CELL PREPARATION METHODS AND CRITERIA FOR SAMPLE ADEQUACY - IAC TASK-FORCE SUMMARY

Issues Cell Preparation Methods Standardized fixation and optimal stai ning Sampling of cervix, sampling error, homogenization of sample, sub sampling Assessment of liquid-based preparations: efficacy and economi c impact Training and transitional procedures before full implementati on of new technologies Criteria for Sample Adequacy Clinician responsi bility for collecting and providing representative sample to laborator y Collection instruments, number of slides Cellular content of samples : evidence of transformation zone (TZ) sampling, number of squamous ce lls present, obscuring factors Screening issues Consensus Position The conventional cervical smear remains the standard method of cervical c ancer screening but has limitations in individual test sensitivity and specificity.Sample takers should: (1) receive appropriate training in sample collection, (2) be held responsible for providing the laborato ry with appropriate samples, and (3) have their performance monitored. The instruments used for sampling should collect cells from both the ectocervix and endocervix; optimally, TZ sampling, represented by the presence of endocervical or squamous metaplastic cells, should be iden tifiable in samples other than atrophic specimens. The adequacy of a s pecimen (as judged microscopically) does not guarantee that it is repr esentative of the cervix. Each cytology report should include a commen t on cellular content/adequacy of the specimen. Liquid-based preparati ons may overcome many of the inherent problems with the conventional c ervical smear. Ongoing Issues We need further data on the cost-effecti veness of making two slides from cervical specimens and/or using two s amplers rather than a single one. Do we have enough information to mak e recommendations as to the appropriate type of sampler to be used in particular situations, such as routine screening? What is the best met hod of screening for/detecting endocervical glandular neoplasia? How a re such terms as unsatisfactory and inadequate defined in cervical cyt ology classifications other than the Bethesda System? What number and types of epithelial cells should be present (visualized) in a cervical smear or liquid-based preparation for it to be considered adequate? D o we need to have evidence of TZ sampling in specimens taken during th e follow-up period after treatment of squamous intraepithelial lesion or after detection of endocervical glandular neoplasia? What criteria for obscuring factors, such as blood and inflammation, should be used in assessing adequacy? Cost-benefit analyses of utilizing liquid-based preparations are needed. Should we inform women about the technical d etails of the test methods available or chosen by the laboratory? Are women in a position to decide which method is the most appropriate to assess their cervical scrape sample? We need to obtain move informatio n about the properties of proprietary liquid fixative/transport media with respect to inactivation of viral pathogens, tuberculosis and othe r bacterial pathogens and suitability for immunobiologic and molecular tests, etc. We need to obtain more information on the use of stoichio metric stains and the limitations of Papanicolaou stain for image anal ysis systems. The use of liquid-based preparations for nongynecologic cytopathology and ancillary tests must be considered, including criter ia for adequacy. We need to obtain more information on the time requir ed for and best methods of training experienced cytotechnologists to b ecome competent at assessing liquid-based cervical preparations.