Prostate Cancer Overview
Each year, roughly 220,000 American men are diagnosed with prostate cancer. The risk of prostate cancer increases with age. Over 80% of prostate cancers are diagnosed in men at or above age 65.
The walnut-sized prostate gland plays an important role in sexual function. It manufactures the semen that carries sperm out of the body. It also affects urinary function since the urethra (tube that carries urine from the bladder to the penis) passes through the gland, and a small muscle that controls urine flow is positioned at the tip of the gland closes to the penis. Therefore, almost all radical prostate cancer treatments carry some risk of sexual or urinary side effects.
Prostate cancer (PCa) is not a single disease. There are at least 20 different cell lines that have been identified for laboratory research purposes. They don’t all behave alike. While most PCa cases are slow growing – giving a patient time ample time to consider treatment, active surveillance or no treatment at all depending on life expectancy – perhaps 15% of cell lines are potentially deadly. That is, they may not signal their presence by elevated PSA, and they may progress silently and quickly, spreading beyond the gland before they are detected. It is therefore important to diagnose each case accurately.
Detection and diagnosis
Prostate cancer rarely has symptoms in its early stages. In fact, by the time symptoms like blood in urine or semen, urinary difficulties, back pain or hip pain appear, it is likely that the cancer has already spread beyond the prostate capsule. The majority of PCa that is found early is the result of the PSA (prostate specific antigen) blood test. Several prostate conditions can cause an elevated or rising PSA so the test hints at prostate cancer but does not truly detect it. Until recently, suspicion of PCa led to a needle biopsy which, if positive, acted as both detection (finding cancer) and diagnosis (lab analysis).
Until fairly recently, all prostate biopsies were done under transrectal ultrasound (TRUS) guidance. Since ultrasound does not “see” differences in tissue, an array of 12-14 needles is directed systematically but blindly into the gland. Unfortunately, this approach misses PCa at least 30% of the time, leading to more future tests; or, it may capture low-risk PCa yet miss higher risk disease, leading to undertreatment.
Better detection before biopsy
Today’s imaging is revolutionizing detection of PCa. When a PSA test comes back suspiciously high, the next step should be a multiparametric MRI of the prostate under a powerful 3T magnet. This is called 3TmpMRI, and when performed and interpreted at an expert center, it is 99% accurate in distinguishing healthy from unhealthy tissue. In fact, it defines the size, shape and location of any prostate tumor(s).
Better biopsy method
If 3TmpMRI detects a suspicious lesion, a biopsy is needed in order to diagnose the PCa. The best method involving the fewest needles is a real time MRI-guided targeted biopsy done in the bore (tunnel) of the magnet. When the needles are accurately positioned in the core of the lesion, they selectively sample the most aggressive cells found there. This gives the most accurate diagnosis of aggression, and makes the potentially dangerous cells available for further genomic testing.
Molecular analysis and biomarkers complete the picture
In addition to examining the biopsy tissue samples under the microscope, new tests are available to go even more deeply into the genetic nature of the cancer cells, or of biochemical “signatures” that are linked with various cell lines. This is an additional way to evaluate the aggression level that characterizes one cell line from another. More men carrying a more dangerous type of PCa, such molecular assessment may identify potentially lethal disease much earlier, though aggressive treatment may still be appropriate.
Matching treatment to disease
The most important clinical factors to help match a person’s PCa with the most effective yet least risky treatment are:
- Patient age
- Current PSA
- Cancer aggression level (Gleason score from the biopsy and any genomic information)
- Cancer stage – location, extent, and contained in the gland or not
When a complete diagnosis is made, the next step is for doctor and patient to consider which treatment options best match the PCa. For PCa that is still contained in the gland (localized disease), treatment choices range from radical (total gland) procedures to Active Surveillance.
- Radical treatments carry the greatest risk of urinary, sexual and bowel side effects, even if only temporary (3-18 months)
- Radical prostatectomy removes the entire gland
- Radiation therapies radiate the entire gland
- Image-guided focal ablation therapies
- Active surveillance (defer therapy using diet, etc.) or no treatment (based on life expectancy)
Advanced prostate cancer
Most PCa is detected and diagnosed while it is still localized, but some cases are found when the tumor has penetrated the prostate capsule. In such instances, diagnostic tests including mpMRI, bone scans and PET/CT scans will be done to determine how advanced it is:
- Locally advanced PCa means tumor that has spread into the nearby prostate bed
- Regionally advanced PCa means the tumor has spread into the pelvic lymph nodes and possibly into the pelvic bones or lower part of the spine
- Distant spread means the PCa has metastasized into other organs or more remote bones
Treatment for advanced disease usually begins with androgen deprivation therapy (ADT, sometimes called chemical castration) to deprive the tumor cells of the testosterone that fuels them. Side effects can include mood swings, breast tenderness, hot flashes, loss of bone density, depression, and others.
ADT is not curative, and eventually the PCa “outsmarts” this approach. Chemotherapy is the next step, though the FDA has approved PCa “vaccines” that extend life. Other immunotherapies and cancer vaccines are in clinical trials, as well as novel tailored treatments that deliver cancer-killing agents directly into each cancer cell.
Prevention and holistic treatments
There is research evidence that nutrition, supplements, and lifestyle changes can help control or even prevent prostate cancer. Learn more here.