Knowing your prostate cancer therapy options empowers you to make smart choices.
Prostate cancer is the leading solid organ cancer in the USA and the second most common cause of cancer related death. Worldwide, it is the fourth most common cancer with differing biologic activity in different cultures, probably related to different lifestyles.
Many prostate cancers can be managed conservatively, especially in elderly men. But larger tumors, those with higher Gleason score and higher (and rising) PSA levels, especially in younger men, should be treated more aggressively.
Prostate Cancer Therapy Options
There are many options available to residents of Northern California. Prostate cancer is usually managed with active surveillance, radiation therapy, surgery to remove the cancerous gland, freezing (cryotherapy), or high intensity focused ultrasound (HIFU). Hormonal therapy is used to control cancer that has spread beyond the prostate and is no longer curable, or for very elderly patients with a limited life expectancy.
Prostate cancers that are very small and look to be growing very slowly under the microscope may be watched carefully with periodic rectal exams, PSA blood tests, and biopsies are repeated every 2-3 years to rule out more aggressive tumor growth.
If the cancer appears to be accelerating in growth, or chromosomal studies predict aggressive growth, one or more of the following therapies may be used.
Radiation is given using external beam (IMRT) with the beam being aimed using CT scans to develop a 3 dimensional model of the prostate. The patient goes to the Radiation Therapy office daily for 6-8 weeks (depending on the “recipe” used) to receive small doses of the radiation in the hope of killing the cancer without damaging the normal tissues. With IMRT (Intensity Modulated Radiation Therapy), gold seed markers are placed for CT Scan targeting of the prostate each day of radiation therapy. A variation of externally delivered radiation is Proton Beam Therapy, which used to boast less bladder and rectal side effects as compared to the older 3-D Conformal Therapy, but delivers the beam through the hips, which may weaken the bones and risk fractures. Gamma Knife places very high dose radiation directly at the target in a surgical setting in the hope rapidly of killing the tissue.
Radiation can also be given by implanting radioactive seeds (Brachytherapy) under ultrasound guidance into the prostate gland. The seeds deliver intense doses of radiation to a small area in the hope of not damaging the surrounding organs. In some patients a combination of seeds and external beam radiation may be used. Men commonly have swelling of the prostate for 6-12 months making it more difficult to void.
Adverse effects from radiation mostly relate to the radiation effects on the bladder and rectum. Bladder and rectal burning, frequent urination, diarrhea, and blood in the urine or stool are the most frequent complaints. Erectile dysfunction commonly develops over 1-2 years. Rectal injury resulting in perforation and permanent swelling in the legs from edema were seen in the past, but are very unusual now. In some patients these rectal and bladder problems recur on a permanent basis, but the majority of patients will improve with time after the treatment is ended. Men treated with radiation frequently complain of being tired for 6-12 months, and recent studies indicate that men may later develop new cancers of the bladder and rectum at a rate of 1% per year from having been exposed to radiation.
If a patient has a PSA over 10 or high grade prostate cancer cells, and the Bone Scan shows no cancer in the bones, a Pelvic Lymph Node Dissection may be done to rule out spread to the regional lymph nodes. This is done to prevent giving radiation without benefit (no help if cancer has spread), and it allows the therapist to narrow the beam to expose less of the bowels and lymphatics (less chance of bowel problems and leg swelling from the radiation).
The node sampling may be done using a small lower abdominal incision or by laparoscopy.
Surgical removal of the prostate for cancer is performed with the intention of removing all of the cancerous gland to achieve a cure. This is accomplished over 90% of the time with low-risk prostate cancer (only Gleason 3+3, less than 3 cores positive, PSA under 10) ; 70-90% for intermediate risk cancer (Grade 4 cells present, PSA 10-20, more cores positive); and 50-65% for high risk cancers (Grade 5 cells, PSA over 20, etc.).
Most surgeries are now accomplished using a laparoscopic approach with a DaVinci robot. It offers lower blood loss and equivalent incontinence and erectile dysfunction numbers in high volume centers. The lymph nodes may be sampled at the same setting, and the procedure takes 2.5-3.5 hours. Most men stay one to two nights in the hospital, have a catheter for 1-2 weeks, and return to normal activities in 3-4 weeks.
Common adverse effects associated with radical prostatectomy include those of anesthesia, infection, bleeding (sometimes serious), incontinence (2-5% severe, 25-30% milder), impotence (50-55% for all comers), and stricture of the urethra/bladder neck connection (5-8%). Less commonly seen are fluid collections requiring drainage, rectal tears, and deep vein thrombosis which can lead to pulmonary embolus and death.
Freezing the prostate cancer can be performed using liquid argon under ultrasound guidance. Urethral injuries may occur, and some men require repeat treatments. The success rates are slightly less than seen with radiation, and impotence occurs 90-100% of the time.
About 85-90% of prostate cancers depend on male hormones to grow. In men in whom the cancer has spread beyond the prostate, hormone deprivation will shrink the cancer for an indeterminate period of time (months to many years). Hormone therapy is frequently used to sensitize prostate cancers to the IMRT radiation. Recent studies raise concerns over increased risks of strokes and heart attacks, lower scores on cognitive testing, and diminished coordination in the dominant hand, as well as the documented osteoporosis, hot flashes, impaired sexual function, low energy, impaired blood sugar control, etc. Newly developed PET-CT Scans are now available to evaluate for spread to lymph nodes, bones, or other organs.
After many years of poor response rates to the usual chemotherapy medicines, an explosion of new therapies are coming out specifically for Prostate Cancer. Medicines that kill tumor cells directly, stimulate the man’s immune system to attack the tumor, and prevention of the tumor from growing a blood supply are but a few of the areas being developed. These therapies are for cancers that have spread beyond the prostate and are not treatable with Radiation, Surgery, Freezing, or HIFU.
HIFU is an FDA approved precise and targeted therapy that reduces the risk of complications caused by surgery and radiation.
HIFU uses ultrasound energy, or sound waves, to heat and destroy specifically targeted areas of tissue. During HIFU, the sound waves pass through healthy tissue without causing damage. However, at the focal point of the sound waves (like a magnifying glass focusing the rays of the sun to burn a leaf), the tissue temperature is raised to 90 degrees Celsius, destroying the targeted tissue.
Men opting for focal therapy must have a multiparametric MRI of the prostate to help confirm the biopsy needle did not miss any significant cancer in the areas of the gland to be spared. Patients treated with HIFU wake up and go home without pain or bleeding. They are able to travel the same day, drive the next day, and resume normal activities within a few days. Those with office based jobs can go back to work the next day. A catheter is left in for 5 days to 3 weeks, depending on how much of the gland is treated and/or the degree of swelling.
Focal Therapy is associated with a less than 1% incidence of minimal incontinence (occasional loss of drops of urine), and erectile dysfunction is just under 10%. Sparing of the urethra avoids scar tissue formation which, when present, may diminish the urinary stream. The eventual need for additional therapy is now under 10%.
Total Gland Therapy is necessary for men with significant cancer on both sides of the gland. Incontinence of a few drops of urine (soaking pads is not seen) is limited to 2-3%. Erectile dysfunction is only 10-20% as opposed to the much higher rates seen with surgery or radiation. Scar tissue formation occurs in 10-20% of men who have the whole gland treated due to the involvement of the urethra. We are developing techniques to treat the whole gland while sparing the urethra. Cancer cure rates are comparable to surgery and radiation.
Insurance coverage is coming slowly. A big help is the issuance of a facility billing code by Medicare which will save Medicare patients about $17,000, and help to mainstream HIFU. Hopefully conventional insurance companies will follow suit in the near future. This therapy should not be available only to those who can afford it.