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New Global Approaches to Cervical Cancer Prevention

New Global Approaches to Cervical Cancer Prevention. Dr Martha Jacob FRCOG, MPH EngenderHealth March 2004. Funded by Bill & Melinda Gates Foundation. Barriers to Cervical Cancer Prevention. Early Detections Services – Unavailable, Unreliable Treatment of Precancer Inaccessible

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New Global Approaches to Cervical Cancer Prevention

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  1. New Global Approaches to Cervical Cancer Prevention Dr Martha Jacob FRCOG, MPH EngenderHealth March 2004 Funded by Bill & Melinda Gates Foundation

  2. Barriers to Cervical Cancer Prevention • Early Detections Services – Unavailable, Unreliable • Treatment of Precancer • Inaccessible • Inappropriate • Inadequate follow up of women needing treatment • Lack of monitoring & evaluation, corrective action & improve program performance • Failure to reach target age group • Limited awareness of cervical cancer as a health problem, lack of a policy, lack of political will

  3. Women’s perspectives • Medical profile • Sociocultural and gender influences • Community outreach • Education WOMEN TECHNOLOGY SERVICE • Policies, program structure, management • Availability and accessibility • Quality of services • Health Information Systems • Referrals • Qualified providers • Efficacy • Safety • Procedures & supplies • Labs (including quality control) • Costs • Acceptability Adapted from Simmons et al. The Strategic Approach to Contraceptive Introduction. Studies in Family Planning 28:79-94. 1997

  4. WOMEN TECHNOLOGY SERVICES SCREENING TESTS FOR CERVICAL NEOPLASIA Cytology- Conventional method • Time tested method • Organized programs, periodic re-screening • Unable to achieve consistently high sensitivity and specificity in many settings • Resource intensive: laboratory, consumables, personnel, quality assurance • Programmatic issues

  5. Visual inspection with acetic acid (VIA) 3-5% Acetic Acid (Vinegar) Abnormal epithelium transiently turns white ‘ACETO- WHITE ’ Visual inspection with Lugol’s iodine (VILI) Normal epithelium take up iodine stain and appears mahogany brown Abnormal epithelium not stained and appears yellow. Alternate Screening Tests Immediate results Minimal requirements Subjective - Needs standardized definitions - Regular quality assurance

  6. Cervix with ACETO-WHITE lesion NORMAL CERVIX VIA images Source: EngenderHealth, Wright TC, 1996

  7. HPV testing Detect High Risk HPV types Sample from cervix- similar to PAP Special transport medium Processed in the lab Rapid turn around of results HPV Alternate Screening Tests - contd Objective tests Expensive

  8. WOMEN TECHNOLOGY SERVICES Alternate Screening Tests *For detecting HSIL. Source Personal Communication IARC 2004 Long term impact yet to be evaluated

  9. Screening Abnormality No abnormality Colposcopy & Biopsy No lesion Lesion Reassure Advise on Rescreen Treatment Post treatment FU Traditional Approach:Screen, Diagnosis & Treat *

  10. Colposcopy & Biopsy • Diagnosis – Cytology, Colposcopy and Histology are complementary • Sensitivity 87 to 99% Specificity 23-87% (Mitchell 98) • High sensitivity for high grade lesions, • Less accurate for differentiating metaplasia versus low grade lesions. • Intensive training and sophisticated equipment required.

  11. Ablative Methods Cryosurgery. Diathermy Cold Coagulation. Laser ablation Excision Methods Loop Electrosurgical Excision Procedure (LEEP). Laser Cone. Cold Knife Cone Methods of treatment for Pre Cancer • Decision on treatment modality • Exclusion of invasive lesion • Training and experience of the provider • Availability of resources • Clinical value of method for the patient • Preference of the patient *

  12. Cochrane 2002 Conclusions • No overwhelmingly superior technique to treat cervical intraepithelial neoplasia (CIN) • Cryotherapy viable alternative in limited resource settings • easy to use, • relatively cheap, • associated with lowest morbidity.

  13. Treatment Options Low = < $500; Moderate = $500-$1500; High = > $1500 1 Loop electrosurgical excision procedure 2 Requires use of operating room lighting and equipment JHPIEGO 2003

  14. Strengths Cure rate 85-95% Lowest morbidity Limitations Low cure rate (70 to 90%) related to lesion size, possibly grade and location Confirming the exact nature of lesion not possible Difficult to determine the amount of tissue destroyed Source JHPIEGO Cryotherapy Freezing abnormal tissue CO2 or N2O Single Freeze or Double Freeze Source for Cure rates ACCP review & Cochrane 02

  15. Strengths Cure rate 91-98%(Cochrane 02) Reliable histology specimen with least morbidity. Limitations Pathologic margins often involved and more difficult to interpret Requires intensive training More sophisticated equipment Source PATH Source- Singer & Monaghan LEEP Excise with thin wire loop Cauterize base

  16. Cold Knife Cone Replaced by less invasive excisional or ablative out- patient procedures Excision of wide and deep cervical cones using a surgical knife Cure rate 90-94% (Cochrane 02) Hysterectomy Unacceptable as primary treatment

  17. Screening Abnormality No abnormality Colposcopy & Biopsy No lesion Lesion Reassure Advise on Rescreen Treatment Post treatment FU Traditional Approach: Screen, Diagnosis & Treat *

  18. Screen Test Negative Test Positive Treatment Reassure Advise on Rescreen Post treatment FU Alternate Approach :SCREEN & TREAT *

  19. Reduce the number of steps VIA > Cryotherapy HPV test> Cryotherapy VILI> Cryotherapy Reduce the lost to FU Treatment Single Visit Approach Multiple (2) Visit Approach Increase Availability, Accessibility & Utilization Primary Care –mid level providers Static & Mobile (Outreach) Integrated & Vertical Over treatment Safety Critical concern Under treatment Miss disease Treatment procedure fails Feasibility Acceptability Alternate Approach: Screen & Treat

  20. Screen & Treat Midlevel providers trained to level of competence • Counsel • Screen • Select • Cryotherapy – Double Freeze • Post Treatment Follow Up

  21. Safety: Screen & Treat Screen & Treat performed by Mid level providers • Major Complications 2 cases ( ~6000 procedures) • Minor Complications ~2-4% Safety of cryotherapy for HIV-seroconversion needs further evaluation.

  22. Effectiveness: Screen & Treat Three arm RCT (South Africa) comparing the safety and efficacy of screening (using VIA or HPV test) followed by cryotherapy by mid level providers in reducing the burden of high-grade cervical cancer precursors. ACCP strict selection criteria for cryotherapy • Not suspicious of cancer & • All edges are fully visible with no extension into endocervix beyond cryoprobe. Cryotherapy can be used to treat large proportion of women with positive screening tests.

  23. WOMEN SERVICES TECHNOLOGY Feasibility: Screen & Treat • Primary care facilities • Static • Clinical Outreach (Mobile) • Integrated or Vertical

  24. WOMEN SERVICES TECHNOLOGY Feasibility : Screen & Treat Number of visits • Single visit- Avoids attrition due to lost to FU • Multiple visit- Requires well organized tracking system

  25. WOMEN SERVICES TECHNOLOGY Feasibility : Screen & Treat Reliable supply of refrigerant is crucial • Identify and rely on local suppliers Machines break • Repair & Maintenance (RAM) Services by creating local capacity for common repairs

  26. WOMEN TECHNOLOGY SERVICES Acceptability: Screen & Treat • Satisfied & would recommend to others (95- 99%) • Testing & Treating experience equal to or better than expected (95%) • At 3 months 97% had recommended to others. Source RTCOG & JHPIEGO 2003

  27. Cost-Effectiveness of Screening Strategies Source: Goldie, et al. Policy Analysis of Cervical Cancer Screening Strategies in Low-Resource Settings. Journal of the American Medical Association 2001;285:3107-3115.

  28. Future in Cervical Cancer Prevention VACCINES • Prophylactic Vaccines • Therapeutic Vaccines Combination of screening & Immunization

  29. Conclusions-1 • In countries where infrastructure and quality assurance requirements are consistently met, cytology-based programs can be implemented effectively. • Screen-and-treat approach Safe Effective Feasible Acceptable • Range of trained and competent health providers including non physicians can perform screening tests and cryotherapy. • Screening tests and cryotherapy can be provided at all levels of facilities including primary care settings and integrated with general reproductive care services.

  30. Conclusions-2 HPV testing • HPV test characteristics better than visual tests and cytology • Technical and infrastructure requirements can make it difficult to implement VIA • The sensitivity of VIA is equivalent to or better than cytology; its specificity is lower • Can be implemented in a range of settings • Special attention to regular and consistent quality assurance is required due to its subjective nature VILI • VILI test characteristics may be better than VIA • Demands further research

  31. Thank you Funded by Bill & Melinda Gates Foundation

  32. Sensitivity: the proportion of individualscorrectly identified by the test as having disease. The higher the sensitivity, the fewer infections that will be missed (false negatives). • Specificity: the proportion of individualscorrectly identified by the test as NOT having disease. The higher the specificity, the fewer false positives there will be. The lower the specificity, the more over treatment there will be • Positive Predictive Value refers to the probability of having a disease given a test is positive. • Negative Predictive Value refers to the probability of NOT having a disease given a test is negative.

  33. Liquid based cytology • Merits of LBC debated • Compared to conventional cytology • No statistically significant differences in all diagnostic categories (WNL to HSIL) • Sensitivity & Specificity similar • Specimen adequacy superior • More expensive • Impact on cancer incidence and mortality and cost effectiveness yet to be established

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