Dawn C. Allain

Merkel Cell Polyomavirus in Cutaneous Squamous Cell Carcinoma of Immunocompetent Individuals

Squamous cell carcinoma (SCC) is the second most frequently diagnosed skin cancer. It has a higher incidence in immunosuppressed individuals such as organ transplant recipients and human immunodeficiency virus (HIV) carriers. Recently, a newly described polyoma virus, Merkel cell polyomavirus (MCPyV), was found in Merkel cell carcinoma (MCC), a rare aggressive skin cancer also associated with immunosuppression. We hypothesized that MCPyV would be present in SCCs. To test for the presence of MCPyV in immunocompetent SCC patients, we used PCR primer sets directed against the large T (LT) antigen and VP1 gene of MCPyV. We detected MCPyV in 15% (26/177) of SCC DNA samples and 17% (11/63) of adjacent skin DNA samples from 21 of 58 (36%) individuals studied. We did not detect MCPyV in any matched normal blood DNA (0/57), but observed the presence of MCPyV DNA in 1 of 12 normal mouthwash DNAs. All sequenced SCC samples had a common mutation truncating the LT antigen that provides indirect evidence of viral integration. The presence of MCPyV in approximately 15% of SCCs from immunocompetent individuals warrants evaluation of MCPyV as an etiologic agent in the carcinogenesis of SCC.

Genetic Counseling and Testing for Common Hereditary Breast Cancer Syndromes: A Paper from the 2007 William Beaumont Hospital Symposium on Molecular Pathology

Throughout the past 15 years, the identification of several genes associated with hereditary breast cancer has fueled the growth of clinical genetic counseling and testing services. In addition, increased knowledge of the genetic and molecular pathways of the known hereditary breast cancer genes, as well as an increased understanding of the impact of testing on individuals has added to the ability to identify, manage, and provide psychosocial support for mutation carriers. This review provides an overview of the clinical features, cancer risks, causative genes, and management for hereditary breast and ovarian cancer syndrome, Cowden syndrome, and Li-Fraumeni syndrome. This article summarizes the genetic counseling process and genetic test result interpretation, including a review of the key elements involved in the provision of risk assessment and informed consent, as well as a review of the risks, benefits, and limitations of cancer susceptibility genetic testing.

Germline variation controls the architecture of somatic alterations in tumors.

Studies have suggested that somatic events in tumors can depend on an individuals constitutional genotype. We used squamous cell carcinomas (SCC) of the skin, which arise in high multiplicity in organ transplant recipients, as a model to compare the pattern of somatic alterations within and across individuals. Specifically, we performed array comparative genomic hybridization on 104 tumors from 25 unrelated individuals who each had three or more independently arisen SCCs and compared the profiles occurring within patients to profiles of tumors across a larger set of 135 patients. In general, chromosomal aberrations in SCCs were more similar within than across individuals (two-sided exact-test p-value ), consistent with the notion that the genetic background was affecting the pattern of somatic changes. To further test this possibility, we performed allele-specific imbalance studies using microsatellite markers mapping to 14 frequently aberrant regions of multiple independent tumors from 65 patients. We identified nine loci which show evidence of preferential allelic imbalance. One of these loci, 8q24, corresponded to a region in which multiple single nucleotide polymorphisms have been associated with increased cancer risk in genome-wide association studies (GWAS). We tested three implicated variants and identified one, rs13281615, with evidence of allele-specific imbalance (p-value = 0.012). The finding of an independently identified cancer susceptibility allele with allele-specific imbalance in a genomic region affected by recurrent DNA copy number changes suggest that it may also harbor risk alleles for SCC. Together these data provide strong evidence that the genetic background is a key driver of somatic events in cancer, opening an opportunity to expand this approach to identify cancer risk alleles.

Allele-specific imbalance mapping identifies HDAC9 as a candidate gene for cutaneous squamous cell carcinoma

More than 3.5 million nonmelanoma skin cancers were treated in 2006; of these 700,000 were cutaneous squamous cell carcinomas (cSCCs). Despite clear environmental causes for cSCC, studies also suggest genetic risk factors. A cSCC susceptibility locus, Skts5, was identified on mouse chromosome 12 by linkage analysis. The orthologous locus to Skts5 in humans maps to 7p21 and 7q31. These loci show copy number increases in ∼10% of cSCC tumors. Here, we show that an additional 15–22% of tumors exhibit copy‐neutral loss of heterozygosity. Furthermore, our previous data identified microsatellite markers on 7p21 and 7q31 that demonstrate preferential allelic imbalance (PAI) in cSCC tumors. On the basis of these results, we hypothesized that the human orthologous locus to Skts5 would house a gene important in human cSCC development and that tumors would demonstrate allele‐specific somatic alterations. To test this hypothesis, we performed quantitative genotyping of 108 single nucleotide polymorphisms (SNPs) mapping to candidate genes at human SKTS5 in paired normal and tumor DNAs. Nine SNPs in HDAC9 (rs801540, rs1178108, rs1178112, rs1726610, rs10243618, rs11764116, rs1178355, rs10269422 and rs12540872) showed PAI in tumors. These data suggest that HDAC9 variants may be selected for during cSCC tumorigenesis.

Management options after prophylactic surgeries in women with BRCA mutations: a review.

BACKGROUND Although breast cancer is relatively common, only about 5% of cases are due to inheritance of highly penetrant cancer susceptibility genes. The majority of these are caused by mutations in the BRCA1 and BRCA2 genes, which are also associated with an increased risk of ovarian cancer. Increased surveillance, chemoprevention, and prophylactic surgeries are standard options for the effective medical management of mutation carriers. However, optimal management of female carriers who choose to undergo prophylactic surgeries is still poorly understood. METHODS The authors provide an overview of the current literature regarding medical management options for women carriers of BRCA1 and BRCA2 gene mutations and the implications for those individuals who have chosen to undergo prophylactic surgeries. RESULTS BRCA mutation carriers who opt for prophylactic surgeries are still at risk for development of malignancy, and appropriate monitoring is warranted. CONCLUSIONS There are limited data on the appropriate medical management for BRCA mutation carriers after prophylactic surgeries. However, a management plan can be extrapolated from the general management recommendations for surveillance and other risk-reducing strategies in BRCA-positive individuals.

Differential mutation frequencies in metastatic cutaneous squamous cell carcinomas versus primary tumors

Exome and targeted sequencing studies have identified potential driver mutations for a variety of tumor types. Cutaneous squamous cell carcinoma (cSCC) is one of the most highly mutated cancers but typically is associated with low rates of metastasis and high survival rates. Nevertheless, metastatic cSCC is a significant health threat; up to 8800 individuals die each year of this disease.

MicroRNA expression profiling in metastatic cutaneous squamous cell carcinoma

or sinecatechin may take up to 3 to 16 weeks for complete clearing of AGWs, treatment with IM was much more rapid. This could be explained by the loss of mitochondrial respiration mediated by IM leading to cell death and a cytotoxic reaction within hours. Our histological examination 18 h after treatment confirmed this direct cytotoxic effect of IM in AGWs. So far only surgical therapies show clearance rates approaching 100%. However, only single, protruding AGWs can be treated properly with surgical therapies and cautery can lead to scarring since it is difficult to restrict the effect to the skin lesions only. All those treatments bear the risk of high relapse rates after one to three months, whereas we could show that our patients are still in remission after up to 240 days. Further clinical trials with a longer follow-up period are required to confirm this persistent remission.

Transition to the clinical doctorate: attitudes of the genetic counseling training program directors in North America.

In North America, genetic counseling is an allied health profession where entry level practitioners currently must hold a master’s degree earned from a graduate program accredited by the American Board of Genetic Counseling. This is one of many health care professions that could transition to an entry level clinical doctorate degree. This study explored the attitudes of genetic counseling training program directors toward such a transition. Thirty-one North American program directors were invited to complete an online survey and a follow-up telephone interview. Twenty-one program directors completed the survey and ten directors also completed a follow up phone interview. There was disagreement among the respondents on the issue of transitioning to a clinical doctorate degree (nine in favor, six against and six undecided). Respondents disagreed about whether the transition would lead to higher salaries (six yes, eight no, and seven unsure) or increased professional recognition (eight yes, eight no, and four unsure). Approximately half (n = 10) of directors were not sure if the transition to a clinical doctorate would help or hurt minority recruitment; six thought it would help and four thought it would hurt. However, the majority (n = 13) thought a clinical doctorate would help genetic counselors to obtain faculty positions. If the field transitions to a clinical doctorate, 11 of the directors thought their program would convert, seven were unsure and one thought their program would shut down. Themes identified in interview data included 1) implications for the profession 2) institution-specific considerations and 3) perception of the unknown. Opinions are quite varied at this time regarding the possible transition to the clinical doctorate among genetic counseling training program directors.

Association of BRCA2 K3326* With Small Cell Lung Cancer and Squamous Cell Cancer of the Skin

Background Most pathogenic mutations in the BRCA2 gene carry a high risk of hereditary breast and ovarian cancer (HBOC). However, a stop-gain mutation, K3326* (rs11571833), confers risk of lung cancer and cancers of the upper-aero-digestive tract but only a modest risk of breast or ovarian cancer. The Icelandic population provides an opportunity for comprehensive characterization of the cancer risk profiles of K3326* and HBOC mutations because a single mutation, BRCA2 999del5, is responsible for almost all BRCA2-related HBOC in the population. Methods Genotype information on 43 641 cancer patients and 370 971 control subjects from Iceland, the Netherlands, and the United States was used to assess the cancer risk profiles of K3326* and BRCA2 999del5. BRCA2 expression was assessed using RNAseq data from blood (n = 2233), as well as 52 tissues reported in the GTEx database. Results The cancer risks associated with K3326* are fundamentally different from those associated with 999del5. We report for the first time an association between K3326* and small cell lung cancer (odds ratio [OR] = 2.06, 95% confidence interval [CI] = 1.35 to 3.16) and squamous cell carcinoma of the skin (OR = 1.69, 95% CI = 1.26 to 2.26). Individuals homozygous for K3326* reach old age and have children. Unlike BRCA2 999del5, the K3326* allele does not affect the level of BRCA2 transcripts, and the allele is expressed to the same extent as the wild-type allele. Conclusions K3326* associates primarily with cancers that have strong environmental genotoxic risk factors. Expression of the K3326* allele suggests that a variant protein may be made that retains the DNA repair capabilities important to hormone-responsive tissues but may be less efficient in responding to genotoxic stress.

Variants at the OCA2/HERC2 locus affect time to first cutaneous squamous cell carcinoma in solid organ transplant recipients collected using two different study designs.

Variants at the oculocutaneous albinism 2 (OCA2)/HECT and RLD domain containing E3 ubiquitin protein ligase 2 (HERC2) locus have been associated with pigmentation phenotypes and risk of developing several types of skin cancer.