Cancer CarePoint Blog

Dog's sense of smell could help diagnose a man's prostate cancer

Prostate cancer is the most common cancer malignancy in men, with more than 250,000 cases diagnosed and 28,000 deaths yearly.

Now, man’s best friend may be able to save a man’s life with its nose.

"A new study demonstrated that dogs can be trained to identify and diagnose prostate cancer," said Touro Urologist, Dr. Neil Baum.

Dr. Baum says the trained dogs, out of a study in France, sniffed the urine of men with prostate cancer and were nearly perfect in letting doctors know which ones were positive for prostate cancer and which ones were not.

"They can find it right now in any stage and the dogs are so accurate that when given 66 samples of urine, they were able to identify 63 men with prostate cancer," said Dr. Baum about the study.

For years, man has used dogs to find things we can't see or smell, that's because smelling is the canine's primary sense, said to be 1,000 times more sensitive than humans. A dog has 220 million olfactory receptors in its nose. The receptors are the nerve endings that go to the brain so the smell can be interpreted. Humans only have five million.

"The cells, the prostate cancer, secretes a substance of which has not been identified that can be picked up by dogs," Dr. Baum explained.

So there's some sort of volatile organic compound (VOC) made by cancer cells that we can't smell but dogs can, according to French Researchers. And if doctors can one day figure out what that is, it's possible that a machine can be created to find that compound in urine in a lab.

"Now here's the beauty of this," said Dr. Baum. "At the present time the way of diagnosing prostate cancer is a blood test, the PSA blood test and a digital rectal exam. And if either of those are abnormal, the men have to have a prostate biopsy, which is a little bit uncomfortable and there are some risks involving infection and bleeding following a biopsy. We now believe that if we can identify the substance that is in the urine, men can avoid prostate biopsies."

And remember, early diagnosis can mean the difference in life and death. Now this finding gives new meaning to why dogs are called man's best friend.

Studies in the past have shown promising results using dogs to detect bladder and breast cancer by smelling urine samples.

Source: Meg Farris / Medical Reporter

Doctos Urged to End Prostate Screening in Elderly Men

US panel urges doctors to quit routine prostate cancer screening in men over 75.

Link: MDs urged to end prostate screening in elderly men

Doctors should stop routine prostate cancer screening of men over age 75 because there is more evidence of harm than benefit, a federal task force advised on a hotly debated topic.

The U.S. Preventive Services Task Force, which made the recommendation Monday, reported finding evidence that the benefits of treatment based on routine screening of this age group "are small to none." However, treatment often causes "moderate-to-substantial harms," including erectile dysfunction and bladder control and bowel problems, the task force said.

The new guidance is the first update by the task force on prostate cancer screening since 2002. Its last report concluded there was insufficient evidence to recommend prostate screening for men of all ages.

In recent years, there has been a growing debate about the value of the somewhat imprecise PSA blood test to detect cancer, as well as the value of treating most prostate cancers. A positive result from the test must be confirmed by a biopsy. And even then, there is no foolproof method of identifying aggressive tumors from slow-growing ones. A number of experts contend patients are being overtreated.

"The issue of screening for prostate cancer is frankly an area of medicine that remains somewhat unsettled," said Dr. Durado Brooks, a prostate cancer specialist for the American Cancer Society. "While it's clear there is benefit to a significant number of men, it's equally clear that many men end up being diagnosed and treated for cancers that would likely not have caused them any significant harm."

Most major U.S. medical groups recommend doctors discuss the potential benefits and known harms of prostate screening with their patients and make individual decisions. And most agree such testing shouldn't occur before age 50.

The federal task force, which sets the nation's primary care standards, reviewed past research in reaching its conclusion and "could not find adequate proof that early detection leads to fewer men dying of the disease," task force chairman Dr. Ned Calonge of Denver said in a statement.

The cancer society's advice for screening differs from the task force's because it doesn't set a fixed age to stop screening, Brooks said. It suggests that men shouldn't be offered screening if they aren't expected to live another 10 years.

"That's because every 75-year-old is not created equal," said Brooks.

While some have health problems and aren't likely to live long, others are "very active, very vigorous and have minimal health issues, and many of those men are going to live into their late 80s or 90s," Brooks said.

Prostate cancer is the most common cancer in American men — about 220,000 cases will be diagnosed this year. It is the second leading cause of cancer deaths in men. But most tumors grow so slowly they never threaten lives.

Earlier this year, a study found that older men who already had early-stage prostate cancer were not taking a big risk by not treating it right away. The vast majority were alive 10 years later without significantly worrying symptoms or had died of other causes.

Prostate cancer treatments are tough, especially on older men. Some doctors instead recommend "watchful waiting" to monitor signs of the disease and treat only if they worsen, but smaller studies give conflicting views of the safety of that approach.

Source: Annals of Internal Medicine; Newsweek

Radiation for Prostate Cancer Raises Risk of Other Cancers

Men undergoing external beam radiation for localized prostate cancer may have a slightly increased risk of developing other cancers, researchers report.

Link: Radiation for Prostate Cancer Raises Risk of Other Cancers

The findings could have implications for men trying to decide which treatment is best for their prostate cancer, the researchers said.

"We saw an increased risk for lung, bladder and rectal cancer among patients treated with external beam radiation for prostate cancer," lead researcher Dr. Naeem Bhojani, from the University of Montreal's Department of Urology, said during a Monday teleconference at the American Urological Association annual meeting, in Orlando, Fla.

"However, in absolute terms, the absolute risk associated with the development of secondary malignancies in patients exposed to external beam radiation therapy is quite small," Bhojani said.

Among the treatments for prostate cancer are surgical removal of the prostate, called radical prostatectomy; implanted radioactive seeds that deliver radiation specifically to the prostate gland; and external beam radiation, which is a non-surgical procedure that delivers radiation to the prostate from outside the body.

Bhojani said external beam radiation is probably a better treatment choice for older patients rather than younger patients with longer life expectancies, who may be at risk for developing these secondary cancers.

For the study, by researchers from Canada, Italy and the United States, Bhojani's group collected data on 10,333 men being treated for localized prostate cancer. Among these men, 6,196 had their prostate surgically removed, and 4,137 underwent external beam radiation.

The researchers then looked at the later development of bladder, lung and rectal cancer, to see which treatment was more likely to increase the risk of these malignancies.

They found that men who'd undergone external beam radiation had a threefold increased rate of bladder cancer, a 1.8-fold increased rate of lung cancer, and a 1.7-fold increased rate of colorectal cancer, compared with men who underwent radical prostatectomy.

One cancer expert said he couldn't explain why external beam radiation would increase the risk of these cancers, especially lung cancer.

"I'm not sure how external beam radiation to the pelvis for prostate cancer would increase the risk for lung cancer," said Dr. Bruce Roth, professor of medicine and urologic surgery at Vanderbilt University.

The radiation therapy would be more likely to increase the risk for bladder cancer and colorectal cancer, which are nearer the prostate, he noted.

Roth said it's important to give prostate cancer patients several treatment choices. "I will give them a number of options and let them pick based on the side effect profile. There are many patients who may not be good surgical candidates, therefore you might lean toward external beam radiotherapy," he said.

Source: HealthDay

Radiation for Recurrent Prostate Cancer Appears to Improve Survival

Providing radiation therapy to men with rising prostate-specific antigen (PSA) levels following radical prostatectomy improves survival, a new study suggests.

Link: Radiation for Recurrent Prostate Cancer Appears to Improve Survival

Presenting at the 2008 Genitourinary Cancers Symposium in San Francisco, California, researchers showed that salvage radiotherapy reduced the risk of dying from prostate cancer by more that 60%. Investigators observed the greatest benefit in men with rapidly rising PSA levels, and found that the advantages of therapy appeared to persist even when administered up to 2 years after levels began to rise.

"These findings are the first to support the effectiveness of salvage radiotherapy for improving survival in men with recurrent prostate cancer," lead author Bruce Trock, MD, from Johns Hopkins University School of Medicine in Baltimore, Maryland, told reporters.

"If validated, these results suggest that, for high-risk prostate cancer, radiotherapy should be given promptly when there is evidence of recurrence after radical prostatectomy, as early salvage radiotherapy may improve overall survival." But, he emphasized, this is a retrospective analysis and will require further study.

During an interview with Medscape Oncology, press-conference moderator Howard Sandler, MD, from the University of Michigan Health System in Ann Arbor, said he agreed that more work is needed.

"But I like this study," he noted. "There has been some skepticism among urologists that radiation therapy works and I think there has also been some hesitation to admit the primary treatment failed," he said. "This study shows that men who got salvage radiation lived longer. This should encourage urologists to promptly refer patients to a radiation oncologist."

Recurrence Should Prompt Immediate Radiotherapy, Study Suggests

In the current analysis, researchers compared prostate-cancer-specific survival among men with biochemical recurrence. Of these patients, 160 received salvage radiotherapy alone, 78 received radiation plus hormonal therapy, and 397 had no radiation or hormonal therapy.

After 10 years, 86% of men in the salvage radiotherapy group and 82% of men in the radiation with hormonal therapy group had not died from prostate cancer. The number for men who received no salvage therapy was lower, at 62%. Dr. Trock and his team report that these results did not change after taking into account individual patient characteristics associated with prognosis.

"Early salvage treatment was critical," report the researchers. "Salvage radiotherapy improved prostate-cancer-specific survival only if given up to 2 years after biochemical recurrence."

The benefit of salvage radiotherapy was particularly strong in men with aggressive disease whose PSA levels doubled in less than 6 months. Radiation reduced the risk for prostate cancer death in these patients by 86%.

The researchers found that therapy did not significantly reduce the risk for death among men whose PSA levels doubled in 6 months or more. They suggest this could be because these patients had less aggressive disease and may have done well even without radiation.

Dr. Sandler applauded the researchers. "It is a relatively robust finding that strongly supports the use of radiotherapy in this setting," he said. "But," he added, "this was a restrospective design and patients were not randomly assigned and there is potential for some unknown bias."

Dr. Trock told reporters that despite this new evidence that salvage radiotherapy improves survival, confirmation is needed in other comparable groups of men and ultimately, a randomized clinical trial is required.

The researchers report having financial ties to Oncomethylome Sciences, Johnson & Johnson, and Veridex LLC.

Source: Medscape Medical News

Low Blow: A guy's toughest choice

MSNBC.com writer Mike Stuckey was diagnosed with prostate cancer in April. He chronicles his battle in "Low Blow," a series appearing on MSNBC. Excerpts below.

Link: Low Blow: A guy's toughest choice - Low Blow - MSNBC.com

I had barely begun to digest my diagnosis of prostate cancer when a whole new plate of terms was thrust before me: radical prostatectomy, brachytherapy, watchful waiting, proton beams, cryotherapy.

Welcome to the prostate cancer treatment buffet, where the presence of so many chances for a cure seems too good to be true and, for me, it is. Because there’s no consensus in the medical community on a gold standard treatment for prostate cancer, a patient must choose his own. Welcome to hell.

While the biopsy was painful and nerve-wracking, and the news that I had cancer invoked fear, having to pick my own treatment has easily been the most agonizing part of this ordeal so far.

...I have five reasonable choices: watchful waiting, often going by the term active surveillance these days; surgery done one of two ways; or one of two radiation treatments.

New Ways to Zap Prostate Cancer

Link: New Ways to Zap Prostate CA - Medgadget - www.medgadget.com

A trio of innovations to treat prostate CA is being touted by the University of Wisconsin-Madison:

Directionally emitting radioactive sources, a device for placing needles and seeds, and a super-fast treatment-planning method were developed by UW-Madison engineering physics professor Douglass Henderson and medical physics associate professor Bruce Thomadsen.

To eradicate diseased tissue, physicians implant up to 100 radioactive seeds in the prostate. Like a tiny grain of rice, each seed is cylindrically shaped and emits radiation in all directions-increasing its likelihood of zapping healthy tissue, too.

So, borrowing a concept from nuclear materials handling, Henderson and Thomadsen designed directional seeds-sources with vertical shielding along one side. "I think nobody's done it before because they look at these sources, which are only eight-tenths of a millimeter in outer diameter, and they say there isn't enough space to put shielding," says Thomadsen. "We found you can compress things and you can do it."

As a result, they can implant seeds, particularly at the boundaries between healthy and diseased tissue, that steer radiation where it's needed most.

The press release...