Biomedical subjects

Frederic Cas

Publications and source records attributed to Frederic Cas.

3 recordsLinked to original sources

PubMed2007

Triage of women with ASCUS and LSIL cytology: use of qualitative assessment of p16INK4a positive cells to identify patients with high-grade cervical intraepithelial neoplasia.

BACKGROUND: The identification of a small percentage of high-grade cervical intraepithelial neoplasias (HGCIN) among patients with minor cytological abnormalities (atypical squamous cells of undetermined significance [ASCUS] and/or low-grade squamous intraepithelial lesions [LSIL] group) is a major problem in cytology-based cervical cancer screening. The authors investigated the efficacy of p16INK4a as a biomarker to identify samples of patients with HGCIN among those with an ASCUS or LSIL result in Papanicolaou cytology. METHODS: Consecutive liquid-based cytology specimens of 137 ASCUS and 88 LSIL results were selected from gynecologists who adopted a triage regimen with biopsy under colposcopy 2 months later, independent of the p16INK4a result. p16INK4a stained slides were prepared and independently read by 2 observers, who used a recently described score to categorize p16INK4a stained squamous cells. The endpoint of the study was detection of a biopsy-confirmed HGCIN. RESULTS: The overall sensitivity and specificity of p16INK4a positive cells with a nuclear score >2 for diagnosis of HGCIN in ASCUS and LSIL cases combined was 96% and 83%, respectively. The sensitivity and specificity in the ASCUS group was 95% and 84%, and 100% and 81% in the LSIL group, respectively. Two observers had a high concordance in assessing p16INK4a stained cells (kappa value of 0.841). CONCLUSIONS: These data suggested that the use of p16INK4a as a biomarker combined with nuclear scoring of p16INK4a positive cells in cervical cytology to triage ASCUS and/or LSIL cases allows identification of HGCIN with good sensitivity and specificity.

Adolescent↗

PubMed2005

Evaluation of a nuclear score for p16INK4a-stained cervical squamous cells in liquid-based cytology samples.

BACKGROUND: The p16INK4a gene product is overexpressed strongly in abnormal cervical epithelia and may serve as a valuable biomarker to identify abnormal cells in cervical smears or liquid-based cytology samples. METHODS: The authors performed p16INK4a immunocytochemistry to locate cells that expressed p16INK4a in liquid-based cytology samples and used a nuclear scoring system based on several morphologic criteria to interpret the degree of abnormality of these cells. RESULTS: Among 108 samples that were scored as normal in Papanicolaou-stained, parallel slides, any p16INK4a-positive cells were observed in 13 samples (12%), but only 1 of 108 samples (1%) was scored abnormal after applying nuclear scoring criteria. In the group of 52 low-grade squamous intraepithelial lesion (LSIL) samples, 19 samples (37%) were positive for any p16INK4a reactivity, but only 5 of those samples (10%) were scored abnormal after applying the nuclear score. Among the 50 high-grade squamous intraepithelial lesion (HSIL) samples, 49 samples (98%) were positive for p16INK4a and were scored as abnormal. Comparison of the scoring results of independent observers revealed good reproducibility of the nuclear score. CONCLUSIONS: The current results suggested that p16INK4a enables the location of potentially abnormal cells on liquid-based cytology samples. The nuclear score facilitated interpretation of the degree of abnormality of p16INK4a-stained cells. Thus, locating potentially abnormal cells by p16INK4a immunocytochemistry and their interpretation based on the nuclear score described here may help to identify patients with HSIL in cytologic screening programs and may represent a new approach for reducing the number of equivocal or misinterpreted cytologic specimens.

Adolescent↗

PubMedDate not supplied

Human papillomavirus testing with a liquid-based system: feasibility and comparison with reference diagnoses.

OBJECTIVE: To validate the utilization of cervical specimens collected in the fixative liquid used in the CYTO-screen System (SEROA, Monaco) for oncogenic human papillomavirus (HPV) DNA detection by the Hybrid Capture II technique (HCII) (Digene, Gaithersburg, Maryland, U.S.A) by reference to cytologic and/or histologic results. STUDY DESIGN: A technical feasibility study was conducted on 3 modalities of sample preparation before HCII technique, 1 with a proteinase digestion, I with PBS washing and I using the Digene sample conversion kit recommended for ThinPrep medium preparation (Cytyc Corp., Boxborough, Massachusetts, U.S.A.). The stability of cells after storage at days 28, 60 and 90 was tested on 26 positive samples (13 with high initial indices and 13 with low initial indices). Results of HPV testing were compared to cytologic and histologic results on a sample of 98 smears already identified as high grade squamous intraepithelial lesion (HSIL) (48) or low grade squamous intraepithelial lesion (LSIL) (50). A retrospective analysis was then performed on 995 HPV tests perfornmed routinely in 2003 in terms of comparison with the corresponding cytologic and/or histologic results. RESULTS: The HCII technique after direct treatment by proteinase K appeared to be as effective as the Digene sample conversion kit. By using the first technique, all 26 positive cases remained positive at 60 days, but 4 of 13 (30%) with low indices became negative at 90 days. The sensitivity of HPV testing for detecting biopsy- proven cervical intraepithelial neoplasia (CIN) 2 or worse was 100% in the 50 LSIL and 98% in the 48 HSIL samples. In the retrospective study (n = 995), the cytologic diagnoses of atypical squamous cells of undetermined significance (ASC-US) (n=278), LSIL (n = 137) and HSIL (n = 28) were associated with a positive HPVtest in 44%, 75% and 96% of cases, respectively. On a subsample of 156 patients among 278 with a diagnosis of ASC- US, the sensitivity of HPV testingfor detecting CIN 2 or worse was 88%, specificity 57%, positive predictive value 10% and negative predictive value 99%. Performing HPV testing by the HCII technique for cervical specimens collected in the fixative liquid used in the CYTO-screen System is feasible in the context of an ASC-US cytologic diagnosis.

Adolescent↗