Objective: To analyse the value of biopsies of the transitional zone (TZ) in the detection of prostate cancer and their prognostic value.
Methods: The authors reviewed the literature on directed biopsies of the TZ and discuss the most recent publications concerning the impact of these biopsies on prostatic cancer detection and the prognosis of cancers of the TZ.
Results: There are currently few arguments in favour of biopsies of the TZ during a first series of prostatic biopsies, as the incidence of cancers situated exclusively in the TZ is low and first-line biopsies of the TZ do not significantly increase the cancer detection rate. However, when a suspicion of cancer persists after a first series of negative biopsies, or in patients with a large prostate, biopsies of the TZ can be indicated, as some authors consider that they considerably increase the cancer detection rate. Some authors have suggested that cancers of the TZ have a better prognosis than peripheral cancers because of their more favourable histological characteristics. These results need to be confirmed on larger scale studies.
Conclusions: There are two situations in which biopsies of the TZ have a potential value: (1) as a second-line investigation in the case of persistent suspicion of prostate cancer after a first series of negative peripheral biopsies; (2) in patients with a very large prostate. The prognosis of cancers situated exclusively in the TZ is still poorly known, and the management of this type of cancer must remain the same as that of peripheral cancer.