We hypothesized that SSA life tables’ derived LE predictions differ to OS rates between racial/ethnic groups [6,7]. Our analysis revealed several noteworthy findings.
First, in RP patients, we invariably recorded better OS than that predicted by SSA life tables. The exception to this rule consisted of African-American patients, whose OS virtually perfectly corresponded to their respective LE prediction. It is of interest, that Asian, Hispanic/Latino and Caucasian RP patients exhibited comparable patterns of OS, that exceeded their respective LE predictions to a similar extent. In contrast, African-American RP patients’ OS exhibited virtually no departures from their predicted LE. This observation indicates, that overall survival of African-Americans is worse than that of other racial/ethnic groups. This is applicable, even in the context of younger age of African-Americans relative to the three other racial/ethnic groups.
Second, the above observations indicate, that RP patients, except for African-Americans, exhibit better OS than the general North American population, from which LE predictions are derived. An explanation for the discrepancy between OS of African-Americans versus other racial/ethnic groups can be proposed. It is possible, that the general health of African-Americans as a group is worse than that of the three other racial/ethnic groups and represents the determinant of subsequent survival. This observation is worrisome and may be indicative of the need to correct for potential general health disadvantages in African-Americans, including those treated for localized PCa. Worse general health of African-Americans has been previously reported [12–15]. However, to the best of our knowledge, no previous publication contrasted SSA life tables’ derived predicted LE with OS. In consequence, no previous investigators were able to quantify the overall survival detriment relative to predicted LE in African-Americans. Furthermore, no other investigators contrasted the figures recorded in African-Americans with those recorded for other racial/ethnic groups.
Third, we also examined differences between OS and predicted LE in EBRT patients. Our findings were similar to those described for RP patients. Specifically, OS for Asian, Hispanic/Latino and Caucasian EBRT patients, in general, exceeded that of their predicted LE. However, relative to RP patients, the overall survival benefit was of smaller magnitude. In EBRT patients, the difference between OS and predicted LE in Hispanic/Latinos was roughly half of the benefit recorded in Asians and the long-term survival advantage of Caucasians only corresponded to a fraction of that recorded in Asians. These observations are different from those recorded in RP patients where Asians, Hispanic/Latinos and Caucasians exhibited better OS than respective predicted LE to very similar extents. These differences possibly suggest that general health, which determines OS in these three racial/ethnic groups, differs more appreciably in EBRT patients than in RP patients. Nonetheless, all three racial/ethnic groups (Asians, Hispanic/Latinos and Caucasians) treated with EBRT invariably demonstrate better OS than predicted LE. This phenomenon was not applicable to African-American EBRT patients. Not only did they exhibit worst OS of all examined EBRT racial/ethnic groups (as was also observed in RP patients), but also exhibited worse OS than that of their respective predicted LE as of five years of follow up.
In summary, the SSA life tables’ derived LE predictions underestimate the OS of Asian, Hispanic/Latino and Caucasian RP and EBRT patients. The degree of LE underestimation is most pronounced in RP candidates, in whom the favorable selection bias resulted in best OS. Conversely, the magnitude of the survival benefit is less pronounced in EBRT patients. We also observed a striking difference in OS versus predicted LE in African-Americans, relative to the three other racial/ethnic groups, regardless of treatment type. In both RP and EBRT groups, African-Americans did not exhibit better OS than predicted LE, like it was displayed in the three other racial/ethnic groups. Instead, African-Americans either perfectly followed their respective LE predictions, or their observed survival was inferior to those predictions. The above observations are important in clinical decision making [1,3,8,9]. Specifically, Asian, Hispanic/Latinos and Caucasian patients should be given a benefit of doubt for better LE than that predicted by SSA life tables. Conversely, the opposite applies to African-American patients. Potential conditions underlying the substantially worse survival of African-American patients should be scrutinized with the intent of eradicating this unfavorable survival pattern of African-American localized PCa patients treated with RP or EBRT, and possibly of African-Americans in general [15,16]. To address general health issues, the World Health Organization (WHO) suggests examining physical, emotional and social aspects of general health. Additionally, self-sustainment and personal independence should also be examined in addition to environmental factors . These recommendations are very far reaching and are not exclusively applicable to urological practice and should be addressed in primary and secondary prevention settings.
Despite its novelty, our study has limitations. The first limitation is the nature of the study population, which was diagnosed and treated between 2004 and 2006. The selection of these individuals was dictated by the need of complete ten year follow-up. In consequence, more contemporary data, that had less maturity, could not be included. However, it is possible, that contemporary African-American patients will no longer exhibit the observed survival disadvantage . However, this hypothesis will either be proven or rejected in studies with complete ten year follow up. Second, although Caucasians are well represented in the SEER database, the representation of African-Americans, Hispanic/Latinos and Asians is suboptimal. Oversampling of these patients should be encouraged in the future, to allow better generalizability of observed findings within samples of African-American, Hispanic/Latino and Asian men. Nonetheless, despite those observations, also the smallest sample size in this cohort, namely Asian men treated with either RP (n=1,241) or EBRT (n=1,742), was still adequate. Third, we focused on intermediate and high-risk patients, since these two risk groups represent the optimal patient pool for active treatment [19,20]. Therefore, our analysis did not include patients treated with active surveillance. Fourth, SEER does not provide comorbidities, in consequence, we could not perform a more detailed analysis to examine the underlying comorbidity profiles according to each racial/ethnic group. However, a small proportion of PCa patients die of their disease, even among high risk patients . Furthermore, it may be argued that African-American men may have exhibited the most unfavorable comorbidity profile, especially in the light of previous data displaying marginal differences in cancer-specific mortality between Caucasian and African-American patients .