Imperfect prostate
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Men over age 50 are encouraged to be screened every year for prostate cancer despite some controversy about the blood test to detect it.
Urologists agree that the prostate-specific antigen test has flaws but say it is the best method available for checking and following prostate cancer, along with a rectal examination.
"We are picking up prostate cancer at earlier stages now, most likely due to PSA," said Dr. Al Mariani, Kaiser Permanente chief of surgery in urology. "The test itself is not a terrific test, but it's all we have."
Mammography and Pap screening for women also have been controversial, Mariani said, "but evidence is it saves lives. I think we will find PSA screening affects mortality in the future." For now, he said, "We see earlier treatment."
Men considered to be high risk -- African Americans and anyone with a family history of prostate cancer -- should begin getting annual tests about age 40, the doctors say.
Dr. Gary Lattimer, chief of urology at the Queen's Medical Center, said: "Prostate cancer has really exploded since 1995, which is coincidentally about the time of the PSA (test) becoming easily available. ... It's by far the best serological test available in screening for any cancer."
However, the antigen test is not specific to cancer, the urologists said.
PSA is an enzyme produced by the prostate, a walnut-shaped gland near the bladder and rectum and surrounding the urethra, the tube that empties urine from the bladder.
Elevated PSA levels could be caused by inflammation, infection, trauma or anything that disrupts the prostate and allows the enzyme to escape into the bloodstream, Mariani said.
"It's very sensitive to changes in the prostate," Lattimer said. "So, for instance, you will see it elevated with urinary tract infections, with any kind of manipulation to the prostate. Even with sexual activity, it will sometimes be elevated the next day. So those questions should be asked before drawing the test, so as not to draw a false positive."
Some researchers believe 4.0 nanograms per millimeter of blood -- the threshold for doing a biopsy -- is too high and misses many cancers, according to a recent study by the New England Journal of Medicine.
Recommendations have been made to lower the cutoff level for younger men and raise it for older men, but this also is controversial, Mariani said. It would mean conducting biopsies on many younger men and possibly missing some cancers in older men, he said.
"We (at Kaiser) have stayed pretty much at 4.0, but if a younger man has a worrisome PSA that's less than 4.0, we wouldn't hesitate to biopsy the man."
Lattimer said the PSA test is most valuable by following its rate of increase and general trend over time. Prostate cancer is similar to ovarian cancer in that "they are the only two tumors so strongly age-dependent in severity," he noted.
Most men 90 or older have some prostate cancer, but it is slow-growing and likely has no impact on older men, Lattimer said. But there is a high risk of it spreading and causing death if not caught early in younger men and treated aggressively, he said.
Mariani said the chance of prostate cancer is one out of three when PSA is elevated, using 4.0 as the cutoff. But he said the chance of dying from prostate cancer is less than 10 percent if it is localized and treated definitively.
He said prostate cancer will be found 10 to 20 percent of the time when PSA is normal, less than 4.0, leaving 80 to 90 percent of cases uncertain.
"What the urologist will usually do today, given the uncertainties," Mariani said, "is look at all the facts available, the trend of specific antigen -- is it growing fast and going up or down -- and put that together with rectal exam results and patient risk factors and determine whether to do a biopsy."
"We don't want to biopsy everybody," said Lattimer. "That's the point we're trying to get to, a reasonable number where we find treatable cancers and not put people through biopsies unnecessarily."
A rectal exam should be done as well as a PSA test because it can pick up cancer missed by the blood test, the urologists said.
Lattimer recalled that retired Gen. Norman Schwarzkopf, Desert Storm commander, did not have an elevated PSA when he was diagnosed with prostate cancer in March 1994. His doctor found it in a physical exam.
"I know men both joke about and dread the 'infamous digital rectal exam,' but that's what literally saved my life," Schwarzkopf said at the time.
Mariani said a lot of prostate cancer is seen in autopsies of men, but most died of something else. "There is a saying that a lot more men die with prostate cancer than of it."
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By the numbers
Some facts about prostate cancer:
>> About 700 cases of prostate cancer are diagnosed each year in Hawaii, while 100 men die from the disease.
>> Prostate cancer is the leading type of cancer diagnosed among men of all racial and ethnic groups in Hawaii except Hawaiians.
>> It is the second major cause of cancer deaths among Caucasian, Chinese and Filipino men. Incidence and mortality rates are highest among Caucasian men.
>> Hawaiians have the lowest number of cases, and Chinese have the lowest prostate cancer death rates.
>> About 95 percent of Hawaii men who develop prostate cancer are 55 or older at the time of diagnosis, and more than 75 percent are 65 or older.
>> The Hawaii Tumor Registry shows cases and mortality among Hawaii men increasing until the mid-1990s, when the prostate-specific antigen screen test was adopted. Cases and deaths since have declined for men of all racial/ethnic groups except incidence rates among Hawaiians.
>> The five-year survival rate for men with prostate cancer diagnosed in earliest stages is nearly 100 percent. About 76 percent of prostate cancer cases diagnosed in Hawaii between 1995 and 2000 on an average were done at the earliest stage.
Source: Hawaii Cancer Facts & Figures 2003-2004
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David Derris was diagnosed with prostate cancer in 1996. He has not had therapy since 1998.
Maui prostate cancer
survivor emphasizes
diet and exercise
David Derris, of Kihei, Maui, uses his experience as a prostate cancer survivor to help other men "face the challenge" of the second-leading cause of cancer death in men.
"The good news is that when detected early, and with proper treatment, the results are wonderful," he said. "Over 99 percent of men diagnosed are still alive in five years."
Derris, 66, a retired orthodontist, is Hawaii educational facilitator for the Los Angeles-based Prostate Cancer Research Institute.
He had a biopsy in January 1996 after his prostate-specific antigen, a cancer indicator, started going up and reached "a worrisome level," he said. He was diagnosed with low-grade prostate cancer.
His treatment, using hormone blockage to stop testosterone production and kill malignant cells, was successful, he said.
Derris said he has urinary symptoms from an enlarged prostate, which is what initially took him to a urologist, but he has not had therapy for prostate cancer since April 1998.
"It changed my lifestyle and my diet," he said, suggesting for prevention that men "get away from diets that are high in animal fat and eat more fruits and vegetables, using soy as a source of protein." Regular exercise and stress reduction also are important, he said.
Derris stresses that he does not provide medical advice, just information about resources and questions men can ask their doctors.
The antigen test readings can go up and down, he said, suggesting one test should not be used to make a biopsy or treatment decision. A rectum exam also is an important for detection, he said.
About 15 percent of men with an antigen reading considered normal do have prostate cancer, and a digital rectal exam can alert the physician to a problem when the antigen is in the so-called normal range, he said.
His Prostate Cancer Research Institute Helpline is 808-891-0209. His e-mail is derris@pcri.org. Institute Web sites are www.prostate-cancer.org and www.pcri.org.
