PDE5A and cancer: studied a nationwide cohort of 12,465 male patients with stage I-III colorectal cancer and found that post-diagnosis PDE5 inhibitor use was associated with a reduction in cancer-specific mortality and metastatic progression, with the strongest protective effect observed in those treated after open surgery (adjusted HR 0.82, 95% CI 0.67-0.99; adjusted HR 0.85, 95% CI 0.74-0.98, respectively) (17).