In Dr. Lauren Patton and colleagues’ July JADA article, "Adjunctive Techniques for Oral Cancer Examination and Lesion Diagnosis: A Systematic Review of the Literature," (
Patton LL, Epstein JB, Kerr AR. JADA 2008;139[7]:896–905[Abstract/Free Full Text]
), the authors reviewed OralCDx (Oral CDx Laboratories, Suffern, N.Y.) and concluded that, based on published studies, the test has been demonstrated to be valuable for detecting dysplasia when evaluating "clinically suspicious" lesions. In a review of oral cancer diagnostic aids by another group, Lingen and colleagues1 come to the same conclusion.
Both sets of authors suggest, however, that due to their "evidentiary criteria," the sensitivity of OralCDx for testing "non-suspicious" lesions has not yet been established. This is an invalid criticism of well-designed, double-blind studies in which the entire spectrum of lesions traditionally evaluated by scalpel biopsy were matched with a simultaneously performed brush biopsy.2,3
From a practical clinical perspective, this criticism is pointless. Using the same evidentiary criteria that the authors applied to studies of OralCDx, the sensitivity of the scalpel biopsy for nonsuspicious lesions too harmless-appearing to be subjected to scalpel biopsy is certainly unknown.
What is known is that two biopsies of any type, performed at the same time but on different areas of a lesion, or performed on the same lesion but at different times, are expected to yield different results. As recently highlighted in a study of 200 patients with oral leukoplakia, the agreement rate between two scalpel biopsies of the same lesion was only 56 percent, and underdiagnosis from scalpel biopsy was noted in 29.5 percent of patients.4 Therefore, any studies quoted in the JADA article in which disparities were reported between OralCDx and scalpel biopsy are completely irrelevant, since in all of these studies, the two biopsy samples were obtained by different examiners at different times.
If a transepithelial brush biopsy and a transepithelial scalpel biopsy simultaneously test a lesion, both will sample the same dysplastic or cancerous cells present in that lesion. This will be the case regardless of how the lesion appears clinically. This is precisely why the results of every study, which required lesions to be simultaneously tested with both a brush and scalpel biopsy, demonstrated that these two techniques have, within statistical significance, equivalent sensitivity.2,3
The National Cancer Institute, in its peer-reviewed, evidence-based publication, reported a high sensitivity and specificity for OralCDx for detecting dysplasia "when tested on visually identified lesions."5 Clearly, this includes evaluating all visible lesions, both suspicious and nonsuspicious.
For the dentist in practice, how suspicious an oral lesion appears matters little. Everyone would agree that persistent white and red lesions without an etiology should be evaluated. OralCDx offers dentists a non-invasive, painless, practical and accurate biopsy method of testing all of these lesions. As demonstrated in published studies, there is little doubt that the use of OralCDx to evaluate "nonsuspicious" lesions detects a significant number of dysplasias and early cancers—certainly more than the historic practice of not evaluating these lesions at all. No additional studies evaluating nonsuspicious lesions could possibly change that conclusion.
The use of OralCDx as the first line of defense against oral cancer already has occurred in the evaluation of close to 500,000 oral lesions, which in turn has resulted in the referral of tens of thousands of patients for follow-up scalpel biopsies. Without OralCDx, these patients with dysplasia would have remained without a diagnosis until the cancer was at a more advanced stage. Is there really anything more important to dentists and their patients than achieving this potentially life-saving result?
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