Evaluation of lactate dehydrogenase activity as an index of cervical malignancy

The diagnostic accuracy of an investigational test for cervix cancer screening is studied. The method involves a vaginal tampon that changes colour in relation to LDH activity and can detect preinvasive and invasive cervical lesions. The test was applied in 50 women with CIN, 50 women with histologically proved cervical cancer and in 500 women with no history of malignancy. The test was positive in 54% of CINs and 86% of cervix cancer patients, while it was not specific in 16% and 4% respectively. Among 268 healthy controls the test results were negative in 77.99% and false positive in 12.31%. The test can be performed any day of the menstrual cycle apart from the time of menstruation. It can also be performed, without any serious problem of misinterpretation in women suffering from myomas, vaginal relaxation or menstrual disorders. On the contrary, the test should be avoided if vaginitis or cervicitis are present, since false positive conclusions might be drawn. The test results suggest that the sensitivity of this method was 77% and the specificity 86% if we exclude the benign conditions that influence or possibly influence the colour indication of the tampon.