The role of perineural invasion and other biopsy characteristics as prognostic markers for localized prostate cancer.

The presence of perineural invasion and the finding of Gleason score 7 cancer on three cores in this case signifies a high likelihood of extraprostatic extension. However, the presence of perineural invasion on prostate biopsy does not independently influence the likelihood of prostate-specific antigen recurrence following radical prostatectomy when matched for preoperative Gleason score, prostate-specific antigen, and clinical stage. This is because cases with perineural invasion on needle biopsy are often associated with other adverse preoperative features such as high biopsy Gleason score, multiple cores involved, and high serum prostate-specific antigen levels. The finding of perineural invasion on needle biopsy may aid urologists in deciding whether to resect the neurovascular bundle on the side of perineural invasion. Excising the neurovascular bundle in cases with perineural invasion will reduce the incidence of positive margins by 17.5% of cases. The remaining cases not benefiting from neurovascular bundle excision are equally divided between extremely aggressive tumors with positive margins outside the neurovascular bundle region or positive seminal vesicles and lymph nodes, and less aggressive tumors that are either organ-confined or have very limited extraprostatic extension.