Screening for Prostate Cancer - Should It be Done or Not?
The prostate gland is a gland about the size of chestnut. It is present below the urinary bladder encircling the urethra in males. The prostate gland produces and stores the seminal fluid. The seminal fluid nourishes the sperms. It also dissolves the mucus around the cervix and facilitates the smooth entry of sperms in the female reproductive organs.
Prostate-specific antigen (PSA) is also known as kallikrein-3(KLK3) or gamma- seminoprotein. It is concerned with the liquefaction of semen and permits the free swimming of sperms in the seminal fluid.
Prostate cancer is the commonest cancer in males and is detected early by checking the levels of PSA.
PSA is present in the serum of healthy men and its values are markedly increased in prostate cancer.
A study called the European Randomized Study of Screening for Prostate Cancer published in New England Journal of Medicine (NEJM) has revealed PSA testing is effective in lowering the mortality associated with prostate cancer over an 11-year span.
Data on 182,160 adult men who were aged between 50 to 74 years from eight European countries was taken into account for the purpose of this study. The participants were divided randomly into two groups, one which underwent PSA screening, and the second which was not offered PSA screening.
The two groups were followed up for a period of 11 years. The researchers were specifically looking for mortality due to prostate cancer.
A total of 6963 prostate cancers were diagnosed in the screened group, and 5396 cancers were diagnosed in the non-screened group. Two hundred and ninety nine people died due to prostate cancer in the screened group, where as 462 people died in the non-screened group due to prostate cancer. The overall mortality due to all causes was similar in the two groups.
It was found that there was a significant decrease in men dying from prostate cancer in PSA screened group in contrast to non-screened group. The conclusion drawn from the study was that PSA screening can decrease mortality due to prostate cancer. More data is required to assess the benefits and disadvantages of routine PSA screening in the general population, before it can be widely recommended.
Prostate-Cancer Mortality at 11 Years of Follow-up; Fritz Schroder et al; N Engl J Med 2012; 366:981-990; March 2012