Cervical acid phosphatase: A new biomarker of cervical dysplasia

• Main Authors: Marković Olivera, Marković Nenad
• Format: Article
• Language: English
• Published: Institute of Oncology, Sremska Kamenica, Serbia 2003-01-01
• Series: Archive of Oncology
• Subjects: cervix dysplasia; colposcopy; acid phosphatase; biological markers; cervix neoplasms; vaginal smears
• Online Access: http://www.doiserbia.nb.rs/img/doi/0354-7310/2003/0354-73100304243M.pdf

BACKGROUND: Cervical acid phosphatase (CAP) has recently been described as a biomarker labeling abnormal squamous cells on Pap smears (USPTO #6,143,512). The enzyme activity is presented as a red, granular deposit on a modified Papanicolaou background. This unique property was utilized for development of a test and tools intended for cervical cancer screening. METHODS: We conducted a multicenter, random assignment, assessor blinded, 2-group (test and control), and split-sample design clinical trial on 1,500 subject/specimens to assess safety and efficacy of the new test in comparison with the control for cervical cancer screening in standard Pap test environment. Safety was measured with frequency, severity and relation of adverse events. Efficacy was measured with primary endpoints (portion of positive/abnormal specimens detected, and the false negative rate), and with accuracy (sensitivity/specificity) and predictive values as secondary efficacy endpoints. RESULTS: In March 2003, the recruitment was completed and the first thousand cases were evaluated. There were no serious or related adverse events in both groups. Minor, unrelated adverse events were rare and insignificantly distributed in both groups. Primary endpoints: A Portion of positive/abnormal specimens detected: Pe (new test) = 0.17, Ps (pap test): 0.082; Ps' (American standard): 0.07. Pe >=Ps + beta, for beta = 0.5Ps. B. False negative rate: Pe = 0.05, Ps' = 0.10. Test sensitivity 0.81, specificity: 0.97, PPV: 0.83, NPV: 0.96. Chi-square between test and controls 40.69101 was greater than the critical value of 3.841 (p<0.05). CONCLUSION: We concluded that CAP had added to visibility of Pap test and has enabled cytoscreeners to significantly improve detection of positive/abnormal specimens and reduce false negative rate.