|
New approaches to the diagnosis of oral cancer
Oral
cancer is diagnosed in more than 30,000 individuals in the US
annually, claiming 10,000 lives each year.
Early
detection remains the best way to ensure patient survival and
quality of life. Today, during the 85th General Session of the
International Association for Dental Research, scientists from the
University of California-Irvine present two novel, non-invasive,
ultra-fast imaging approaches to oral cancer detection, diagnostic
screening, and mapping.
More than
2/3 of all oral cancer cases documented by the National Cancer
Institute are diagnosed at an advanced stage. The five-year survival
rate is 75% for those with localized disease at diagnosis, but only
16% for those with cancer metastasis.
Earlier detection of oral lesions would greatly
improve the prognosis of these patients. Accurate
delineation of lesion margins would ensure effective
removal of all the tissue that presents a threat to
the patient’s long-term health.
Two basic
facts indicate that early detection of oral malignancy should be
possible to a far greater extent than is currently seen: (1)
Accounting for 96% of all oral cancers, squamous cell carcinoma is
often preceded by lesions on the oral mucosa.
Malignant
transformation, which is quite unpredictable, occurs in 1-90% of
lesions over five years. Thus, oral cancer is often preceded by
lesions which are visible to the naked eye prior to transformation.
A
non-invasive diagnostic modality would permit regular monitoring of
these lesions, detection of lesion transformation, and the
identification of treatment needs at a very early, relatively
harmless stage. (2) High-risk populations are clearly defined:
tobacco use, alcohol abuse, urban environment, specific ethnicities,
poor diet, and frequent exposure to sunlight. A fast, mobile,
relatively inexpensive and non-invasive diagnostic modality would
permit the early detection and monitoring of oral lesions.
The
researchers describe Three-dimensional Optical Coherence Tomography
(3-D OCT) and Optical Doppler Tomography (ODT), which show surface
and subsurface tissues at near-microscopic levels of resolution,
with the potential for replacing conventional surgical biopsy and
histopathology techniques. Combined with polarimetry, accurate
delineation of lesion margins becomes possible.
Scanning
is painless and non-invasive, lasting less than one minute with a
pen-sized hand-held probe. This device’s resolution or diagnostic
capability may dictate its primary use as an indicator of the need
for biopsy. Later, this modality may progressively reduce the need
for biopsy, define surgical margins, and permit the direct
evaluation of cancer treatments. In combination with OCT-visible
molecular probes, this modality will greatly advance cancer
diagnostics.
|
Now,
keep up to date with daily feeds of newly posted stories about America's
Seniors...click on the box to the left