For prostate cancer, PSA is the most important screening indicator throughout. For patients who need to be diagnosed, it depends on whether the PSA is between 4 and 10 or above 10 before judging how to do further tests; for patients after treatment, there are three criteria – “0.2 ” is the criterion after radical surgery, “1” is the criterion after radical radiotherapy (see “Which prostate cancer patients are suitable for endocrine therapy?”) , “2” is the criterion for endocrine therapy. If PSA continues to rise after endocrine therapy and the test value exceeds 2, it means the effect of endocrine therapy has decreased and further androgen concentration check is needed to clarify the cause. If the androgen concentration rises, it means that the endocrine therapy drugs are not enough to inhibit androgens and need to be increased; but in fact, the androgen concentration of most patients is still at a low level and does not rise, which means that the patient has entered the stage of prostate cancer depression resistance, at which time oral anti-androgen drugs do not work and only maintenance of depression drug injections can be done. In addition to checking androgen levels, it is important to check whether the cancer has recurred if the PSA rises, and this is when the patient needs to have an anal finger examination, as well as an imaging test; but if the PSA is normal, these tests are not necessary. To add a point, the common side effects of drug depot treatment are liver and kidney damage and anemia, so patients need to check blood routine, blood biochemistry, and urine routine at every follow-up, and bone density regularly because of the possibility of osteoporosis due to androgen reduction. The incidence of these side effects is not high, and few patients discontinue the drug because of these side effects. If individual patients react more seriously, they can also switch to other drugs. Note: PSA units in this article are all ng/ml