CHAPTER 4: SCREENING FOR CERVICAL CANCER

More documents

Recommendations

Info

96Chapter 4: Screening for Cervical Cancer4Chapter 4: Screening for Cervical CancerProvidersHPV DNA testing can be done by trained providers at any level of the health caresystem, provided that there is an appropriate laboratory within a reasonable distance,and that reliable transport is available for specimens. Clinic needs for HPV testing arethe same as for Pap smears and visual methods.IndicationsHPV is not generally used on its own as the primary screening test. It is mainly used incombination with cytology to improve the sensitivity of the screening or as a triage toolto assess which women with borderline Pap results need to be referred for colposcopy.The main indication is a Pap result of “atypical cells of undetermined significance”(ASC-US). Of the women with this lesion, only those who test positive for high-risk HPVwill need to be referred for colposcopy and biopsy, significantly reducing the number ofcolposcopies.Laboratory facilitiesThe HPV laboratory requires a special clean room to avoid contamination, and highlytrained technicians. It also requires equipment and reagents as specified by themanufacturers of the test.RECOMMENDATIONHPV DNA tests as primary screening methods, at this time, are recommended foruse only in pilot projects or other closely monitored settings. They can be used inconjunction with cytological or other screening tests, where sufficient resourcesexist. HPV DNA-based screening should not begin before 30 years of age.Visual methodsTwo visual methods are available:• visual inspection with acetic acid (VIA);• visual inspection with Lugol’s iodine (VILI).PS10VIA and VILIAbnormalities are identified by inspection of the cervix without magnification, afterapplication of dilute acetic acid (vinegar) (in VIA) or Lugol’s iodine (in VILI). When vinegaris applied to abnormal cervical tissue, it temporarily turns white (acetowhite) allowingthe provider to make an immediate assessment of a positive (abnormal) or negative
Chapter 4: Screening for Cervical Cancer 97(normal) result. If iodine is applied to the cervix, precancerous and cancerous lesionsappear well-defined, thick, and mustard or saffron-yellow in colour, while squamousepithelium stains brown or black, and columnar epithelium retains its normal pinkcolour.Because they do not rely on laboratory services, VIA and VILI are promising alternativesto cytology where resources are limited. They are currently being tested in large,cross-sectional, randomized controlled trials in developing countries. Until data fromthese studies are available, VIA and VILI are recommended by WHO only for use inpilot settings, because the impact on cervical cancer incidence and mortality is stillunproven. In research settings, VIA has been shown to have an average sensitivity fordetection of precancer and cancer of almost 77%, and a range of 56% to 94%.The specificity ranges from 74% to 94% with an average of 86%. Low-levelmagnification does not improve the performance of VIA over and above that of nakedeye visualization. One study has shown that VILI can detect 92% of women withprecancer or cancer, a sensitivity considerably higher than that of either VIA or cytology.Its ability to identify women without disease is similar to that of VIA (85%), and lowerthan that of Pap smears. One study showed that VILI had a higher reproducibility thanVIA. VIA and VILI can be performed in clinics and other outpatient facilities. They areboth short procedures and cause no pain. Assessment is immediate, and no specimenis required.4Chapter 4: Screening for Cervical CancerAdvantages• VIA and VILI are relatively simple and can be taught to nurses, nurse-midwives andother health workers.• Assessment is immediate and no transport, or laboratory equipment or personnel, isneeded.• The tests are likely to be less costly than other approaches in routine use.• Results are available immediately, eliminating the need for multiple visits in mostcases, and reducing loss to follow-up.• They could potentially be used in an approach based on screening and treatingwomen in a single visit (see Chapter 5).Disadvantages• Because of the low positive predictive value of the test (see Annex3), a considerable number of women who test positive do nothave disease, resulting in excessive diagnosis and treatment, andunnecessary anxiety.• Visual tests cannot be relied on in postmenopausal women, because thetransformation zone of these women is often inside the cervical canal.Annex3Annex 3
Page 1: 794CHAPTER 4: SCREENING FOR CERVICA
Page 4 and 5: 82Chapter 4: Screening for Cervical
Page 22 and 23: 100Chapter 4: Screening for Cervica
Page 28 and 29: 106
Page 30 and 31: 108 PS 6: Obtaining Informed Consen
Page 32 and 33: 110PS 7: Taking a History and Perfo
Page 38 and 39: 116PS 8: Taking a Pap SmearPS 8PS 8
Page 40 and 41: 118PS 8: Taking a Pap SmearPS 8PS 8
Page 42 and 43: 120 PS 9: Collecting Samples for HP
Page 44 and 45: 122 PS 9: Collecting Samples for HP
Page 46 and 47: 124PS 10: Visual Screening MethodsP
Page 49 and 50: Chapter 5: Diagnosis and Management
Page 69 and 70:
PS 11: Colposcopy, Punch Biopsy and
Page 71 and 72:
PS 11: Colposcopy, Punch Biopsy and
Page 73 and 74:
PS 12: Cryotherapy 151PRACTICE SHEE
Page 75 and 76:
PS 12: Cryotherapy 153Figure PS12.2
Page 77 and 78:
PS 13: Loop Electrosurgical Excisio
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
PS 14: Cold Knife Conization 161PRA
Page 85 and 86:
PS 14: Cold Knife Conization 163At
show all

CHAPTER 4: SCREENING FOR CERVICAL CANCER

Create successful ePaper yourself

Delete template?

Save as template?