Treatment-Related Side Effects
Because the prostate is close to several vital structures, prostate cancer and its treatment strategies can disrupt normal urinary, bowel, and sexual functioning.
Urinary function—Under normal circumstances, the urinary sphincters (bands of muscle at the base of the bladder and at the base of the prostate) remain tightly shut, preventing urine that’s stored in the bladder from leaking out. During urination, the sphincters are relaxed and the urine flows from the bladder through the urethra and out of the body.
- Prostatectomy—the surgical removal of the prostate—the bladder is pulled downward and connected to the urethra at the point where the prostate once sat. If the sphincter at the base of the bladder is damaged during this process, some degree of urinary Incontinence or leakage may occur. Approximately 1 in 5 men will have some component of mild leakage after surgery. This rarely occurs after radiation therapy (about 1 in 100 men).
- Radiotherapy— radiotherapy is targeted to the prostate, but the bladder is next to the prostate and the urethra runs through the middle of the prostate, and both will receive some radiation therapy dose. Fortunately these structures are fairly resistant to radiation therapy. However, they can become irritated during and months after radiation therapy, which manifests as usually a mild increase in urinary frequency and urgency. This can also manifest as nocturia, or waking up more at night to urinate.
This figure is from the ProtecT trial and shows that about 20% of men use at least 1 pad per day the rest of their life (for 10+ years), and that almost no men who undergo radiation therapy have leakage.
This figure is from the ProtecT trial and shows that around the time of radiation therapy and for a few months after it is more common with radiation therapy to wake up at night more to urinate (nocturia), and then this mostly resolves. Nocturia is less common after surgery.
Bowel function—Solid waste that’s filtered out of the body moves slowly down the intestines, and, under normal circumstances, the resultant stool is excreted through the rectum and then anus. Damage to the rectum can result in bowel problems, including rectal bleeding, diarrhea, or urgency.
- Prostatectomy— It is very rare (<1%) for men to have altered bowel function after surgery. In rare cases of locally advanced prostate cancer where the cancer invades the rectum, surgery may result in rectal damage.
- Radiotherapy— radiotherapy is targeted to the prostate, but the rectum sits right behind the prostate. With modern radiation therapy (IMRT or IGRT or brachytherapy) it is very rare to have moderate/severe bowel problems. During radiation therapy you may experience softer stools and rarely diahrea (<10%). These symptoms resolve. With modern radiation only 2-3% of men years after treatment will have bothersome rectal bleeding after modern radiation therapy. Discuss with your Doctor the type of radiation therapy, as older forms of radiation therapy (called 3D conformal) can increase rectal side effects significantly.
This figure is from the ProtecT trial and shows that around the time of radiation therapy and for a few months after it is more common with radiation therapy to have a slightly worse overall bowel function compared to surgery. This is transient and largely resolves by 1 year post-treatment.
Sexual function— Erectile function is a complex process that consists of 4 main components that all can be affected by prostate cancer treatment; libido (sex drive), mechanical ability to spontaneously achieve a firm erection, organism/climax, and ejaculating.
- Libido is most commonly affected by hormone therapy, or treatment that decreases your testosterone. You can have a low libido and still obtain an erection, but it is usually more difficult for men who have less interest in sex.
- Mechanical ability: This is controlled by nerves and vessels that are intimately associated with the prostate and structures near the penis. It is the ability to achieve a firm erection. The mechanical ability is what is affected usually from surgery or radiation therapy.
- Organism/climax: It can be more difficult after treatment to achieve a climax, especially if libido is low or your erections are not as firm as they used to be. Also, sometimes there can be some discomfort initially after treatment when you climax. This usually is transient and will resolve.
- Ejaculate: The prostate and seminal vesicles are removed/irradiated during treatment, and it is common to have a minimal or no ejaculate after treatment. So although you may be able to have an erection and reach an orgasm, nothing will come out.
- Prostatectomy— Since the 1980s, most men are treated with what is termed a “nerve-sparing” prostatectomy. The goal of the procedure is to 1st take the prostate and seminal vesicles out, and 2nd if possible spare the nerves adherent or adjacent to the prostate. Sparing these nerves have been shown to result in improved rates of erectile function after surgery. Most large USA and European studies have shown that approximately 50% of men after surgery who have the ability to have an erection before surgery, will maintain this ability long-term. Ask your Doctor about the PIVOT, PROSTQA, and ProtecT studies for my information.
- Radiotherapy— Similar to surgery, damage to blood vessels and nerves after radiation therapy can result in decreased erectile function over time. In general, radiation therapy has less of an impact on erectile function in the first 5-10 years after treatment, and approximately 60-70% of men who have baseline erectile function before treatment will keep erectile function after treatment. However, radiotherapy causes a delay in erectile function decline, and by 15 years after treatment with surgery or radiation therapy very few men (<15%) have functional erections without using devices or aids.
Newer techniques with radiation therapy, termed “vessel sparing” radiation therapy has shown promising results to improve the preservation of erectile function closer to 80% for men with baseline erectile function. Ask your radiation oncologist about vessel sparing radiation therapy.
This figure below is from the PROSTQA study, a multi-center study from top centers around the country. You can see that in general, men treated with surgery have better baseline erectile function (often because you must be young and healthy to have surgery), and this declines after treatment, and the starts to partially recover. Also you can appreciate the benefit of nerve sparing surgery. Panel B on the right shows that after radiation therapy there is a small decline in sexual function, but a larger one if radiation therapy is given with hormone therapy.
This figure below is from the ProtecT trial and shows that at baseline only 67% of men have erections firm enough for intercourse. For men that have surgery this drops initially to about 15% over the first year, and improves to about 25-30% after some recovery has occurred over the next 1-2 years. Therefore, about 40-50% of men after surgery who have good erectile function at baseline will remain potent and have erections firm enough for intercourse. The yellow line for radiation therapy is actually radiation therapy combined with 6 months of hormone therapy for these men. This is why you see that at 6 months only 25% of men still have erectile function, because the hormone therapy decreases erectile function and libido. As these men’s testosterone recovers after they stop the hormone therapy you can appreciate that the sexual function rebounds to about 35-40% of men having erectile function, and that stays relatively stable over time. In general of men that are potent who get radiation therapy alone 60-70% will keep erectile function long-term.
Fertility—As part of the removal of the prostate, the seminal vesicles and part of the vas deferens are removed, disrupting the connection to the testes. Orgasm may still occur, however ejaculation will be dry and natural conception will not be possible. After surgery, radiation therapy, or hormone therapy, you are unlikely to be fertile. You should discuss fertility preservation before you undergo any treatment if possible.