Oral cancer has been growing at an alarming rate with new cases annually exceeding 640,000 worldwide, two-thirds of which occur in developing countries. In India, it is the most common form of cancer and of cancer-related deaths in men (83,000 new cases and 46,000 deaths yearly), the study authors noted. The Indian state of Kerala, where the study was conducted, records a notably high incidence of oral cancer: 20.9% for males and 12.6% for females.
"Visual screening for oral cancer is easy, effective, and cheap -- it only takes five minutes to save a life," the researchers noted.
“It only takes five minutes to save a life.”
Their objective was to create a simple screening tool to detect oral premalignancies in a general healthcare setting and validate its diagnostic accuracy using a dentist's examination as the gold standard.
"Due to the varied clinical presentation of early lesions, many cases are missed at the general healthcare setting," the researchers pointed out. "If these cases could be picked up at their early asymptomatic stage, better preventive strategies can be instituted, before they progress to advanced malignancies."
They developed the Screening Tool for Oral Premalignancies (STOP) as a way to detect these premalignancies in such settings without the need for much training. The tool uses scores listed on a sheet of paper to detect four oral premalignancies: white lesions, white lesions with ulcers, mucosal change, and persistent ulcers. It also uses color coding to illustrate risk, ranging from green to red, highlighting the severity of the stage.
The connecting thread
Oral epithelial dysplasia (OED) is a histopathologic marker of malignant potential in oral premalignancies. Currently, oral premalignancies have been evaluated as separate, individual disorders, but they need to be incorporated under a common umbrella, with OED as the connecting thread, according to the study authors.
Clinical examinations have been found to be more effective in detecting OED than staining with toluidine blue, they added.
The study was conducted for one month beginning in September 2006 using patients age 18 years and older who were treated in the dental department at a general hospital in Thiruvananthapuram, the capital of Kerala. The study used 255 patients (mean age = 43 years), including 59 who had been identified by dentists as having oral premalignancies.
Dental students used STOP during an oral examination of the patients who were subsequently evaluated by a dentist.
Of the 255 patients, 135 presented with oral symptoms; the most common were changes in appearance, oral burning, and irritation. Oral premalignancies (n = 59) were higher among males, since alcohol consumption and smoking are more prevalent in this group, according to the study authors. Among the patients with oral premalignancies, 58% were smokers, 60% chewed tobacco, and 41% drank alcohol.
Almost three-quarters of the participants (71%) who had white lesions were smokers, and 88% of those who showed mucosal change chewed tobacco.
Simple scoring method
The researchers found that a score of 4 on the screening tool's list -- the highest possible score indicating the presence of all four features (white lesions, white lesions with ulcers, mucosal change, and persistent ulcers) -- had 96.6% sensitivity and 99% specificity, compared with scores of individual items.
Notably, the screening tool's positive predictive value was 96.6%, the negative predictive value was 99.9%, and it had a reliability coefficient of 0.874.
The researchers recommended that a large prospective study should be done to refine the tool. They also suggest a new nomenclature -- Mucosal Disorders with Oral Epithelial Dysplasia risk (MD-OEDr) -- to decode OED in clinical terms with risk alert for clinical severity and complementing histopathology diagnosis in relevant cases.
"STOP is recommended for opportunistic screening in the busy general healthcare setting, and staging can give a clinical severity risk alert for patients and doctors which can be used for prevention and subsequent management," they concluded. "It is simple and short and can be administered by general dental surgeons to detect a wide variety of oral premalignancies."
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