Limitations of the National Comprehensive Cancer Network® (NCCN®) Guidelines for Prediction of Limited Life Expectancy in Men with Prostate Cancer

Abstract

Purpose National Comprehensive Cancer Network prostate cancer guidelines for the prediction of life expectancy recommend subtracting 50% of life table predicted longevity for those in the lowest quartile of health. However, it is unclear how to identify these men and if their survival is uniform. Materials and Methods We sampled records of 1,482 men diagnosed with prostate cancer from 1998 to 2004 at 2 VA hospitals. We identified men in the lowest quartile of health by age using Charlson scores, calculated their NCCN predicted life expectancy, and compared this with observed median survival in aggregate and across comorbidity subgroups. Results Men with Charlson scores of 2+ (age less than 75 years) and 3+ (age 75 years or older) comprised the lowest quartile of health. Among those younger than 65, 65 to 69, 70 to 74, 75 to 79 and 80 years or older, observed survival vs NCCN predicted life expectancy in years was similar at 10.4 vs 11.1, 10.0 vs 7.8, 6.2 vs 6.4, 4.4 vs 4.9 and 3.7 vs 3.3, respectively. Yet within the lowest quartile there was significant heterogeneity in survival among men with differing Charlson scores. For example, men age 65 to 69 years with Charlson scores 2, 3 and 4+ had an observed median survival greater than 13.3, 9.4 and 4.3 years, respectively. NCCN guidelines misclassified 10-year life expectancy in 24% and 56% of men age less than 65 and 65 to 69 years, and 5-year life expectancy in 18% of men age 70 to 74 years. Conclusions While NCCN predictions matched observed survival on average for the lowest quartile of health, there was substantial heterogeneity in survival by Charlson scores. More granular assessments of life expectancy should be used for those at highest risk for mortality.