Conditional relative survival and competing mortality in patients who underwent surgery for lung cancer: A nationwide cohort study

We aimed to investigate the conditional relative survival (CRS) and competing mortality in patients who underwent surgery for newly diagnosed lung cancer. Using a nationwide population‐based database, we calculated 5‐year CRS on 1 to 5 years survival after surgery. These rates were reported according to age, sex, socioeconomic status, comorbidities and treatment received. We also estimated cause‐specific mortality with the consideration of competing risk. We identified 34 349 patients newly diagnosed with primary lung cancer from 2007 to 2013. The 5‐year CRS after surgery was 71.7% at baseline improving steadily to 85.4% by 5 years, suggesting evidence of persistent excess mortality risk. Throughout the period, lung cancer was the most common cause of death, contributing to 83.6% mortality 1 year after surgery and 66.3% 5 years after surgery. Other causes of death included cardiovascular disease and respiratory disease, which increased continuously with time after surgery. CRS rates for patients with lung cancer improved over time but did not reach the level of the general population even 5 years after surgery. Although the main cause of death continues to be lung cancer, death from noncancer causes increased with time after surgery. Evidence‐based decisions could be made on the dynamic risk profiles of the patients. What's new? Traditional cumulative survival estimates calculated at the time of cancer diagnosis do not reflect changes in prognosis over time. Here, using a nationwide population‐based database, the authors found that conditional relative survival for patients with lung cancer improved over time but did not reach the level of the general population even 5 years after surgery. Whereas the main cause of death continued to be lung cancer, death from non‐cancer causes increased with time after surgery, suggesting the need for continued surveillance and care in lung cancer patients. Evidence‐based decisions could be made on the dynamic risk profiles of cancer patients.