According to Beresford et al. [104], whenever BF is observed after RP, the current practice is to treat patients with salvage therapy once metastatic disease has been excluded, without the need for imaging or histological evidence of local recurrence, accepting that current techniques may not be sensitive enough to detect small volume local disease at low PSA values and slow PSA kinetics. The gene discussed is KLK3; the disease is metastatic neoplasm.