Dental screening for oral cancer

[Guest]

Your second link is for another page of this patient support website. He discusses but provides neither links nor results of studies which have essentially nothing to do with the risks and benefits of oral cancer screening. Screening isn't helpful just because you have a gut feeling it should be helpful. If you're worried about oral cancer, don't smoke, chew tobacco, or drink too much, although if you smoke or drink, you have a lot of other big health worries which are much more important than a cancer which affects 0.1% of the male population (less in women). Sure, if you have a sore that doesn't heal, you should have it checked out, just as you should get checked out a sore which won't heal anywhere else on your body. As of this time, however, screening technologies are unproven and not recommended by independent panels of public health officials. Those are the facts.

[Cooper]

Screening isn't helpful just because you have a gut feeling it should be helpful.

To me, that statement sounds ludicrous. These aren't anyone's "gut feelings", these are the recommendations of dentists who routinely perform oral cancer screening during a dental examination. None of the inconclusive studies you cited suggest not having oral screening, not even the outdated 1999 Canadian report that you base your opinion on. What it does say is that "there is insufficient evidence to recommend inclusion or exclusion of screening for oral cancer". I'm a firm believer in hearing both sides of any argument as long as it's based on relative/current studies that supports opposing positions. The final decision as to whether or not to have oral cancer screening is ultimately that of the informed patient.

[rguer]

If you're a cocksucker (and therefore more likely to have HPV), especially one who smokes or is HIV+, your risk is higher than in the general population. The cost/benefit for the general population probably doesn't apply to you.

 

I have known about as many men with oral cancer as women with breast cancer. To me, it does not seem to be a particularly rare disease.

[Guest]

To me, that statement sounds ludicrous. These aren't anyone's "gut feelings", these are the recommendations of dentists who routinely perform oral cancer screening during a dental examination. None of the inconclusive studies you cited suggest not having oral screening, not even the outdated 1999 Canadian report that you base your opinion on. What it does say is that "there is insufficient evidence to recommend inclusion or exclusion of screening for oral cancer". I'm a firm believer in hearing both sides of any argument as long as it's based on relative/current studies that supports opposing positions. The final decision as to whether or not to have oral cancer screening is ultimately that of the informed patient.

 

You're displaying your complete lack of knowledge in the area of scientific studies and public health again. I haven't cited any studies. What I have cited are links to the latest conclusions drawn by the public health experts of the U.S. and Canada. Of course, those links do have references to the studies they used to base those conclusions. I suspect that the reason the Canadian Task Force hasn't updated its recommendations lately is because there are no new data to change these recommendations, but if you want more recent recommendations, you can look at those from the National Institutes of Health/National Cancer Institute:

http://www.cancer.gov/cancertopics/pdq/screening/oral/HealthProfessional/page1

These were written in 2012:

Benefits

There is inadequate evidence to establish whether screening would result in a decrease in mortality from oral cancer.

 

Magnitude of Effect: No evidence of benefit or harm.

 

Study Design: Evidence obtained from one randomized controlled trial.

Internal Validity: Poor.

Consistency: Not applicable (N/A).

External Validity: Poor.

 

The basis of their conclusions is on this page:

http://www.cancer.gov/cancertopics/pdq/screening/oral/HealthProfessional/page2

 

They evidence wasn't so good regarding the new adjunctive screening methods, either:

Adjunctive techniques to visual examination

Techniques such as toluidine blue staining, brush biopsy/cytology, or fluorescence imaging as the primary screening tool or as an adjunct for screening have not been shown to have superior sensitivity and specificity for visual examination alone or to yield better health outcomes.[11,21] In a RCT conducted in Keelung County, Taiwan, 7,975 individuals at high risk of oral cancer due to cigarette smoking or betel quid chewing were randomly assigned to receive a one-time oral cancer examination after gargling with toluidine blue or a blue placebo dye.[22] The positive test rates were 9.5% versus 8.3%, respectively, (P = .047). The detection of premalignant lesions was not statistically different (rate ratio = 1.05; 95% CI, 0.74–1.41). The number of overall oral cancers diagnosed within the short follow-up period of 5 years was too small for valid comparison (six in each group).

 

The operating characteristics of the various techniques used as an adjunct to oral visual examination are not well established. A systematic literature review of toluidine blue, a variety of other visualization adjuncts, and cytopathology in the screening setting revealed a very broad range of reported sensitivities, specificities, and positive predictive values when using biopsy confirmation as the gold standard outcome.[23] In part, this was due to varying study populations, sample size and settings, as well as criteria for positive-clinical examinations and for scoring a biopsy as positive.

 

Evidence of Harm Associated With Screening

Harms associated with screening for oral cancer are poorly studied in any quantifiable way.[17] However, there are some unavoidable harms that would be associated with routine screening, including:

 

Detection of cases that are already incurable, leading to increased morbidity.

Unnecessary treatment of lesions that would not have progressed (overdiagnosis).

Psychologic consequences of false-positive tests.[24]

An additional potential harm is misdiagnosis and resulting under- or over-treatment, given the subjective pathology judgments in reading biopsies of oral lesions. When 87 biopsy diagnoses of oral lesions were compared between 21 local pathologists and double-reading by two of three central pathologists in a multicenter study of patients with prior upper aerodigestive tract cancers, agreement was only fair-to-good (kappa weighted-statistic = 0.59; 95% CI, 0.45–0.72).[25] In a bivariate categorization of carcinoma in situ plus carcinoma versus less serious lesions, the agreement was poor, but with very wide CIs (kappa-statistic = 0.39; 95% CI, -0.12–0.97). The investigators in the same study analyzed an agreement between the local and central pathologists on clinically normal tissue adjacent to 67 biopsied clinically-suspicious lesions. The agreement on clinically normal tissue was better than for visibly abnormal lesions, but still not in the excellent range (kappa weighted-statistic = 0.75; 95% CI, 0.64–0.86).[26]

[Guest]

If you're a cocksucker (and therefore more likely to have HPV), especially one who smokes or is HIV+, your risk is higher than in the general population. The cost/benefit for the general population probably doesn't apply to you.

 

I have known about as many men with oral cancer as women with breast cancer. To me, it does not seem to be a particularly rare disease.

 

It's interesting that a quote from the website cited by Cooper demonstrates why those oral cancers caused by HPV aren't going to be found by your dentist's screenings--they're typically found at the base of the tongue or tonsils or back of the throat and would require a laryngoscope or mirrors placed in the back of the throat to be seen. And that's if they could be seen; HPV-associated oral cancers don't typically show the visible changes associated with the tobacco/alcohol-related oral cancers:

Another obstacle to early discovery (and resulting better outcomes) is the advent of a virus, HPV16, contributing more to the incidence rate of oral cancers, particularly in the posterior part of the mouth (the oropharynx, the tonsils, the base of tongue areas) which many times does not produce visible lesions or discolorations that have historically been the early warning signs of the disease process.

 

I have done thousands of pap smears, and found many cervical cancers (all caused by the same cancer-causing strains of HPV) in my career, but these were found due to cytological samplings, not due to visible changes. I takes a pathologist looking at cells in a microscope in order to detect cervical cancer early.

 

As for the comment about knowing as many men with oral cancer as women with breast cancer, I hope you meant that jokingly (or "tongue in cheek," so to speak), and not as serious evidence that our national statistics showing a 0.1% prevalence of oral cancers in men and 9% prevalence of breast cancers in women is incorrect. Or maybe you just know a whole lot of tobacco-chewing, liquor-guzzling cock-suckers and very, very few women?

[Cooper]

You're displaying your complete lack of knowledge in the area of scientific studies and public health again. I haven't cited any studies.

 

Seriously, you "haven't cited any studies"? I will, once again, disagree with you unless you are saying that the studies you referenced from the "Canadian Task Force" and the "USPSTF", and used to cite the following information, are not considered "studies".

 

You wrote, and I quote: "It's interesting to see that the Canadian Task Force specifically discourages it:

For population screening, there is fair evidence to specifically exclude screening for oral cancer (grade D recommendation). For opportunistic screening during periodic examinations, there is insufficient evidence to recommend inclusion or exclusion of screening for oral cancer (grade C recommendation).

http://www.cda-adc.ca/jcda/vol-65/issue-11/617.html"

 

In addition your also cited this study: "The U.S. Preventive Services Task Force (USPSTF) concludes that the evidence is insufficient to recommend for or against routinely screening adults for oral cancer.

Rating: I Recommendation.

Rationale: The USPSTF found no new good-quality evidence that screening for oral cancer leads to improved health outcomes for either high-risk adults (i.e., those over the age of 50 who use tobacco) or for average-risk adults in the general population. It is unlikely that controlled trials of screening for oral cancer will ever be conducted in the general population because of the very low incidence of oral cancer in the United States. There is also no new evidence for the harms of screening. As a result, the USPSTF could not determine the balance between benefits and harms of screening for oral cancer.

 

http://www.uspreventiveservicestaskf.../oralcanrs.htm"

 

In spite of your unnecessary and condescending remarks, I will state that I have read all the information provided in this thread and have found it to be most helpful in bringing a better awareness to oral cancer. Your contributions have been most appreciated.

 

Coop

[rguer]

I have done thousands of pap smears, and found many cervical cancers (all caused by the same cancer-causing strains of HPV) in my career, but these were found due to cytological samplings, not due to visible changes. I takes a pathologist looking at cells in a microscope in order to detect cervical cancer early.

 

And the examination of a throat swab by a pathologist would probably be substantially more expensive than a visual exam by a dentist, even with the advent of automated pap smears.

 

So there's no reasonable way to detect non-symptomatic HPV-related throat and mouth cancer?

 

As for the comment about knowing as many men with oral cancer as women with breast cancer, I hope you meant that jokingly (or "tongue in cheek," so to speak), and not as serious evidence that our national statistics showing a 0.1% prevalence of oral cancers in men and 9% prevalence of breast cancers in women is incorrect.

 

It says nothing about the general population, but I think it does say something about a specific subpopulation.

 

Or maybe you just know a whole lot of tobacco-chewing, liquor-guzzling cock-suckers and very, very few women?

 

I wouldn't say I know very, very few women, and I have never hung around in chawing circles, but yes, I do seem to know a lot of liquor-guzzling cock-suckers.

[Guest]

Seriously, you "haven't cited any studies"? I will, once again, disagree with you unless you are saying that the studies you referenced from the "Canadian Task Force" and the "USPSTF", and used to cite the following information, are not considered "studies".

 

 

Those are not studies. Those are consensus statements written by a group of this nation's (and Canada's) foremost public health experts, whose job it is to review all of the available data (of course, they did look at a number of studies, among other evidence. in order to arrive at their conclusions). It's these experts' job to go through all of the data and make recommendations based on facts rather than on emotion, intuition, or financial interest.