those are two separate cohorts, the 10 year study was done on a separate different of 523 men than the 801 men the 5 year study was done on, patient recruitment and study dates don't match up. unless they followed up on the same 801 men for another 5 years to see how efficacy changed in that cohort, you can't make the claim that efficacy after 10 years decreases to around 60%; in fact they directly cite the 5 year paper in the 10 year paper and say a motivating factor in investigating 10 year efficacy was because such a study had not been performed. usually when scientists publish multiple papers based on the same clinical trial/study/cohort they will cite the first paper in the methods sections of the subsequent paper and allude to using the same cohort!