Prostate cancer is common. It's also deadly. About 220,000 men in the United States will learn that they have prostate cancer this year. Despite tests to detect it early and several effective treatments, the disease kills about 27,000 men in the United States each year.
On the other hand, many men with prostate cancer have tiny tumors that pose no significant threat to their health. For these men, early detection and treatment provides no benefit. So, it's a big challenge to learn how to detect the dangerous tumors while leaving the others alone. That's not easy.
To make matters worse, non-cancerous enlargement of the prostate, a nearly universal part of aging for men, may mimic prostate cancer . For example, the prostate-specific antigen (PSA) blood test may be high. This can raise concern about prostate cancer even when no cancer is present.
Clearly, we need better ways to identify men who have early prostate cancer requiring treatment. That's why the results of a new research study from Iceland are notable. The study links a gene mutation to an increased risk of aggressive prostate cancer. Interestingly, the mutation is located on a gene – called BRCA2 – known to increase the risk of cancers of the breast and ovary among women.
In this new research, scientists reviewed cases of prostate cancer in Iceland from the last 50 years. They selected study subjects with prostate cancer who also had female relatives with breast cancer. Researchers discovered that men who carried a particular BRCA2 gene mutation tended to have the worst forms of prostate cancer.
For example, men with the BRCA2 mutation had:
· Onset of prostate cancer at a younger age
· More advanced prostate cancer
· Shorter survival
The effect on survival was particularly striking. On average, those with the mutation lived just 2 years from the time of diagnosis. Non-carriers of the mutation survived more than 12 years.
It's hard to know whether these results will have a big impact on prostate cancer detection or treatment. The mutation was found in less than 6% of study subjects with prostate cancer. The rate might have been lower if these men did not have relatives with breast cancer. This mutation might be even rarer outside Iceland.
Still, the findings suggest that looking for mutations in genes with known links to cancer could provide valuable information. It's easy to imagine that genetic testing could someday be a routine part of screening for prostate cancer (and other cancers). Perhaps the results could be used to predict the need for aggressive treatment.
by Harvard Publications
Tuesday
Link Between Severe Acne and Prostate Cancer
(Ivanhoe Newswire) A higher risk of prostate cancer may be linked to severe acne.
New research from Johns Hopkins Bloomberg School of Public Health in Baltimore finds men who took tetracycline -- an antibiotic used to treat severe acne -- for four years or longer were 70 percent more likely to develop prostate cancer over a 10-year period than men who had taken the drug, or had taken it for a shorter time.
But the studys authors urge caution in interpreting their findings. They note the small number of participants who had used tetracycline for at least four years -- 0.5-percent of the 34,629 men in the study -- the indirect assessment of severe acne, and the fact that acne can have several causes.
The research looked at the link between severe acne and prostate cancer because recent studies found the acne-related bacterium Propionibacterium acnes in one third of prostate samples taken from men with prostate cancer. The tissue containing P. acnes was more likely to be inflamed. Inflammation is believed to be an important part of the development of prostate cancer.
Researchers say it is unlikely tetracycline itself would raise the risk of prostate cancer . They believe one possible explanation for the acne-prostate cancer link is that men who develop severe acne may be more likely to have stronger inflammatory immune responses when P. acnes goes into the prostate.
SOURCE: International Journal of Cancer, 2007;121:2688-2692
New research from Johns Hopkins Bloomberg School of Public Health in Baltimore finds men who took tetracycline -- an antibiotic used to treat severe acne -- for four years or longer were 70 percent more likely to develop prostate cancer over a 10-year period than men who had taken the drug, or had taken it for a shorter time.
But the studys authors urge caution in interpreting their findings. They note the small number of participants who had used tetracycline for at least four years -- 0.5-percent of the 34,629 men in the study -- the indirect assessment of severe acne, and the fact that acne can have several causes.
The research looked at the link between severe acne and prostate cancer because recent studies found the acne-related bacterium Propionibacterium acnes in one third of prostate samples taken from men with prostate cancer. The tissue containing P. acnes was more likely to be inflamed. Inflammation is believed to be an important part of the development of prostate cancer.
Researchers say it is unlikely tetracycline itself would raise the risk of prostate cancer . They believe one possible explanation for the acne-prostate cancer link is that men who develop severe acne may be more likely to have stronger inflammatory immune responses when P. acnes goes into the prostate.
SOURCE: International Journal of Cancer, 2007;121:2688-2692
Friday
Prostate Specific Antigen
A prostate-specific antigen (PSA) test measures the amount of prostate-specific antigen in the blood. PSA is released into a man's blood by his prostate gland . Healthy men have low amounts of PSA in the blood. The amount of PSA in the blood normally increases as a man's prostate enlarges with age. PSA may increase as a result of an injury, a digital rectal exam , sexual activity ( ejaculation ), inflammation of the prostate gland ( prostatitis ), or prostate cancer .
Prostate cancer often grows very slowly, without causing major problems. Detecting prostate cancer early and treating it may prevent some health problems and reduce the risk of dying from the cancer. However, some treatments for prostate cancer can cause other problems, such as controlling urination (incontinence) or erection problems (erectile dysfunction). Some men may choose not to have a PSA test or treat prostate cancer if it is detected. For example, a man older than age 75 who has no bothersome symptoms of prostate cancer may choose not to treat the cancer if it is found, so he would not need a PSA test.
Prostate cancer often grows very slowly, without causing major problems. Detecting prostate cancer early and treating it may prevent some health problems and reduce the risk of dying from the cancer. However, some treatments for prostate cancer can cause other problems, such as controlling urination (incontinence) or erection problems (erectile dysfunction). Some men may choose not to have a PSA test or treat prostate cancer if it is detected. For example, a man older than age 75 who has no bothersome symptoms of prostate cancer may choose not to treat the cancer if it is found, so he would not need a PSA test.
Thursday
Biology of Prostate Specific Antigen
Prostate-specific antigen (PSA) is an androgen-regulated serine protease produced by both prostate epithelial cells and prostate cancer (PCa) and is the most commonly used serum marker for cancer . Prostate specific antigen (PSA) is a protein produced by the cells of the prostate gland. Prostate-specific antigen is present in small quantities in the serum of normal men, and is often elevated in the presence of prostate cancer and in other prostate disorders.
PSA is a major protein in semen , where its function is to cleave semenogelins in the seminal coagulum. Prostate Specific Antigen is secreted into prostatic ducts as an inactive 244–amino acid proenzyme (proPSA) that is activated by cleavage of seven N-terminal amino acids. PSA that enters the circulation intact is rapidly bound by protease inhibitors, primarily alpha1-antichymotrypsin, although a fraction is inactivated in the lumen by proteolysis and circulates as free PSA
A PSA blood test is the most effective test currently available for the early detection of prostate cancer. Higher than normal levels of PSA are associated with both localized and metastatic prostate cancer (CaP).
Prostate-specific antigen (PSA), also known as kallikrein III, seminin, semenogelase, γ-seminoprotein and P-30 antigen is a 34 kD glycoprotein manufactured almost exclusively by the prostate gland ; PSA is produced for the ejaculate where it liquifies the semen and allows sperm to swim freely. PSA is also believed to be instrumental in dissolving the cervical mucous cap, allowing the entry of sperm.
In addition to measuring human Prostate Specific Antigen in blood, tissue samples can be stained for the presence of PSA in order to determine the origin of maligant cells that have metastasized.
Source:
Steven P. Balk, Yoo-Joung Ko, Glenn J. Bubley
From the Cancer Biology Program, Hematology-Oncology Division, Beth Israel Deaconess Medical Center , Harvard Medical School , Boston, MA.
PSA is a major protein in semen , where its function is to cleave semenogelins in the seminal coagulum. Prostate Specific Antigen is secreted into prostatic ducts as an inactive 244–amino acid proenzyme (proPSA) that is activated by cleavage of seven N-terminal amino acids. PSA that enters the circulation intact is rapidly bound by protease inhibitors, primarily alpha1-antichymotrypsin, although a fraction is inactivated in the lumen by proteolysis and circulates as free PSA
A PSA blood test is the most effective test currently available for the early detection of prostate cancer. Higher than normal levels of PSA are associated with both localized and metastatic prostate cancer (CaP).
Prostate-specific antigen (PSA), also known as kallikrein III, seminin, semenogelase, γ-seminoprotein and P-30 antigen is a 34 kD glycoprotein manufactured almost exclusively by the prostate gland ; PSA is produced for the ejaculate where it liquifies the semen and allows sperm to swim freely. PSA is also believed to be instrumental in dissolving the cervical mucous cap, allowing the entry of sperm.
In addition to measuring human Prostate Specific Antigen in blood, tissue samples can be stained for the presence of PSA in order to determine the origin of maligant cells that have metastasized.
Source:
Steven P. Balk, Yoo-Joung Ko, Glenn J. Bubley
From the Cancer Biology Program, Hematology-Oncology Division, Beth Israel Deaconess Medical Center , Harvard Medical School , Boston, MA.
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