Conditional survival among patients with carcinoma of the lung

Objective: One- and 5-year probabilities of survival or death change once a patient has already survived greater than or equal to 1 year after diagnosis. The current paper reports these probabilities for lung cancer patients according to histologic subtype, stage, and age at diagnosis. Methods: Cumulative observed survival rates were calculated and compared among 95,283 patients with histologically confirmed lung cancer (diagnosed from 1983 to 1992 and followed through 1995) by the life-table method using population-based tumor registries participating in the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute, On the basis of the cumulative survival estimates, we derived the probability of death in the next year, conditioned on having already survived to the start of the year (annual hazards), and the probability of survival conditioned on having already survived greater than or equal to 1 year (conditional survival), These rates were reported according to histologic subtype, stage, and age groups. Results: At the time of diagnosis, annual hazard rates differ greatly among histologic subtypes. However, by 5 years after diagnosis, the rates become similar. Bronchioloalveolar carcinoma displays the lowest annual hazards and small-cell carcinoma displays the highest annual hazards, Stage-age subcategories within histologic subtypes continue to show large differences in annual hazard rates. Five-year conditional survival probabilities are also reported, providing survival information that is consistent to that obtained from the annual hazards. Conclusions: One- and 5-year prognosis for lung cancer patients is influenced by years already survived and histology, stage, and age at diagnosis. Annual hazards and conditional survival provides useful and more relevant information than conventional survival estimates for patients and their physicians. These statistics can be directly obtained from cumulative survival estimates and should be more widely reported.