Choosing Treatment
Many men will turn to their primary care providers for objective information regarding their treatment options. Long-term morbidity profiles of RP, RT, and brachytherapy do not clearly show one treatment to be superior to the others.5 Each patient’s risks must be assessed, and evidence-based information must be provided for patients to make an informed decision regarding treatment options.
A highly selected group of low-risk patients have the option of management by active surveillance.16,48 Patients with intermediate- or high-risk cancers who have a life expectancy exceeding 10 years should be encouraged to proceed with RP or RT.5 Class I evidence has shown a survival benefit with RP alone.46 RT has shown survival benefit only when used in combination with ADT.53 At this time, there is no direct evidence as to whether brachytherapy reduces prostate cancer mortality because randomized clinical trials to address this question have not been completed.5
Up to one-half of patients who undergo RP and one-third of those undergoing RT develop erectile dysfunction.5,52,58,61,63 Ten percent of RP patients develop long-term urinary incontinence,61 and a similar proportion of RT patients develop long-term proctitis.58 For some patients with low-risk cancers, baseline function and quality-of-life consequences may be enough to sway their decision regarding which treatment option to choose.5,58
EMERGING THERAPIES
In order to reduce the adverse effects of radical therapy, new focal therapies are being developed. Cryotherapy freezes specific areas of the prostate with cooling probes,64 and high-intensity focused ultrasound uses hyperthermia to cause instantaneous irreversible coagulative necrosis of the targeted tissue65; these are two of the most widely accepted focal therapies. Both options offer the advantages of diminished side effects of incontinence and erectile dysfunction and can be completed in a single outpatient treatment session.16,64,65 These procedures require considerable technical skill and are not currently offered in all communities.
Primary prevention may be a possible future direction for the management of prostate cancer. One large trial demonstrated the use of 5- reductase inhibitors to prevent prostate cancer in at-risk men66; further trials are ongoing. 5- Reductase inhibitors (eg, finasteride, dutasteride) prevent the conversion of testosterone to dihydrotestosterone (DHT), which is a more potent agonist for prostate growth.16 Finasteride has been proven safe and effective in reducing the risk for prostate cancer, regardless of risk stratum, and may reduce the risk for high-grade cancers.6,66,67
Attempts to treat prostate cancer with immunotherapy have begun to yield encouraging results. Treatment of metastatic castration-recurrent prostate cancer with sipuleucel-T cancer, a vaccine for the treatment of prostate cancer, showed a four-month survival benefit.2,68 Sipuleucel-T is made from dendritic cells in the patient’s immune system; currently, the vaccine is being produced in small quantities due to limitations in insurance coverage.2
Statin use may reduce the risk for prostate cancer recurrence among men who have undergone RP or RT for localized or locally advanced prostate cancer.69,70 Researchers analyzed database records of 1,319 prostate cancer patients who had undergone RP. For each patient, use or nonuse of statins at the time of surgery was determined, as was PSA progression following surgery. Statin use was associated with a 30% lower risk for PSA recurrence, with statin users taking the highest doses experiencing the most benefit. Additional studies are needed to confirm these results.69,70
DIETARY SUPPLEMENTATION
It is largely unknown whether prostate cancer can be prevented or modified by diet and lifestyle. Global differences in mortality rates and disease patterns associated with immigrant populations suggest that nutrition may play a role in the development of prostate cancer, but data are lacking.
A population-based cohort study of 525 men diagnosed with localized or advanced-stage prostate cancer examined the association of dietary intake of folate, riboflavin, vitamin B6, vitamin B12, and methionine with prostate cancer survival.71 Use of vitamin B6 was found to improve survival of men with localized disease but not with advanced-stage cancer. Dietary intake of folate, riboflavin, vitamin B6, and methionine was not associated with increased prostate cancer survival.71
Investigators for the randomized, placebo-controlled Selenium and Vitamin E Cancer Prevention Trial (SELECT),1 which included 35,533 men from 427 participating sites throughout North America, concluded that selenium or vitamin E, alone or in combination, did not prevent prostate cancer in this population of relatively healthy men.1,16,72
CONCLUSION
Screening for prostate cancer has almost doubled the chance that a man will be diagnosed with prostate cancer in his lifetime, and about 85% of men diagnosed with prostate cancer will undergo active treatment.19 Overtreatment of nonaggressive tumors may result in adverse effects detrimental to the patient’s quality of life, whereas early detection of aggressive tumors may lead to curative therapies being performed while the cancer is still confined to the prostate.1,2,16,19 Differences between outcomes of localized versus advanced disease are remarkable, with associated five-year survival rates of 100% versus 31.7%, respectively.6