The Nature Genetics magazine reported that the discovery of three molecular subtypes of lung cancer (piano, forte and mezzo forte) in people who have never smoked. These insights will help unlock the mystery of how lung cancer arises in people who have no history of smoking and may guide the development of more precise clinical treatments.

There are three subtypes of lung cancer in never smokers that have distinct molecular characteristics and evolutionary processes. ‘In the future we may be able to have different treatments based on these subtypes,’ experts said.

In this large epidemiologic study, the researchers used whole-genome sequencing to characterize the genomic changes in tumor tissue and matched normal tissue.

The researchers combed the tumor genomes for mutational signatures, which are patterns of mutations associated with specific mutational processes, such as damage from natural activities in the body (for example, faulty DNA repair or oxidative stress) or from exposure to carcinogens.

Mutational signatures act like a tumor’s archive of activities that led up to the accumulation of mutations, providing clues into what caused the cancer to develop.

In this study, the researchers discovered that a majority of the tumor genomes of never smokers bore mutational signatures associated with damage from endogenous processes, that is, natural processes that happen inside the body.

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