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The cancers of the skin, melanoma and the keratinocyte cancers, basal cell andsquamous cell carcinomas (BCC and SCC), are among the most common cancersin white populations. While ultraviolet radiation (UVR) is their principal cause,links with non-UVR-related factors have also been noted. Ultimately, theinteraction of these elements results in malignancy however, understanding oftheir specific contributions remains incomplete. This thesis reports findings fromsix studies aiming to investigate gaps in current knowledge of the role of UVR andnon-UVR-related risk factors on skin cancer. The papers are groupedaccording to the aspects of skin cancer epidemiology and aetiology they address. The first two papers address the descriptive epidemiology of melanoma inEngland, a country with low ambient solar UVR. They arise from ecologicalstudies using national melanoma registration data and document rising trends inmelanoma incidence by anatomic site (Paper 1), and by region of residence andsocio-economic deprivation (Paper 2). Their findings were consistent with thesuggestion that increases in recreational UVR exposure are driving rises inmelanoma rates. These results emphasise both the need to closely monitor UVRexposure and melanoma trends and the importance of public health campaigns. The second group of three papers considers the assessment of associations ofnutritional factors with keratinocyte cancer. Two studies use data from aprospective cohort to evaluate the relationship between dietary intake (Paper 3)and blood concentrations (Paper 4) of omega-3 and omega-6 polyunsaturatedfatty acids (PUFA) in relation to BCC and SCC risk. Associations with both PUFAtypes were observed. In addition, Paper 5, a three-way correlational assessment,demonstrated that questionnaire and blood circulating levels of omega-3 PUFAwere highly correlated with measures of skin bioavailability. Collectively, thesestudies give evidence for associations of these nutrients with skin cancer and forthe utility of both intake and biomarker measures for assessing the relationships. The final paper explores the relationship between a widely cited non-UVR riskfactor, namely scars and cancers of the skin. It reports a systematic review of allpublished observational studies quantifying this association. While innumerablecase reports were found, quantitative analyses were rare. The review identifieda major gap in the literature where knowledge of scar malignancies is notevidence-based, but rather founded mainly on cumulative anecdotal reporting. Taken together, this body of published work highlights the largely unrecognisedcomplexity of the aetiology of cancers of the skin. Future research must bebroad in scope in order to advance understanding of the interaction betweenUVR and other risk factors and to provide a base for health messages aimed atreducing the burden of these malignancies.

The goal of this project is to create an optimal environment for healing at anincision site in the abdominal fascia. Long cycles of recurring hernias are one of the major complications that patients can endure following surgery. This research project will compare various mesh material embedded with mesenchymal stromal cells (MSC's) to find the optimal environment to enhance hernia repair. The four mesh materials that will be used in this study are Bard Colla Mend, Vicryl Knitted Mesh, Gore-Tex Soft Tissue Patch, and Bard Mesh. Mesh supports have been used in the treatment of hernia repair and MSC's have been used to treat cartilage and cutaneous tissue repair. Since MSC's attach to a collagen matrix, we predict that the MSC's will adhere to the mesh materials. We also predict that MSC's once attached to the mesh materials, will increase the amountof collagen and elastin production at the incision site. The Cell Titer 96 Cell Proliferation Assay will be used to measure the number of MSC's that adhere to the mesh and stains will be used to measure collagen and elastin production. Future studies will examine how MSC's along with mesh supports can be used to strengthen hernia repair sites. Hopefully, this will diminish or eliminate the vicious cycle of hernia reappearance.