Recently a test called 4K Score has become available that overcomes some of the current disadvantages of standard PSA.
The 4K test uses 4 different types of PSA proteins along with other clinical information in an algorithm to predict the percent risk for the patient having high grade cancer (Gleason 7 or higher) on biopsy. In several peer reviewed publications, the 4K test has shown to improve predictability for aggressive cancer both in biopsy specimens as well as in patients who have had their prostates surgically removed.
The 4K test may be done in any patient with an abnormal DRE or elevated PSA in whom an initial or repeat biopsy is being considered. The 4K score can be used to select men who are at risk for aggressive cancer who need treatment. Men with a low 4K score may feel safer to defer biopsy.
A second important advancement in prostate cancer detection is the avalability of multi parametric MRI.
After the blood test shows a man has a significant risk for having aggressive cancer and he decides to have a biopsy it would be ideal to have an imaging test to see if he has a visible cancer that can be biopsied. Until recently prostate cancer was the only cancer where blind biopsies were being done, with an image used only to guide where to biopsy. With availability of mpMRI, imaging can used as a triage test for men at risk for aggressive prostate cancer to further confirm the validity of the blood test findings. Patients with a visible lesion on imaging could have a targeted biopsy. A lesser number of biopsies may be required since there is a target area to biopsy.
Several scenarios are possible with patients getting both an MRI and 4K test
If PSA is elevated, 4K is high and MRI is abnormal,Transperineal Fusion Biopsy is the best way to diagnose and plan for treatment.My recommendations are based on how I treat prostate cancer. My goal is to detect cancer early when it is confined to a portion of the prostate so that I can treat the patient's one half of the prostate to preserve potency.To this end a trans perineal biopsy is helpful to diagnose all cancers more accurately, reduce missed diagnosis of significant cancers and plan partial or Hemi therapy. If my goal was to remove the whole prostate as it is done during robotic prostatectomy then trans perineal biopsy may not be necessary for initial diagnosis.
Studies have shown that 40 to 60% of new cancers are confined to one half of the prostate and therefore may be amenable to Hemi therapy. I recommend a targeted Fusion Biopsy with 4-6 samples from the abnormal area and a few samples of the rest of the prostate (since MRI will miss 15% or more of cancers). I prefer the transperineal biopsy because it is done under anesthesia, is more comfortable for the patient, and allows me to sample all the areas that are important. A transrectal biopsy, although more convenient for me does not provide the concierge type of care that I want to give my patients who have prostate cancer. I want to provide a very thorough diagnostic workup and documentation to plan proper procedures so that the patient can have the benefit of minimally invasive procedures with as few side effects as possible.
I always do biopsies of the Apex on both sides,Central Zone,Transition Zone and
Anterior Prostate as part of my Transperineal Biopsies because these areas are either missed on Transrectal Biopsies or inadequately sampled. Documenting cancers in these areas is important both for planning proper treatment and to preserve critical functionality such as sexual function and continence.
If PSA is elevated, 4K is high, and MRI is normal, I recommend a Transperineal Systematic Biopsy taking about 12 -20 cores to adequately sample an average sized prostate. I prefer to do a transperineal rather than a transrectal biopsy because a tranperineal biopsy is able to sample the anterior prostate and areas near the urethra which are missed with the traditional transrectal biopsy
If PSA is elevated,4K is low and MRI is normal, then it is a matter of shared decision whether to do a biopsy. Older men with limited life expectancy may choose to follow up with repeat PSA and biopsy only if PSA continues to rise at unacceptable doubling times. Younger men may wish to proceed with biopsy anyway.
I Inform my patients that there is more than one correct option and it is matter of understanding the benefits, risks and side effects
For a treatment such as HIFU, which I recommend as treatment of choice for most patients who have unilateral (one sided) cancer it is important to document by MRI and sample by transperineal biopsy all areas of prostate. Sampling the apex and anterior prostate, and areas near the urethra helps to preserve continence and not miss significant cancer.
After a biopsy shows a man has prostate cancer, the next challenge is to identify men who require immediate treatment versus those that can be monitored. The number of risk assessment tools and nomograms based on serum PSA level, extent of cancer, and biopsy Gleason Score are used to risk stratify men with localized prostate cancer. Men who have very low risk cancer can undergo active surveillance while men with low risk and intermediate risk may need active surveillance or some form of immediate treatment. A significant number of men who have low risk features on biopsy are found to have more aggressive disease at prostatectomy. There are several genomic tests now available that can assess the probability of developing metastasis or predict progression after initial treatment. Some genomic tests can also provide personalized information about how aggressive a cancer is from biopsy data. These tests can be used in addition to 4K Score to determine the type of treatment a patient needs. If the tests show low risk of progression, the patient may choose a lower risk treatment such as HIFU and avoid the risks of incontinence and impotence associated with more radical treatments.