Treatment Options Increasing for Prostate Cancer

But reliable screening procedures remain elusive, panel of experts says

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THURSDAY, March 24, 2005 (HealthDay News) -- Successful surgeries, highly targeted radiation therapy, new insights in molecular biology and a drug that may be effective in preventing the disease are all signs of progress in the fight against prostate cancer, according to a gathering of experts in New York City on Wednesday.

"There has been a 25 percent decrease in mortality from prostate cancer in the last decade" due, in part, to earlier detection of the disease and improved treatment, said Dr. Peter Scardino, surgeon and chairman of the department of urology at Memorial Sloan-Kettering Cancer Center in New York.

That's important, he said, because prostate cancer will hit one out of six men in his lifetime and is the second leading cause of cancer death in men, with about 30,000 deaths expected in 2005, according to the American Cancer Society. That number is expected to increase as the U.S. population ages, since prostate cancer primarily strikes men 55 and older.

Scardino, alongside two colleagues from Sloan-Kettering and two experts from the National Cancer Institute, spoke at the conference on the very latest advances in the treatment of prostate cancer.

"Surgery is highly effective for serious cancers," Scardino said, as he listed cutting-edge techniques allowing more targeted removal or destruction of malignant tissue with fewer side effects.

Laparoscopy -- minimally invasive, video-guided surgery of the internal organs -- is one good example. Scardino said fewer than 10 percent of patients are being operated on using laparoscopy, but that number will probably increase to 75 percent in 10 years as more doctors learn the technique.

He emphasized that doctors are still on a big learning curve in mastering this procedure, so patients eager for the surgery -- which offers shorter recovery time with fewer side effects -- should investigate risks and benefits carefully before they opt for this relatively new surgery.

Similar advances in technology have dramatically improved radiotherapy treatment, said Dr. Michael J. Zelefsky, chief of Brachytherapy Service at Sloan-Kettering.

Three-dimensional conformal radiotherapy (3D-CRT), which uses a computer to show internal organs in three dimensions, allows doctors to "target the radiation with exquisite accuracy, sparing normal tissue and resulting in a dramatic reduction in side effects," said Zelefsky.

Furthermore, this pinpoint technology has allowed doctors to use much higher and more effective doses of radiation when treating cancer, because the risk of damaging healthy tissue has been reduced, he explained.

In his own study comparing the effects of higher radiation doses to lower doses, he found that increasing the radiation dose "resulted in a [improved] clearance of cancer from 50 percent to 91 percent," Zelefsky said.

Early animal studies in genetics and molecular biology are also showing promise in preventing prostate cancer, reported Sloan-Kettering oncologist Dr. Howard J. Scher. He pointed to the role of tumor-suppressing genes called PTEN in preventing the spread of prostate malignancies.

Prevention of prostate cancer is a major, and more elusive, goal of health professionals, the doctors reported. They highlighted the current controversy surrounding blood-based screening for prostate-specific antigen (PSA), which thousands of American men undergo every year.

Scardino noted that although PSA screening has become very popular, it has not yet proven to be a reliable marker for prostate cancer. In one way, the test may even be too sensitive -- detecting small, slow-growing tumors that may not ever require treatment, he said.

"The PSA levels in the blood go from plus or minus 30 percent variability every year, so one test is not enough, and there is still no proven effect of the test," Scardino said. "Still, regular screening with a digital rectal exam and PSA can detect almost all cancers when they are curable."

Doctors from the National Cancer Institute (NCI) had more promising news as they discussed the results of a six-year study of the effect of the drug finasteride, known to help in treating benign prostate growth, on preventing the occurrence of prostate cancer.

In the study, 18,000 healthy men took either a daily dose of 5 milligrams of the drug or a placebo for six years. According to the researchers, finasteride reduced the prevalence of prostate cancer by 25 percent. However, there was troubling news as well: Men who took the drug but still contracted prostate cancer experienced a slightly higher rate of more aggressive cancers -- a paradoxical finding that requires more study, the NCI experts said. Finasteride is not yet approved for use by the U.S. Food and Drug Administration.

The study also found that about 15 percent of men with PSA levels at or below 4 -- traditionally considered a "no-risk" concentration -- actually had tissue biopsies positive for prostate cancer. That surprising discovery will also require more study, the researchers said.

"That really caught our attention," said Dr. Howard L. Parnes, from NCI's Division of Cancer Prevention.

Dr. Leslie Ford of the NCI reported that the public needs to be better informed about preventing cancer.

"Patients are very sophisticated about preventing heart disease. They have gotten the message across the board that if you pay attention to your blood pressure and cholesterol levels, you will prevent heart disease.

"This concept hasn't caught on in cancer prevention because we haven't been able to produce the numbers," she said. "We need more positive results from trials and a greater understanding by the public of the long process of cancer development and the importance of preventive strategies."

More information

For more information about prostate cancer, visit the National Cancer Institute.

SOURCES: Leslie G. Ford, M.D., associate director, clinical research, National Cancer Institute; Howard L. Parnes, M.D., Division of Cancer Prevention, National Cancer Institute; Peter T. Scardino, M.D., chairman, Department of Urology and Head of Prostate Cancer Program, Memorial Sloan-Kettering Cancer Center, New York City; Howard I. Scher, M.D., oncologist, Memorial Sloan-Kettering Cancer Center, New York City; Michael J. Zelefsky, M.D., chief, Brachytherapy Service, Memorial Sloan-Kettering Cancer Center, New York City; March 23, 2005, seminar, New Frontiers in Prostate Cancer Treatment and Prevention, New York City

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