Perineural invasion and prostate cancer progression: is there a link?

The authors determined the association between perineural invasion (cancer on the nerves inside the prostate) and disease progression in men with prostate cancer on active surveillance (watchful waiting).  

Active surveillance is common in early stage (stage I or II) prostate cancer. It involves actively monitoring patients for signs of cancer progression without using any treatments. Perineural invasion (PNI) is present in 7% to 43% of prostate tissue samples and usually correlates with a more advanced cancer. Some studies suggest that PNI increases the risk of biochemical recurrence, metastatic disease (cancer spread out from the prostate) and prostate cancer death. Biochemical recurrence is the increase in prostate specific antigen (PSA – protein elevated in the blood in the presence of prostate cancer) levels indicating cancer return.

Further studies are needed to understand the significance of PNI on outcomes of prostate cancer.

The authors aimed to determine the link between PNI and poor outcomes in prostate cancer patients on active surveillance.

302 patients were included in this study. 4% of patients had PNI at baseline (beginning of the study).

41% of patients developed clinical progression (tumor growth or cancer progression). Patients with PNI had a significantly shorter clinical progression-free survival (patients who did not experience progression) than patients without PNI. Patients with PNI had a 1-year survival of 82% compared to 93% in men without PNI. 2-year survival with PNI was 27% compared to 67% in men without PNI. 3-year survival with PNI was 27% compared to 58% in men without PNI. Patients with PNI had a 2.39 times increased risk of clinical progression. Patients with PNI had a 2.21 times increased risk of experiencing disease progression.

The authors concluded that PNI was associated with an increased risk of clinical progression in prostate cancer patients on active surveillance.