A SEER database analysis of conditional survival for prostate cancer patients
14506 Background: Survival probability changes for patients who have already survived one or more years following diagnosis, and is more accurately represented by conditional survival. The specific aims of this study were to determine the 5-year conditional survival rates for prostate cancer patients. Methods: Using the Surveillance, Epidemiology, and End Results (SEER 11) database from the NCI, we analyzed 66,822 prostate cancer patients diagnosed between 1988 and 1994 that were staged using the SEER-modified AJCC staging system (3rd edition). Using the life table method, we computed observed 5-year conditional survival, stratified by stage, age, and race, for patients who had already survived 0 to 5 years after diagnosis. Results: For each category, we compared baseline 5-year observed survival at diagnosis with 5-year observed conditional survival after having already survived 5 years. Survival decreased from 79% to 67% for Stage I, decreased from 80% to 71% for Stage II, decreased from 83% to 75% for Stage III, but increased from 38% to 49% for Stage IV patients. Survival rates did not change for patients <70 years (79–80%), but decreased from 61% to 55% for patients >70 years old. Although blacks (60–62%) had lower survival than whites (69–71%), no race had any appreciable change in their conditional survival for those who had survived 5 years from diagnosis. Conclusions: For prostate cancer patients who have already survived some time after diagnosis, the expected 5-year conditional survival increases for Stage IV patients, but decreases for other stages and for older patients. Conditional survival can provide more accurate longer term prognostic information for prostate cancer patients who have already survived a number of years after diagnosis. No significant financial relationships to disclose.