A SUMOylation-defective MITF germline mutation predisposes to melanoma and renal carcinoma.

So far, no common environmental and/or phenotypic factor has been associated with melanoma and renal cell carcinoma (RCC). The known risk factors for melanoma include sun exposure, pigmentation and nevus phenotypes; risk factors associated with RCC include smoking, obesity and hypertension. A recent study of coexisting melanoma and RCC in the same patients supports a genetic predisposition underlying the association between these two cancers. The microphthalmia-associated transcription factor (MITF) has been proposed to act as a melanoma oncogene; it also stimulates the transcription of hypoxia inducible factor (HIF1A), the pathway of which is targeted by kidney cancer susceptibility genes. We therefore proposed that MITF might have a role in conferring a genetic predisposition to co-occurring melanoma and RCC. Here we identify a germline missense substitution in MITF (Mi-E318K) that occurred at a significantly higher frequency in genetically enriched patients affected with melanoma, RCC or both cancers, when compared with controls. Overall, Mi-E318K carriers had a higher than fivefold increased risk of developing melanoma, RCC or both cancers. Codon 318 is located in a small-ubiquitin-like modifier (SUMO) consensus site (ΨKXE) and Mi-E318K severely impaired SUMOylation of MITF. Mi-E318K enhanced MITF protein binding to the HIF1A promoter and increased its transcriptional activity compared to wild-type MITF. Further, we observed a global increase in Mi-E318K-occupied loci. In an RCC cell line, gene expression profiling identified a Mi-E318K signature related to cell growth, proliferation and inflammation. Lastly, the mutant protein enhanced melanocytic and renal cell clonogenicity, migration and invasion, consistent with a gain-of-function role in tumorigenesis. Our data provide insights into the link between SUMOylation, transcription and cancer.

Pregnancy promotes melanoma metastasis through enhanced lymphangiogenesis.

The relationships of pregnancy and melanoma have been debatable. Our aim was to assess the influence of gestation on the course of melanoma in a classic murine model of tumor progression and in women. B16 mouse melanoma cells were injected in nonpregnant or pregnant mice on day 5 of gestation. Animals were evaluated for tumor progression, metastases, and survival. Tumor sections were analyzed for lymphatic and blood vessel number and relative surface and expression of angiogenic growth factors. Finally, primary melanomas from pregnant and nonpregnant women, matched for age and tumor thickness, were also considered. Tumor growth, metastasis, and mortality were increased in B16-injected pregnant mice. Tumors displayed an increase in intratumoral lymphangiogenesis during gestation. This increased lymphatic angiogenesis was not observed in normal skin during gestation, showing its specificity to the tumor. An analysis of melanoma from pregnant and matched nonpregnant women showed a similar increase in lymphatic vessels. Tumors from pregnant mice had increased expression of vascular endothelial growth factor A at the RNA and protein levels. The increased vascular endothelial growth factor A production by melanoma cells could be reproduced in culture using pregnant mouse serum. In conclusion, pregnancy results in increased lymphangiogenesis and subsequent metastasis. Caution should be applied in the management of patients with advanced-stage melanoma during gestation.

Familial melanoma: clinical factors associated with germline CDKN2A mutations according to the number of patients affected by melanoma in a family.

BACKGROUND: Features associated with an increased frequency of cyclin-dependent kinase inhibitor 2A (CDKN2A) mutations have been identified in families with 3 or more patients with cutaneous melanoma (CM). However, in families with 2 patients with CM, which represent the majority of familial melanoma, these factors have been rarely studied. OBJECTIVE: We investigated association of 3 clinical features with the presence of a CDKN2A mutation in a family by extent of CM family clustering (2 vs ≥3 patients with CM among first-degree relatives in a family). METHODS: We included 483 French families that comprised 387 families with 2 patients with CM (F2 families) and 96 families with 3 or more patients with CM (F3+ families). Three clinical factors were examined individually and in a joint analysis: median age at diagnosis younger than 50 years, and 1 or more patient in a family with multiple primary melanoma or with pancreatic cancer. RESULTS: The frequency of CDKN2A mutations was higher in F3+ families (32%) than in F2 families (13%). Although early age at melanoma diagnosis and occurrence of multiple primary melanoma in 1 or more patient were significantly associated with the risk of a CDKN2A mutation in F2 families, early age at melanoma diagnosis and occurrence of pancreatic cancer in a family were significantly associated with CDKN2A mutations in F3+ families. LIMITATIONS: The study was not population based. CONCLUSIONS: This study shows that factors associated with CDKN2A mutations differ by extent of CM family clustering. It indicates that, in France, families with 2 patients with CM are eligible for genetic testing especially when there is an early age at CM diagnosis and/or 1 or more patients with multiple primary melanoma.

Sentinel lymph node biopsy or nodal observation in melanoma: a prospective study of patient choices.

BACKGROUND: There is no consensus regarding the therapeutic utility of sentinel lymph node biopsy (SLNB) versus that of nodal observation (NO) in melanoma. OBJECTIVE: To prospectively evaluate a standardized counseling procedure and its effect on patient choices to undergo SLNB or NO. METHODS: In four centers, patients with melanoma eligible for SLNB or NO received a complete counseling procedure that included verbal information from dermatologists and surgeons, a detailed information sheet, and a written consent form. Data collected included patient and tumor characteristics, counseling conditions, and specialties of informing doctors. Factors influencing patients' choices were studied using multivariate analysis. RESULTS: Of 343 consecutive patients, 309 were offered SLNB and NO and received complete verbal and written information from a dermatologist alone (62%) or in association with a surgeon (38%). Approximately half took advice from trusted persons, and half asked for additional time before making a decision; 268 (86.7%) ultimately decided to undergo SLNB. Multivariate analysis showed that older patients, those with a head and neck melanoma, and those informed without a surgeon present were more likely to prefer NO. CONCLUSIONS: This counseling procedure was easily implemented in clinical practice. Patients favored SLNB but were able to understand uncertainties and express preferences.

Fetal microchimeric cells participate in tumour angiogenesis in melanomas occurring during pregnancy.

Melanoma is a major malignancy in younger individuals that accounts for 8% of all neoplasias associated with gestation. During pregnancy, a small number of fetal cells enter the maternal circulation. These cells persist and then migrate to various maternal tissues where they may engraft and differentiate, particularly if there is organ damage, adopting the phenotype of the host organ. To understand the relationship between melanoma and pregnancy, we analyzed these tumors in both humans and mice. Fetal cells were detected in 63% of human primary melanomas versus 12% in nevi during pregnancy (P = 0.034) and in 57% of B16 melanomas in pregnant mice but never in normal skin (P = 0.000022). More than 50% of these fetal cells expressed the CD34, CD31, or von Willebrand factor endothelial cell markers. In addition, the Lyve-1 lymphatic antigen was expressed by more than 30% of fetal cells in mice. In conclusion, we show that melanomas during pregnancy frequently harbor fetal cells that have an endothelial phenotype. Further studies are needed to assess whether the fetal contribution to lymphangiogenesis may alter the prognosis of the maternal tumor.

Merkel cell carcinoma of the skin: pathological and molecular evidence for a causative role of MCV in oncogenesis.

Merkel cell carcinoma (MCC), a skin tumour with neuroendocrine features, was recently found to be associated with a new type of human polyomavirus, called Merkel cell virus (MCV). We investigated the specificity of this association as well as a causal role of MCV in oncogenesis. DNA and RNA from ten cases of MCC were analysed using PCR and RT-PCR. DNA from 1241 specimens of a wide range of human tumours was also analysed. The DIPS technique was used to identify the integration locus of viral DNA sequences. Array CGH was performed to analyse structural alterations of the cell genome. MCV DNA sequences were found in all ten cases of MCC and in none of the 1241 specimens of other tumour types. Clonal integration of MCV into the host genome was seen in all MCC cases and was checked by FISH in one case. A recurrent pattern of conserved viral sequences which encompassed the replication origin, the small tumour (ST), and the 5' part of the large tumour (LT) antigen DNA sequences was observed. Both ST and LT viral sequences were found to be significantly expressed in all MCCs. Neither recurrent site of integration nor alteration of cellular genes located near the viral sequences was observed. The tight association of MCV with MCC, the clonal pattern of MCV integration, and the expression of the viral oncoproteins strongly support a causative role for MCV in the tumour process. This information will help the development of novel approaches for the assessment and therapy of MCC and biologically related tumours.

BRCA1, BRCA2, TP53, and CDKN2A germline mutations in patients with breast cancer and cutaneous melanoma.

PURPOSE: From epidemiological studies it appears that breast cancer (BC) and cutaneous melanoma (CMM) in the same individual occur at a higher frequency than expected by chance. Genetic factors common to both cancers can be suspected. Our goal was to estimate the involvement of "high risk" genes in patients presenting these two neoplasia, selected irrespectively from family history and age at diagnosis. EXPERIMENTAL DESIGN: Eighty two patients with BC and CMM were screened for BRCA1, BRCA2, TP53, CDKN2A and CDK4 (exon 2) germline mutations. RESULTS: Deleterious mutations were identified in 6 patients: two carriers of a BRCA1 germline mutation, two carriers of TP53 germline mutations (one of which also harbored a BRCA2 deleterious mutation, the other one a BRCA2 unclassified variant), and two carriers of a CDKN2A germline mutation. In addition, 6 variants of unknown signification were identified in BRCA1 or BRCA2 genes. Regarding family history, 3/13 (23%) patients with a positive family history of BC or CMM were carriers of a germline mutation, whereas only 3/69 (4%) patients without family history were carriers of a germline mutation. CONCLUSION: Our findings show that few patients with BC and CMM who lacked family histories of these cancers are carriers of deleterious germline mutations in four of the five genes we examined. We describe for the first time, two simultaneous BRCA2 and TP53 mutations, suggesting that analysis in more than one gene could be performed if a patient's personal or familial history does not match a single syndrome.

F-18 fluorodeoxy-D-glucose positron emission tomography scan in the initial evaluation of patients with a primary melanoma thicker than 4 mm.

Metabolic imaging with F-18 fluorodeoxy-D-glucose positron emission tomography is one of the most sensitive and non-invasive techniques, and has proved useful in melanoma. We designed, in 2004, at the Institute Gustave Roussy, a prospective study to determine the value of F-18 fluorodeoxy-D-glucose positron emission tomography scanning in the detection of regional and/or distant metastasis in 25 new patients referred for the treatment of a primary melanoma thicker than 4 mm (tumor node metastases stage T4). The sentinel lymph node biopsy was proposed for all the patients without a palpable regional lymph node. Abnormal positron emission tomography scan findings were correlated to available histological data and to the course of the disease. The F-18 fluorodeoxy-D-glucose positron emission tomography scan identified 0/2 intact primary melanomas, 1/4 residual primary melanomas after limited excision, 0/6 lymph node basins with micrometastasis, 4/4 lymph node basins with enlarged palpable lymph nodes and 0 distant metastasis. The sensitivity and specificity of positron emission tomography scans for microscopic lymph node disease in basins were, respectively, 0 and 92%. A false-positive F-18 fluorodeoxy-D-glucose positron emission tomography result in a cervical basin led to a useless cervical lymph node dissection. In three patients, the positron emission tomography scan was positive in distant sites but none of these foci represented a true metastasis. In conclusion, it is not useful to include a positron emission tomography scan in the initial work-up of patients with primary melanoma, even in patients with thick primary melanomas (>4 mm). Sentinel lymph node biopsy remains the technique of choice for the most accurate initial staging.

Age and clear eyes are associated with an increased risk of cutaneous squamous cell carcinomas in vemurafenib-treated melanoma patients.

Cutaneous squamous cell carcinoma (cSCC) is a frequent side-effect of vemurafenib treatment. The main aim of this study was to identify the clinical risk factors associated with the development of cSCC in melanoma patients treated with vemurafenib. We carried out a retrospective study, including 63 consecutive melanoma patients treated with vemurafenib for BRAF-mutant metastatic melanoma in an oncodermatological department. Clinical and follow-up data were collected and analysed, and a comparison of the subgroups who did and did not develop cSCC was performed. A total of 42.9% of patients (n=27) treated with vemurafenib developed one or more cSCC. Patients with cSCC were significantly older (P=0.01). Clear eyes were also associated with a higher risk of developing cSCC (odds ratio=3.50; 95% confidence interval: 1.08-12.43). Three patients developed cSCC more than 1 year after the initiation of treatment (12, 16 and 18 months, respectively). Clinicians should be vigilant in older patients undergoing vemurafenib therapy as well as patients with clear eyes as they seem to be at increased risk of developing cSCC, even late after the initiation of treatment.