Efficiency of an inexpensive liquid-based cytology performed by cytocentrifugations: a comparative study using the histology as reference standard

Comparative study of conventional exfoliative cytology and centrifuged liquid-based cytology in oral leukoplakia and oral squamous cell carcinoma patients

Background

This study aims to compare the efficacy between conventional exfoliative cytology (EC) and centrifuged liquid-based cytology (CLBC) in control, leukoplakia, and oral squamous cell carcinoma (OSCC) patients. Oral leukoplakia and oral cancer require an early definitive diagnosis for better prognostic outcome. Oral EC, a minimally invasive technique that involves the examination of desquamated cells from the tissue surfaces used as a method of early diagnosis. CLBC is a modified technique that is used to achieve improved quality of the cytology findings.

Materials and Methods

A comparative study was done in 30 subjects, of which, 10 cases from control group, 10 oral leukoplakia, and 10 OSCC cases. These subjects were selected according to the appropriate inclusion and exclusion criteria. The cases in each group underwent conventional as well as CLBC. The comparison was carried out between these groups with respect to the cellular and background stromal factors. Appropriate qualitative evaluation of the samples was collected and statistical analysis was done using the Chi-squared test. The significance level of value was P < 0.05.

Results

Significant results were obtained for certain parameters such as cellular overlap clear background, uniform distribution in control, leukoplakia, and OSCC with a P = 0.004**, P = 0.001**, P = 0.006** using CLBC.

Conclusion

CLBC is better and give clearer vision as compared to conventional cytology and can be used in the early diagnosis.

Comparative evaluation of conventional cytology and a low-cost liquid-based cytology technique, EziPREP™, for cervicovaginal smear reporting: A split sample study

Background:

Liquid-based cytology (LBC) for cervical cancer screening offers several advantages over conventional cytology. However, the extremely high cost of the current approved devices precludes widespread application of LBC technique in resource-constrained countries. This study aimed to evaluate the performance of an indigenous low-cost LBC technique, EziPREP™ (EP), against conventional preparations (CPs) for cervical cancer screening.

Materials and Methods:

A cross-sectional split-sample study with consecutive cervical sampling was conducted on 515 women attending the clinic at our institute. CP smears were prepared as per the standard technique using spatula and endocervical brush followed by detaching the head of brush into the fixative vial of EP. The EP samples were processed as per the manufacturer's protocol. Both CP and EP smears were stained using standard Papanicolaou stain protocol. Both sets of smears were evaluated for staining quality, morphologic details, and cytologic diagnoses. Cytologic diagnoses were correlated with cervical biopsy findings, wherever available. Performance characteristics of the two techniques were calculated.

Results:

The unsatisfactory rate for CP was 1.0%, while on EP, 1.3% smears had inadequate cellular material. The staining quality and morphological details were comparable in both sets of smears. The detection of infections and epithelial cell abnormality was more, though not statistically significant in EP smears. There was a 98% concordance in cytologic diagnosis between CP and EP smears. Cytohistologic concordance was observed in 96% of cases for both CP and EP smears. Although the time taken for processing and staining of smears was higher for EP (2.5 min for EP per smear and 1.6 min for CP per smear), the screening time reduced from 6.5 min per smear for CP to 2.2 min in EP smears.

Conclusion:

EP provides monolayered cervical smears with vivid morphological details, leading to reduced screening time and relatively higher pick-up of infections and low-grade cervical lesions as compared to conventional smears. The availability of such low-cost devices may enable wider application of cytology-based cervical cancer screening in low-resource countries.

Self-sampling for human papillomavirus DNA detection: a preliminary study of compliance and feasibility in BOLIVIA

BACKGROUND

Cervical cancer incidence and mortality rates in Bolivia are among the highest in Latin America. This investigation aims to evaluate the possibility of using simple devices, e.g. a cotton swab and a glass slide, for self-sampling in order to detect human papillomavirus (HPV) DNA by PCR in cervico-vaginal cells.

METHODS

In the first phase of our study we evaluated the use of a glass slide as a transport medium for cervical cells. A physician took paired-cervical samples from 235 women. One sample was transported in Easyfix® solution and the other sample was smeared over a glass slide. Both were further analyzed and compared for human DNA recovery and HPV detection. A kappa value was determined to evaluate the agreement between the HPV DNA detection rates. In the second phase of the study, 222 women from the urban, peri-urban and rural regions of Cochabamba were requested to perform self-sampling using the following devices: a cotton swab combined with a glass slide, and a vaginal tampon. Women gave their opinion about the self-sampling technique. Finally, the agreement for high risk-HPV detection between self- and physician-collected samples was performed in 201 samples in order to evaluate the self-sampling technique.

RESULTS

Firstly, the comparison between Easyfix® solution and the glass slide to transport clinical samples gave a good agreement for HPV DNA detection (κ = 0.71, 95% CI 0.60-0.81). Secondly, self-sampling, especially with cotton swab combined with glass slide, would generally be preferred over clinician sampling for a screening program based on HPV detection. Finally, we showed a good agreement between self- and physician collected samples for high risk-HPV detection (κ = 0.71, 95% CI 0.55-0.88).

CONCLUSIONS

Simple devices such as a cotton swab and a glass slide can be used to perform self-sampling and HPV DNA detection. Furthermore, most Bolivian women preferred self-sampling over clinician-sampling for cervical cancer screening.

Validation of Novaprep(®) HQ+ liquid-based cytology medium for high-risk human papillomavirus detection by hc2

Background

Preanalytical conditions determine the reliability and validity of bioassays. Therefore, the analytic performances of biological tests need to be determined when preanalytical steps differ from those recommended by the manufacturer. The objective of the study was to assess the analytic performance of the hc2 test for the detection of high-risk HPV DNA from cells stored in the new Novaprep® HQ+ medium.

Methods

Repeatability, reproducibility, method comparison and stability (-20 °C, +4 °C, +20 °C and +40 °C up to six months) were evaluated from HPV16 and HPV18 positive cell lines diluted in the Novaprep® HQ+ medium and the reference Specimen Transport Medium (STM). A series of cervical samples with atypical squamous cells of undetermined significance (ASC-US) cytology and stored in the Novaprep® HQ+ medium was also tested.

Results

Coefficients of variation for repeatability and reproducibility were less than 8 %. Method comparison showed perfect agreement in hc2 results when the HPV-positive cells were diluted in HQ+ and reference media. Stability experiments demonstrated that the storage conditions did not alter the hc2 test results. Furthermore, clinical samples were adequately preserved for hc2 testing.

Conclusions

Overall, our data show that the new Novaprep HQ+ medium is suitable for high-risk HPV testing by hc2.

Comparison of specimen adequacy and smear quality in oral smears prepared by manual liquid-based cytology and conventional methods

BACKGROUND

Liquid-based cytology (LBC), recommended in the mass screening of potentially malignant cervical and oral lesions, suffers from high cost owing to the use of expensive automated devices and materials. Considering the need for cost-effective LBC techniques, we evaluated the efficacy of an inexpensive manual LBC (MLBC) technique against conventional cytological technique in terms of specimen adequacy and smear quality of oral smears.

MATERIALS AND METHODS

Cytological samples were collected from 21 patients using a cytobrush device. After preparation of a conventional smear, the brush containing the remaining sample was immersed in the preservative vial. The preserved material was processed by an MLBC technique and subsequently, direct smears were made from the prepared cell button. Both conventional and MLBC smears were stained by routine Papanicolaou technique and evaluated by an independent observer for the thickness of the smear, cellular distribution, resolution/clarity of cells, cellular staining characteristics and the presence of unsatisfactory background/artifacts. Each parameter was graded as satisfactory; or satisfactory, but limited; or unsatisfactory. Chi-square test was used to compare the values obtained (significance set at P ≤ 0.05).

RESULTS

MLBC technique produced a significant number of satisfactory smears with regard to cell distribution, clarity/resolution, staining characteristics and background/artifacts compared to conventional methods.

CONCLUSIONS

MLBC is a cost-effective cytological technique that may produce oral smears with excellent cytomorphology and longer storage life.

A Shandon PapSpin liquid-based gynecological test: A split-sample and direct-to-vial test with histology follow-up study

BACKGROUND

Studies for liquid-based Papanicolaou (Pap) tests reveal that liquid-based cytology (LBC) is a safe and effective alternative to the conventional Pap smear. Although there is research on ThinPrep and SurePath systems, information is lacking to evaluate the efficiency and effectiveness of systems based on cytocentrifugation. This study is designed to determine the sensitivity and specificity of the Shandon PapSpin (ThermoShandon, Pittsburgh, Pennsylvania, USA) liquid-based gynecological system. We used split-sample and direct-to-vial study design.

MATERIALS AND METHODS

2,945 women referred to prophylactic check-up were enrolled in this study. Split sample design was used in 1,500 women and residual cervical cytology specimen from all these cases was placed in fluid for PapSpin preparation after performing conventional smear. The direct-to-vial study was carried out in another cohort of 1,445 women in whom the entire cervical material was investigated using only the PapSpin technique. Follow up histological diagnoses for 141 women were obtained from both study arms following 189 abnormal cytology cases. 80 LBC cases from the split sample group and 61 LBC cases in the direct-to-vial group were correlated with the histology results. The sensitivity and secificity of the conventional smear and PapSpin tests in both study arms were compared.

RESULTS

In the split sample group, conventional smears showed a higher proportion of ASC-US (atypical cells undetermined significance): 31 (2.1%) vs 10 (0.7%) in PapSpin (P = 0.001). A higher proportion of unsatisfactory samples was found in the conventional smear group: 25 (1.7%) vs 6 (0.4%) cases (P = 0.001). In the split sample group, the sensitivity of the conventional and PapSpin tests was 68.7% vs 78.1%, and the specificity 93.8% vs 91.8%, respectively. In the direct to vial group PapSpin sensitivity was 75.9% and specificity 96.5%. The differences in sensitivity and specificity were not significant. The positive predictive values for the conventional and PapSpin methods were not different in the split sample group: 88.0% vs 86.2% and 95.7% in the direct-to-vial group. Also, no differences were found for negative predictive value (82.1, 86.8% and 80.0% respectively).

CONCLUSIONS

PapSpin showed good qualitative results in both study arms, even after the material splitting in the first study arm, and is a good alternative to the conventional Pap smear. Additionally, the PapSpin method offers several advantages such as the opportunity to prepare duplicate slides, option for HPV DNA testing and cell block preparations from residual material. Microscopic evaluation of thinner cell preparations is less time consuming than the conventional Pap smears.

Value of centrifugated liquid-based cytology by Papanicolaou and May-Grünwald in oral epithelial cells

For many years, liquid-based cytology (LBC) has been developed for cervical cancer screening and not oral cancer, as it requires automated devices. The aim of this study was to compare the utility of centrifugated CLBC preparation with that of direct preparation in oral lesions, by Papanicolaou (Pap) and May Grünwald-Giemsa's (MGG) methods. A total of 100 consecutive cases of oral lesions were investigated. We compared the results obtained by the CLBC performed by cytocentrifugation with those obtained by direct smear applying Pap and MGG methods. The comparison between CLBC and direct smears was based on the thickening or adequacy of the smear, distribution of cells and staining quality. All smears in CLBC and direct preparation were found adequate. For thickness of the smear, 40% and 42% were excellent, 33% and 30% were good, and 27% and 28% were acceptable by LBC and direct preparation, respectively. For the distribution of cells and scantiness of background elements, 92 (92%) smears of the CLBC have revealed clear, well distributed smears, compared to 70 (70%) of those in direct preparation. For the staining quality with the Pap method, 39% and 69% were excellent staining quality, 25% and 20% were good, and 36% and 11% were acceptable for CLBC and direct preparation, respectively. In MGG method, 9% and 22% were excellent staining quality, 23% and 36% were good and 68% and 43% were acceptable for CLBC and direct preparation respectively. CLBC performed by cytocentrifugation is inexpensive, and reduces inadequate smears and background staining.

Barriers to adoption of recent technology in cervical screening

The Pap smear is one of the modern success stories in the field of preventive medicine. Since its introduction as a screening test, there has been a dramatic reduction in the incidence of cervical cancer. However, the search for a better screening test continues. The new technologies, including liquid-based cytology (LBC), Human Papilloma Virus (HPV) testing and automated or machine-assisted screening have been introduced. However, there is continuous debate about whether society's limited resources are better spent on reaching the underserved rather than on these technologies. Another question is whether these technologies create yet another kind of disparity in delivering preventive care. For example, despite the wide use of LBC (99% of tests submitted to our laboratory are LBC), conventional Pap smears are still used to screen/follow up some women. It is not clear why some providers continue to prefer conventional smear over LBC and what are the barriers for adopting LBC in cervical cancer screening. We hypothesize the lower cost of conventional compared to LBC Pap testing, patient's lower socio-economic indices, a patient's medical history and provider's subspecialty/training all appear to play a role in the choice of using conventional Pap testing rather than LBC. Unintentionally, this choice results in repeat testing, delayed treatment and potentially higher costs than intended. The ultimate goal of this review article is to understand and explore possible barriers and disparities to adopting new technology in cancer screening.

Quantitative real-time polymerase chain reaction analysis of the type distribution, viral load, and physical status of human papillomavirus in liquid-based cytology samples from cervical lesions

Human papillomavirus (HPV) 16 DNA can be integrated into the DNA of cells, thereby disrupting E2 gene expression, which leads to increased expression of the E6 and E7 viral oncogenes and progression to cancer. However, the relationships among HPV viral load, cytologic diagnosis, and HPV integration status remain unclear. The aim of this study was to evaluate the HPV type distribution, viral load, and HPV 16 integration status, and then investigate their relationships with precancerous and cancerous lesions among Japanese women of different age groups. Liquid-based cytology (LBC) samples were examined by quantitative real-time polymerase chain reaction (PCR). The overall mean prevalences of HPV were higher in younger women and lower in middle-aged women among the age groups. The positivity rate of HPV 16 peaked at a younger age than that of all HPV subtypes. The HPV 16 viral load per cell decreased from a low-grade squamous intraepithelial lesion (LSIL) to a cancerous lesion (257.4 for LSIL, 76.9 for high-grade squamous intraepithelial lesions, and 35.7 for cancerous lesions). The average HPV 16 DNA copy numbers for three different HPV 16 integration statuses were 64.1 for the episomal form, 465.5 for the mixed form, and 0.4 for the integrated form. Furthermore, the mean age of patients with the pure integrated form of HPV 16 was more than 10 years older than those of patients with the episomal and mixed forms. Quantitative real-time PCR appears to be a useful method for quantitative and physical status analyses of HPV in cervical cancer screening with LBC samples.

Evaluation of combined general primer-mediated PCR sequencing and type-specific PCR strategies for determination of human papillomavirus genotypes in cervical cell specimens

A strategy combining human papillomavirus general primer (mainly the PGMY primers)-directed PCR sequencing and type-specific PCR is presented. DNA samples were first tested in general primer-mediated PCR. The amplified fragments of positive samples after ethidium bromide-stained DNA gel analysis were further sequenced, and corresponding DNA samples were further analyzed by PCR using type-specific primers for human papillomavirus (HPV) types 16, 18, 31, and 52. The comparison of the results of 157 samples analyzed by this strategy in parallel with the Hybrid Capture 2 tests and with the HPV INNO-LiPA (Innogenetics line probe assay) shows that this method is suitable for HPV detection and genotyping in cervical cell samples. Although the PCR sequencing method is as sensitive as the HPV INNO-LiPA for HPV detection, our method allows the identification of a broader range of HPV types. In contrast, the HPV INNO-LiPA was less time-consuming and better identified coinfections.

ASC-H in Pap test--definitive categorization of cytomorphological spectrum

OBJECTIVE

The American Society for Colposcopy and Cervical Pathology (ASCCP) guidelines for management of ASC-H is colposcopic examination followed by biopsy. HPV testing (HPVT) is recommended after a negative biopsy result. More definitive interpretation of ASC-H could prevent discomfort and minimize the cost. The purpose of this study was to evaluate association of various cytomorphological patterns of ASC-H with various clinical scenarios.

METHODS

We reviewed SurePath (TriPath Imaging, Inc. Burlington, NC, USA) cervical smears interpreted as ASC-H in 161 women (mean age, 37 {15 to 78} years), over 24 months (2002 to 2003). HPVT (Digene, Hybrid Capture II HPV test, Digene Corporation, Gaithersburg, MD, USA) was performed in 20% of cases (33/161) and biopsy results were available in 54 cases (19 with and 35 without HPVT).

RESULTS

HPVT was positive in 64% (21/33) cases, and negative in 36% (12/33) cases. In the follow-up biopsies of 71% (15/21) of cases with positive HPVT, 27% showed HPV changes or CIN1, 27% showed CIN2-3, and 46% were negative for epithelial abnormality. Follow-up biopsies from cases with negative HPVT (33%, 4/12 cases), 8% showed CIN1 and 25% were negative for any epithelial abnormality. Six cytomorphological patterns of ASC-H correlated with different clinical categories in relation to HPVT and biopsy results. 35% (19 out of 54 ASC-H cases in which biopsy results were available) could be interpreted definitively as HSIL by cytopathology, 11% (6/54) cases as LSIL with cyanophilic atypical parakeratotic pattern, and 31% (17/54) cases as reactive, with HPV status. The interpretation had to be continued as ASC-H in 22% (12/54) cases.

CONCLUSION

ASC-H demonstrated a spectrum of cytomorphological patterns. Some of these patterns in liquid-based cervical smears may be more specifically interpreted as LSIL, HSIL, or benign if HPV status is known.