Limits of classical screening. Challenges.

Classical screening and its limits

  • From the age of 40, an annual palpation from the intestine is recommended.

  • Furthermore, the determination of a blood value of PSA (PSA means "prostate specific antigen"). This protein is formed by the prostate cells can be detected in the blood. Values ​ greater than 4 ng / ml are morbidly increased and must be clarified.
  • This is usually done through a ultrasound-guided biopsy.

However, not all sections of the prostate are equally well accessible to palpation and biopsy. Small changes in the inner portion of the prostate gland can not be palpated with the finger and the biopsy needle can not reach all regions equally well.

Here, up to 40% of cancers are not detected at biopsy, whether due to the small size, or due to the situation in the front portions of the prostate gland, which can not be reached by a biopsy needle of the usual length. In 36-40% of cases an underestimation of malignancy occurs because the biopsy was performed from a peripheral area of ​​the tumor.

A further problem is that also benign changes in the prostate, such as benign enlargement, but also inflammation, lead to an increase in PSA. On the other hand, studies have shown that 27% of malignant changes have only a slight increase of this value of only 2-4 ng / ml and these men are therefore not supplied with further clarification, if the palpation doesn't deliver a conspicuous diagnosis.

Thus, the above-mentioned measures have a limited accuracy in the detection of malignant changes in the prostate. According to data from the literature the accuracy of palpation is at 23-45%, for the PSA at 25%, for transrectal ultrasound at 50% and for the biopsy in 35%.

Another important aspect should be mentioned here, which means a major dilemma in the search and the proper treatment of prostate cancer. Autopsy studies (results from sections) come to the following results depending on age:

Age of the deceased Discovery of
malignant cells
30-40 years 30%
50-60 years 50%
>85 years 75%

If we take into account the whole range of variation of aggressiveness, from very low-grade changes that don't require treatment for the whole life, to highly aggressive tumors that need to be treated as early as possible, so in the future not only the question arises of whether a cancer is existing, but rather the question of the exact estimation of biological activity, in order to develop the adequate customized therapeutic consequence.

The early detection of a tumor therefore is just as important as avoiding over-diagnosis and over-treatment, coupled with the enormous psychological burden for the patient if there is no survival advantage.

Challenges to the imaging

The challenges to the imaging are:
  • Finding changes
  • Accurate localization for biopsy planning

  • Assessing the aggressiveness
  • Precise information about the size, expansion, differentiation from the surrounding structures
  • Exclusion of metastases in the vicinity, the lymph nodes and distant organs

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Multiparametric MRI -
der new gold standard for prostate imaging