3 ms·

>Prostate cancer is somewhat unique by having a very sensitive blood marker (PSA) being available which can be monitored easily over time. Cancer antigens such

>Prostate cancer is somewhat unique by having a very sensitive blood marker (PSA) being available which can be monitored easily over time. Cancer antigens such as PSA and CA-125 can also increase due to non-cancerous causes. Pretty much all of them increase in any kind of inflammation whether it is due to bacteria or something else and more. So their main use is getting a baseline once the cancer is diagnosed and monitoring it later on. Funny story, a professor once had a patient with prostate cancer, treated and cancer free afterwards. Every 6 months the patient would visit for screening and his PSA was through the roof( think >1k while normal levels are at most around 3ng/mL). After performing CT scans etc the patient was found cancer free. Another PSA test would return normal after a couple days. This story repeated several times with the professor slowly sliding into madness from it. Turns out the patient was getting anxious about the screening the day before so he smoked some weed which increases PSA secretion. And of course weed is illegal here so he didn't want to admit it.

pintxo 6y ago
Should have stressed the "over time" part more. Yes PSA is sensitive to sex and sport (esp. cycling), and also to inflammation. Plus you personal PSA value depends on the actual size of your prostate. That's why getting an early PSA baseline is important, so you know what value is "good". Also you might not want to take drastic action based on a single "bad" PSA.
- HeadsUpHigh 6y ago
  No, you got it wrong. You get a baseline PSA measurement AFTER the diagnosis. That way you can see if the patient responds to treatment and also monitor for recurrence. Cancer antigens are NEVER to be used for diagnosis. Chemotherapy is too destructive to be used without 100% certainty. We've had a woman with high CA125 and it turns out it was tuberculosis in the reproductive system... Everyone wanted to start chemo, the symptoms matched etc...
  - shard 6y ago
    In my father's case, our family doctor requested a prostate cancer screening after seeing PSA levels from regular blood tests rise over the course of a year. We received the cancer diagnosis after the screening.
  - pintxo 6y ago
    PSA is definitivly used for early screening prior to diagnosis [1]. But we might use the word baseline for different things. As PSA is influenced by the patients physiology and activity [1], it can be helpful to understand what the non-cancer baseline/standard PSA value for a specific patient is, this would need to be established by multiple tests over a couple of years. This can help in distinguishing noise from signal later. After surgery the PSA baseline is zero (by definition, the generating organ has been removed). Any value above zero indicates either metastasis in other body parts or a really bad surgeon. After non-surgery primary treatment (radiation, ...) the PSA does not (necessarily) fall to zero, so here one takes the lowest value after treatment (with a grace period) as the baseline. [1] https://www.cancer.org/cancer/prostate-cancer/detection-diagnosis-staging/tests.html https://www.cancer.org/cancer/prostate-cancer/detection-diag...

pintxo 6y ago

Should have stressed the "over time" part more. Yes PSA is sensitive to sex and sport (esp. cycling), and also to inflammation. Plus you personal PSA value depends on the actual size of your prostate. That's why getting an early PSA baseline is important, so you know what value is "good". Also you might not want to take drastic action based on a single "bad" PSA.

HeadsUpHigh 6y ago
No, you got it wrong. You get a baseline PSA measurement AFTER the diagnosis. That way you can see if the patient responds to treatment and also monitor for recurrence. Cancer antigens are NEVER to be used for diagnosis. Chemotherapy is too destructive to be used without 100% certainty. We've had a woman with high CA125 and it turns out it was tuberculosis in the reproductive system... Everyone wanted to start chemo, the symptoms matched etc...
- shard 6y ago
  In my father's case, our family doctor requested a prostate cancer screening after seeing PSA levels from regular blood tests rise over the course of a year. We received the cancer diagnosis after the screening.
- pintxo 6y ago
  PSA is definitivly used for early screening prior to diagnosis [1]. But we might use the word baseline for different things. As PSA is influenced by the patients physiology and activity [1], it can be helpful to understand what the non-cancer baseline/standard PSA value for a specific patient is, this would need to be established by multiple tests over a couple of years. This can help in distinguishing noise from signal later. After surgery the PSA baseline is zero (by definition, the generating organ has been removed). Any value above zero indicates either metastasis in other body parts or a really bad surgeon. After non-surgery primary treatment (radiation, ...) the PSA does not (necessarily) fall to zero, so here one takes the lowest value after treatment (with a grace period) as the baseline. [1] https://www.cancer.org/cancer/prostate-cancer/detection-diagnosis-staging/tests.html https://www.cancer.org/cancer/prostate-cancer/detection-diag...