Active surveillance is a valuable treatment option in patients with newly diagnosed low-risk prostate cancer. Studies considering a watchful waiting approach showed favourable cancer-specific survival rates in such patients and it is assumed that patients benefit from a definitive therapy if life expectancy exceeds 10-15 years. Therefore active surveillance is especially valuable in older men and in patients with an elevated comorbidity profile.Precise identification of histologically and clinically insignificant prostate cancers is still not possible today. Active surveillance includes regular PSA measurements combined with follow-up biopsies; however, no standardized protocol exists so far. Histological progression in the follow-up biopsy and PSA elevation are the most important criteria for initiating definitive therapy.Today only a minority of low-risk patients join an active surveillance protocol and a substantial proportion of these men leave such a protocol early without evidence of progression. The psychological burden of living with an untreated cancer seems to be responsible for this. Active surveillance has the potential to lead to undertreatment as there is some evidence that prolonged treatment delay might adversely affect outcome of definitive therapy.
