Irene A M van der Avoort

Catharina Ziekenhuis, Eindhoven, North Brabant, Netherlands

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Publications (13)41.35 Total impact

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    Article: High levels of p53 expression correlate with DNA aneuploidy in (pre)malignancies of the vulva.
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    ABSTRACT: The molecular pathogenesis of human papilloma virus-unrelated vulvar squamous cell carcinoma is not well known. Whether malignant progression of lichen sclerosus and differentiated vulvar intraepithelial neoplasia to vulvar squamous cell carcinoma could be accompanied by altered DNA content has not been studied extensively. DNA content in isolated nuclei of microdissected normal vulvar epithelium (n = 2), lichen sclerosus (n = 9), differentiated vulvar intraepithelial neoplasia (n = 13), and squamous cell carcinoma (n = 17) from 22 patients was measured via DNA image cytometry. For additional analysis, 6 differentiated vulvar intraepithelial neoplasia lesions were selected, bringing the number of patients to 28. p53 expression was determined by immunohistochemistry on consecutive tissue sections. Thirty-eight percent (5/13) of differentiated vulvar intraepithelial neoplasia lesions and 65% (11/17) of squamous cell carcinomas were DNA aneuploid or tetraploid. In lesions that contained differentiated vulvar intraepithelial neoplasia and adjacent squamous cell carcinoma, the ploidy status of differentiated vulvar intraepithelial neoplasia did not exceed that of squamous cell carcinoma. We observed a strong correlation between high p53 expression and DNA aneuploidy. This relation was also present at the level of a single nucleus, measured by sequential image cytometry of p53 immunohistochemistry followed by DNA image cytometry on formalin-fixed tissue sections. Similarly, we found p53-positive nonproliferating cells with increased DNA content in the superficial compartment of 6 additional solitary differentiated vulvar intraepithelial neoplasia lesions that were not associated with squamous cell carcinoma, indicating ascending aneuploid cells from the basal compartment. DNA ploidy measurements suggest that differentiated vulvar intraepithelial neoplasia has a higher malignant potential than lichen sclerosus and thus is a more likely precursor of squamous cell carcinoma. Furthermore, high p53 expression correlates with increased DNA content and aneuploidy; but it requires further research to unveil a possible causal relation.
    Human pathology 10/2010; 41(10):1475-85. · 3.03 Impact Factor
  • Article: A patient with lichen sclerosus, Langerhans cell histiocytosis, and invasive squamous cell carcinoma of the vulva.
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    ABSTRACT: We report a patient with vulvar lichen sclerosus, Langerhans cell histiocytosis (LCH), and later vulvar cancer. In LCH, high amounts of non functional Langerhans cells are present in the affected tissue, making it possible that LCH may have contributed to vulvar cancer development in this patient.
    American journal of obstetrics and gynecology 08/2010; 203(2):e7-10. · 3.28 Impact Factor
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    Article: The prognostic value of blood and lymph vessel parameters in lichen sclerosus for vulvar squamous cell carcinoma development: an immunohistochemical and electron microscopy study.
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    ABSTRACT: The objective of the study was to quantify vessel type and density in lichen sclerosus (LS) to find a marker for its malignant potential. Quantitative analysis was performed on paraffin-embedded tissue samples of 28 patients with LS (7 adjacent to vulvar squamous cell carcinoma, 21 solitary) and immunohistochemical staining for CD34 (vascular and lymphangiogenic lymph endothelial cells), D2-40 (lymphatic-specific marker), and alpha-SMA (pericyte marker). Electron microscopy was performed on fresh tissue. No significant differences in vessel density or other vessel parameters could be demonstrated between the 2 groups. In hyalinized lesions, vessel diameter, and alpha-SMA positivity was reduced compared with nonhyalinized lesions. Electron microscopy revealed detachment of pericytes from vascular endothelial cells and increased thickening of basement membrane, whereas endothelial cell function did not appear strongly impaired. Malignant potential of LS cannot be predicted by vessel characteristics. Hyalinization in LS is associated with pericyte detachment from the basal lamina of vascular endothelial cells.
    American journal of obstetrics and gynecology 08/2010; 203(2):167.e1-8. · 3.28 Impact Factor
  • Article: Lichen sclerosus: treatment and follow-up at the departments of gynaecology and dermatology.
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    ABSTRACT: To compare the treatment and follow-up of patients with lichen sclerosus (LS) at the departments of Gynaecology and Dermatology at the Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands, to evaluate the need for a multidisciplinary vulvar clinic. Treatment and follow-up data of all women with histologically proven (between January 1995 and January 2001) anogenital LS visiting the outpatient clinics of the departments of Obstetrics & Gynaecology and Dermatology were collected (last date of follow-up: January 2008). Eighty-four patients with LS were included in this study, 10 patients (12%) of which were treated by both specialties. At the Gynaecology department, LS patients more often received surgical treatment, topical estrogens, and lidocaine ointment, whereas at the Dermatology department, local class 2/3 corticosteroids were more often prescribed. Follow-up frequencies were similar in both specialties and took place at 3 to 4 visits in the first year and at least once a year afterward. One patient developed vulvar squamous cell carcinoma. This patient had withdrawn from follow-up and had her condition diagnosed with carcinoma 74 months after the LS had been diagnosed. Although no hospital guidelines existed, management of patients with LS agreed with current recommendations in the literature, although differences in secondary and supportive therapy existed owing to differences in expertise. The relatively high percentage of patients treated by both specialties with a high frequency of visits emphasizes the need for a multidisciplinary clinic for vulvar disease.
    Journal of Lower Genital Tract Disease 04/2010; 14(2):118-23. · 1.07 Impact Factor
  • Article: Lichen Sclerosus: Treatment and Follow-Up at the Departments of Gynaecology and Dermatology
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    ABSTRACT: Objective: To compare the treatment and follow-up of patients with lichen sclerosus (LS) at the departments of Gynaecology and Dermatology at the Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands, to evaluate the need for a multidisciplinary vulvar clinic. Materials and Methods: Treatment and follow-up data of all women with histologically proven (between January 1995 and January 2001) anogenital LS visiting the outpatient clinics of the departments of Obstetrics & Gynaecology and Dermatology were collected (last date of follow-up: January 2008). Results: Eighty-four patients with LS were included in this study, 10 patients (12%) of which were treated by both specialties. At the Gynaecology department, LS patients more often received surgical treatment, topical estrogens, and lidocaine ointment, whereas at the Dermatology department, local class 2/3 corticosteroids were more often prescribed. Follow-up frequencies were similar in both specialties and took place at 3 to 4 visits in the first year and at least once a year afterward. One patient developed vulvar squamous cell carcinoma. This patient had withdrawn from follow-up and had her condition diagnosed with carcinoma 74 months after the LS had been diagnosed. Conclusions: Although no hospital guidelines existed, management of patients with LS agreed with current recommendations in the literature, although differences in secondary and supportive therapy existed owing to differences in expertise. The relatively high percentage of patients treated by both specialties with a high frequency of visits emphasizes the need for a multidisciplinary clinic for vulvar disease.
    Journal of Lower Genital Tract Disease 03/2010; 14(2):118-123. · 1.07 Impact Factor
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    Article: Vulvar squamous cell carcinoma development after diagnosis of VIN increases with age.
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    ABSTRACT: The purpose of the present study is to investigate the trends in incidence of both usual (u) and differentiated (d) vulvar intraepithelial neoplasia (VIN) separately, their malignant potential and the relation with other HPV related anogenital lesions in the Netherlands during a 14-year-period. The incidences of both types of VIN and vulvar SCC were retrieved from the Nationwide Netherlands Database of Histo- and Cytopathology. Population data were retrieved from the Database of Statistics Netherlands. In the study period, the incidence of uVIN and dVIN increased, while the incidence of vulvar SCC remained stable. The overall percentage of uVIN patients that were later diagnosed with vulvar SCC was 5.7%, which was significantly lower than the percentage for dVIN patients (32.8%). In addition to this 5.6-fold increased conversion rate, the time of progression from dVIN to SCC development was significantly shorter than that of uVIN (p=0.005). Percentage of uVIN patients that were later diagnosed with SCC significantly increased with age (p=0.005), whereas the time to SCC significantly shortened with age (p=0.05). Forty-one percent of uVIN patients had a past, concomitant or future HPV-associated lesion of the lower genital tract, which is in contrast to the 3% for dVIN patients. An increase in diagnoses of both uVIN and dVIN has not led to an increase in vulvar SCC incidence. The malignant potential of dVIN is higher than that for uVIN. For uVIN the malignant potential increases with age.
    European journal of cancer (Oxford, England: 1990) 01/2009; 45(5):851-6. · 4.12 Impact Factor
  • Article: A panel of p16INK4A, MIB1 and p53 proteins can distinguish between the 2 pathways leading to vulvar squamous cell carcinoma
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    ABSTRACT: Two pathways leading to vulvar squamous cell carcinoma (SCC) exist. The expression of proliferation- and cell-cycle-related biomarkers and the presence of high-risk (hr) HPV might be helpful to distinguish the premalignancies in both pathways. Seventy-five differentiated vulvar intra-epithelial neoplasia (VIN)-lesions with adjacent SCC and 45 usual VIN-lesions (32 solitary and 13 with adjacent SCC) were selected, and tested for hr-HPV DNA, using a broad-spectrum HPV detection/genotyping assay (SPF10-LiPA), and the immunohistochemical expression of MIB1, p16INK4A and p53. All differentiated VIN-lesions were hr-HPV- and p16-negative and in 96% MIB1-expression was confined to the parabasal layers. Eighty-four percent exhibited high p53 labeling indices, sometimes with parabasal extension. Eighty percent of all usual VIN-lesions were hr-HPV-positive, p16-positive, MIB1-positive and p53-negative. Five (of seven) HPV-negative usual VIN lesions, had an expression pattern like the other HPV-positive usual VIN lesions. In conclusion, both pathways leading to vulvar SCC have their own immunohistochemical profile, which can be used to distinguish the 2 types of VIN, but cannot explain differences in malignant potential. © 2008 Wiley-Liss, Inc.
    International Journal of Cancer 12/2008; 123(12):2767 - 2773. · 5.44 Impact Factor
  • Article: A panel of p16(INK4A), MIB1 and p53 proteins can distinguish between the 2 pathways leading to vulvar squamous cell carcinoma.
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    ABSTRACT: Two pathways leading to vulvar squamous cell carcinoma (SCC) exist. The expression of proliferation- and cell-cycle-related biomarkers and the presence of high-risk (hr) HPV might be helpful to distinguish the premalignancies in both pathways. Seventy-five differentiated vulvar intra-epithelial neoplasia (VIN)-lesions with adjacent SCC and 45 usual VIN-lesions (32 solitary and 13 with adjacent SCC) were selected, and tested for hr-HPV DNA, using a broad-spectrum HPV detection/genotyping assay (SPF(10)-LiPA), and the immunohistochemical expression of MIB1, p16(INK4A) and p53. All differentiated VIN-lesions were hr-HPV- and p16-negative and in 96% MIB1-expression was confined to the parabasal layers. Eighty-four percent exhibited high p53 labeling indices, sometimes with parabasal extension. Eighty percent of all usual VIN-lesions were hr-HPV-positive, p16-positive, MIB1-positive and p53-negative. Five (of seven) HPV-negative usual VIN lesions, had an expression pattern like the other HPV-positive usual VIN lesions. In conclusion, both pathways leading to vulvar SCC have their own immunohistochemical profile, which can be used to distinguish the 2 types of VIN, but cannot explain differences in malignant potential.
    International Journal of Cancer 10/2008; 123(12):2767-73. · 5.44 Impact Factor
  • Article: MIB1 expression in basal cell layer: a diagnostic tool to identify premalignancies of the vulva.
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    ABSTRACT: Lichen sclerosus, high-grade usual vulvar intraepithelial neoplasia (VIN) and differentiated VIN have a different malignant potential. The objective of this study was to quantify the proliferative activity in the basal region of the epithelium of vulvar premalignancies. Furthermore, we investigated whether MIB1 expression in the basal region of vulvar epithelium can be helpful in diagnosing differentiated VIN, which may be hard to discern from normal epithelium. MIB1 was used to immunohistochemically visualise proliferating cells within formalin-fixed, paraffin-embedded, archival tissue sections of different vulvar premalignancies (N=48) and normal vulvar epithelium (N=16). Automatic digital image analysis software was developed to quantify the proliferating fraction in different parts of the epithelium (MIB1 positivity index). MIB1 expression differed among the various vulvar premalignancies; a MIB1-negative basal cell layer was a distinct feature of normal vulvar epithelium. No MIB1-negative basal cell layer was noted in differentiated VIN or other vulvar premalignancies. Owing to this negative cell layer, the MIB1 proliferation index in normal vulvar epithelium was significantly lower than in vulvar premalignancies. In conclusion, MIB1 expression can be a helpful tool in diagnosing a premalignancy and has additional value especially to distinguish differentiated VIN neoplasia from normal vulvar epithelium, but cannot explain the differences in malignant potential.
    Modern Pathology 08/2007; 20(7):770-8. · 4.79 Impact Factor
  • Article: p14ARF and p16INK4A, two products of the same gene, are differently expressed in cervical intraepithelial neoplasia.
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    ABSTRACT: To study the expression patterns of two different tumor suppressor proteins p16INK4A and p14ARF in cervical lesions. Both proteins are encoded by the same INK4A/ARF gene on chromosome 9p21. The expression patterns of these two proteins, both playing a central role in the cell cycle, were analyzed in detail in CIN, carcinomas, and normal epithelium to test the hypothesis that p16INK4A positive cells also demonstrate p14ARF expression. Serial tissue sections of 9 CIN1 lesions, 10 CIN2 lesions, 12 CIN3 lesions, and 7 carcinomas were stained with monoclonal antibodies against p16INK4A and p14ARF. The short fragment polymerase chain reaction hybridization line probe assay was used to detect HPV. Normal epithelium was negative for both proteins. Marked immunoreactivity (++) for p16INK4A and p14ARF was observed in 5/7 carcinomas, 10/12 CIN3, and 1/10 CIN2 lesions and 0/9 CIN1 lesions. Simultaneous expression (+ or ++) was found in 19/22 CIN2/3 and not in CIN1 lesions. The fraction of p16INK4A-stained cells increased with CIN-grade. Overexpression of p14ARF was observed in a subpopulation of p16INK4A positive cells, and exclusively found in lesions infected with high-risk HPV. In two CIN3 lesions with early stromal invasion, p14ARF positivity was mainly found in the invasive cells. In carcinomas, all cells showed p16INK4A expression, whereas p14ARF was limited to the peripheral cells of the invasive tumor nests and individual migrating tumor cells. Overexpression of p14ARF is limited to a fraction of the p16INK4A-expressing cells and therefore it is likely that p14ARF- and p16INK4A expression are not induced by the same mechanisms. Before expression of p14ARF can be linked to invasion or invasive phenotype, larger series of (micro-) invasive squamous lesions need to be studied.
    Gynecologic Oncology 07/2006; 101(3):487-94. · 3.89 Impact Factor
  • Article: Phenotypic characteristics of male subfertility and its familial occurrence.
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    ABSTRACT: Genetic factors can attribute to male subfertility. A case-control study was carried out to investigate familial occurrence of male subfertility and the phenotypic characteristics of familial male subfertility. The medical data and family histories of 253 severely subfertile men who were candidates for intracytoplasmic sperm injection were compared to the data from 243 randomly selected men. The prevalence of male fertility problems among brothers and maternal uncles of subfertile men was significantly higher than among controls (brothers 10.4% vs 0.5% and maternal uncles 1.7% vs 0.2%). The phenotypes of subfertile men with a positive family history more often showed normal levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) compared to the phenotypes of subfertile men with a negative family history. In addition, subfertile men with a positive family history had a lower percentage of motile sperm. Genetic aberrations, including a chromosomal abnormality or a microdeletion of the Y chromosome, were present in 13.8% of the severely subfertile men. Male subfertility appears to have a familial occurrence, especially among brothers and maternal uncles. Furthermore, examination of the data suggests that subfertile men with a familial occurrence of male subfertility more often have normal levels of FSH and LH and a lower percentage of motile sperm.
    Journal of Andrology 25(5):819-23. · 2.97 Impact Factor
  • Article: Underestimation of subfertility among relatives when using a family history: taboo bias.
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    ABSTRACT: Family history is widely used in clinical practice and research in order to study genetic aspects of disorders in general, and is recommended as a tool in the assessment of male subfertility. Unfortunately, little is known about the validity of this tool. In this survey, we sent questionnaires to 474 randomly selected men aged 25-40 years in order to collect data on subfertility among them and their relatives. A nonresponder study was also conducted in order to evaluate selection bias. A personal interview was also performed with some respondents in order to gauge how well the data corresponded with questionnaires that were returned. Two hundred forty-three men (51.3%) completed the questionnaire. The responders reported a significantly lower prevalence of subfertility among their relatives than among themselves. Among brothers, the reported prevalence was about 5 times lower (ie, 3.6%) than among responders (15.3%). The nonresponder study and personal interviews showed that these differences were not caused by a selective response to the survey or by the use of a questionnaire instead of a personal interview. We conclude that subfertility among relatives is severely underestimated through the use of family history, probably because of the taboo of discussing subfertility. Knowledge of subfertility may spread selectively within families, causing substantial misclassification. Therefore, researchers and clinicians should be aware that an inquiry of family history is likely to lead to underestimation of subfertility among relatives.
    Journal of Andrology 24(2):285-8. · 2.97 Impact Factor
  • Article: p14ARF and p16INK4A, two products of the same gene, are differently expressed in cervical intraepithelial neoplasia
    [show abstract] [hide abstract]
    ABSTRACT: Objective.To study the expression patterns of two different tumor suppressor proteins p16INK4A and p14ARF in cervical lesions. Both proteins are encoded by the same INK4A/ARF gene on chromosome 9p21. The expression patterns of these two proteins, both playing a central role in the cell cycle, were analyzed in detail in CIN, carcinomas, and normal epithelium to test the hypothesis that p16INK4A positive cells also demonstrate p14ARF expression.Methods.Serial tissue sections of 9 CIN1 lesions, 10 CIN2 lesions, 12 CIN3 lesions, and 7 carcinomas were stained with monoclonal antibodies against p16INK4A and p14ARF. The short fragment polymerase chain reaction hybridization line probe assay was used to detect HPV.Results.Normal epithelium was negative for both proteins. Marked immunoreactivity (++) for p16INK4A and p14ARF was observed in 5/7 carcinomas, 10/12 CIN3, and 1/10 CIN2 lesions and 0/9 CIN1 lesions. Simultaneous expression (+ or ++) was found in 19/22 CIN2/3 and not in CIN1 lesions. The fraction of p16INK4A-stained cells increased with CIN-grade. Overexpression of p14ARF was observed in a subpopulation of p16INK4A positive cells, and exclusively found in lesions infected with high-risk HPV. In two CIN3 lesions with early stromal invasion, p14ARF positivity was mainly found in the invasive cells. In carcinomas, all cells showed p16INK4A expression, whereas p14ARF was limited to the peripheral cells of the invasive tumor nests and individual migrating tumor cells.Conclusions.Overexpression of p14ARF is limited to a fraction of the p16INK4A-expressing cells and therefore it is likely that p14ARF− and p16INK4A expression are not induced by the same mechanisms. Before expression of p14ARF can be linked to invasion or invasive phenotype, larger series of (micro-) invasive squamous lesions need to be studied.
    Gynecologic Oncology.