As I do not have a vested interest in which treatment you choose (as I do not perform prostatectomies or coordinate prostate radiation), throughout this book, I will call it as I see it! I believe that the medical literature is not likely, in its current format, to represent the true extent of erectile dysfunction after radiation therapy for prostate cancer. In contrast to surgery, it is the minority of patients in the first year after radiation who run into erectile function problems, but erectile dysfunction rates peak probably somewhere between three and five years after the completion of radiation.Understanding that there are no studies that compare radiation to surgery at the same center (absence of a randomized study), my review of the current literature suggests that the incidence of erectile dysfunction three years after both radical prostatectomy and prostate radiation are approximately the same. Thus, when I see patients who are deciding which intervention to pursue, surgery or radiation, I always tell them the same thing, “You should never base your decision on which intervention to choose on your future sexual function as it appears that the chances of you developing erection problems three years after both is approximately the same.”
CHAPTER 2
PROSTATE ENLARGEMENT AND SEXUAL DYSFUNCTION
| I.Prostate Anatomy II.Prostate Growth—Benign Prostatic Hyperplasia III.Treatment of BPH/LUTS IV.Surgical Treatment of BPH/LUTS V.How Does BPH/LUTS Affect Erectile Function |
I. Prostate Anatomy
The prostate gland is classically described as a walnut-sized structure that lies behind the pubic bone in the pelvis (see Figure 1, Chapter 1). This analogy is somewhat misleading as the prostate varies dramatically in size, practically being nonexistent in a young child to being very small in the young adult and increasing in size as we age. This increasing size, which we will talk about further later, is predominantly related to hormonal surges that occur. It is a structure known as a gland, which is filled with cells and tissues that produce fluids. Running through the tissue of the prostate are ducts (pretty much in the same way that your home’s air conditioning system has ducts) and the purpose of these ducts is to deliver the prostatic fluid into the urethra.
The prostate lies below the bladder and it surrounds the urethra, which passes from the bladder out through the penis. If you think of an apple that you have just cored, the apple itself is the prostate and the cored portion is the urethra. The prostate gland secretes fluid from many ducts into the urethra. Directly in front of the prostate is the pubic bone, and directly behind it is the rectum. It is important to understand that the pelvis, and particularly the male pelvis, is a relatively tight area with multiple organs and structures in very close communication. The prostate lies directly against the front surface of the rectum, and this is why when a physician places his or her finger in the rectum, the prostate can be easily felt and examined.
The primary function of the prostate is to produce a portion of semen. You will remember from Chapter 1 that semen is a combination of fluids coming from the seminal vesicles, the prostate and the vas deferens. The latter is the structure that transports sperm from the testicle. The seminal vesicles produce the vast majority of the semen, but a significant portion of it is produced by the prostate.The purpose of this prostate fluid is to balance the pH of the semen.The seminal vesicle fluid is predominantly alkaline and the prostatic fluid is predominantly acidic, so there is a balance once these two are mixed together. This balance is critical to the nourishment and protection of sperm as they are being stored and delivered into the vagina during sexual intercourse.The prostate,or more accurately the cells (epithelial cells) in the gland, produce an enzyme called prostate specific antigen (PSA). PSA is a chemical which gets delivered into the blood and is used as a screening test for prostate cancer. PSA has a vital function in semen in that it dissolves the semen clot once it is deposited in the vagina and allows sperm to swim out from the liquid toward the cervix.
II. Prostate Growth—Benign Prostatic Hyperplasia (BPH)
In a boy, the prostate weighs about 5 gm and in a young man it grows to approximately 20 gm. Beyond the fourth decade in life, it is inevitable that the prostate will grow, and prostates have been removed which are in excess of 200 grams. Increase in size is due to increase in the size and number of the glands within the prostate itself. As the prostate grows, it impinges upon the urethra, which results in an obstruction of urine flow from the bladder. This leads to symptoms known as lower urinary tract symptoms (LUTS). BPH (benign prostatic hyperplasia) is the pathological entity that causes the symptoms known as LUTS. Now, it is important to understand that BPH is a benign process and by no means does it infer prostate cancer. In fact, many prostate cancers occur in small glands with very small amounts of BPH. Hyperplasia is a word that means overgrowth of cells. It is important to understand that BPH is not a precursor to the development of prostate cancer.
| Table 1 • Symptoms of Lower Urinary Tract Symptoms (LUTS) Associated With BPH |
| •Decreased urine stream •Having to strain to empty bladder •Frequent urination (frequency) •Getting up at night to urinate (nocturia) •Urine stream stopping and starting (intermittency) •Difficulty starting urine stream (hesitancy) •Feeling bladder is not empty at end of urination (incomplete emptying) |
The classic lower urinary tract symptoms include (Table 1): 1) incomplete emptying of the bladder—patients will often complain that they go to the bathroom, and five to ten minutes later, they need to return because they feel their bladders are not completely emptied; 2) frequency of urination— patients often complain about having to go to the bathroom very frequently, some men every thirty minutes during the day; 3) intermittency—this refers to a urine stream that is interrupted as you are urinating, in a staccato style; 4) urgency of urination, which implies that the patient has to get to the bathroom very quickly once he gets the first sensation that his bladder is full; 5) weak stream—men will notice that the force of their streams have decreased from when they were young men and they will have to strain to empty their bladders fully; 6) nocturia—this means having to get up in the middle of the night to pass urine. Some men have to do this more than every hour during sleep. You can imagine how sleep deprived these men can be. Appended to this chapter is the questionnaire which your physician is most likely to give you if you have symptoms consistent with LUTS.This questionnaire is known as the International Prostate Symptoms Score (IPSS). Below the questionnaire are scores which indicate level of symptoms. You can score yourself at the end of this chapter and see exactly where you stand. This is a useful test to do periodically to see what the progress of your BPH might be.
Prostate growth is related to hormone production. I previously talked about testosterone and its important role in male sexual development.Within the prostate, the testosterone is degraded to a hormone called dihydrotestosterone (DHT). It is DHT which causes most of the prostate growth. In fact, in men who have no testosterone and cannot produce DHT, the prostate is generally underdeveloped