In this cohort study of a Chinese prostate cancer screening population (n = 441), participants from the CSC group consistently exhibited a lower age, prostate volume, and PSA parameter values, including the tPSA and PSA density (PSAD) levels, than did those from the OSC group. Furthermore, for all patients whose PCa lesions were confirmed by transperineal prostate biopsy, the curative approach was more effective for patients screened with the CSC method than for those screened with the OSC method, as reflected in the lower GS and ISUP stage and earlier TNM stage.
Although the relationship between the screening method and the detection rate or prognosis of PCa patients remains controversial, previous studies have demonstrated differences in overall PCa incidence during screening due to differences in the proportions of subjects screened with a CSC or OSC approach. For example, of all 2159 males with screening-detected PCa from 13 CSCs and 3 OSCs, 57 (21.0%) underwent prostate biopsy, 34 (59.6%) were confirmed to have PCa, and the average cancer detection rate at the first screening was 1.57%. In that study, there were no significant differences in the distributions of PCa incidence between community centers and screening centers 16. Another study reported that among 6903 males with a high risk of prostate cancer enrolled from 16 CSCs, 148 underwent prostate biopsy, and 79 (53.4%) had PCa; therefore, the total PCa detection rate was 1.14% 17. Furthermore, studies have investigated differences in the clinical characteristics and prognoses of patients with PCa from CSCs or OSCs. A recent study reported that the percentages of patients with initial PSA levels greater than 50 ng/mL, a GS of 8 or greater, and clinical stage D disease were significantly lower in patients who underwent PSA screening alone (without presenting with clinical symptoms). The 5-year overall survival and cancer-specific survival rates in the CSC group (91.3% and 98.2%, respectively) were significantly better than those in the OSC group (86.4% and 94.9%, respectively) 18. Furthermore, PSA screening was an independent predictor of cancer-specific survival. Xu et al. found that a PSA-based screening method applied to patients from a CSC identified more patients with early-stage PCa, including a significantly higher percentage of patients in stage T1-2 and N0 and with a Gleason ≤ 6, than with a later or clinical diagnosis. They also found that overall and prostate cancer-specific survival rates were significantly greater in the CSC group than in the OSC group 19. Similar to our results, more community-screened patients were found to have PSA levels < 20 ng/ml (55.2 vs. 22.4%), a GS < 7 (60.3 vs. 34.1%), organ-confined tumors (87.9 vs. 26.8%), and opportunities for radical prostatectomy (50.0 vs. 18.3%) than clinically diagnosed patients 20.
Despite these encouraging results, it is important to note the limitations of these findings. First, it is likely that some of the men in our study underwent repeat PSA testing after an elevated PSA result, and the fear of prostate biopsy may have impaired the potential for the early detection of prostate cancer. Second, we used only PSA as the initial screening parameter if the PSA level was suspicious, followed by MRI in the CSC group, while in the OSC group, due to the presence of clinical symptoms, the MRI examination rate was greater. In our study, as we included only participants with available MRI and PSA data in the two groups, there may have been some selection bias. Finally, this was a retrospective study. We noticed that a relatively high proportion of participants in the CSC group withdrew during the follow-up period, especially due to family psychosocial factors. Thus, these patients had incomplete clinical data and had to be excluded.
In summary, this study revealed that PSA screening in community service centers was associated with a lower incidence of PCa. Currently, prostate cancer screening methods based on PSA are urgently needed in China. Compared to patients screened due to clinical symptoms, PCa patients screened with community models had earlier disease stages and a better chance of receiving curative treatment. Therefore, it is important to gradually establish comprehensive screening methods and follow-up systems in China. In addition, more scientifically rigorous and strict, ethics-based clinical trials should be conducted.