1. Lumps in the prostate gland that is often asymptomatic. This lump is detected during a Digital Rectal Examination (DRE) performed by a doctor. This cancer can also be detected by an elevation of the Prostate-Specific-Antigen (PSA) in the blood. PSA is also a tumor marker.
   
   
2. Difficulty in passing urine due to obstruction to the passage of urine.
   
   
3. Back pain due to spread of cancer to the bone (metastases).
   
   
4. Weakness or swelling of lower limbs due to cancer obstruction of the lymphatic channels

Point 2, 3, 4 are symptoms of advanced prostate cancer.

No signs are specific for prostate cancer. It is safer to see a doctor first to exclude other causes of symptoms such as urinary tract infection, benign prostate hyperplasia, urinary stones, etc.