Freezing prostate cancer as effective as surgery
19 March 2009
The so-called 'male lumpectomy' — a minimally invasive interventional
radiology treatment for prostate cancer — is as effective as surgery in
destroying diseased tumours and can be considered a first-line treatment
for patients of all risk levels and particularly those who have failed
radiation, according to studies released at the Society of
Interventional Radiology's 34th Annual Scientific Meeting [1,2].
Additionally, the use of 3-D transperineal mapping biopsy for
determining the extent of prostate cancer — when compared with the
commonly used transrectal ultrasound (TRUS) biopsy — heavily impacted
how patients' disease was managed in 70% of the cases.
"Our data show that focal cryoablation is as good for prostate cancer
control as any other treatment, including surgery, radiation and hormone
therapy, but it is less invasive and traumatic for patients, preserves
sexual and urinary function and has no major complications.
"Interventional radiologists tailor treatment to each patient's
disease. Instead of removing the entire prostate, or freezing the entire
prostate or using radiation on the entire prostate, interventional
radiologists can find out where the cancer is and just destroy the
cancer," said study author Gary M. Onik, MD, interventional radiologist
and director of the Center for Safer Prostate Cancer Therapy in Orlando,
"We've reached a tipping point: treating only the tumour instead of
the whole prostate gland is a major and profound departure from the
current thinking about prostate cancer," added Onik.
With cryoablation, interventional radiologists insert a probe
through the skin, using imaging to guide the needle to the tumour; the
probe then circulates extremely cold gas to freeze and destroy the
cancerous tissue. This minimally invasive treatment targets only the
cancer itself, sparing healthy tissue in and around the prostate gland
rather than destroying it, as traditional approaches do, noted the
professor at the University of Central Florida.
"You can go home on the same day of the procedure, and you can repeat
the treatment, if needed, in later years," said Onik. Additionally, Onik
presented results of a 3-D biopsy method that provides superior
information on the extent and grade of prostate cancer as opposed to the
current standard TRUS biopsy.
Calling focal cryoablation a male lumpectomy reflects the origins of
this approach in the breast-sparing surgery that replaced radical
mastectomy as the preferred treatment for breast cancer, said Onik.
Unlike breast lumpectomy, a surgical lumpectomy for prostate cancer
is not technically feasible; so to treat just a portion of the prostate,
minimally invasive cryoablation is needed.
Cryoablation (or cryo or cryotherapy) spares as much as possible of
the prostate gland and its neurovascular bundles, limiting the side
effects of bladder control problems (incontinence) and erectile
dysfunction (impotence) that result from more radical prostate cancer
treatments. It also represents an advantage over "watchful waiting,"
because all treatment options are preserved.
"Any risks are fewer and lesser in intensity than surgery; so if you
have the equivalent chance of cancer being cured with far less chance of
having any complications, why wouldn't you choose it?" asked Onik.
"There is no question that we can eradicate prostate cancer (when
that cancer has not spread to other parts of the body) by freezing it
and that there is a better way to 'map' the disease," said Onik.
He studied 120 men who had focal cryoablation over the past 12 years,
including testing the levels of prostate-specific antigen (PSA) in the
blood. Of those patients, 112 (93%) had no evidence of cancer — in spite
of 72 being labelled medium to high risk for cancer recurrence.
"There were no local recurrences in the areas we treated, and with
the ability to re-treat the 7% of patients who developed a focus of
cancer at a different site in the gland; cryoablation was 100 percent
effective in local control of the patient's disease," said Onik.
He reported that 85 percent of the men retained sexual function. Of
those who did not have previous prostate surgery, all remained
continent. "Incontinence becomes a big issue with many patients. For
some it's a more important side effect than impotence," said Onik.
According to Onik, the 3-D transperineal biopsy complements the focal
cryoablation approach because earlier detection of smaller tumours
increases the likelihood that a small tumor can be treated using
In his study, Onik restaged 180 patients who had previously undergone
TRUS mapping biopsies who were considering conservative management for
their cancer. The results showed that 70% of the men would have their
management changed by the new information provided by mapping.
Through mapping, more than 50% of men who were diagnosed with cancer
on one side of the prostate gland with traditional TRUS biopsy had
undetected cancer on the other side as well, he said.
Management of prostate cancer is in great part determined by the
Gleason score, a cancer ranking method indicating tumour grade and stage
and the extent and location of a patient's disease.
"When we restaged the men, we found that 22 percent of them
experienced an increase in their Gleason score — meaning that they had a
more aggressive cancer than was originally thought from their original
biopsy. The 3-D mapping biopsy provided life-saving information," said
"This biopsy technique allows us to map the location of the tumor
with tremendous precision and has the potential to greatly affect the
decisions we make about treating prostate cancer," Onik said. "The data
are unequivocal. If you're doing 'watchful waiting,' get mapped. If
you're having radiation or hormone therapy or thinking about getting a
'nerve-sparing' radical prostatectomy, get mapped. If TRUS doesn't show
all the cancer that's present, you're not going to have the proper
treatment," said Onik.
With 3-D transperineal mapping, a grid placed over the perineum (the
area of skin between the rectum and the scrotum) allows an
interventional radiologist to accurately map the location of each biopsy
core removed. The cores are taken through the skin rather than through
the rectum, allowing many more cores to be removed — about 50 compared
to 10-12 in a TRUS biopsy.
The mapping grid also allows the location of the tumour to be known
much more precisely, allowing an interventional radiologist to
cryoablate (freeze) only the tumour and not the whole prostate gland.
Controversy surrounds the treatment of prostate cancer, which usually
grows slowly and initially remains confined to the prostate gland, said
Growing evidence of overdetection and overtreatment in many men with
low-risk tumours has led to a concept in the medical community of
"watchful waiting" or observing a man's disease progression prior to
Many patients, however, feel uncomfortable with this strategy and may
proceed to radical or aggressive treatment, said Onik. "When men must
choose between 'watchful waiting' and high-morbidity whole-gland
treatments (like surgery and radiotherapy), a lumpectomy-type treatment,
which has so markedly changed the management of breast cancer for women,
is a welcome 'middle ground' addition for those with prostate cancer,"
"Interventional cryoablation for prostate cancer is not experimental.
This is a treatment option that doctors should discuss with their
patients early on," emphasized Onik.
Most people don't realize that you can surgically remove the whole
prostate and, in 20% of the cases, the cancer can be left (called a
positive margin), said Onik, who works in consultation with urologists.
Doctors should discuss cryoablation with patients early on, he
advised, noting that recently the American Urological Association issued
a best practice statement that indicated that cryotherapy is an option
for men who have clinically organ-confined prostate cancer of any grade
with negative metastatic evaluation. Since this interventional treatment
is not widely known to doctors and patients, individuals will need to
pursue it on their own, he added.
More information about prostate cancer, cryoablation and
interventional radiology can be found online at
1. Abstract 75: "Focal Therapy for Prostate Cancer — 120 Patients
With Up to 12-Year Follow-up," G. Onik, Center for Safer Prostate Cancer
Therapy, Orlando, Fla., SIR 34th Annual Scientific Meeting March 7-12,
2. Abstract 198: "3D Prostate Mapping Biopsy Has a Potentially
Significant Impact on Prostate Cancer Management," G. Onik, M. Miessau;
Center for Safer Prostate Cancer Therapy, Orlando, Fla., SIR 34th Annual
Scientific Meeting March 7-12, 2009.
Both abstracts can be found at
About prostate cancer
Prostate cancer, the most common non-skin cancer in America, forms in
the tissues of the prostate (a gland in the male reproductive system
found below the bladder and in front of the rectum). Prostate cancer
affects one in six men, usually older men.
As men age, the prostate may get bigger and block the urethra or
bladder. This may cause difficulty in urination or can interfere with
sexual function. It is estimated that there are more than 2 million
American men currently living with prostate cancer.
Older age, African American race and a family history of the disease
can all increase the likelihood of a man being diagnosed with the
disease. As men increase in age, their risk of developing prostate
cancer increases exponentially. An estimated 230,000 new cases are
diagnosed annually in the United States, with nearly 30,000 annual
African American men have higher incidence and at least double the
mortality rates compared with men of other racial and ethnic groups.
Historically, prostate cancer has been considered an older man's
disease; however the incidence is increasing in men in their 40s and
Prostate cancer usually grows slowly and initially remains confined
to the prostate gland. While some types of prostate cancer grow slowly
and may need minimal or no treatment, other types are aggressive and can
A diagnosis of prostate cancer can be scary not only because it can
be life-threatening, but also because invasive treatments can cause side
effects such as bladder control problems and erectile dysfunction
(impotence). Men are classified as being at low, intermediate or high
The criteria used to categorize the risk include the results of the
prostate-specific antigen (PSA) blood test (which looks for a protein
produced by the prostate gland and can help detect cancer), tumour
aggressiveness and the clinical stage of the tumour.
Source: The US Society of Interventional
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