Background: Survivors of stage I lung cancer are at increased risk of subsequent malignancies. Specific data on risk of subsequent malignancies are underreported in the literature. We studied the incidence of stage I lung cancer and the incidence of all second malignancies in survivors.
Methods: Data from the Surveillance, Epidemiology and End Results 9 database were analyzed to calculate the incidence of stage I lung cancer and subsequent malignancies from 1998 to 2007. The risk of subsequent malignancies is reported as a standardized incidence ratio (observed incidence [O]/expected incidence [E]).
Results: The incidence rate of stage I lung cancer increased slowly from 1988 (8, confidence interval [CI]: 7.6-8.4) to 2003 (9.2, CI: 8.9-9.6) and more rapidly from 2003 to 2007 (11.2, CI: 10.8-11.7). The risk of developing a second lung cancer is highest in the first year with the O/E at 6.78 (CI: 6.29-7.31) and continues to be high at 10 years (O/E 4.12; CI: 4.44-4.80). Laryngeal cancer has the highest incidence in the first year (O/E 9.78; CI: 7.51-12.51) and continues to be high at 10 years (O/E 3.55; CI: 1.77-6.34). For gastrointestinal cancers, there is increased risk of colon (O/E 1.33; CI: 1.22-1.44), esophagus (O/E 2.29; CI: 1.85-2.89), and stomach (O/E 1.43; CI: 1.15-1.75) cancers. The increased risk of bladder cancer (O/E 1.83; CI: 1.65-2.03) remains high even at 10 years after the diagnosis of stage I lung cancer.
Conclusions: There is increasing incidence of stage I lung cancer. Survivors of stage I are at increased risk of certain second malignancies.