{"id":233,"date":"2023-05-29T14:34:19","date_gmt":"2023-05-29T02:34:19","guid":{"rendered":"https:\/\/urologywaikato.co.nz\/?page_id=233"},"modified":"2023-10-18T12:15:04","modified_gmt":"2023-10-17T23:15:04","slug":"psa","status":"publish","type":"page","link":"https:\/\/urologywaikato.co.nz\/patient-resources\/psa\/","title":{"rendered":"PSA"},"content":{"rendered":"
[et_pb_section fb_built=”1″ _builder_version=”4.17.0″ _module_preset=”default” global_colors_info=”{}”][et_pb_row column_structure=”2_3,1_3″ use_custom_gutter=”on” gutter_width=”2″ _builder_version=”4.17.0″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”2_3″ _builder_version=”4.17.0″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.21.0″ _module_preset=”default” hover_enabled=”0″ global_colors_info=”{}” sticky_enabled=”0″]<\/p>\n
PSA is a blood test used to look for or\u00a0screen for prostate cancer.PSA is a normal part of the fluid made by the prostate so all men have PSA in their ejaculate (semen) . It helps to break down the seminal clot so the sperm can swim away and try and find the egg. A very small amount of PSA leaks from the prostate into the blood and can be measured in a blood test.<\/p>\n
So all men will have some PSA in their bloodstream and on testing.\u00a0 As the prostate enlarges more PSA is made and more PSA leaks into the bloodstream. This means that there is really no normal value for PSA, but should relate to the size of the prostate. As this is hard to measure accurately most doctors use age-adjusted PSA on the basis that younger men have in general smaller prostates and older men larger prostates. For men under 50 PSA should be less than 2.5, men 50-60 below 3.5, 60-70 4.5 and over 70 below 6.5.<\/p>\n
AGE<\/td>\n | Upper limit of PSA<\/td>\n<\/tr>\n |
Less than 50 years old<\/td>\n | 2.5<\/td>\n<\/tr>\n |
50-60 years old<\/td>\n | 3.5<\/td>\n<\/tr>\n |
60-70 years old<\/td>\n | 4.5<\/td>\n<\/tr>\n |
70+ years old<\/td>\n | 6.5<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\nWhat causes the PSA test to be increased?<\/h4>\nThe level of PSA is increased by many things, only one of which is\u00a0 prostate cancer but conversely some prostate cancers do not cause an increase in PSA. So a rectal examination to feel the surface of the prostate should also be done with a PSA blood test. The commonest cause for a raised PSA is an enlarged benign prostate, other causes are inflammation, and catheterisation. Although unproven it is probably a good idea to do your PSA test more than 48 hours after sexual intercourse and 48hrs after riding a bicycle.<\/p>\n What other blood test can I have?<\/h4>\nPSA belongs to a class of compounds called proteases, that is they break down proteins. To stop this happening about 75% of the\u00a0 PSA released by normal prostate tissue is bound to a carrier molecule and 25% is not, this is called free PSA.\u00a0 For reasons that are unclear prostate cancers tend to release more bound PSA than free PSA. This can measured by a version of the PSA test called a ratio test.\u00a0Free to Total PSA ratios below\u00a012% mean a 1 in 2 chance of having prostate cancer, while a ratio test above 21% carries a low risk of prostate cancer.<\/p>\n Do I need to starve for a PSA test?<\/h4>\nNo, but you should try and not have sex for at least 2 days before the test, and maybe not ride a bike for a few days. Both activities may squeeze PSA out of the prostate and into the blood stream, causing a false rise (elevation) in the PSA test. Sex or a biopsy it’s a difficult choice.<\/p>\n For a longer discussion on PSA, and PSA screening please see<\/h4>\n |