There were no statistical differences between the 3 SOTR groups in Gleason scoring on prostate biopsies and cTNM staging. Radical prostatectomy (RP) was the most common treatment in all 3 groups and included 68.4% of all patients with PC diagnosis. Global 5 year survival was found to be 79.9%, 85.5% and 41.6% in RTR, HTR and CTR, respectively.
There was an increased standard incidence ratio (SIR) of PC found in all SORs when compared with the national population: 41.9 (OR 43.02; 95% CI, 30.7-60.3], P < 0.0001). This increased SIR was also found in each individual SOR group: RTR SIR 40.2 (OR, 41.3; 95% CI, 27.7-61.4], P < .0001), HTR SIR 48.4 (OR, 49.6; 95% CI, 28.8-85.4], P < .0001), and CTR SIR 38.9 (OR 40.03; 95% CI, 18.1-85.4], P < 0.0001).
Standardized mortality ratio (SMR) was also increased in the cumulative SORs at 18.75 (OR, 19.2; 95% CI, 5.8-69.8, P <.0001]. Statistically significantly increased SMR was also found in RTR (20, OR 20.04; 95% CI: 4.4-91.6, P =.006) and CTR (SMR 50; OR, 48.8; [95% CI, 6.2-382.8, P = 0.0224] but not HTR (SMR 0, OR 13.2 [95% CI, 0.77-226.4, P = 0.85).
The authors concluded that based on their protocol, systematic screening of PC in post SOTRs could not be recommended. Consequently, the decision to screen for PC should follow a similar discussion as with the general population. The author’s protocol led to diagnosing many low-risk prostate cancers that increased the SIR but did not lead to decreases in SMR. Therefore this led to an overall “overdiagnosis” of prostate cancer in the SOTR population.
The authors emphasized the decision to screen for PC in SOTRs should be individualized and that utilization of MRI prior to prostate biopsies to eliminate very-low and low-risk prostate cancers from diagnosis should be strongly considered. Active surveillance (AS) is also a reasonable option in these patients as well.
The findings from this study is important to contrast with overall PC statistics that were recently published in the Morbidity and Mortality Weekly Report (MMWR).3 The authors evaluated data from population-based cancer registries within the US and found a total of 3.1 million new cases of PC diagnosed between 2003 and 2017. Age-adjusted incidence decreased from 155 per 100,000 in 2003 to 105 per 100,000 in 2017. Localized, regional, distant, and unknown stage PC was reported as 77%, 11%, 5% and 7%, respectively. Localized cases decreased from 78% in 2003 to 70% in 2017, and distant cases increased from 4% in 2003 to 8% in 2017.
Overall incidence of prostate cancer decreased between 2003 and 2017 (average annual percent change [AAPC]; 2.5%) but increased for cases diagnosed at distant stage (AAPC = 2.2%). Five-year relative survival was 97.6% between 2001 and 2016. 5-year survival for distant prostate cancer improved from 28.7% in 2001-2016 to 32.3% during 2011 to 2016. The 10-year relative survival for local prostate cancer was 100%.
It is important to evaluate these findings in the background of the 2018 US Preventive Services Task Force (USPSTF) recommendations on PC screening, which concluded that the decision to be screened for prostate cancer should be an individual one for men aged 55 to 69 years old, while men 70 years and older should not be screened for prostate cancer with PSA4. These guidelines reported that PSA-based screening in men between 55 and 69 years old was found to prevent approximately 1.3 deaths from prostate cancer over approximately 13 years per 1000 mean screened. PSA screening may also prevent approximately 3 cases of metastatic PC per 1,000 men screened. This must be weight with potential false positives as well as potential AEs such as erectile dysfunction, urinary incontinence, and fecal urgency.
When comparing the findings from the recent MMWR publication to Waeckel et al, there appears to be a clear difference in 5-yearyear survival. This difference is most likely multifactorial, with a patient’s medical history and immunosuppressive regimen playing key roles. Future studies will need to further clarify if there is any significant difference in immunosuppressive regimens and the risk for PC, and if alterations in this regimen could potentially reduce the risk of PC. Until there are more data, a specific post-SOT PC screening protocol is most likely not required, although real world data may continue to suggest otherwise.
- Hall EC, Pfeifer RM, Segev DL, Engels EA. Cumulative incidence of cancer after solid organ transplantation. Cancer. 2013;119(12):2300-8. doi:10.1002/cncr.28043.
- Waeckel T, Ait Said K, Altieri M, Belin A, Doefler, Tillou X. Over-diagnosed prostate cancer in solid organ recipients: lessons learned from the last 3 decades. Int Urol Nephrol. 2020. doi:10.1007/s11255-020-02636-2
- Siegel DA, O’Neill ME, Richards TB, Dowling NF, Weir HK. Prostate cancer incidence and survival, by stage and race/ethnicity-United States, 2001-2017. MMWR Morb Mortal Wkly Rep. 2020 Oct 16;69(41):1473-1480. doi: 10.15585/mmwr.mm6941a1.
- US Preventive Services Task Force, Grossman DC, Curry SJ, Owens DK, Bibbins-Domingo K, Caughey AB, et al. Screening for Prostate Cancer: US Preventive Services Task Force Recommendation Statement. JAMA. 2018 May 8; 319(18):1901-1913. doi: 10.1001/jama.2018.3710.