BackgroundWhile many studies have reported on occupational allergic contact dermatitis amongst dental personnel, studies on the relevance of patch testing in dental patients are scarce.ObjectivesTo... Show moreBackgroundWhile many studies have reported on occupational allergic contact dermatitis amongst dental personnel, studies on the relevance of patch testing in dental patients are scarce.ObjectivesTo determine the frequency and clinical relevance of contact allergy in patients with intra- and perioral complaints.MethodsA total of 360 patients with intra- and perioral complaints suspected of having a contact allergy were patch-tested with the dental allergen series, European Baseline Series, and extended Amsterdam Baseline Series at Amsterdam University Medical Centers between January 2015 and November 2021.ResultsA total of 285 patients (79.2%) had a positive patch test reaction for either one (18.6%) or multiple allergens (60.6%). Sodium tetrachloropalladate was the most sensitising allergen with 98 patients (27.2%) testing positive, followed by nickel sulphate (23.3%), methylisothiazolinone (15.6%), and fragrance mix I (14.2%). Clinical relevance was found in 68 of 208 patients (32.7%), with patients having one (15.4%) or multiple (17.3%) patch test reactions clinically relevant to their (peri)oral complaints.ConclusionsClinically relevant patch test reactions were frequently seen in dental patients. Although this study provides us with a better understanding on the frequency and clinical relevance of contact allergy in dental patients, further studies are needed to confirm our results. Show less
Ipenburg, N.A.; Sharouni, M.A. el; Doorn, R. van; Diest, P.J. van; Leerdam, M.E. van; Rhee, J.I. van der; ... ; Netherlands Fdn Detection 2022
Although clinical aspects of melanoma have been extensively studied, the literature largely concerns relatively healthy 20-70 years old patients. Special populations, such as the elderly, children,... Show moreAlthough clinical aspects of melanoma have been extensively studied, the literature largely concerns relatively healthy 20-70 years old patients. Special populations, such as the elderly, children, patients with multiple primary melanoma and those with familial melanoma, are frequently excluded from clinical studies. The studies presented in this thesis were aimed to assess prognostic factors and management of patients with clinically localized melanoma, in particular among the aforementioned special populations. Show less
Ipenburg, N.A.; Hage, J.A. van der; Newton-Bishop, J.A.; Harland, M.; Kukutsch, N.A.; Helgadottir, H.; ... ; Doorn, R. van 2020
Background: Mitotic rate is a strong predictor of outcome in adult patients with primary cutaneous melanoma, but for children and adolescent patients this is unknown.Objective: We sought to assess... Show moreBackground: Mitotic rate is a strong predictor of outcome in adult patients with primary cutaneous melanoma, but for children and adolescent patients this is unknown.Objective: We sought to assess the prognostic value of primary tumor mitotic rate in children and adolescents with primary melanoma.Methods: This was a cohort study of 156 patients who were <20 years of age and who had clinically localized cutaneous melanoma. Patients <12 years of age were classified as children and those 12 to 19 years of age as adolescents. Clinicopathologic and outcome data were collected. Recurrence-free and melanoma-specific survival were calculated. Univariable and multivariable analyses were performed using Cox proportional hazard models.Results: Thirteen of 156 patients (8%) were children. The mitotic rate was >= 1/mm(2) in 104 patients (67%) and correlated with increasing Breslow thickness. A positive sentinel node was found in 23 of 61 patients (38%) in whom a sentinel lymph node biopsy specimen was obtained. The median follow-up was 61 months. Five-year melanoma-specific and recurrence-free survival rates were 91% and 84%, respectively. Mitotic rate was a stronger predictor of outcome than tumor thickness and was the only factor independently associated with recurrence-free survival.Limitations: This research was conducted at a single institution and the sample size was small.Conclusion: Mitotic rate is an independent predictor of recurrence-free survival in children and adolescents with clinically localized melanoma. Show less
Ipenburg, N.A.; Nieweg, O.E.; Ahmed, T.; Doorn, R. van; Scolyer, R.A.; Long, G.V.; ... ; S. lo 2019
Background Identifying patients with sentinel node-negative melanoma at high risk of recurrence or death is important. The European Organisation for Research and Treatment of Cancer (EORTC)... Show moreBackground Identifying patients with sentinel node-negative melanoma at high risk of recurrence or death is important. The European Organisation for Research and Treatment of Cancer (EORTC) recently developed a prognostic model including Breslow thickness, ulceration and site of the primary tumour. The aims of the present study were to validate this prognostic model externally and to assess whether it could be improved by adding other prognostic factors. Methods Patients with sentinel node-negative cutaneous melanoma were included in this retrospective single-institution study. The beta values of the EORTC prognostic model were used to predict recurrence-free survival and melanoma-specific survival. The predictive performance was assessed by discrimination (c-index) and calibration. Seeking to improve the performance of the model, additional variables were added to a Cox proportional hazards model. Results Some 4235 patients with sentinel node-negative cutaneous melanoma were included. The median follow-up time was 50 (i.q.r. 18 center dot 5-81 center dot 5) months. Recurrences and deaths from melanoma numbered 793 (18 center dot 7 per cent) and 456 (10 center dot 8 per cent) respectively. Validation of the EORTC model showed good calibration for both outcomes, and a c-index of 0 center dot 69. The c-index was only marginally improved to 0 center dot 71 when other significant prognostic factors (sex, age, tumour type, mitotic rate) were added. Conclusion This study validated the EORTC prognostic model for recurrence-free and melanoma-specific survival of patients with negative sentinel nodes. The addition of other prognostic factors only improved the model marginally. The validated EORTC model could be used for personalizing follow-up and selecting high-risk patients for trials of adjuvant systemic therapy. Show less
Ipenburg, N.A.; Gruis, N.A.; Bergman, W.; Kester, M.S. van 2016