Support for the use of Mohs Micrographic Surgery for Skin Cancer

In this thesis, different aspects of the quality of standard excision and Mohs micrographic surgery for skin cancer are analysed and compared. The results presented in this thesis should help patients and clinicians to position Mohs micrographic surgery better in their skin cancer treatment strategies

Differences in rate of complete excision of basal cell carcinoma by dermatologists, plastic surgeons and general practitioners

__Background:__ Due to the increasing incidence of basal cell carcinoma (BCC) and rising health care costs, health care insurance companies seek ways to shift skin surgery for BCC from secondary to primary care. __Objectives:__ To study the differences in complete excision of BCC by general practitioners (GPs), dermatologists, and plastic surgeons. Methods: A retrospective cross-sectional study of pathology records of 2,986 standard excisions of primary BCCs performed by a GP, dermatologist, or plastic surgeon in the area of Southwest Netherlands between 2008 and 2014. To compare the risk of an incomplete BCC excision between the specialties, the odds ratio (OR) was used adjusted for patient age, sex, tumor site, size, and histological subtype. __Results:__ BCCs were completely excised by GPs in 70%, which was lower than the 93% by dermatologists and 83% by plastic surgeons (p < 0.001). Compared to the dermatologist, BCCs which were excised by a GP were 6 times higher at risk of an incomplete excision (adjusted OR 6, 95% CI 5-8) and 2 times higher at risk when excised by a plastic surgeon (adjusted OR 2, 95% CI 2-3). __Conclusion:__ BCCs were more often completely exc

Rare disease registries : Potential applications towards impact on development of new drug treatments

Background: Low prevalence, lack of knowledge about the disease course, and phenotype heterogeneity hamper the development of drugs for rare diseases. Rare disease registries (RDRs) can be helpful by playing a role in understanding the course of the disease, and providing information necessary for clinical trial design, if designed and maintained properly. We describe the potential applications of a RDR and what type of information should be incorporated to support the design of clinical trials in the process of drug development, based on a broad inventory of registry experience. We evaluated two existing RDRs in more detail to check the completeness of these RDRs for trial design. Results: Before and during the application for regulatory approval a RDR can improve the efficiency and quality in clinical trial design by informing the sample size calculation and expected disease course. In exceptional circumstances information from RDRs has been used as historical controls for a one-armed clinical trial, and high quality RDRs may be used for registry-based randomized controlled trials. In the post marketing phase of (conditional) drug approval a disease-specific RDR is likely to provide more relevant information than a product-specific registry. Conclusions: A RDR can be very helpful to improve the efficiency and quality of clinical trial design in several ways. To enable the applicability and optimal use of a RDR longitudinal data collection is indispensable, and specific data collection, prepared for repeated measurement, is needed. The developed checklist can help to define the appropriate variables to include. Attention should be paid to the inclusion of patient-relevant outcome measures in the RDR from the start. More research and experience is needed on the possibilities and limitations of combining RDR information with clinical trial data to maximize the availability of relevant evidence for regulatory decisions in rare diseases