For the Oral Maxillofacial Surgeon: Frequently Asked Questions about OralCDx

Q: What is OralCDx indicated for and is it a substitute for a scalpel biopsy?

A: OralCDx, the transepithelial oral brush biopsy with computer-assisted analysis, is used to test common, harmless-appearing, small white and red spots to determine if they are dysplastic. These small, subtle lesions would not be selected and referred for a scalpel biopsy and instead, would be “watched”. OralCDx is not intended to evaluate suspicious oral lesions that would otherwise be referred for an immediate scalpel biopsy. OralCDx is not competitive with the scalpel biopsy but enhances its frequency and utility in detecting early, treatable disease.

Q: ” How accurate is OralCDx?

A: OralCDx was recently referenced by the National Cancer Institute and has been the subject of well controlled, randomized, clinical trials. In every study in which the same lesion was simultaneously tested with both a brush and scalpel biopsy, OralCDx was shown to have a sensitivity and specificity well over 90%. Within statistical significance, the sensitivity of OralCDx for the detection of dysplasia and carcinoma is approximately equal to that of the scalpel biopsy. In addition, the positive and negative predictive values of OralCDx have been repeatedly shown in published studies to be substantially greater than other accepted life-saving tests such as the Pap smear, mammogram, or PSA.

Q: If OralCDx and scalpel biopsies have approximately equal sensitivity, what is
the particular advantage of each test?  Why are abnormal OralCDx results
followed by a scalpel biopsy?

A: Because of its less invasive nature, OralCDx is more likely to be used on lesions that would have not have been subjected to immediate biopsy. When the OralCDx test result is abnormal, a scalpel biopsy is then performed to provide additional information regarding the nature and degree of the abnormality that the brush biopsy found. Specifically, the degree of dysplasia or carcinoma can only be provided with a scalpel biopsy. Thus while the brush biopsy and scalpel biopsy have about the same sensitivity, the scalpel biopsy is more specific than the brush biopsy. 

Q: Dentists refer me patients with abnormal OralCDx results and when I do a scalpel biopsy, they often are negative. Are these false positives?

A:  No. About 15% of all OralCDx cases will be “atypical” but that does not mean that that these patients all have precancer or cancer. In fact, most patients with an “atypical” brush biopsy will prove, on scalpel biopsy, to have a benign process, and only about a third will have dysplasia. This one third value has now been confirmed in 5 published studies. With those numbers in mind, consider the following:
 
A dentist with 100 harmless looking oral lesions that would not warrant a scalpel biopsy tests them with OralCDx. About 15 will be “atypical” and referred to you for a scalpel biopsy. Of these, approximately 3 will prove on scalpel biopsy to be dysplastic and 12 will be negative. Does that mean the 12 cases were false positives? No, because without OralCDx, all 100 patients would have required scalpel biopsy to find the 3 precancers and then you would have performed 97 scalpel biopsies which were negative. With OralCDx, only 15 patients required scalpel biopsy. Similarly, the vast majority of scalpel biopsies you perform on highly suspicious lesions prove to be negative and only few will prove to be dysplastic or cancer.

Q: Should I perform a scalpel biopsy on every patient with an “atypical” or “positive” OralCDx result?

A: For “positive” OralCDx results – definitely since almost always, these will prove to be dysplastic or cancer. For “atypical” OralCDx results, it depends on the case. If the lesion looks red and inflammatory or benign and the patient is reliable, you can have the patient return after a short observation period and if the lesion persists, retest it with OralCDx or perform a scalpel biopsy. On the other hand, if the “atypical” lesion is a bit worrisome clinically or if it is a white lesion which usually persists, than you should not delay a scalpel biopsy.

Q: Are there certain lesions that are more difficult to test with OralCDx?

A: Yes, very thick white lesions or those on keratinized tissues such as the hard palate and attached gingiva require many more rotations with the brush and firmer pressure to obtain a good sample. Pinpoint bleeding is a good indication that the brush has penetrated through all layers of the lesion. Ulcerations should be brushed at the periphery to ensure that the sample is adequate. 

Q: How can OralCDx help prevent oral cancer in patients?

A: Consider the role of the cervical Pap smear in gynecology: In 1950, cervical cancer was the leading cause of cancer death in American women. Between 1955 and 1992, the incidence of cervical cancer in the US declined by 74%, and it now ranks 14th in frequency.  The reason for this precipitous drop was that gynecologists stopped waiting for their patients to present with “suspicious” symptoms (such as inter-period bleeding) that trigger a scalpel biopsy. They instead started to use the cervical Pap smear to detect dysplasia, years before they could transform into cancer and cause those suspicious symptoms.

OralCDx is a test that identifies dysplasia in common spots that do not have suspicious clinical features – years before dysplasia could become a problem. These are spots that general dentists do not suspect contain abnormal cells. Just like the Pap smear helps to prevent cervical cancer by detecting cervical dysplasia and colonoscopy is widely being advertised in TV ads as a method of preventing colon cancer by detecting abnormal polyps, OralCDx can now help prevent oral cancer by detecting oral dysplasia.

Q: Are there additional indications for OralCDx for the OMS?

A: 1) OralCDx can be utilized on patients referred by the general dentist with a lesion that appears entirely innocuous and which, in your clinical judgment, does not warrant a scalpel biopsy. It allays the fears of the patient and provides the referring dentist assurance that the lesion was tested to rule out dysplasia.

2) Within a given lesion, dysplastic changes are often multi-centric with normal epithelium intervening between areas of dysplasia. Incisional biopsy samples, therefore, may not be representative of the true nature of the lesion. OralCDx offers a noninvasive method of sampling large portions of a lesion.

3) OralCDx may be employed as a method of long-term surveillance of persistent or multiple areas of leukoplakia. OralCDx is a noninvasive method of evaluating these lesions and alerts the surgeon when tissue is required for histologic sampling.

5) OralCDx may be used for patients with lesions who refuse a surgical biopsy or to when a surgical biopsy is contraindicated because of poor health or inability to safely perform the procedure.

Q: Is OralCDx similar to “adjunctive oral cancer visualization aids” that are currently being marketed? 

A: No. OralCDx is a “test.” There are only two tests for oral dysplasia and cancer, the brush biopsy and the scalpel biopsy. This is because these are the only two methods that have a demonstrated sensitivity and specificity to the detection of these abnormalities.

Performing a thorough soft tissue exam using a standard white examination light, and then using either a brush biopsy or a scalpel biopsy to test any unexplained tissue changes that are observed, is the only way to know that you are not missing a precancerous or cancerous abnormality in your patients.

Q: How can I obtain more information and training?

A: Training in the use of OralCDx is provided with two free CE credits through the American Dental Association CE Online (www.adaceonline.org).  Additional patient brochures, oral lesion education guides, and waiting room display materials are available from the American Dental Association. Test kits for OralCDx are available from most dental distributors. To learn more, logon to www.oralcdx.com.