PROSTATE CRYOABLATION
INDICATION OVERVIEW

The prostate is a muscular gland about the size of a walnut, located in the pelvis below the urinary bladder and in front of the rectum. It is comprised of several small glands encased in the prostate capsule.

As cancer of the prostate is typically slower growing when compared to other forms, symptoms and signs of prostate cancer often do not appear until the cancer has spread within the prostate capsule and beyond to seminal vesicles and potentially other organs. Consequently, the potential for prostate cancer cures are high when detected early.

Prostate cancer is the fifth leading cause of male mortality world wide. Whilst the incidence is high, the mortality rates are considerably less. Radical treatment for prostate cancer, while oncologically effective, is associated with significant post treatment functional impairment1.

Patients with low and intermediate-risk cancer characteristics can be offered focal therapy which is a proposed treatment approach in development that aims to eradicate all known foci of cancer while minimizing damage to adjacent structures necessary for the preservation of urinary, sexual, and bowel function2.

The application of focal cryotherapy shows promise in bridging the gap between active surveillance and more aggressive therapies3.


a. Symptoms

Cancer growing inside the prostate usually causes no symptoms until the cancer grows large enough to begin affecting other organs, such as the bladder or urethra. Early symptoms of prostate cancer will likely not exist. This is why screening for prostate cancer is important.

The following symptoms of prostate cancer may occur:

  • Delayed or slowed start of urinary stream
  • Painful or burning urination
  • Painful ejaculation
  • Difficulty in having an erection
  • Blood in urine or semen

b. Tests, Diagnosis and Staging

When it comes to whether or not an individual is likely to receive a prostate cancer diagnosis during his lifetime, one should consider the following risk factors: age, family history, ethnicity, environment, diet, genes, and occupation.

Two initial tests are commonly used to screen for prostate cancer. When used together, these screening tests can detect abnormalities that might suggest prostate cancer.

Digital Rectal Exam (DRE)
To perform a DRE, your doctor will insert a gloved finger into the rectum and feel along the back rectal wall for the presence of lumps, enlargements, or hard, coarse, jagged, or uneven areas that may indicate cancer or other prostatic diseases.

Prostate-Specific Antigen (PSA)
Prostate-specific antigens are biomarkers that are found in the blood, fluids, and tissues. When an individual’s PSA level is considered elevated it can indicate the presence of prostate cancer. If the PSA level rises quickly over two or three tests, it may be a sign of a large or fast-growing tumor.

PSA testing combined with DRE helps screen prostate cancers at their earliest stage.
If certain symptoms or the results of early detection tests – a PSA blood test and/or DRE – suggest that you might have prostate cancer, your doctor will recommend further testing.

Transrectal Ultrasound (TRUS)
TRUS testing is utilized after PSA and DRE testing indicates the presence of possible cancer. The doctor will insert a lubricated ultrasound probe into the rectum behind the prostate. The TRUS probe creates sound waves and the patterns form a picture of the prostate and allow the doctor to see any abnormalities.

Needle Biopsy
Through a needle biopsy, multiple samples of tissue are extracted for pathological testing. The needle biopsy will be performed in conjunction with a TRUS, with the ultrasound images guiding the placement of the needle.

Saturation Biopsies or 3D Mapping Biopsie
If the initial needle biopsy does not indicate cancer, but your physician suspects cancer is present or the exact location of the cancer is needed, a saturation biopsy or 3D global mapping biopsy can be used for further diagnostic testing. Saturation biopsies generally mean that more than 20 different biopsies are taken. TRUS is used to guide the biopsy.

When a biopsy confirms the presence of prostate cancer, your doctor will determine the extent (stage) of the cancer. A staging system is a standard way for your doctor to describe how far a cancer has spread. The American Joint Committee on Cancer (AJCC) TNM system is a widely used staging system for prostate cancer.

Once testing is complete, your doctor assigns your cancer a stage. This helps determine your treatment options.

Prostate cancer staging

Stage I
The cells closely resemble normal cells and the gland feels normal to the examining finger.

Stage II
More of the prostate is involved and a lump can be felt within the gland.

Stage III
The tumor has spread through the prostate wall and the lump can be felt on the surface of the gland.

Stage IV
The tumor has invaded nearby tissue.


References
 1. Tay KJ, Schulman A, Sze C et al. Expert Rev Anticancer Ther 2017; 17(8): 737-43  
 2.
Focal Therapy for Prostate Cancer: Possibilities and Limitations European Urology 58(1):57-64 · March 2010  
 3.
Barqawi AB, Stoemenova D, Krughoff K et al. J Urol. 2014; 192(3): 749-53