Well, the answer is no!
PSA is affected by many other factors, raised PSA levels may be associated with cancer but not necessarily.
Infections, Benign prostatic hypertrophy, and various other factors can be responsible for the rise in PSA levels.
Unfortunately, our medical system advises undergoing a biopsy to confirm the diagnosis of Prostate cancer, once PSA levels are high.
A biopsy is not only an invasive procedure difficult to go through but also leads to various side effects, such as incontinence, Erectile dysfunction, impotence, etc. It also has a major side effect of leading to the spread of tumor cells in the entire body!
Important early warning signs of Prostate cancer are:
A) Beginning of loss of bladder control
B) frequent painful obstructed urination, especially at night
C) Blood in the urine
D) Reduced urinary flow
Another important test that is non-invasive and can do an early diagnosis of Prostate cancer is CTC count ( Circulating tumor cell count).

Dr. Kalpana Shekhawat M.D.
Director Freedom Age
Functional & Metabolic Medicine specialist

http://www.freedomage.in/is-psa-the-test-to-know-if-you-have-prostate-cancer/