Damian Dovarganes/Associated Press The panel said that some premalignant conditions found in mammograms should not be identified as “carcinoma.”
A group of experts advising the nation’s premier cancer research
institution has recommended changing the definition of cancer and
eliminating the word from some common diagnoses as part of sweeping
changes in the nation’s approach to cancer detection and treatment.
The recommendations, from a working group of the
National Cancer Institute,
were published on Monday
in The Journal of the American Medical Association. They say, for
instance, that some premalignant conditions, like one that affects the
breast called
ductal carcinoma in situ,
which many doctors agree is not cancer, should be renamed to exclude
the word carcinoma so that patients are less frightened and less likely
to seek what may be unneeded and potentially harmful treatments that can
include the surgical removal of the breast.
The group, which includes some of the top scientists in cancer
research, also suggested that many lesions detected during breast,
prostate, thyroid, lung and other cancer screenings should not be called
cancer at all but should instead be reclassified as IDLE conditions,
which stands for “indolent lesions of epithelial origin.”
- 音節
- le • sion
- 発音
- líːʒən
- レベル
- 社会人必須
- lesionの変化形
- lesions (複数形)
[名]
1 《病理学》損傷；（組織の）障害, 病変；病巣.
2 障害, 損害.
- 音節
- ep • i • the • li • um
- 発音
- èpəθíːliəm
[名]（複〜s, -li・a 〔-li
〕）《生物》上皮（組織）（表皮・血管内壁など）.
-li・al
[形]
While it is clear that some or all of the changes may not happen for
years, if it all, and that some cancer experts will profoundly disagree
with the group’s views, the report from such a prominent group of
scientists who have the backing of the National Cancer Institute brings
the discussion to a higher level and will most likely change the
national conversation about cancer, its definition, its treatment and
future research.
“We need a 21st-century definition of cancer instead of a
19th-century definition of cancer, which is what we’ve been using,” said
Dr. Otis W. Brawley, the chief medical officer for the American Cancer
Society, who was not directly involved in the report.
The impetus behind the call for change is a growing concern among
doctors, scientists and patient advocates that hundreds of thousands of
men and women are undergoing needless and sometimes disfiguring and
harmful treatments for premalignant and cancerous lesions that are so
slow growing they are unlikely to ever cause harm.
The advent of highly sensitive screening technology in recent years
has increased the likelihood of finding these so-called
incidentalomas —
the name given to incidental findings detected during medical scans
that most likely would never cause a problem. However, once doctors and
patients are aware a lesion exists, they typically feel compelled to
biopsy, treat and remove it, often at great physical and psychological
pain and risk to the patient. The issue is often referred to as
overdiagnosis, and the resulting unnecessary procedures to which
patients are subjected are called overtreatment.
Cancer researchers warned about the risk of overdiagnosis and
overtreatment as a result of new recommendations from a government panel
that heavy smokers be given an annual CT scan. While the policy change,
announced on Monday but not yet made final, has the potential to save
20,000 lives a year, some doctors warned about the cumulative radiation
risk of repeat scans as well as worries that broader use of the scans
will lead to more risky and invasive medical procedures.
Officials at the National Cancer Institute say overdiagnosis is a
major public health concern and a priority of the agency. “We’re still
having trouble convincing people that the things that get found as a
consequence of mammography and P.S.A. testing and other screening
devices are not always malignancies in the classical sense that will
kill you,” said Dr. Harold E. Varmus, the Nobel Prize-winning director
of the National Cancer Institute. “Just as the general public is
catching up to this idea, there are scientists who are catching up,
too.”
Joe Raedle/Getty Images An expert panel says lesions found in some cancer screenings should not be called cancer but should instead be reclassified.
One way to address the issue is to change the language used to
describe lesions found through screening, said Dr. Laura J. Esserman,
the lead author of the report in The Journal of the American Medical
Association and the director of the Carol Franc Buck Breast Care Center
at the University of California, San Francisco. In the report, Dr.
Esserman and her colleagues said they would like to see a
multidisciplinary panel convened to address the issue, led by
pathologists, with input from surgeons, oncologists and radiologists,
among others.
“Ductal carcinoma in situ is not cancer, so why are we calling it
cancer?” said Dr. Esserman, who is a professor of surgery and radiology
at the University of California, San Francisco.
Such proposals will not be universally embraced. Dr. Larry Norton,
the medical director of the Evelyn H. Lauder Breast Center at Memorial
Sloan-Kettering Cancer Center, said the larger problem is that doctors
cannot tell patients with certainty which cancers will not progress and
which cancers will kill them, and changing terminology does not solve
that problem.
“Which cases of D.C.I.S. will turn into an aggressive cancer and
which ones won’t?” he said, referring to ductal carcinoma in situ. “I
wish we knew that. We don’t have very accurate ways of looking at tissue
and looking at tumors under the microscope and knowing with great
certainty that it is a slow-growing cancer.”
Dr. Norton, who was not part of the report, agreed that doctors do
need to focus on better communication with patients about precancerous
and cancerous conditions. He said he often tells patients that even
though ductal carcinoma in situ may look like cancer, it will not
necessarily act like cancer — just as someone who is “dressed like a
criminal” is not actually a criminal until that person breaks the law.
“The terminology is just a descriptive term, and there’s no question
that has to be explained,” Dr. Norton said. “But you can’t go back and
change hundreds of years of literature by suddenly changing
terminology.”
But proponents of downgrading cancerous conditions with a simple name
change say there is precedent for doing so. The report’s authors note
that in 1998, the World Health Organization changed the name of an
early-stage urinary tract tumor, removing the word “carcinoma” and
calling it “papillary urothelial neoplasia of low malignant potential.”
When a common Pap smear finding called “cervical intraepithelial
neoplasia” was reclassified as a low-grade lesion rather than a
malignancy, women were more willing to submit to observation rather than
demanding treatment, Dr. Esserman said.
“Changing the language we use to diagnose various lesions is
essential to give patients confidence that they don’t have to
aggressively treat every finding in a scan,” she said. “The problem for
the public is you hear the word cancer, and you think you will die
unless you get treated. We should reserve this term, ‘cancer,’ for those
things that are highly likely to cause a problem.”
The concern, however, is that since doctors do not yet have a clear
way to tell the difference between benign or slow-growing tumors and
aggressive diseases with many of these conditions, they treat everything
as if it might become aggressive. As a result, doctors are finding and
treating scores of seemingly precancerous lesions and early-stage
cancers — like ductal carcinoma in situ, a condition called Barrett’s
esophagus, small thyroid tumors and early prostate cancer.
But even after years of aggressively treating those conditions, there
has not been a commensurate reduction in invasive cancer, suggesting
that overdiagnosis and overtreatment are occurring on a large scale.
The National Cancer Institute working group also called for a greater
focus on research to identify both benign and slow-growing tumors and
aggressive diseases, including the creation of patient registries to
learn more about lesions that appear unlikely to become cancer.
Some of that research is already under way at the National Cancer
Institute. Since becoming director of the institute three years ago, Dr.
Varmus has set up a list of “provocative questions” aimed at
encouraging scientists to focus on critical areas, including the issue
of overdiagnosis and molecular tests to distinguish between slow-growing
and aggressive tumors.
Another National Cancer Institute program, the Barrett’s Esophagus
Translational Research Network, or Betrnet, is focused on changes in the
esophageal lining that for years have been viewed as a precursor to
esophageal cancer. Although patients with Barrett’s are regularly
screened and sometimes treated by burning off the esophageal lining,
data now increasingly suggest that most of the time, Barrett’s is benign
and probably does not need to be treated at all. Researchers from
various academic centers are now working together and pooling tissue
samples to spur research that will determine when Barrett’s is most
likely to become cancerous.
- 音節
- e • soph • a • gus
- 発音
- isɑ'fəgəs | iːsɔ'f-
[名]（複-gi 〔-d
ài〕）《解剖学》食道(gullet).
[形]
“Our investigators are not just looking for ways to detect cancer
early, they are thinking about this question of when you find a cancer,
what are the factors that might determine how aggressively it will
behave,” Dr. Varmus said. “This is a long way from the thinking 20 years
ago, when you found a cancer cell and felt you had a tremendous risk of
dying.”
