Men with localized prostate cancer have two basic treatment options: radiation therapy or surgery. As they decide which course to take, they will most likely consult a whole host of people -- their general physician, their urologist, family and friends, literature, and the Internet. Unfortunately, those with the "M.D." after their names are not necessarily considered the experts by these patients.
"(Patients) rely more on stories from friends and relatives, and the Internet, than they do their primary care doctor or their urologist," said Dr. Jerrold Sharkey in a talk at the 2005 American College of Physicians (ACP) meeting in San Francisco. Sharkey is from the Urology Health Center in New Port Richey, FL, and the University of South Florida in Tampa.
But it is ultimately the physicians who must lead their patients down the right path, especially because healthcare advocacy groups currently offer men a mixed message about prostate cancer screening, let alone treatment.
"The American Urological Association and American Cancer Society advise yearly prostate-specific antigen (PSA) exam and digital rectal exam (DRE) starting at age 50, or starting at age 40 if there is a family history or if the patient is African-American," Sharkey said. "The ACP advises only patient counseling. The National Cancer Institute does not have any recommendations about prostate cancer screening."
"I think the patients will really rely on our judgment, and you should encourage them to screen," he added, speaking to an audience of internal medicine specialists. "The earlier screening is done, you get treatable disease, you get organ confinement, and there is a decreased death rate from prostate cancer."
Should diligent screening result in a cancer diagnosis, Sharkey outlined the patient advisory strategy that he has developed in his practice over the last 34 years when discussing treatment options. While radical prostatectomy and radiotherapy have their pluses, Sharkey acknowledged that he is a true proponent of brachytherapy.
Prostate cancer basics
The risk factors for this disease include age (over 60), family history, diet, and hormones (the ratio of testosterone to estrogen). The tumor stage that is most commonly seen is T1c, which is marked by an elevated PSA but is not palpable and requires identification with biopsy.
Sharkey said his group performs transrectal, ultrasound-guided biopsy, with 14-16 samples per side. This procedure is done at their surgical center with the patient under sedation.
Sharkey said that a PSA level of 2.5 ng/mL warrants further investigation. Gleason scores are determined by the pathological structure of the tumor, with a score of 2-6 representing a slow growth tumor, Gleason 7 indicating a fairly fast-growing tumor; and a score of 8-10 representing an aggressive cancer with the potential to spread.
In terms of imaging, Sharkey said he generally orders a CT of the abdomen and pelvis, as well as a bone scan to check for metastases. "For most of the low-risk patients, these studies are usually negative," he said. "These are done partly to reassure patients, but also as a baseline for future treatment."
When weighing treatment options, Sharkey suggested three issues that need to be considered: the prognosis of the cancer by stage, a life expectancy of more than 10 years, and patient comfort level.
"What I find is that when patients come into discuss (their treatment), a third of them just want (the prostate) out of there," he said. "Another third may not want to have surgery at all. Another third come in with reams of papers, and have spent weeks and weeks on research, and they'd like to go over all the kinds of treatment."
Surgery, radiation
Fewer local failure rates are a major advantage of radical prostatectomy. This method also allows for detailed pathological analysis to identify candidates for adjuvant therapy, Sharkey said. However, the procedure does require multiple days in the hospital, the use of indwelling catheters for as long as two weeks, and as long as a month lost from work. Another option is the less invasive laparoscopic prostatectomy, which requires longer operating time, but a shorter hospital stay.
"What are the advantages to a radical prostatectomy?" Sharkey asked. "(The prostate) is out, and a lot of patients feel comfortable with that."
In most instances surgery will be coupled with adjuvant radiation therapy (external beam, intensity modulated, and/or brachytherapy), hormone treatment, neoadjuvant chemotherapy, or some combination of these methods.
Sharkey cited research that conventional external-beam radiation therapy (EBRT) alone may not do the trick. EBRT dosages at 70 Gy or less have biopsy-proven local recurrence rates that range from 23% to 65%, he said.
Of course the next step up in radiotherapy is either 3D conformal EBRT or intensity-modulated therapy (IMRT). The advantages of 3D conformal IMRT are its suitability for a wide range of patients, higher doses than EBRT, and minimal side effects. The downside includes a long treatment time (seven weeks or more), as well as technical difficulties such a prostate motion.
"Basically ... IMRT is conformal radiation therapy with a computer that targets only the prostate. Radiation therapy can be focused just up to a certain point, and then it spills over and the bladder and rectum can be affected," Sharkey said.
Brachytherapy
There's no doubt that brachytherapy packs a wallop when it comes to radiation dose. "You are giving them almost one and a half to two times the dose of radiotherapy, but without the spill effect to other organs," Sharkey said.
Brachytherapy can de delivered with either palladium (103Pd) or iodine (125I) seeds, although Sharkey said he preferred the former. Patients who are best-suited for this type of treatment will have T1-T2 stage cancer and a PSA of less than 20 ng/mL.
"In our practice, we only use 103Pd (TheraSeed, GE Healthcare Bio-Sciences, Chalfont St. Giles, U.K.)," he explained. "The reason we only use 103Pd is because it has a short half-life ... of about 17 days. That means that the irritating symptoms that patients may get with brachytherapy are gone within two and a half weeks."
Because brachytherapy is a low-energy source of radiation with a rapid dose falloff, the outpatient procedure allows for high intraprostatic dosages -- almost twice that of EBRT -- with minimum risk to the organs nearby.
Published reports would back up this claim. Between 4% to 15% of patients experience urinary retention as a perioperative complication, but this usually generally resolves in 24-48 hours, Sharkey said.
In terms of erectile dysfunction (ED), previous studies have shown that most patients with brachytherapy-induced ED responded favorably to sildenafil (Viagra) with a 92% actuarial rate of potency preservation at six years. Other studies have also indicated that radiation doses to the proximal penis are predictive of brachytherapy-induced ED, with the strongest predictors of potency preservation being dose to the bulb of the penis, postimplant prostate CT volume, and patient age (International Journal of Radiation Oncology, Biology, and Physics, March 15, 2002, Vol. 52:4, pp. 893-902; November 15, 2002, Vol. 54:4, pp. 1055-1062).
Sharkey and colleagues conducted a retrospective review of patients at their institution who were treated either with brachytherapy or radical retropubic prostatectomy during a 12-year period. They found that prostatectomy offered no benefits over brachytherapy, with the latter resulting in 99% freedom from PSA failure versus 97% with surgery (Brachytherapy, January 2005, Vol. 4:1, pp. 34-44).
Sharkey updated these results during his ACP talk. Since 1993, his group has treated 2,000 patients. "When you define 'cured,' obviously when the prostate is gone (after prostatectomy), there's no PSA left, so we use a PSA of less than 0.4 ng/mL as a sign of cure. For radiation therapy, we use what we call the ASTRO definition ... three successive rises in PSA is considered a failure," he said.
For a low-risk group, they reported a 91% success rate with seeds and 94% success rate with prostatectomy. For an intermediate-risk group, the success rate was 90% versus 58% for prostatectomy. For the high-risk group, seeds were effective in 88% of the cases versus 43% of prostatectomy procedures.
Of those patients who required reseeding, 78% experienced freedom from PSA recurrence. Sharkey pointed out that reseeding was more common in the first few years that his group performed brachytherapy. "I have not reseeded a patient in the last eight years," he said.
Patient choice
While others will certainly weigh in on which treatment option is the best, ultimately the patient has to decide for himself, Sharkey said. It is incumbent upon the urologist to make sure the patient understands all the facts.
"Does the patient understand the details of his treatment program, and the nature of the potential complications?" he asked. "Let the patient decide based on the issues and factors that are most important to him."
By Shalmali Pal
AuntMinnie.com staff writer
May 3, 2005
Related Reading
Ultrasound-guided biopsy identifies outer prostate benign hyperplasia, April 15, 2005
Tamoxifen can reduce breast pain in prostate cancer patients, April 14, 2005
Prostate cancer family history does not predict benign hyperplasia, April 4, 2005
Ethnicity, marital status affects treatment decisions in prostate cancer, March 29, 2005
Brachytherapy for prostate cancer yields good long-term results, March 14, 2005
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