Active surveillance and watchful waiting are wait-and-see approaches for cancer. They are used because you may get better (or not get worse) without treatment. And if the cancer continues to grow or spread, you and your doctor will decide what to do next.
Active surveillance means that you are being watched closely by your doctor without having treatment unless your problem gets worse. During this time, you will have regular checkups and tests, such as biopsies or blood work.
Some prostate cancers grow so slowly that men who choose active surveillance may be able to delay or avoid having surgery or radiation.
With testicular cancer, surgery may be all the treatment a man needs. Surveillance allows these men to delay or avoid other treatments.
Watchful waiting also means that you'll be watched closely by your doctor without having treatment unless your problem gets worse. But the goal of watchful waiting is to only treat symptoms that bother you rather than cure the cancer. Men who are near the end of their lives and men who have other serious medical conditions and aren't well enough to have aggressive treatments often choose watchful waiting.