METHODS: Two villages were selected as the sampling frame based on prevalence of tobacco and betel quid chewing habit. Respondents were asked to check their mouth for presence of lesion or abnormalities. Education on oral cancer, including MSE, was provided. Subsequently, respondents were asked to perform MSE. Finally, a clinical oral examination (COE) was done by a specialist and the presence of oral mucosal lesions was recorded.
RESULTS: Almost 64.5 percent of respondents exhibited high levels of difficulty and low mucosal visualization and retracting ability, whereas 3.0 percent demonstrated high attention level when performing MSE. Prevalence of oral mucosal lesions was 59.0 percent, whereas the prevalence of oral potentially malignant disorders (OPMDs) was 9.0 percent. Detection of oral lesions by respondents using MSE was lower than detection by the gold standard. Sensitivity and specificity of MSE for detection of all types of lesions were 8.6 and 95.0 percent respectively. When analyzing each lesion type separately, MSE was found to be most sensitive in detection of swellings (10.0 percent), and most specific in identifying white lesions (97.8 percent). For detection of OPMDs, although specificity was high (98.9 percent), sensitivity (0 percent), and +LR (0) was poor.
CONCLUSION: MSE is not an effective self-screening tool for early detection of potentially malignant lesions for this population.
METHODS: Detailed, retrospective clinico-pathological analysis of potentially malignant lesions undergoing malignant transformation, from a 590 patient cohort treated by interventional laser surgery and followed for a mean of 7.3 years, was undertaken. Clinical outcome was documented at study census date (31 December 2014).
RESULTS: A total of 99 patients (16.8%) developed cancer: 71 (12%) seen "unexpectedly" upon excision and 28 (4.8%) progressing to malignancy at a median of 87.3 months post-surgery. Thirty "unexpected" excisions were micro-invasive (42.3%) arising primarily in severely dysplastic precursors (75%) at ventro-lateral tongue and floor of mouth sites (54.5%); 1 patient (1.4%) had a cancer-related death, whilst 58 (81.7%) were disease free. A total of 19 of 28 "progressive" cancers (67.9%) arose at new sites, with erythroleukoplakia a significant predictor of malignancy (P = .0019). Nine (32.1%) developed at the same precursor site, with 6 (77.7%) on the ventro-lateral tongue and floor of mouth. Three (10.7%) were micro-invasive, 9 patients (32.1%) died from metastatic disease and 12 (42.9%) were disease free (P < .001).
CONCLUSION: Squamous carcinoma may arise at the site of a precursor lesion as transformation or new-site development via field cancerisation. Whilst interventional surgery facilitates early diagnosis and treatment of occult disease, thus reducing risk from same-site transformation, new-site cancer is a significant long-term risk for patients with potentially malignant disorder.