Diagnostic performance evaluation of lateral flow florescence immunoassay (LFIA)- based point-of-care platforms in the measurement of selected cancer makers; PSA, CEA and CA125

Abstract

Background: In Uganda, cancer diagnosis has been largely dependent on conventional methods such as histopathology. These methods although very accurate they however require specialized facilities with trained personnel which is very expensive of which it can only handle a few samples per day and have a long turn-around-time. These limitations have hindered their effective utility in facilities and call for the piloting of better diagnostic technologies. There is emerging use of point-of-care (PoC) test in health facilities. These LFIA-Point of care (PoC) platforms have the advantage of being very simple to use, robust, cost-effective, can generate results in real-time and do not require a specialized facility or a lot of prior processing of samples to be used. Despite these advantages that make them a suitable option for cancer diagnosis, these platforms need serious validation of their performance for the several parameters they measure before widespread use for the clinical management of patients. Objective: This study evaluated the performance of selected point-of-care platforms in measurement of selected cancer markers; PSA, CEA and CA125. Methods: Duplicate analysis of samples was performed on the Roche Cobas 6000 and Finecare and FluoroCare Point of Care device. Using the results of the Roche Cobas 6000 as a reference, the sensitivity, specificity and positive/negative predictive values and likelihood ratios were calculated using standard methods. Results: At the recommended cancer diagnostic cutoffs (CEA 6ng/L, PSA 4ng//L, and CA125, 35 unit/mL), the performance characteristics of Wondfo Finecare analyzer CEA test had a sensitivity of 95.12 % (95% CI 83.47 – 99.40) and Specificity 93.65% (95% CI 84.53 – 98.24). Positive and Negative predictive values were 90.69% (95% CI 79.01 – 96.18) and 96.72% (95% CI 88.41 – 99.13) respectively. The Wondfor Finecare PSA test on the other hand had a sensitivity of 95.24 % (95% CI 83.84 – 99.42) and specificity of 88.46% (95% CI 76.56 – 95.65). Positive and negative predictive values were 88.92% (95% CI 75.74 – 93.40) and 95.85% (95% CI 85.60 – 98.90) respectively. The FluoreCare CA125 test had a sensitivity of 92.50 % (95% CI 79.61 – 98.43), with a specificity of 72.46% (95% CI 60.38 – 82.54). Positive and negative predictive values were 69.13% (95% CI 60.19 – 76.75) and 93.55% (95% CI 82.86 - 97) respectively Conclusion: Wondfo Finecare PoC had a high sensitivity of for both serum CEA and PSA 95.24% and 95.12% and high specificity of 93.65 on CEA but a low of 88.46 on serum PSA. This means that Wondfo Finecare can be used as both a confirmatory test and as well as a screening test. Fluorecare for serum CA125 can be used as a screening test but not as a confirmatory test for ovarian cancer because a high sensitivity of 92.5% and low specificity of 72.46%.