Management Guidelines for Abnormal Pap Smear &
Transcription
Management Guidelines for Abnormal Pap Smear &
Management Guidelines for Abnormal Pap Smear & Preinvasive Disease of the Cervix FOREWORD Cervical cancer is the 4th most common cancer among women in Singapore. The incidence of cervical cancer has declined from 18.1 per 100,000 population for the years 1968-72 to 14.2 per 100,000 population between 1993-97. However, the incidence rate in Singaporean women remains higher than that of developed countries. In 1998, the Ministry of Health set up the Cervical Cancer Screening Committee to develop an organised population-based cervical cancer screening programme to reduce cervical cancer mortality. It was recognised that evidence-based management guidelines were necessary for the evaluation and management of women with different grades of cervical abnormality detected by the cervical cancer screening programme. A workgroup, chaired by A/Prof Ho Tew Hong with representatives from the Chapter of Obstetrics & Gynaecology, Academy of Medicine, Singapore, Obstetrical & Gynaecological Society of Singapore, Society for Colposcopy & Cervical Pathology of Singapore, Singapore General Hospital, National University Hospital and KK Women’s & Children’s Hospital was formed to develop a set of management guidelines for handling abnormal Pap smears. The CervicalScreen Singapore: Management Guidelines for the Abnormal Pap Smear and for Preinvasive Disease of the Cervix will be a useful guide for clinicians in the management of patients with abnormal Pap smears. I would like to extend my sincere thanks to the workgroup for their commitment and hard work in developing the guidelines. Dr Lam Sian Lian Chief Executive Officer Health Promotion Board i PREFACE Whilst the incidence of cervical cancer in Singapore has decreased slightly in the last 25 years, much can still be done to reduce the rates of cervical cancer further. The primary aim of the CervicalScreen Singapore Programme is to further reduce the incidence and mortality from cervical cancer through early detection. An important aspect of this Programme is to guide general practitioners on the management guidelines for screened cervical abnormalities. A Workgroup consisting of representatives from Chapter of Obstetrics & Gynaecology, Academy of Medicine of Singapore, Obstetrical and Gynaecological Society of Singapore, the Society for Colposcopy and Cervical Pathology of Singapore, Singapore General Hospital, National University Hospital and KK Women’s & Children’s Hospital met on several occasions to work out consensus management guidelines for abnormal PAP smear and for preinvasive disease of the cervix. Views from international experts were sought and the consensus guidelines of Bethesda 2001 were also taken into account. These consensus guidelines are formulated specifically for the purpose of the oncoming CervicalScreen Singapore Programme. Ho Tew Hong Clinical Associate Professor Chairman of Workgroup CervicalScreen Singapore: Management Guidelines for Abnormal Pap Smear and Preinvasive Disease of the Cervix iii CONTENTS Foreword i Preface iii 1. CervicalScreen Singapore 1 2. Terminology for Cervical Smear Reporting 3 3. Management Protocol for ‘Negative for Malignant Cells’ Smears 7 4. Management Protocol for Unsatisfactory Smears 5. Management Protocol for Abnormal Smears 9 11 5.1 Management of Abnormal Smear (no past history of CIN or genital tract cancer) 12 5.2 Management of Abnormal Smear (following treatment for CIN or CGIN) 17 5.3 Management of the Abnormal Smear in Pregnancy 17 6. Pap Smears After Hysterectomy 18 7. Management of Preinvasive Disease of the Cervix 20 7.1 HPV 21 7.2 CIN 1 22 7.3 CIN 2 and CIN 3 23 7.4 Suspicion of Microinvasion on Cervical Biopsy 24 7.5 Adenocarcinoma-in-situ 25 7.6 Management of the Abnormal Smear and CIN in Pregnancy 26 7.7 Involvement of Margins after Cone Biopsy or LEEP for CIN 27 8. Special Situations 28 8.1 Abnormal Smear (ASC-US / LSIL) & Unsatisfactory or Normal Colposcopy 29 8.2 Abnormal Smear (ASC-H / HSIL) & Unsatisfactory or Normal Colposcopy 30 8.3 Atypical Glandular Cells 31 8.4 Endocervical Adenocarcinoma in-situ on Pap smear 32 8.5 Adenocarcinoma on Pap smear 33 References 34 Acknowledgements 38 iv 1 CERVICALSCREEN SINGAPORE 1 1 CERVICALSCREEN SINGAPORE 1. Age Group to be Screened and Screening Interval 1.1 Entry to Screening Programme • All women who have ever had sex are advised to have their first Pap smear by the age of 25 1.2 Frequency of Screening • Pap smears are taken once every 3 years 1.3 Discharge from Screening • A woman can be discharged from screening at 65 years of age if the smear taken at 65 years is negative and there was a previous negative smear within the last 3 years • However if a woman, who has had sexual intercourse, has never had a Pap smear, she should still undergo screening irrespective of her age 1.4 Women who have never had Sexual Intercourse • Women who have never had sexual intercourse need not have Pap smear screening • However if these women have any symptoms, they should consult a doctor Note : Consider screening at an earlier age and at more frequent intervals if high risk characteristics are present. High risk characteristics include: • • • • • • • Multiple sexual partners (either partner) Onset of sexual intercourse at an early age HPV infection History of STD HIV infection Immunosuppression Cigarette smoking 2 2 TERMINOLOGY FOR CERVICAL SMEAR REPORTING 3 TERMINOLOGY FOR CERVICAL SMEAR REPORTING 2 (A) List of terminology 1. Unsatisfactory 2. Negative for Malignant Cells 3. Abnormal Smears 3.1 Squamous Lesions 3.1.1 Atypical Squamous Cells • undetermined significance (ASC-US) • cannot exclude high grade lesion (ASC-H) 3.1.2 Low-Grade Squamous Intraepithelial Lesion (LSIL) • HPV effect • mild dyskaryosis 3.1.3 High-Grade Squamous Intraepithelial Lesion (HSIL) • moderate dyskaryosis • severe dyskaryosis • severe dyskaryosis, cannot rule out invasive carcinoma 3.1.4 Squamous Cell Carcinoma 3.2 Glandular Lesions 3.2.1 Atypical Glandular Cells • undetermined significance • favour neoplastic 3.2.2 Endocervical Adenocarcinoma-in-Situ 3.2.3 Adenocarcarcinoma 3.3 Others 3.3.1 Carcinoma • others - specify • not further specified 3.3.2 Other Malignant Tumours • specify (B) Definitions • Unsatisfactory A smear that is unreliable for the detection of cervical epithelial cell abnormalities. 4 A smear comprising mainly endocervical cells is also considered unsatisfactory, unless the smear was intended to specifically evaluate the endocervical canal. • Negative for Malignant Cells The smear shows no dyskaryotic or malignant cells ie. no cytological evidence of Cervical Intraepithelial Neoplasia (CIN), glandular dysplasia or malignancy. This category includes those in which cells showing reactive changes are present, and also those in which micro-organisms are identified. • Squamous Lesions Atypical Squamous Cells • undetermined significance • cannot exclude high grade lesion There are cells showing cytologic changes suggestive of a dysplastic squamous lesion that is quantitatively or qualitatively insufficient for a definitive interpretation. Undetermined Significance (ASC-US) Cytologic changes suggestive of a low grade squamous lesion but lack criteria for definitive interpretation. Cannot Exclude High Grade Lesion (ASC-H) Cytologic changes suggestive of a high grade squamous lesion but lack criteria for definitive interpretation. Low-Grade Squamous Intraepithelial Lesion (LSIL) • HPV effect • mild dyskaryosis HPV Effect Squamous cells present showing stringent criteria of HPV effect ie. koilocytes in superficial or intermediate squamous cells or sharply delineated perinuclear halos in parabasal cells. Mild Dyskaryosis Cytologic changes indicative of CIN I. 5 TERMINOLOGY FOR CERVICAL SMEAR REPORTING If fewer than these are seen because of paucity of cells, poor fixation, air- drying artefact, thick smearing, or covering of blood, inflammatory exudate or other contaminants, the smear is considered unsatisfactory. 2 A satisfactory smear should show well-preserved and well-visualised squamous cells covering at least one-third of the area of a regular glass slide surface. High-Grade Squamous Intraepithelial Lesion (HSIL) TERMINOLOGY FOR CERVICAL SMEAR REPORTING 2 • moderate dyskaryosis • severe dyskaryosis • severe dyskaryosis, cannot rule out invasive carcinoma Moderate Dyskaryosis Cytologic changes indicative of CIN 2. Severe Dyskaryosis Cytologic changes indicative of CIN 3. Severe Dyskaryosis, Cannot Rule Out Invasive Carcinoma Cytologic changes indicative of at least CIN 3, but with features of possible invasive tumour. Squamous Cell Carcinoma Cytologic changes indicative of an invasive squamous cell carcinoma. • Glandular Lesions Atypical Glandular Cells • undetermined significance • favour neoplastic There are cells showing cytologic changes suggestive of a dysplastic glandular lesion that are quantitatively or qualitatively insufficient for a definitive interpretation. Where possible, these are qualified as to whether the abnormal cells are of endocervical or endometrial origin. Undetermined Significance Cytologic changes which exceed those of a reactive process but lack criteria for a definitive interpretation of a dysplastic glandular lesion. Favour Neoplastic Cytologic changes suggestive of a glandular dysplasia or adenocarcinomain-situ or adenocarcinoma, but lack criteria for definitive interpretation. Endocervical Adenocarcinoma-in-Situ Cytologic changes indicative of endocervical adenocarcinoma-in-situ. Adenocarcarcinoma Cytologic changes indicative of an invasive adenocarcinoma. • Others Carcinoma • others - specify • not further specified Other Malignant Tumours • specify 6 3 MANAGEMENT PROTOCOL FOR “NEGATIVE FOR MALIGNANT CELLS” SMEARS 7 PAP SMEAR NEGATIVE SMEARS 3 Negative for malignant cells Atrophic changes No endocervical cells seen (without inflammation) Repeat in 1 year (use of an endocervical brush in addition to the cervex brush/spatula is recommended) Specific micro-organisms identified Treat appropriately changes & resolve as clinically indicated Inflammatory changes Endometrial cells seen Treat any infection or atrophy Repeat in 4 – 6 months Correlate with clinical findings, patient’s age, hormonal and menstrual status 2nd smear similar changes changes resolve Treat any infection or atrophy Repeat in 4 – 6 months 3rd smear similar changes Routine screening schedule Routine screening schedule Refer gynaecologist Refer gynaecologist if necessary Note : Clinically suspicious looking cervix irrespective of the Pap smear result must be referred for colposcopy. 8 4 MANAGEMENT PROTOCOL FOR UNSATISFACTORY SMEARS 9 PAP SMEAR UNSATISFACTORY SMEARS 4 Unsatisfactory Treat any infection Give a course of estrogen if post-menopausal with atrophic changes Repeat in 3 months 2nd smear unsatisfactory Repeat in 3 months Negative for malignant cells Satisfactory and negative 3rd smear unsatisfactory Refer for colposcopy Routine screening schedule Note : Clinically suspicious looking cervix irrespective of the Pap smear result must be referred for colposcopy. 10 5 MANAGEMENT PROTOCOL FOR ABNORMAL SMEARS 11 5.1 Management of Abnormal Smear (No past history of CIN or genital tract cancer) PAP SMEAR Atypical squamous cells Undetermined significance (ASC-US) Refer for colposcopy Repeat in 6 months ABNORMAL SMEARS 5 Cannot exclude high grade lesion (ASC-H) - Atypical squamous cells - Low-grade squamous intraepithelial lesion - High-grade squamous intraepithelial lesion Negative for malignant cells Refer for colposcopy Repeat in 6 months Resume routine screening if negative for malignant cells 12 PAP SMEAR Low-grade squamous intraepithelial lesion (LSIL) Mild dyskaryosis or not otherwise specified 5 HPV effect ABNORMAL SMEARS Repeat in 6 months Negative for malignant cells HPV effect and / or more severe abnormality Repeat in 1 year If negative for malignant cells, may resume routine screening Colposcopy 13 Colposcopy PAP SMEAR Squamous cell carcinoma ABNORMAL SMEARS 5 High-grade squamous intraepithelial lesion (HSIL) Moderate dyskaryosis or Severe dyskaryosis Severe dyskaryosis, cannot rule out invasive carcinoma Colposcopy Colposcopy (urgent appointment) 14 Urgent referral to gynaecologist PAP SMEAR Endocervical adenocarcinomain-situ Colposcopy * Colposcopy Adenocarcinoma *Colposcopist to refer to management guidelines 8.3 15 Urgent referral to gynaecologist ABNORMAL SMEARS 5 Atypical glandular cells -Undetermined significance -Favour neoplastic PAP SMEAR Carcinoma (specified or not further specified) Other malignant tumours ABNORMAL SMEARS 5 Urgent Referral To Gynaecologist Other indications for referral : a. Abnormal vaginal bleeding, eg. post-coital, post-menopausal or intermenstrual, should always be investigated and the woman referred for a specialist opinion. b. Clinically suspicious looking cervix irrespective of the Pap smear result must be referred for colposcopy. 16 5.2 Management of Abnormal Smear (Following treatment for CIN or CGIN) PAP SMEAR Unsatisfactory Atypical squamous or glandular cells, dyskaryosis of any degree Suspicious of invasive carcinoma or adenocarcinoma, or malignant cells seen Negative for malignant cells Resume follow up schedule after treatment for CIN ABNORMAL SMEARS 5 Treat any infection Give a course of estrogen if post-menopausal with atrophic changes Repeat in 3 months 2nd smear unsatisfactory Colposcopy Colposcopy Colposcopy (urgent appointment) 5.3 Management of the Abnormal Smear in Pregnancy The same as in the non-pregnant patient 17 6 PAP SMEARS AFTER HYSTERECTOMY 18 1. Hysterectomy for benign disease (a) Normal Pap smear history (b) Histopathology of cervix known and is benign with no dysplastic/ neoplastic changes Subtotal hysterectomy Should continue to have Pap smears according to the screening programme 3. Hysterectomy where histology not known • One base-line Pap smear of vaginal vault • If this is normal, then no further smears are required 4. Immunosuppressed women (due to disease or therapy) • Should continue to have Pap smears of the vault at yearly intervals 5. Women with a past history of CIN (a) If excision margin was involved or not adequately assessed histologically • Follow up should be at the discretion of the gynaecologist • Vault smears should in general be taken at least yearly (b) CIN (CIN 1 / 2 / 3) completely excised at hysterectomy • Vault smears for five years yearly • Two yearly subsequently 6. Women previously treated for VAIN, or invasive gynaecological malignancy • These women should be followed up by the treating gynaecologist/ • gynaecological oncologist PAP SMEARS AFTER HYSTERECTOMY 2. 6 • These women, in the absence of symptoms, need not have any • further Pap smears 7 MANAGEMENT OF PREINVASIVE DISEASE OF THE CERVIX 20 7.1 HPV HPV on Biopsy Repeat Pap smear + colposcopy in 6 months Treat : i. If any associated CIN, according to guidelines for CIN ii. If condylomas present 7 HPV No CIN MANAGEMENT OF PREINVASIVE DISEASE Yearly Pap smear x 2 If negative for malignant cells, may return to routine 3 yearly screening 21 7.2 CIN 1 CIN 1 on Biopsy Observation Treatment Repeat Pap smear and colposcopy + biopsy in 6 months Ablation * or Excision Persistent CIN I - cytology (ASC-US / LSIL) - colposcopy + biopsy Refer Section 7.3 Treatment Or Observation Normal Follow-up Pap smear at 3 – 6 months MANAGEMENT OF PREINVASIVE DISEASE 7 Progression - cytology (ASC-H / HSIL) - colposcopy + biopsy - If observation, patient must be compliant to follow-up - Repeat Pap smear and colposcopy + biopsy in 6 months - Consider treatment if CIN I persistent for 12 months from first histological diagnosis Pap smear + colposcopy at 12 months Yearly Pap smear x 4 Return to routine 3 yearly screening * Refer to criteria for ablation in 7.3 Note : The management of CIN I is controversial; patients can be managed by either observation or treatment. If immunocompromised patient, suggest treatment as CIN less likely to regress. 22 7.3 CIN 2 and CIN 3 CIN 2 / CIN 3 on Biopsy Treat Excision - LEEP / LLETZ - Laser cone - Cold knife cone Follow-up Pap smear at 3 - 6 months Pap smear + colposcopy at 12 months Pap smear 6 monthly for second year Yearly Pap smear 23 MANAGEMENT OF PREINVASIVE DISEASE 7 Ablation - The upper limit of the lesion is completely visualised - The whole transformation zone is seen on colposcopy - There is no discrepancy of more than one grade between cytology, colposcopy or biopsy - There is no suspicion of microinvasive / invasive disease on cytology, colposcopy or biopsy - There is no suspicion of any glandular lesion on cytology, colposcopy or biopsy - The patient will be compliant to follow up 7.4 Suspicion of Microinvasion on Cervical Biopsy SUSPICION OF MICROINVASION on Biopsy Cone biopsy of cervix MANAGEMENT OF PREINVASIVE DISEASE 7 Subsequent management according to histology of cone biopsy Note : For suspected microinvasion a single large cone biopsy specimen with clear margins is necessary for adequate histopathological interpretation. A LEEP may not be adequate. A cold knife cone under anaesthesia is preferred. 24 7.5 Adenocarcinoma-in-situ ADENOCARCINOMA-IN-SITU on Biopsy Cone biopsy + endocervical curettage (ECC) Invasion present Manage according to guidelines for cervical cancer No invasion Margins involved Adequate specimen and margins clear If fertility desired or desire to preserve uterus Total hysterectomy Follow patient closely Note : For cone biopsy for adenocarcinoma-in-situ, a single large specimen with clear margins is necessary for adequate histopathological interpretation. A LEEP may not be adequate. A cold knife cone under anaesthesia is preferred. 25 MANAGEMENT OF PREINVASIVE DISEASE Completed family 7 Recommend expert opinion 7.6 Management of the Abnormal Smear and CIN in Pregnancy 1. Colposcopic evaluation should be undertaken to exclude invasive disease, by a colposcopist experienced in colposcopy in pregnancy. 2. If a high grade lesion is suspected on colposcopy, a biopsy is indicated to exclude possible invasive disease. Cervical biopsy is safe in pregnancy. 3. If CIN 2 or 3 is present, colposcopic review should be done in the second or third trimester to exclude any possible progression to invasive disease. 4. Treatment of CIN should be deferred till at least 8 weeks post-partum, when the lesion should be reassessed. If the patient is breast feeding, local application of estrogen before the colposcopic reassessment may assist accurate evaluation. MANAGEMENT OF PREINVASIVE DISEASE 7 Note : The management of labour is not influenced in any way by the presence of CIN, irrespective of severity. 26 7.7 Involvement of Margins after Cone Biopsy or LEEP for CIN Involvement of Resection Margins Margin positive for CIN I Margin positive for CIN 2 or 3 Repeat Pap smear and colposcopy at 3 months Repeat excision or hysterectomy Pap smear abnormal colposcopy unsatisfactory or normal Biopsy Follow up according to schedule for CIN Review Pap smear by pathologist CIN I CIN 2 / CIN 3 Individualise treatment Ablation* or excision Excision or hysterectomy Consider expert opinion * Refer to criteria for ablation in 7.3 27 MANAGEMENT OF PREINVASIVE DISEASE 7 Pap smear negative for malignant cells Colposcopy normal 8 SPECIAL SITUATIONS Note: Management should be individualised. Consider expert opinion including pathology review. 28 8.1 Abnormal Smear (ASC-US / LSIL) & Unsatisfactory or Normal Colposcopy Atypical squamous cells-undetermined significance (ASC-US) / Low-grade squamous intraepithelial lesion (LSIL) Colposcopy satisfactory + normal vulva / vaginal normal Colposcopy unsatisfactory vulva / vagina normal Do ECC Pap smear abnormal colposcopy normal ECC positive Repeat Pap smear in 6 months ASC-US or LSIL Negative for malignant cells Repeat Pap smear + colposcopy in 6 months, consider cone biopsy or LEEP if persistent at 12 months ASC-H/ HSIL ECC negative Pap smear & colposcopy normal Repeat Pap smear + colposcopy in 6 months Abnormal Normal Repeat Pap smear in 6 months Yearly Pap smear x 2 Negative for malignant cells If negative for malignant cells, resume 3 yearly screening Yearly Pap smear x 2 Legend : ECC Note : Pap smear abnormal colposcopy unsatisfactory Cone biopsy or LEEP Endocervical currettage Cone biopsy or LEEP If negative for malignant cells, resume 3 yearly screening Management should be individualised. Consider expert opinion including pathology review. 29 8 Pap smear & colposcopy normal Estrogen treatment if post-menopausal. Repeat Pap smear & colposcopy in 3 months SPECIAL SITUATIONS Repeat Pap smear & colposcopy in 6 months 8.2 Abnormal Smear (ASC-H / HSIL) & Unsatisfactory or Normal Colposcopy Atypical squamous cells cannot exclude high grade lesion (ASC-H) / High-grade squamous intraepithelial lesions (HSIL) Colposcopy satisfactory & normal Vulva / vagina normal Colposcopy unsatisfactory Vulva / vagina normal Review Pap smear by pathologist Not conclusive for ASC-H / HSIL ASC-H / HSIL Repeat Pap smear & colposcopy in 3 - 6 months SPECIAL SITUATIONS 8 Pap smear & colposcopy normal Repeat Pap smear in 6 months If negative for malignant cells, yearly Pap smear x 2 Review Pap smear by pathologist ASC-H / HSIL Not conclusive for ASC-H / HSIL Pap smear abnormal colposcopy normal ASC-US or LSIL ASC-H / HSIL Repeat Pap smear + colposcopy in 6 months, consider cone biopsy or LEEP if persistent at 12 months If negative for malignant cells, to resume 3 yearly screening 30 Cone biopsy or LEEP Follow algorithm as in 8.1 8.3 Atypical Glandular Cells Atypical glandular cells -undetermined significance -favour neoplastic Colposcopy Abnormal Biopsy Normal or unsatisfactory Review Pap smear by pathologist AIS / SIL High suspicion of neoplastic lesion Manage according to guidelines for cervical cancer Low suspicion of neoplastic lesion Repeat Pap smear & colposcopy + ECC in 4 – 6 months Consider pelvic ultrasound Cone biopsy and D&C or endometrial sampling * Normal Normal Pap smear 6 mthly x 2 If negative for malignant cells, yearly Pap smear x 2 If negative for malignant cells, resume 3 yearly screening * If risk factors for Ca endometrium are present, or the patient is symptomatic or > 40 years D&C (+ hysteroscopy) is advised for endometrial tissue evaluation Note : If histology of cone biopsy and D&C normal to investigate for disease in ovary, fallopian tubes and peritoneum. 31 8 Manage according to histology of lesion AGUS SPECIAL SITUATIONS Carcinoma 8.4 Endocervical Adenocarcinoma-in-situ on Pap Smear Endocervical Adenocarcinoma-in-situ on Pap Smear Colposcopy No lesion on cervix Lesion on cervix SPECIAL SITUATIONS 8 Squamous intraepithelial lesion Cone biopsy + ECC D&C if risk factors for Ca endometrium present, symptomatic or >40 years Legend: ECC Cone biopsy + ECC D&C if risk factors for Ca endometrium present, symptomatic or >40 years AIS biopsy Adenocarcinoma Cone biopsy + ECC Manage according to guidelines for cervical cancer Endocervical currettage Note : If histology of cone biopsy and D&C normal to investigate for disease in ovary, fallopian tubes and peritoneum. 32 8.5 Adenocarcinoma on Pap Smear Adenocarcinoma on Pap Smear Lesion on cervix No lesion on cervix Colposcopy normal AIS Manage according to guidelines for cervical cancer Cone biopsy + ECC and D&C SPECIAL SITUATIONS Adenocarcinoma D&C + hysteroscopy Cone biopsy of cervix 8 Squamous intraepithelial lesion or no dysplasia Biopsy Note : If histology of D&C and cone biopsy normal to investigate for for disease in ovary, fallopian tubes and peritoneum. 33 REFERENCES 34 Duncan ID (ed). Guidelines for clinical practice and programme management 2nd edition. National Health Service Cervical Screening Programme Publication No. 8 1997. 2. Screening to prevent cervical cancer: Guidelines for the management of women with screen detected abnormalities. Report by the National Health and Medical Research Council for the Organised Approach to preventing cancer of the cervix. Australian Government Publishing Service, Canberra 1994. 3. IARC Working Group on Evaluation of Cervical Cancer Screening Programmes. “Screening for squamous cervical cancer: Duration of low risk after negative results of cervical cytology and its implication for screening policies.” Br Med J 1986; 293: 659-64. 4. From the Centres for Disease Control and Prevention. Incidence of Pap test abnormalities within 3 years of a normal Pap test - United States, 1991 - 1998. JAMA 2000; 284 (21): 2714-5. 5. Gram IT, Macaluso M, Stalsberg H. Incidence of cervical intraepithelial neoplasia grade III, and cancer of the cervix uteri following a negative Pap smear in an opportunistic screening. Acta Obstet Gynecol Scand 1998; 77 (2): 228-32. 6. Mitchell MF, Schottenfeld D, Tortolero-Luna G, Cantor SB, Richards-Kortum R. Colposcopy for the diagnosis of squamous intraepithelial lesions: A metaanalysis. Obstet Gynecol 1998; 91 (4): 626-31. 7. M I Shafi, DM Luesley, JA Jordan, JA Dunn, TP Rollason, M Yates. Randomised trial of immediate versus deferred treatment strategies for the management of minor cervical cytological abnormalities. British Journal of O&G 1997; 104: 590-4. 8. Flannelly G, Kitchener H. Every woman with an abnormal cervical smear should be referred for treatment: debate. Clin Obstet Gynecol 1995; 38 (3): 585-91. 9. Manetta A, Keefe K, Lin F, Ahdoot D, Kaleb V. Atypical glandular cells of undetermined significance in cervical cytologic findings. Am J Obstet Gynecol 1999; 180 (4): 883-8. 35 REFERENCES 1. 10. Kim TJ, Kim HS, Park CT, Park IS, Hong SR, Park JS, Shim JU. Clinical evaluation of follow-up methods and results of atypical glandular cells of undetermined significance (AGUS) detected on cervicovaginal Pap smears. Gynecol Oncol 1999; 73 (2): 292-8. 11. McIndoe WA, McLean MR, Jones RW, Mullins PR. The invasive potential of carcinoma in situ of the cervix. Obstet Gynecol 1984; 64 (4) : 451-8. 12. Cox JT. Management of cervical intraepithelial neoplasia. Lancet 1999; 353 (9156): 857-9. 13. Shafi MI, Luesley DM. Management of low grade lesions: Follow-up or treat? Ballieres Clin Obstet Gynaecol 1995; 9 (1): 121-31. 14. G Flannelly, D Anderson, HC Kitchener, E M F Mann, M Campbell, P Fisher, F Walker. Management of women with mild and moderate cervical dyskaryosis. BMJ; 308: 1399-403. 15. Martin-Hirsch PL, Paraskevaidis E, Kitchener H. Surgery for cervical intraepithelial neoplasia. Cochrane Database Syst Rev 2, CD001318, 2000. 16. Duggan BD, Felix JC, Muderspach LI, Gebhardt JA, Groshen S, Morrow CP, Roman LD. Cold-knife conization versus conization by the loop electrosurgical excision procedure: a randomized, prospective study. Am J Obstet Gynecol 1999; 180 (2 Pt 1): 276-82. 17. Narducci F, Occelli B, Boman F, Vinatier D, Leroy JL. Positive margins after conization and risk of persistent lesion. Gynecol Oncol 2000; 76 (3): 311-4. REFERENCES 18. Dobbs SP, Asmussen T, Nunns D, Hollingworth J, Brown LJ, Ireland D. Does histological incomplete excision of cervical intraepithelial neoplasia following large loop excision of transformation zone increase recurrence rates? A six year cytological follow up. Br J Obstet Gynaecol 2000; 107 (10) : 1298-301. 19. K Mohamed-Noor, MA Quinn, J Tan. Outcomes after cervical cold knife conization with complete and incomplete excision of abnormal epithelium: A review of 699 cases. Gynecologic Oncology 1997; 67: 34-8. 20. Grainne Flannelly, Heather Langhan, Lata Jandial, Evelyn Mann, Marion Campbell, Henry Kitchener. A study of treatment failures following large loop excision of the transformation zone for the treatment of cervical intraepithelial neoplasia. British Journal of O&G 1997; 104: 718-22. 36 21. ES Andersen, B Pedersen, K Nielsen. Laser conization : The results of treatment of cervical intraepithelial neoplasia. Gynecologic Oncology 1994; 54: 201-4. 22. WP Soutter, A de Barros Lopes, Astrid Fletcher, JM Monaghan, ID Duncan, E Paraskevaidis, HC Kitchener. Invasive cervical cancer after conservative therapy for cervical intraepithelial neoplasia. Lancet 1997; 349: 978-80. 23. Shin CH, Schorge JO, Lee KR Sheets EE. Conservative management of adenocarcinoma in situ of the cervix. Gynecol Oncol 2000; 79 (1): 6-10. 24. Ostor AG, Duncan A, Quinn M, Rome R. Adenocarcinoma-in-situ of the uterine cervix : An experience with 100 cases. Gynecol Oncol 2000; 79 (2): 207-10. 25. Palle C, Bangsboll S, Andreasson B. Cervical intraepithelial neoplasia in pregnancy. Acta Obstet Gynecol Scand 2000; 79 (4): 306-10. 26. Woodrow N, Permezel M, Butterfield L, Rome R, Tan J, Quinn M. Abnormal cervical cytology in pregnancy: Experience of 811 cases. Aust N Z J Obstet Gynaecol 1998; 38 (2) : 161-5. 27. Milne DS, Wadehra V, Mennim D, Wagstaff TI. A prospective follow up study of women with colposcopically unconfirmed positive cervical smears. Br J Obstet Gynaecol 1999; 106 (1) : 38-41. 28. Roche DH, Spicer N. The clinical significance of atypical squamous cells of undetermined significance: A laboratory audit of cervical reporting. N Z Med J 2001 23; 114 (1126) : 64-6. 30. Law KS, Chang TC, Hsueh S, Jung SM, Tseng CJ, Lai CH. High prevalence of high grade squamous intraepithelial lesions and microinvasive carcinoma in women with a cytologic diagnosis of low grade squamous intraepithelial lesions. J Reprod Med 2001; 46 (1): 61-4. 37 REFERENCES 29. Lambert B, Boivin Y, Lepage Y. Atypical squamous cells of undetermined significance (ASC-US): clinical-cytological significance. Int J Gynecol Cancer 1999; 9 (4): 329-32. ACKNOWLEDGEMENTS 38 Workgroup Members Chairperson Clinical Assoc Prof Ho Tew Hong Dr Chew Sung Hock KK Women’s & Children’s Hospital Assoc Prof A Ilancheran Academy of Medicine, Singapore Dr Lee I Wuen Raffles Hospital Assoc Prof Lim Fang Kan National University Hospital Dr Lim-Tan Soo Kim Singapore General Hospital Dr Jeffrey Low KK Women’s & Children’s Hospital Dr Quek Swee Chong KK Women’s & Children’s Hospital Dr Pritam Singh Society for Colposcopy & Cervical Pathology of Singapore Dr Tay Eng Hseon Obstetrical & Gynaecological Society of Singapore Clinical Assoc Prof Tay Sun Kuie Singapore General Hospital Assoc Prof Tham Kok Fun National University Hospital 39 ACKNOWLEGEMENTS Members 3 Second Hospital Avenue, Singapore 168937 www.hpb.gov.sg / www.healthylife.org.sg Copyright © HPB B E 368-02 November 2002 Designed & printed by Grace Communications Pte Ltd