KLK3 and cancer: As shown in Table 1 the 756 at-risk men with incomplete follow-up differed from the 1791 men with complete follow-up, as follows, age (35.6% vs. 26.0% ≥ 60 years), smoking history (48.5% vs. 39.6%), personal cancer history (1.3% vs. 0.3%), Wave 1 PSA ≥ 4 ng/mL (13.5% vs. 5.5%), and Wave 1 DRE (64.7% vs. 76.3% negative and 20.0% vs. 10.3% missing).