In the past, the term watchful waiting meant no treatment until the development of metastatic disease, at which time androgen ablation (hormonal) therapy was initiated.
Today, men who have very low to low risk prostate cancer, and who choose no immediate treatment as an alternative to immediate treatment, are closely monitored with intervention -if necessary- at a time when cure is still possible.
We now refer to this as Active Surveillance (also formally called Expectant Management) with selective delayed curative intervention. This means that men undergo periodic evaluations including PSA tests, digital rectal examinations, and prostate biopsies.
If there is evidence that the cancer is progressing, treatment is recommended with the intention of curing the disease.