Prostate Cancer Screening : Worth It or Not?
Prostate cancer is a disease that has engulfed men from all parts of the world. Such a widespread about the disease has led to increase concern whether prostate cancer screening is really helpful. A recent review found that this screening procedure does not provide much evidence on survival benefit.
Prostate cancer screening know as PSA or Prostate Specific Antigen reduced the mortality risk of prostate cancer by barely 20% in the best case scenario, as per the reports of the University of Texas Health Science Center published in July-August issue of the CA: A Cancer Journal for Clinicians. The life time risk result from the screening is shifted from 3% to 2.4% but it has not come without paying a price. The risk of diagnosis has increased from 6%-9% with no screening to 17% -20% of heavily screened individuals. The researchers have also noted that unresolved issues with PSA threshold argue against the efficiency of the screening.
According to experts, the PSA screening should be conducted only in mutual decision making program between the individuals and their physicians. For the past 20 years, prostate cancer screening is based on the blind faith of early detection rather than being based upon the evidence of decreased mortality rates. Experts also commented that decrease in the costs of healthcare can only be possible if the testing is done on the basis of evidences rather than on the basis of faith or profit based medicinal practice.
It has been estimated that 55% of men who are 50 years or older get a PSA screening every year out of which 75% get tested at least once in their life time. This dramatically affected the incidence rates of prostate cancer; as lifetime risks of diagnoses increased significantly after the introduction of PSA screening in the US in 1980s. According to the statistics, it was 7.3% in 1977 while it has risen to 17% in 2005. Finding more cases in prostate cancer is a poor goal as it gets virtually present in men as they get older. The main aim is to reduce the risks of death due to prostate cancer and its morbidity or other related healthcare expenses.
Since the year 1993 which is only 4-5 years after the screening was introduced, there is a continuous decline in age-adjusted death rate due to prostate cancer which was 39.3 per 100,000 men to 24.6 in 2005. A group of experts said that the decrease cannot be attributed to screening because the disease has a very long natural history. Other things that can explain the decrease in mortality rate can be significant innovations and improvements such as surgery, hormonal therapies and radiation during the same period in which screening proliferated. According to the computer models, 29% to 50% of the prostate cancers detected by screening do not have the possibilities of having clinical significance and therefore were over-diagnosed.
Only around 10% men with localized prostate cancer choose for active surveillance in place of treatment, which come with higher risk of urinal, sexual and bowel related complications. Whether the screening saves lives from prostate cancer or not can only be verified with a well-conducted, well-designed and prospective randomized scientific trial. Some of the trials that have already been published are:
- The Quebec study which found that 16% extra death cases in screening group compare to non-screening group.
- According to a Swedish trial, 47% higher rates of diagnosis and 4% higher risks of deaths due to prostate cancer randomized to screening as compared to those that were not offered the screening procedure.
- Interim analysis of US Prostate, Lung, Colorectal and Ovarian Cancer Screening test revealed that there are no significant differences between the two.
- An interim analysis of European Randomized Study of Screening for Prostate Cancer (ERSPC) revealed a ratio of 0.80 in mortality rate that favored screening but near double in incidence.
The ERSPC says that in order to prevent one death due to prostate cancer, 1410 people need to be screened and 48 more prostate cancer cases need to be treated. Thus, a man who undergoes screening has 48 more times risks to be harmed through screening than he can be saved, 9 years after the diagnosis.