Liquid-based cytology

Transcription

1 Liquid-based cytology Claire Bourgain UZBrussel Introduction LBC for gynaecological cytology has been introduced in Belgium a decade ago There is no consensus On performance compared to conventional cytology On price/quality assessment On technical recommendations for quality assessment, review techniques, reflex HPV testing, ancillary stainings There are no randomized studies comparing LBC to LBC Topic: Surepath vs Thinprep comparison For technical issues For cytological criteria 2 1

2 LBC in Belgium Cervical cancer screening by cytology Conventional or validated LBC technique HPV for triage of ASC-US 3 Liquid-based cytology techniques FDA approved ThinPrep Filtration and collection of vacuum-packed cells on a membrane and transferring to the glass slide Surepath Centrifugation and sedimentation through a density gradient Not FDA approved Cytoscreen Turbitec Cellslide Papspin Centrifugation and sedimentation by manual techniques 4 2

3 Liquid-based versus conventional cytology Sampling Fixation Smear Staining Reading LBC manual cervexbrush before smear liquid medium standard pooled cells automatically thin layer selected population possibly automatic experience needed short time Ancillary standard technologies (HPV) Conventional manual cervexbrush or other after smear spray or alcohol not standard only the smeared cells manual variable thickness no cell selection lab function experience needed normal time possible 5 Liquid-based versus conventional cytology 6 Ronco et al, BMJ,

4 Liquid-based versus conventional cytology Randomized controlled studies Colposcopy and histology as golden standard No improvement of HSIL detection by LBC LBC/Conv % Sensitivity HSIL+ 57,1/55,2 LSIL+ 79,1/75,6 ASC-US+ 90,4/88,2 Specificity 97/96,7 78,8/81,2 64,6/71,3 Arbyn et al, Obstet Gynecol, Cytology results for LBC Surepath versus Conventional Colgan et al, Cancer,

5 Cytology results for LBC Surepath versus Conventional Colgan et al, Cancer, Cytology results for LBC ThinPrep versus Conventional Schledermann et al, Diagnost Cytopath,

6 ThinPrep vs Conventional 11 ThinPrep vs Conventional 12 6

7 Cytology results for LBC ThinPrep versus Surepath versus Conventional Nance, Diagnost Cytopath, LBC versus conventional cytology 14 7

8 Liquid-based versus Conventional Improvement of smear quality Increased diagnosis of ASC-US and LSIL No significant increase of HSIL detection Insufficient data comparing the performance of both FDA approved techniques 15 Liquid-based FDA-approved devices Surepath ThinPrep 16 8

9 Cell sample collection ThinPrep SurePath Fixation PreserveCyt fluid CytoRich fluid Storage 6 month C Broom Vial Rotate clockwise 5 times Push broom to bottom, swirl discard the broom Rotate clockwise 5 times Drop broom in solution Storage 6 weeks at 4 C4 4 weeks room temperature 17 Cell sample collection ThinPrep Surepath 18 9

10 Preparation technique ThinPrep PreserveCyt fluid Methanol No vortex 1slide No gradient centrifugation Filter No sedimentation No staining SurePath CytoRich fluid Ethanol Vortex 48 slides Gradient centrifugation No filter Sedimentation Staining 19 Adequacy assessment Bethesda 2001 for LBC preparations 5000 evaluable cells 10 endocervical or metaplastic cells Surepath 13mm 20mm ThinPrep 20 10

11 Cytological criteria of LBC Less obscuring cells Epithelial cells are slightly smaller More single cells TBS: LSIL nuclei enlargement of 3 x Decreased cytoplasmic area in HSIL LBC: Nuclei enlarged 2-1,52 x Statistically decreased cytoplasmic area x LSIL-HSIL N/C ratio increase from 33% to 50% Caveat: bland dyskaryosis 21 NILM, Candida spec 22 11

12 NILM, Clue cells 23 NILM, Clue cells 24 12

13 NILM, EMC 25 LSIL 26 13

14 LSIL, ThinPrep 27 HSIL, ThinPrep 28 14

15 HSIL 29 AIS, Surepath 30 15

16 AIS, Surepath 31 Reflex HPV testing Possible on both ThinPrep and SurePath samples Should include positive and negative controls From test kit From own samples Causes for rejection Inadequate specimen according to cytological evaluation Improperly labeled specimen or name discrepancies Specimen leaked in transit Insufficient quantity of specimen Specimen collected on male patients Specimen older than 21 days in SurePath fixative Specimen older than 3 months in PreservCyt fixative Specimen collected in vial that expired according to label 32 16

17 Ancillary techniques- Pro ExC Topoisomerase IIA and Mini chromosome maintenance protein 2 Immunocytochemical assay with a cocktail of monoclonal antibodies on a blank slide generated with BD SurePath system Positive signal is a nuclear staining Responsible for DNA integrity, accumulate in cells after neoplastic transformation and aberrant entry in S-phaseS TOP2A: unravels excessive DNA coiling in transcription and replication MCM protein: forms a complex at DNA replication initiation and elongation, maintains genome stability in S-phaseS 33 Ancillary tehcniques ProEx C 34 Tambouret et al, Arch Pathol Lab Med,

18 Conclusions Criteria for Thinprep and Surepath Similar cytological criteria can be applied Criteria do not differ from conventional cytology Specific technical recommendations apply for Sampling and sample preservation Reflex HPV testing Ancillary stainings No significant increase of HSIL detection BUT: no prospective comparative studies Insufficient data for application of rapid review techniques 35 18