Reply to The 5-year relative survival of older patients with prostate cancer is insignificantly different from the 5-year survival of all men of a similar age.

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We thank Drs. Lehrer and Rheinstein for their interest in our study1 and their comments regarding the important topic of prostate cancer screening in healthy older men. They reported estimates of 5-year relative survival among men in the United States with prostate cancer as they age, comparing age ranges of 75 to 79 years, 80 to 84 years, and ≥85 years. Relative survival is defined as the overall survival of patients with prostate cancer divided by the overall survival of a similar cancer-free population.2 It is appropriate to consider a prognosis statistic and compare it with the life expectancy of the patients. However, problems inherent to defining a sufficiently similar cancer-free population (necessary for estimating relative survival) pose challenges to the interpretation of this analysis. The comparison of multiple age groups, including one at the extreme of life expectancy, may introduce additional bias. Nevertheless, the trend reported by the authors is consistent with the results of our study, namely that men with prostate cancer fare worse than those without prostate cancer, and that the older men are when diagnosed with prostate cancer, the worse the prognosis.1 Lehrer and Rheinstein raised concerns that the relative survival rates for men in these older age ranges are not substantially different from the survival probabilities in the United States among all men of those ages. They argued that the comparable percentages across groups are evidence that healthy older men would not benefit from screening. Critically, however, their relative survival estimates did not account for the varying disease stage or aggressiveness of prostate cancer. Our study demonstrated that the absolute incidence of specifically high-risk prostate cancer increased with age among all men in Norway.1 By measuring relative survival using all prostate cancer, Lehrer and Rheinstein have diluted the mortality risk by including men with low-risk prostate cancer. Men with low-risk disease most likely were diagnosed because their physicians thought they were healthy enough to warrant the workup required to diagnose prostate cancer (ie, they were healthier than the normal population).3 The comparable values for SEER*Stat relative survival and life expectancy for the general population suggest that, overall, healthier-than-average older men with above-average life expectancies might lose their survival advantage if they are diagnosed with prostate cancer. The results of our study using Norwegian data indicated that it is men aged 70 to 79 years who have the greatest absolute incidence of being diagnosed with high-risk prostate cancer.1 High-risk disease comprises localized prostate cancers that are curable with definitive treatment but highly prone to becoming metastatic or fatal.4 With a life expectancy of >10 years, a healthy man aged 70 to 79 years could live long enough to develop metastatic disease or die of his cancer. Current National Comprehensive Cancer Network guidelines actually recommend radical therapy for men with high-risk disease whose expected survival is >5 years.5 We do not advocate for the universal screening of older men. Rather, the results of our study1 suggest that older men are among those with the highest incidence of potentially lethal disease. Conversations regarding the pros and cons of screening may be worthwhile for those older men who are healthy enough to benefit from the treatment of high-risk disease. No specific funding was disclosed. Tyler M. Seibert was supported by grant K08EB026503 from the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health for work performed as part of the current study. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Dr. Seibert also has received grant funding from Varian Medical Systems, past honoraria for providing medical education materials from WebMD Inc, and honoraria from HealthLytix Inc for work performed outside of the current study. Minh-Phuong Huynh-Le reports no conflicts of interest.