Host phenotype characteristics and MC1R in relation to early-onset basal cell carcinoma.

Basal cell carcinoma (BCC) incidence is increasing, particularly among adults under the age of 40 years. Pigment-related characteristics are associated with BCC in older populations, but epidemiologic studies among younger individuals and analyses of phenotype-genotype interactions are limited. We examined self-reported phenotypes and melanocortin 1 receptor gene (MC1R) variants in relation to early-onset BCC. BCC cases (n=377) and controls with benign skin conditions (n=390) under the age of 40 years were identified through Yale's Dermatopathology database. Factors most strongly associated with early-onset BCC were skin reaction to first summer sun for 1 hour (severe sunburn vs. tan odds ratio (OR)=12.27, 95% confidence interval (CI)=4.08-36.94) and skin color (very fair vs. olive OR=11.06, 95% CI=5.90-20.74). Individuals with two or more MC1R non-synonymous variants were 3.59 times (95% CI=2.37-5.43) more likely to have BCC than those without non-synonymous variants. All host characteristics and MC1R were more strongly associated with multiple BCC case status (37% of cases) than a single BCC case status. MC1R, number of moles, skin reaction to first summer sun for 1 hour, and hair and skin color were independently associated with BCC. BCC risk conferred by MC1R tended to be stronger among those with darker pigment phenotypes, traditionally considered to be at low risk of skin cancer

PTCH mutations and deletions in patients with typical nevoid basal cell carcinoma syndrome and in patients with a suspected genetic predisposition to basal cell carcinoma: a French study

The patched (PTCH) mutation rate in nevoid basal cell carcinoma syndrome (NBCCS) reported in various studies ranges from 40 to 80%. However, few studies have investigated the role of PTCH in clinical conditions suggesting an inherited predisposition to basal cell carcinoma (BCC), although it has been suggested that PTCH polymorphisms could predispose to multiple BCC (MBCC). In this study, we therefore performed an exhaustive analysis of PTCH (mutations detection and deletion analysis) in 17 patients with the full complement of criteria for NBCCS (14 sporadic and three familial cases), and in 48 patients suspected of having a genetic predisposition to BCC (MBCC and/or age at diagnosis ⩽40 years and/or familial BCC). Eleven new germline alterations of the PTCH gene were characterised in 12 out of 17 patients harbouring the full complement of criteria for the syndrome (70%). These were frameshift mutations in five patients, nonsense mutations in five patients, a small inframe deletion in one patient, and a large germline deletion in another patient. Only one missense mutation (G774R) was found, and this was in a patient affected with MBCC, but without any other NBCCS criterion. We therefore suggest that patients harbouring the full complement of NBCCS criteria should as a priority be screened for PTCH mutations by sequencing, followed by a deletion analysis if no mutation is detected. In other clinical situations that suggest genetic predisposition to BCC, germline mutations of PTCH are not common

Melanocortin-1 Receptor, Skin Cancer and Phenotypic Characteristics (M-SKIP) Project: Study Design and Methods for Pooling Results of Genetic Epidemiological Studies

Background: For complex diseases like cancer, pooled-analysis of individual data represents a powerful tool to investigate the joint contribution of genetic, phenotypic and environmental factors to the development of a disease. Pooled-analysis of epidemiological studies has many advantages over meta-analysis, and preliminary results may be obtained faster and with lower costs than with prospective consortia. Design and methods: Based on our experience with the study design of the Melanocortin-1 receptor (MC1R) gene, SKin cancer and Phenotypic characteristics (M-SKIP) project, we describe the most important steps in planning and conducting a pooled-analysis of genetic epidemiological studies. We then present the statistical analysis plan that we are going to apply, giving particular attention to methods of analysis recently proposed to account for between-study heterogeneity and to explore the joint contribution of genetic, phenotypic and environmental factors in the development of a disease. Within the M-SKIP project, data on 10,959 skin cancer cases and 14,785 controls from 31 international investigators were checked for quality and recoded for standardization. We first proposed to fit the aggregated data with random-effects logistic regression models. However, for the M-SKIP project, a two-stage analysis will be preferred to overcome the problem regarding the availability of different study covariates. The joint contribution of MC1R variants and phenotypic characteristics to skin cancer development will be studied via logic regression modeling. Discussion: Methodological guidelines to correctly design and conduct pooled-analyses are needed to facilitate application of such methods, thus providing a better summary of the actual findings on specific fields

Incidence of cancer in first-degree relatives of basal cell carcinoma patients.

Contains fulltext : 80253.pdf (publisher's version ) (Closed access)There is evidence to suggest that genetic factors play an important role in the development of basal cell carcinomas (BCCs), and that skin neoplasms might be a sign for a genetic predisposition to cancer. We investigated whether the incidence of visceral and skin malignancies among first-degree relatives of BCC-patients was increased. Postal questionnaires were sent to 249 BCC-patients, who were divided into two groups (young = BCC under the age of 51 years and older = BCC over the age of 50 years), and asked them about cancer in their first-degree relatives. The reported numbers of cancer among the relatives were compared with the expected numbers based on sex and age-specific population-based incidence rates. The accuracy of the reported diagnoses was verified. A total of 157 BCC-patients reported 277 malignancies in 1,272 relatives. The incidence of the following cancers was higher than expected in relatives from young BCC-patients: bone and soft tissue (O/E = 3.91; 95% CI: 1.43-8.66), skin (O/E = 2.13; 95% CI: 1.30-3.29) and digestive tract (O/E = 1.59; 95% CI: 1.10-2.23). In relatives of older BCC-patients, only the incidence of digestive tract cancer was higher than expected (O/E = 1.44; 95% CI: 1.08-1.89). Diagnoses that were verified turned out to be accurate in 87% of the cases. This study suggests that the risk of certain cancers, particularly that of the digestive tract, in first-degree relatives of BCC-patients is increased. These findings may indicate a genetic predisposition to both skin and visceral malignancies in this patient group

Basal cell carcinoma: a paradigm for targeted therapies

INTRODUCTION: Basal cell carcinoma (BCC) is the most frequent cancer with increasing incidence over the last decades. Standard of care is surgical excision, upon which complete tumour clearance is achieved in most cases. However, a small subgroup of patients will have remnants of disease post-excision and require further treatment options. Over 90% of all BCCs carry a mutation in PTCH 1 or SMO, two conducting proteins of the Hedgehog pathway (Hh). Therefore, inhibition of the Hh pathway is a promising option for systemic first-line therapy. Vismodegib was the first developed of these small molecules, which was approved by the FDA in January 2012. AREAS COVERED: The authors review current treatment modalities for BCC and discuss current developments in pharmacological therapy. The current literature including meta-analyses, the Cochrane database and registered as well as completed randomized controlled trials. EXPERT OPINION: Hh inhibitors are a new promising treatment option for patients with advanced or metastatic BCC. Phase I and II clinical trials with the Hh inhibitor, vismodegib, showed a significant reduction in tumour size and appearance of new tumours with relatively good tolerability. Nevertheless, further investigation on new molecules and the effectiveness of an intermittent dosing regimen is necessary