Diagnostic yield of calcofluor white in the identification of Candida albicans in oral squamous cell carcinoma

BACKGROUND: Although oral cancer is multifactorial in origin only few had evaluated the diagnostic parameters for candidal infection in oral squamous cell carcinoma (OSCC). AIMS: To compare and assess the accuracy of Calcofluor White (CFW) to that of conventional staining methods to identify the presence of candidal infection in OSCC. METHODS: Archival collections of 43 OSCC were retrieved for this investigation. Standard staining protocol was followed for the index test (CFW) and reference standard (Periodic Acid Schiff). Two examiners were blinded for either one of the staining techniques. Diagnostic test evaluation and Kappa statistic was calculated using MedCalc software. RESULTS: The study comprised 37 males, six females, and their mean age at the time of presentation was 51 (range 23 to 75 years). The sensitivity and specificity of CFW was 75.8% (CI 57.7 to 88.9%) and 10.0% (CI 0.2 to 44.5%). While the positive predictive and negative predictive values were 63.1% (CI - 50.6-74.0%) and 67.0% (CI - 49.2-81.0%). CONCLUSION: Our results show minimal agreement with PAS with a Kappa score of 0.148 (95% CI = 0.39 to 0.09). Overall detection rate was similar for both the index test and reference standard although there was considerable number of intermediate test results. Sensitivity of CFW was comparable to that of earlier studies but specificity was low and the degree of concordance was 60.4%. Although CFW staining can come with high false positive they are a useful test for ruling out candida infection when the test result is negative.