Vitamin D axis and its role in skin carcinogenesis: a comprehensive review

Vitamin D (VD) is a secosteroid hormone that is mainly synthesized in the skin upon exposure to UVB radiation. VD is widely known for its role in calcium metabolism; however, multiple endocrine, paracrine and autocrine functions of VD have been described, including a prominent role on carcinogenesis. In recent years, multiple associations between VD deficiency and different types of cancer have been described, supported by evidence of anti-proliferative, anti-angiogenic, pro-apoptotic, cell-differentiating and anti-invasive effects of this hormone. An immunomodulatory role of VD associated to cancer microenvironment has also been suggested. Regarding skin cancer, it has been shown that VD inhibits tumor development in basal cell carcinoma, squamous cell carcinoma, and melanoma in vitro. Some studies have suggested that lower VD levels may be a risk factor for skin cancer, while others have shown the opposite; there is also preliminary evidence on the role of VD supplementation for the prevention of melanoma in vivo. In this review, we explore the mechanisms of VD effects on carcinogenesis and the available scientific evidence of the interplay between VD and the genesis of both non-melanoma and melanoma skin cancer. (AU)

Falta de reconocimiento de osteoporosis y omisión de tratamiento en adultos mayores con fractura de cadera en Chile / Missed diagnosis of osteoporosis and failure to treat adults with hip fracture in Chile

BACKGROUND: Hip fractures are the most severe complication of osteoporosis, yet patients who suffer hip fracture rarely receive adequate treatment. AIM: To assess diagnosis and treatment of osteoporosis in patients with hip fracture. PATIENTS AND METHODS: A retrospective study in 203 patients admitted for hip fracture surgery at two medical institutions in Santiago, Chile. Clinical data from 101 patients from the Hospital Clínico Pontificia Universidad Católica de Chile (a university tertiary care hospital, HCPUC) and 102 patients from Hospital de Urgencia de la Asistencia Pública (a public emergency hospital, HUAP) were reviewed. We also evaluated incidence of new fractures, further treatment of osteoporosis and functionality, by means of a telephonic survey of 48 per cent of patients (n = 99) 12.3 +/- 5.3 months after hip fracture in HCPUC and 16.5 +/- 3.0 months for HUAP. RESULTS: A previous diagnosis of osteoporosis was present in 2.9 per cent and 1 per cent of cases, and treatment prior to fracture in 3.9 per cent and 0 per cent of cases from HCPUC and HUAP, respectively. None of the patients in HUAP were diagnosed with osteoporosis during hospital stay or given treatment for this condition at discharge, in comparison to 0.9 per cent (n = 1) and 2 per cent (n = 2), respectively, in HCPUC. Seven and six percent of cases presented prior hip fractures. Telephonic follow up of patients revealed that 75.6 per cent persisted without treatment for osteoporosis. At follow up, 2.9 per cent and 3 per cent of patients in HCPUC and HUAP had presented new hip fractures. At the time of survey 30.9 per cent and 34 per cent of patients, respectively, were considered invalid. CONCLUSIONS: Missed diagnosis and failure to treat osteoporosis occurred in over 90 per cent of patients admitted for hip fracture, regardless of the different complexities in the hospitals of admission. The data suggest that lack of medical action on these issues may play a role in failure to prevent new hip fractures.