Over the past two decades, there has been a notable shift in the natural history and epidemiology of lung cancer. Previously there was a greater preponderance of central lung tumours with a squamous cell pathology, over time there appears to be a shift towards more peripheral lung tumours which more commonly have an adenocarcinoma cell type. The rate of squamous cell lung cancer in men in 2000 was 20.3 per 100 000 and has steadily declined over time to a rate of 11.2 per 100 000 in 2020 in the USA.1 Similar declines have been observed in the incidence of large-cell and small-cell lung cancer. In contrast, there is a relative increase in the proportion of patients with lung cancer that are due to adenocarcinomas. Furthermore, with the advent of lung cancer screening, there is increasing awareness of synchronous multiple lung cancers with a prevalence of at least 5% of non-small cell lung cancer.2 We have also observed a cohort of patients with adenocarcinoma with a mixed lipidic and acinar pattern but with several other ground glass nodules with the potential of developing into an adenocarcinoma. Furthermore, with improving treatment there are patients with lung cancer presenting several years after their initial treatment with a new primary lung cancer. The key implication of these changes in the natural history of lung cancer is to highlight the importance of treatment strategies that are focused on lung preservation.

A multicentre trial conducted in Japan has demonstrated that segmental resections …