Frequently Asked Questions
1. What is the biomarker?
MarkPap Test processed cervical specimen (CAP + Pap) is a biomarker for decision making whether to continue with gynecological diagnostic procedures, including HPV testing, colposcopy/biopsy/histology, and the follow-up therapy with surgery. Its role in the control of HPV vaccination is under consideration.
2. Is Cervical Acid Phosphatase (CAP) a biomarker?
Yes, CAP is a specific indicator of cervical cell abnormality. It is the main, but not a single cytological sign of cervical dysplasia. It is exclusively present in abnormal squamous cervical cells and indicates an abnormal condition. CAP, as a biomarker, is entirely negative in normal squamous cells obtained from upper epithelial layers (Pap smear).
3. Is CAP specific for any pathological condition?
Yes, CAP is specific for all conditions classified by 2001 BS in diagnostic categories ASC-US and above.
4. Are any other cells in the specimen CAP positive?
Histiocytes and endocervical cells, which are morphologically distinct from squamous cells, are positive and serve as positive control for processing adequacy.
5. What is the percent of false positive normal squamous cells?
Close to none. Above 99.99% are negative.
6. What is the percent of false negative abnormal squamous cells?
Close to none. Above 99.98% are positive.
7. What is the meaning of FN and FP rates found in clinical trials?
These are rates of the Diagnostic Accuracy and depend upon the human examiners (specimen screeners), not the method.
8. What is the Diagnostic Accuracy of MarkPap test compared with predicate IVDD for cervical cancer screening?
Better sensitivity, equivalent specificity, if Adjudicated Cytological Truth is used as "gold" standard, and a dramatic reduction of false negative results.
9. Where we can see the original data from clinical trials?
Web site: http://www.bioscicon.com/publications.
10. CAP is present in the cytoplasm. Is this obscuring the visibility of nuclear changes?
Only on rare individual cells that should not interfere with the pathologist's decision. However, there is a destaining option to remove the marker. In our experience, there was no need to apply destaining on 2,500 specimens.
11. Is CAP present in other tissues?
No, CAP is specific for cervical epithelial tissue.
12. CAP is a member of acid phosphatase family present in many tissues. What is the specificity?
Different iso-enzyme profiles are present in different cells, e.g., tartrate-resistant acid phosphatase in hairy cell leukemia. CAP follows a unique maturation and differentiation pattern resulting in a reduction of enzyme activity along it.
13. In which tissue acid phosphatase plays similar role?
- Prostate acid phosphatase (PAP) in prostaitc cancer
- Tartrate resistant acid phosphatase in hairy cell leukemia
- Serum acid phosphatase in bone resorption caused by cancer
- Breast cancer indicating difference between IDC and ISDC
- Megakaryocytes/platelets system
14. Could CAP be used on cervical tissues?
Yes, but not for screening purposes.
15. Could CAP be used without PAP (Papanicolaou staining)?
Yes, but this will not be Pap test anymore.
16. What is the stability of MarkPap slides?
Several months for fixed, not processed smears. Beyond five years for processed and mounted slides.
17. What is the stability of specimens in MarkPap solution?
At least two months at room temperature. Longer stability if refrigerated or frozen.
18. How CAP can detect HPV infection?
CAP is positive in proliferating koilocytes which are known to be HPV infected cells. Degenerative koilocytes are CAP (-).
Koilocytes are abnormal (dysplastic) squamous cells found in HPV induced cervical lesions (warts, CIN and cancer) characterized by cytoplasmic and nuclear signs such as micro-vacuolization and formation of cavities (Gr. koilos - hollow) in cytoplasm, and/or karyopyknosis (shrinkage), karyorhexis (fragmentation), karyolysis (dissolution) or binucleation of the nuclei. CAP could be positive in cells with all and each of these cytological signs of dysplasia. See examples on Gallery 2 page.
19. Could CAP distinguish between HPV types?
No, but CAP positive koilocytes could be an early indication for the need of HPV DNA/RNA testing. MarkPap test could become a pre-HPV screening.
Clinical Trials of MarkPap® System for cervical cancer screening
At present, MarkPap® Research Kit is available in the US for research purposes only
MarkPap LLC is recruiting potential clinical sites, laboratory sites and contract research organizations for conducting a large clinical trial (10,000 subject/specimens) required to support an application to the Food and Drug Administration (FDA) for Pre-Marketing Approval (PMA) of BioSciCon's MarkPap® Test Kit (manufactured by Ricca Chemical Company, Arlington, TX).
Conditions required for clinical sites
- Colposcopy clinics servicing Pap test positive patients. Required minimal frequency of colposcopies: 20/day, 100/week/ 400/month.
- Ob/GY offices providing Pap test examination (conventional and liquid-based) for general population. Required frequency of Pap test specimen sampling: 5/day, 20/week, 80/month.
- GP offices accredited for providing Pap test to general population. Required frequency of Pap test specimen sampling: 1/day, 5/week, 20/month.
Conditions required for laboratory sites
- Cytopathology laboratory
- Cytopathology unit in a Clinical Pathology laboratory
- Cytopathology unit in Hospital Department of Pathology
Requirements per unit
- Accreditation for providing Pap test staining and interpretation
- At least 10,000 Pap tests per year
- At least 2 cytotechnologists with passing grade on the last proficiency testing
- At least one pathologist/cytopathologist for signing-out reports
- A standing interest to install and use a digital image capturing and forwarding unit
Conditions required for Contract Research Organization (CRO)
- Ability to organize within three months a study that will include at least 50 clinical sites, three laboratory sites, and one research site, which will be able to recruit 10,000 subjects within three months, obtain 10,000 specimens, split them onto two slide/samples, stain specimens with the standard Papanicolaou staining and with the MarkPap test, screen stained specimens by 2001 Bethesda System terminology and by MarkPap version of 2001 BS, organize independent rescreening of all (10,000) control slides by a panel of experts (to be used as Adjudication Cytology Truth, or "gold" standard), to report back the results from Pap test to specimen providers, to report research results to the research site, and to provide detailed paper evidence for the conduct of the study during a period of six months.
- Ability to use electronic systems for recording activity and reporting results to the sponsor's study monitoring team.
- Option: Ability to prepare documents necessary for the sponsor to submit a PMA application to FDA within three months from the end of the study.
- Priority will be given to CRO that will be able and will wish to invest in this development for a proper return.
Interested people should contact MarkPap LLC via e-mail: email@example.com.
Drs. Markovic's new book "What every woman should know about cervical cancer" has been published by Springer, 2008. Please visit Press Release page on this web site.