.K., examined lung cancers from seven patients, including smokers, ex- smokers and never smokers.

It found that after the first genetic mistakes that cause the cancer, it can exist undetected for many years until new, additional faults trigger rapid growth of the disease.

The researchers hoped this study will help improve early detection of the disease.

Currently, two-thirds of patients with lung cancer are diagnosed with advanced forms of the disease when treatments are less likely to be successful.

"Survival from lung cancer remains devastatingly low with many new targeted treatments making a limited impact on the disease," study author Charles Swanton, professor of the Cancer Research U.K. said in a statement.

"By understanding how it develops we've opened up the disease's evolutionary rule book in the hope that we can start to predict its next steps."

The study also highlighted the role of smoking in the development of lung cancer, saying that many of the early genetic faults are caused by smoking.

But as the disease evolved these became less important with the majority of faults now caused by a new process generating mutations within the tumor controlled by a protein called APOBEC.

The wide variety of faults found within lung cancers explains why targeted treatments have had limited success, the study said.

Attacking a particular genetic mistake identified by a biopsy in lung cancer will only be effective against those parts of the tumor with that fault, leaving other areas to thrive and take over.

Over 40,000 people are diagnosed with lung cancer each year. Despite some positive steps being made against the disease, it remains one of the biggest challenges in cancer research, with fewer than 10 percent surviving for at least five years after diagnosis.

"This fascinating research highlights the need to find better ways to detect lung cancer earlier when it's still following just one evolutionary path," Professor Nic Jones, chief scientist of the Cancer Research U.K., said.

"If we can nip the disease in the bud and treat it before it has started traveling down different evolutionary routes we could make a real difference in helping more people survive the disease, " Jones said.