Question: PSA and Tumor Markers for Prostate Bone Metastasis? This message pertains to the utility of Prostate Specific Antigen (PSA), for the treatment of Advanced Prostate Cancer.
PSA writes Dr. John Lee (Harmone Balance for Men) is produced both within the Prostate Gland and the Breast Tissue. He further writes that the normal cells produce PSA, an anti angiogenesis defence when there are abnormally growing cells in the prostate. This seems to indicate that the PSA has no correlation with what is happening in the bone and anywhere outside prostate. Is this correct?
There are further questions:
(a) How do we monitor bone metastasis and other situations where the cancer has escaped out of prostate. (non-Bone Scan/MRI options)
(b) Are there other prostate tumor markers that can tell us the tumor loads/tumor activity in non prostate areas such as the bones.
(c) Will Acid Phosphatase levels inform us the status of prostate metastasis on bone.
(d) Are Osteoblastic/Osteocystic/Osteocytic rates right parameters to track.
Sam
Answer: There are a few misconceptions here.
* PSA is manufactured almost exclusively by prostate cells. Although there are a few other cell types that can make minute quantities of it, their contribution is so small that PSA is indeed, for all practical purposes, a prostate-_specific_ marker.
However, that doesn't mean it measures only cells that reside in the prostate gland.
* In a person with normal prostatic health, prostate cells reside only in the prostate gland. But in a person with advanced prostate cancer, most of his prostate cells have traveled to areas outside the prostate, typically the bones and lungs.
Therefore, for men with advanced prostate cancer, PSA is normally the single best way of tracking the cancer, since it correlates so well with the number of prostate cells in the body -- both within the gland (if it's still there) and outside the gland, and thus presumably cancerous.
(a) To specifically find bone metastases, one would normally use an imaging technique, such as a bone scan, a CT scan, and/or a PET scan (preferably one that uses 11C-choline rather than 18F-FDG). It's unclear why someone would try to monitor bone metastasis without any attempt to image the bones, so I don't know what prompts the question. (Not all imaging techniques use radioactive tracers, for example. And if expense is an issue, then maybe consider simple X-rays.)
(b) There are indeed other tumor markers, but none of them are specific to rogue prostate cells that are in the _bones_, as opposed to rogue prostate cells generally. Such tumor markers include: PSMA, PAP, NSE, CGA, and CEA.
(c) Yes and no. PAP (prostatic acid phosphatase) is useful as a tumor marker, but no tumor marker, so far as I know, can possibly differentiate betwee bone and non-bone metastasis.
(d) Yes and no. If you're focusing only on the bone, then you are interested in overall rates of bone-building (osteoblastic) and bone-resorption (osteoclastic) activity. But you won't know _where_ the activity is occurring.
Most importantly: In a person has advanced prostate cancer, bone issues are one of the consequences. But it's much more important to tend to the cancer itself than to focus on only one of its consequences. If a car is heading downhill and its brakes are failing, one of the consequences will be tiretread left on the roadway. Rather than trying to measure and track the tiretread, it's more important to find a turnoff, or a soft ditch, or (best) an alternate braking system.
Good luck!
(BTW, I'm now also a member of the PCa tribe.)
Question: Cancer deaths usually result from metastasis? Unless the primary site of the cancer is a vital organ such as liver or lung, are most cancer deaths caused by the metastasis to vital organs? What I mean is, if you have a cancer of the breast/tongue/ovary/prostate... ALONE that has not spread to other organs, then you don't die from it. (But yes, I know cancer eventually always spread and metastasizes.)
Answer: According to an article, "Metastasis is the transfer of malignant tumors from one organ to a distant organ. It is the most common cause of death in cancer patients."
http://content.karger.com/produktedb/produkte.asp?typ=fulltext&file=OCL2005069S01014
Question: Questions about prostate cancer? As my father was diagnosed with PC (75 yo, gleason 8, psa 11, stage T2b)I wanted to help him as he doesn't have any access to the Internet. After 2 months of searching I can now say that I'm quite good informed about the disease, the treatments etc. But I still have some critical questions: what is the turning point, after which this "mild" form of cancer turns into an agressive one and kills the patient? Does it happen after it escapes from the gland and causes metastases? Does it always escape from the capsule and treatment(any treatment) tries to keep it there as long as possible? I would very much appreciate if someone could answer these questions.
Answer: Prostate cancer is one of the most "curable" forms of cancer. many men live for years with it. overall there is a disease free survival rate of 70-85% for 5 years and a 45-75% for 10 years. most men diagnosed with prostate cancer are over age 65 and have other health issues. many men will die WITH prostate cancer but not BECAUSE of prostate cancer.
the gleason score correlates closely with the prognosis.
a gleason score over 8 and staging of T3-T4 is considered advanced stage disease.
a gleason score of 8-10 is a moderately invasive cancer and more prone to metastisize. it is also usually faster growing than lower gleason score tumors. but the T2b means that the cancer is contained within the prostate and has not spread-and hopefully with treatment it won't. prostate cancer does not always escape from the capsule or metastisize. it does not suddenly turn aggressive and "kill" the patient.
The treatments are designed to kill the cancer cells. (except surgical removal of the prostate) It's not about trying to keep the cancer encapsulated but getting rid of it. cancer cells are mutations and as such any damage to them from treatments will disable them from reproducing. the healthy cells are effected by the treatments as well but because they are normal cells they can repair themselves and replicate. as the cancer cells die off, the healthy cells reproduce and take their place. usually after treatments, the persons psa will go way down. i don't know what type of treatment your father is having but i do know that they are all very effective. there have been a lot of studies on prostate cancer and it is one of the cancers that is understood better than some others. if the cancer metastisizes then it becomes more serious but as of now, your father does not have any mets-so that is a good thing.
i am a radiation therapist and about half my patients are being treated for prostate cancer with very good results. and by the way they all do not lose their manly manhood! hope this info helps. good-luck to you and your father.
