U-M finds prostate cancer culprit
Friday, October 28, 2005
U-M finds prostate cancer culprit
By Christina Stolarz and Doug Guthrie / The Detroit News
Medical researchers at the University of Michigan have identified a likely cause of prostate cancer they say could lead to more effective treatments and possibly a cure.
Scientists have discovered a recurring pattern of scrambled chromosomes that causes certain genes to merge — an abnormal gene activity occurring only in prostate cancer, the leading cancer diagnosis for men in the United States. An estimated 232,000 new cases of prostate cancer will be reported this year, according to the American Cancer Society.
Identifying the specific genes involved may now lead to a new, more accurate test — of the blood or urine — to detect prostate cancer, and possibly more effective methods of treatment, said Dr. Arul M. Chinnaiyan, the U-M pathology professor who directed the research. The closer medical researchers are to nailing down a cause, the closer they are to finding its cure, he said.
“We’d like to think it’s the first step,” he said. “A lot of work still needs to be done.”
While similar forms of the abnormal gene activity have been detected in “liquid” cancers like leukemia and lymphoma, this is the first evidence it’s occurred in solid tumors like prostate cancer. The finding also suggests similar gene activity may be involved in the development of other soft-tissue cancers such as cancer of the breast, lung, ovaries and colon.
The study’s results were published Thursday in Science Magazine.
Chinnaiyan said researchers “stumbled” across the discovery mid-year; the initial findings were sent to a researcher at Harvard University for independent verification.
“We knew that we’d made an important observation. We actually were looking for something else,” he said.
“To actually find a recurrent gene combination in this type of cancer was a surprise.
“It was sort of a serendipitous or eureka moment.”
Prostate cancer is the second most common cause of cancer-related deaths for men (the first is lung cancer), claiming the lives of an estimated 30,350 men this year, according to the American Cancer Society.
Closer to home, about 14 percent of men statewide each year will be diagnosed with prostate cancer at some point in their lives, and 3 percent of will die each year, according to the Michigan Cancer Consortium.
In 2001, there were 8,662 new prostate cancer cases in Michigan; for every 100,000 men, it was diagnosed in 175 white men and 243 black men.
This medical breakthrough will offer hope to many prostate cancer patients, said Michael Rice, president of the Prostate Cancer Coalition of Michigan.
“It’s great news. One of the commodities that any cancer patient needs is hope,” said Rice, 63, of Lansing, who was diagnosed with prostate cancer more than nine years ago. “I expect great things to come out of this.”
Rice had surgery to remove his prostate, and underwent hormone therapy, chemotherapy and radiation treatments at U-M soon after doctors learned that the cancer spread to his bones.
West Bloomfield Township resident Freddie Scott, 53, said the findings are a huge medical advancement.
“You always look for a positive,” said Scott, a former Detroit Lions wide receiver. He was diagnosed with prostate cancer four years ago and quickly underwent surgery at Providence Hospital in Southfield.
Researchers hope to find out how to identify inhibitors for the specific genes, to parallel the development of a drug designed to target the gene fusion that causes leukemia.
U-M, which already has filed an application to patent the research, will launch new studies to verify if gene fusion can cause prostate cancer in research animals. They also will broaden their study to determine if unique chromosomal rearrangements can be identified in other forms of cancer.
In 22 samples of prostate cancer tissues, researchers found the same gene fusion 91 percent of the time. Analysis of 221 historical cases, including 167 tumor and 54 benign prostate tissue samples showed the same gene fusion in 95 percent of the samples. No evidence of the combination was found in any of the benign samples.
“This finding is an important advance,” said Dr. Jacob Kagan, program director for the Cancer Biomarkers Research Group at the National Cancer Institute, a sponsor of the research study. U-M scientists worked in collaboration with researchers from Harvard’s Brigham and Women’s Hospital.
Chinnaiyan expects this breakthrough could have broader implications. “To identify the possible biological basis of this cancer is a major finding, but the possibility is even larger when you consider that other solid tumors may also have a common basis that we just haven’t found yet,” he said. “Once somebody finds something like this, and knows what to look for, discoveries could come rapidly.”
About prostate cancer
It is the leading cancer diagnosis for men in the United States, according to the American Cancer Society, which estimates 232,000 new cases will be reported this year.
Risk factors: There may be an increased risk in men older than 65 who have a family history of prostate cancer and a diet high in animal fat or meat.
Symptoms: Urinary problems like pain or burning during urination, frequent urination and a weak flow; frequent pain in the lower back, hips and upper thighs; and blood in the urine or semen.
Treatments: Doctors may remove the entire prostate or only part of it; radiation; and hormone therapy.
By the numbers
It is the second most common cause of cancer-related deaths for men, costing an estimated 30,350 lives this year.
In 2001, there were 8,662 new prostate cancer cases in Michigan; and it was diagnosed in 175 per 100,000 white men and in 243 per 100,000 black men.
In 2002, an estimated 1,015 Michigan men died from prostate cancer.
Sources: American Cancer Society and Prostate Cancer Coalition of Michigan