Cervical Cytology Practice Guidelines. American Society of Cytopathology

Controls in quality assessment in gynecologic cytology: A rational approach to workload limits for the ThinPrep imaging system

Major components of good quality assurance (QA) in cytology laboratories are measuring the screening accuracy of cytotechnologists (CTs) and determining appropriate workload limits for them. Currently, the FDA approved workload limits for image assisted Paps, however, are too high. In addition, the CLIA 88 mandated QA measures, by themselves, are insufficient to accurately measure the screening performance of CTs. Although the use of "controls" is fundamental to good practice in the clinical laboratory; this has not been emphasized in gynecologic cytology. In this review, we underscore the importance of using controls, such as monitoring morning and afternoon abnormal rates, in assessing CT performance and assigning reasonable workload limits. Using controls, however, requires significant alteration in the laboratory workflow, and much lower and variable workload limits for CTs, compared to those approved by FDA.

Evaluation of 100% rapid rescreening of negative cervical smears as a quality assurance measure

OBJECTIVE

The objective of this study was to compare the performance of 100% rapid rescreening, 10% random rescreening and the review of smears selected on the basis of clinical criteria, as a method of internal quality control of cervical smears classified as negative during routine screening.

METHODS

A total of 3149 smears were analysed, 173 of which were classified as positive and 2887 as negative, while 89 smears were considered unsatisfactory. The smears classified as negative were submitted to 100% rapid rescreening, 10% random rescreening, and rescreening based on clinical criteria. The rescreening stages were blinded and results were classified according to the Bethesda 2001 terminology. Six cytologists participated in this study, two of whom were responsible for routine screening while the other four alternated in carrying out rescreening so that no individual reviewed the same slide more than once.

RESULTS

The 100% rapid rescreening method identified 92 suspect smears, of which 42 were considered positive at final diagnosis. Of the 289 smears submitted to the 10% rescreening method, four were considered abnormal but only one was confirmed positive in the final diagnosis. Of the 690 smears rescreened on the basis of clinical criteria, 10 were considered abnormal and eight received a positive final diagnosis.

CONCLUSIONS

The 100% rapid rescreening method is more efficient at detecting false-negative results than 10% random rescreening or rescreening on the basis of clinical criteria, and is recommended as an internal quality control method.

Primary care physicians' awareness and adherence to cervical cancer screening guidelines in Texas

BACKGROUND

Cervical cancer screening guidelines were created to help healthcare professionals in appropriate screening utilizing the PAP test. However, significant variation in cervical cancer screening among primary care physicians has been noted. Knowledge of the awareness of and adherence to cervical cancer screening guidelines by primary care physicians will help determine how best to disseminate and educate these physicians regarding the guidelines in hopes of reducing unnecessary screening and improving screening for under screened populations.

METHODS

A cross-sectional, mailed survey involving Family Medicine (FP), Community Internal Medicine (CIM), and Obstetrics/Gynecology (OB) physicians practicing in a large University-affiliated, multi-specialty group practice associated with an 186,000-member HMO in Central Texas (n = 177) was conducted in 2001-2002.

RESULTS

Most physicians performed PAP testing (50.4%). PAP screening was noted to vary significantly by specialty (P < 0.0001). All OBs were aware of at least one published guideline, compared to 96% of FPs and 91% of CIMs (P < 0.05). A wide variation was reported regarding adherence to published guidelines. In addition, there was significant intraspecialty variation regarding adherence to the physicians' own specialty's guidelines.

CONCLUSIONS

While most physicians in the primary care setting perform PAP tests and are aware of published guidelines for PAP screening, adherence to the published guidelines varies considerably even in the same clinical setting.

Human Papillomavirus Genotyping by the DNA Chip in the Cervical Neoplasia

Human papillomavirus (HPV) is implicated as an etiologic agent in neoplasitc lesions of the cervix. In this study, we used an HPV DNA chip to detect the type-specific sequence of HPV from cervical swabs in women with biopsy- proven neoplastic lesions of the cervix. Four hundred seventy-one patients were involved and classified into four groups based on the cytopathologic diagnosis: group I (normal, n = 290), group II (low-grade squamous intraepithelial lesions (SIL), n = 68), group III (high-grade SIL, n = 51), and group IV (invasive cervical cancer, n = 55). HPV detection rates were 17.6% (51 of 290), 73.5% (50 of 68), 92.2% (47 of 51), and 95.2% (59 of 62) in patients of group I to group IV, respectively. HPV-16 was the most frequent type (21.8%) in all specimens tested, and significantly increased the prevalence by advancing the grade of the cervical lesions (P < 0.01). The next frequent virus types were HPV-18 and HPV-58. The prevalence of multiple HPV infections was 37.3, 43.7, 27.7, and 28.8%, and no significant difference was detected between each group (P > 0.05). This suggests that the HPV DNA chip is a sensitive diagnostic tool for the detection of HPV in cervical specimens, and that it would provide more useful information on viral genotype and multiple HPV infections. Taken together, molecular biological data on HPV might be beneficial for the prevention and management of cervical neoplastic lesions.

Improving Cytologic Samples from the Uterine Cervix: A Simple Visual Instruction

OBJECTIVE

To improve the quality of smears from uterine cervix.

MATERIALS AND METHODS

Fifteen photographs of different types of cervixes (nulliparous, multiparous, ectopia, and others) were shown to a group of physicians and technicians who send samples to our laboratory. We had previously evaluated accuracy of sampling the transformation zone and compared results of the test group with our previous evaluation using Student's t test.

RESULTS

The rate of transformation zone sampling increased from 45% to 77% (p = 0.0001) after physicians and technicians saw the photographs and received instructions.

CONCLUSIONS

This method is simple and very effective for the improving sampling of the uterine cervix by clinicians and other health providers.

HPV oligonucleotide microarray-based detection of HPV genotypes in cervical neoplastic lesions

BACKGROUND

In this study we examined the use of a new-human papillomavirus (HPV) detection method, the HPV oligonucleotide microarray system (Biomedlab Co., Korea), which we compared with the well-established HPV DNA detection system (Hybrid Capture II; HC-II, Digene Co.). This new method prompted us to develop a new HPV genotyping technique, using the oligonucleotide microarray, to detect the generic and type-specific sequence of HPV types. In particular, we undertook the evaluation of the clinical efficacy of the HPV oligonucleotide microarray for detecting HPV in cervical neoplastic lesions.

METHODS

One hundred forty patients were involved and classified into three groups according to their histopathologic diagnoses: Group I (nonspecific chronic cervicitis; n = 61), Group II (low-grade squamous intraepithelial lesion (SIL); koilocytosis, and mild dysplasia; n = 39), and Group III (high-grade SIL; moderate, severe dysplasia and in situ carcinoma; n = 40). Cytological diagnoses were based on the Bethesda System and cervical samples were analyzed by the two methods. The HPV oligonucleotide microarray detected 15 types of high-risk HPV (HPV-16/-18/-31/-33/-35/-39/-45/-51/-52/-56/-58/-59/-66/-68/-69) and 7 types of low-risk HPV (HPV-6/-11/-34/-40/-42/-43/-44).

RESULTS

In 105 of the 140 cervical samples (75%), HPV DNAs were examined using the HC-II method. HPV detection rates using the HPV microarray agreed with those of HC-II. One HC-II-positive, but HPV microarray-negative, case occurred in the low-grade SIL (Group II) and was later confirmed negative for HPV. The other HPV microarray-positive but HC-II-negative case was found to be HPV-18 by PCR. Low-risk types of HPV were detected in 3 of 39 low-grade SIL cases (Group II) using the HPV microarray. HPV-16 was the most frequent type (32.1%) in all specimens tested, and was significantly more frequent in low-grade or high-grade intraepithelial lesions (Groups II or III) than in normal controls (Group I) (P < 0.05). HPV-58 was the second most common type (17.5%) in Group III. The HPV microarray was found to have advantages in terms of identifying the HPV genotypes and cases of multiple HPV infection. Double HPV infections were detected in 12 cases and triple HPV infections in 7 cases. Two cases were positive for four types of HPV (HPV-16/18/33/35, HPV-16/18/58/68). The sensitivity of HPV testing (HC-II; 94.9%, HPV microarray; 93.7%) for identifying patients with squamous intraepithelial lesion was significantly better than the sensitivity of cytology (77.1%, P < 0.05). On using multiple logistic regression analysis to estimate the relative risk of SIL versus HPV type, HPV-16-positive cases were found to have a 7.5-fold risk of SIL (95% CI = 3.28-16.51; P < 0.01). HPV-33 and HPV-58 were found to be significantly related to high-grade SILs (P < 0.01).

CONCLUSIONS

Our results suggest that the HPV oligonucleotide microarray is highly comparable to HC-II for detecting HPV in cervical specimens. The HPV oligonucleotide microarray provides useful information on viral genotype and multiple HPV infections in HPV-related cervical lesions. Genetic information on HPV in cervical specimens might be a particular benefit of the new procedure in the management of cervical neoplastic lesions

Estimating the percentage of Papanicolaou smears that can be reproducibly identified: modeling Papanicolaou smear interpretation based on multiple blinded rescreenings

BACKGROUND

Multiple blinded rescreenings of Papanicolaou (Pap) smears for litigation purposes is based on the assumption that a subset of Pap smears can be reproducibly identified. The size of this subset is not known.

METHODS

To estimate the size of the subset of Pap smears that can be reproducibly identified, a model was constructed based on the results of repeated blinded screenings in the AutoPap Primary Screening System Trial. Additional analysis came from data in the literature.

RESULTS

Routine and AutoPap-assisted screening both have a detection rate for all detected abnormal cases of < 50%. Models with only two subsets or types of slides each with a different detection rate correlated well with the available data. Data from multiple rapid reviews strongly supported the existence of additional definable subsets. Although the percentage of cases with an expected detection rate of 100% in a three-subset model might have been as high as 30% of the abnormal cases detected in a single review, all estimates that included a second subset of slides with at least a 50% detection rate limited the percentage of slides in the 100% sensitive subset of slides to < 2% of all abnormal slides and < 6% of all abnormal slides detected by a single screening.

CONCLUSIONS

Repeated screenings of Pap smears allowed more accurate models of the sensitivity of Pap-smear screening and the overall incidence of abnormal cases. The data strongly supported the existence of multiple subsets of Pap smears, which can be defined by repeated blinded rescreenings. The percentage of slides that can be reproducibly identified was small.