[Metameric macular and papular skin mastocytosis]. / Mastocytose cutanée maculopapuleuse métamérique.

BACKGROUND: Mastocytosis is characterised by the presence of abnormal quantities of mastocytes in one or more organs. Although it occurs in systemic forms of mastocytosis, isolated skin involvement is the predominant presentation, particularly in children, in the form of more or less extensive though non-systematic lesions. Herein, we report a case of maculopapular cutaneous mastocytosis that is unusual in terms of its metameric topography. PATIENTS AND METHODS: A 16-year-old youth presented with an erythematous maculopapular rash of 18 months' duration and involving pruritic inflammatory episodes strictly localised in segment T8 to the left. The skin biopsy showed a significant increase in the number of dermal mastocytes (CD117+). No KIT mutations were found in the skin lesions nor in the unimpaired skin of the opposite side. Further investigations ruled out systemic mastocytis. DISCUSSION: Herein, we report a case of cutaneous mastocytosis that is unusual in terms of its metameric disposition. There have been only two previous reports of segmental cutaneous mastocytis. The two pathological hypotheses involved precessional dermatitis that renders the skin surface susceptible to homing, and somatic mosaicism (type 1) with local mastocyte proliferation.

Frequent intragenic rearrangements of DPYD in colorectal tumours.

Dihydropyrimidine dehydrogenase is a crucial enzyme for the degradation of 5-fluorouracil (5FU). DPYD, which encodes dihydropyrimidine dehydrogenase, is prone to acquire genomic rearrangements because of the presence of an intragenic fragile site FRA1E. We evaluated DPYD copy number variations (CNVs) in a prospective series of 242 stage I-III colorectal tumours (including 87 patients receiving 5FU-based treatment). CNVs in one or more exons of DPYD were detected in 27% of tumours (deletions or amplifications of one or more DPYD exons observed in 17% and 10% of cases, respectively). A significant relationship was observed between the DPYD intragenic rearrangement status and dihydropyrimidine dehydrogenase (DPD) mRNA levels (both at the tumour level). The presence of somatic DPYD aberrations was not associated with known prognostic or predictive biomarkers, except for LOH of chromosome 8p. No association was observed between DPYD aberrations and patient survival, suggesting that assessment of somatic DPYD intragenic rearrangement status is not a powerful biomarker to predict the outcome of 5FU-based chemotherapy in patients with colorectal cancer.

Molecular patterns in deficient mismatch repair colorectal tumours: results from a French prospective multicentric biological and genetic study.

BACKGROUND: To test the prognostic value of tumour protein and genetic markers in colorectal cancer (CRC) and examine whether deficient mismatch repair (dMMR) tumours had a distinct profile relative to proficient mismatch repair (pMMR) tumours. METHODS: This prospective multicentric study involved 251 stage I-III CRC patients. Analysed biomarkers were EGFR (binding assay), VEGFA, thymidylate synthase (TS), thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) expressions, MMR status, mutations of KRAS (codons 12-13), BRAF (V600E), PIK3CA (exons 9 and 20), APC (exon 15) and P53 (exons 4-9), CpG island methylation phenotype status, ploidy, S-phase, LOH. RESULTS: The only significant predictor of relapse-free survival (RFS) was tumour staging. Analyses restricted to stage III showed a trend towards a shorter RFS in KRAS-mutated (P=0.005), BRAF wt (P=0.009) and pMMR tumours (P=0.036). Deficient mismatch repair tumours significantly demonstrated higher TS (median 3.1 vs 1.4) and TP (median 5.8 vs 3.5) expression relative to pMMR (P<0.001) and show higher DPD expression (median 14.9 vs 7.9, P=0.027) and EGFR content (median 69 vs 38, P=0.037) relative to pMMR. CONCLUSIONS: Present data suggesting that both TS and DPD are overexpressed in dMMR tumours as compared with pMMR tumours provide a strong rationale that may explain the resistance of dMMR tumours to 5FU-based therapy.

Lack of referral for genetic counseling and testing in BRCA1/2 and Lynch syndromes: a nationwide study based on 240,134 consultations and 134,652 genetic tests.

Based on nationwide data from the French national cancer institute (INCa), we analyzed the evolution of cancer genetics consultations and testing over time, and the uptake of targeted tests in relatives of families with BRCA1/2 or MMR genes mutation. Genetic testing and consultations for familial high-risk individuals are exclusively funded and monitored by the INCa in France. All nationwide cancer genetics centers reported annually standardized parameters of activity from 2003 to 2011. The analysis included a total of 240,134 consultations and 134,652 genetic tests enabling to identify 32,494 mutation carriers. Referral for hereditary breast and ovarian cancer (HBOC) or colorectal cancer predisposition syndromes represented 59 % (141,639) and 23.2 % (55,698) consultations, respectively. From 2003 to 2011, we found a dramatic and steady increase of tests performed for BRCA1/2 (from 2,095 to 7,393 tests/year, P < 0.0001) but not for MMR genes (from 1,144 to 1,635/year, P = NS). The overall percentage of deleterious mutations identified in the probands tested was 13.8 and 20.9 % in HBOC and Lynch syndromes, respectively. Pooled analysis for BRCA1/2 and Lynch syndrome tests showed an inverse relationship between the percentage of mutation detected and the absolute number of tests performed over the time (overall Cochran-Armitage test for trend: P < 0.001). In families with BRCA1/2 or MMR identified mutations, there was an average number of 2.94 and 3.28 relatives performing targeted tests, respectively. This nationwide study shows a lack of referral and genetic testing in Lynch as compared to HBOC syndromes. Only a third of relatives of a proband with a predisposing mutation performed a targeted test. Enhanced information about benefit of genetic testing should be given to clinicians and patients for Lynch syndrome and relatives of a proband carrying an identified predisposing mutation.

Concerted nonsyntenic allelic loss in human colorectal carcinoma.

Familial polyposis coli (FPC) is caused by an autosomal dominant gene on chromosome 5, and it has been proposed that colorectal cancer in the general population arises from loss or inactivation of the FPC gene, analogous to recessive tumor genes in retinoblastoma and Wilms' tumor. Since allelic loss can be erroneously scored in nonhomogeneous samples, tumor cell populations were first microdissected from 24 colorectal carcinomas, an additional nine cancers were engrafted in nude mice, and nuclei were flow-sorted from an additional two. Of 31 cancers informative for chromosome 5 markers, only 6 (19%) showed loss of heterozygosity of chromosome 5 alleles, compared to 19 of 34 (56%) on chromosome 17, and 17 of 33 (52%) on chromosome 18. Therefore, it appears that (i) FPC is a true dominant for adenomatosis but not a common recessive gene for colon cancer; and (ii) simple Mendelian models involving loss of alleles at a single locus may be inappropriate for understanding common human solid tumors.

Performance of office hysteroscopy and endometrial biopsy for detecting endometrial disease in women at risk of human non-polyposis colon cancer: a prospective study.

The objective of this study was to report the value of diagnostic hysteroscopy and endometrial biopsy for the detection of complex atypical hyperplasia or cancer in asymptomatic human non-polyposis colon cancer (HNPCC) patients. The secondary objective was to evaluate the accuracy of hysteroscopy, using endometrial biopsy as a gold standard. Consecutive patients at risk of HNPCC evaluated between January 1, 1999, and June 30, 2006 were included if they underwent diagnostic hysteroscopy at least once. Patients with a history of hysterectomy and those unwilling to undergo diagnostic hysteroscopy were not included. Yearly follow-up evaluations included diagnostic hysteroscopy, with endometrial biopsy. Hysteroscopic and histologic findings were recorded and compared. We included 62 patients, of whom 13 had mismatch repair gene mutations and 49 met Amsterdam II criteria. Of 125 attempted hysteroscopies, 11 (8%) failed. Hysteroscopy showed normally appearing mucosa in 46 cases, nonmalignant lesions in 65 cases, and possibly malignant lesions in 3 cases with abnormal uterine bleeding. Endometrial biopsy was attempted in 116 cases and failed in 12 (10%). Three cases each of simple hyperplasia and of cancer were diagnosed. No preinvasive or invasive lesions were found in asymptomatic women. When compared to endometrial biopsy, sensitivity of hysteroscopy was 100% for the detection of hyperplasia or cancer. No cases of cancer were diagnosed in asymptomatic patients in our study. However, diagnostic hysteroscopy ensured the diagnosis of endometrial adenocarcinoma in HNPCC women with bleeding. Nevertheless, usefulness and optimal modalities of screening remain to be determined.

[Endometrial cancer in HNPCC syndrome]. / Cancer de l'endomètre du syndrome HNPCC Actualisation des données.

The Hereditary Non-Polyposis Colorectal Cancer syndrome (HNPCC) has initially been described as a predisposition to colorectal cancers (CRC). Subsequently, other cancers, such as endometrial cancers (EC), have been added. The objective of this review was to update data on endometrial cancers of HNPCC syndrome. Endometrial cancers of the HNPCC syndrome are characterized by a younger age at diagnosis (46-48 year old), and a higher cumulative risk along life (30% at 70 years). Complex atypical hyperplasia seems to occur before the cancer, but the transition between precursors and cancer seems to be short. Histology of endometrial cancers of the HNPCC syndrome appears quite similar to that of sporadic cases, except for non-endometrioid lesions which seem more frequent and could occur in younger women. Screening of endometrial cancer in predisposed women should associate annual clinical examination, transvaginal sonography and endometrial sampling. Unfortunately, available data on screening by sonography show that this test seems poorly accurate, with no asymptomatic cancer or hyperplasia recognized and interval cancers between screenings. Endometrial biopsy appears as the most interesting method, since 11 asymptomatic cancers and 14 hyperplasia have been diagnosed in 175 mutation carriers. Diagnostic hysteroscopy seems also interesting, but requires further evaluation. Prophylactic hysterectomy confers a complete protection against endometrial cancer. However, perioperative morbidity (especially in women with history of colorectal surgery) and long-term effects of ovarian suppression should also be considered. Screening of endometrial cancer remains the main objective of the management of those patients. Endometrial biopsy should have a larger place.

Turcot syndrome confirmed with molecular analysis.

Turcot syndrome is clinically characterized by the occurrence of primary brain tumor and colorectal tumor and has, in previous reports, been shown associated with germline mutations in the genes APC, MLH1, MHS6, and PMS2. To date, only few families have been documented by molecular analysis. We report two new families with Turcot syndrome to illustrate and review its characteristics and facilitate diagnosis. Molecular analysis revealed two germline mutations, one in the MLH1 gene and one in MSH2. The latter has never been describe in the literature. Personal and familial relevant anamnestic data from patients with glioma might aid in the diagnosis of genetic disorders. The subsequent molecular characterization may contribute to the appropriate care of affected patients and asymptomatic gene carriers.

STK11 status and intussusception risk in Peutz-Jeghers syndrome.

BACKGROUND: Peutz-Jeghers syndrome (PJS) is caused by germline STK11 mutations and characterised by gastrointestinal polyposis. Although small bowel intussusception is a recognised complication of PJS, risk varies between patients. OBJECTIVE: To analyse the time to onset of intussusception in a large series of PJS probands. METHODS: STK11 mutation status was evaluated in 225 PJS probands and medical histories of the patients reviewed. RESULTS: 135 (60%) of the probands possessed a germline STK11 mutation; 109 (48%) probands had a history of intussusception at a median age of 15.0 years but with wide variability (range 3.7 to 45.4 years). Median time to onset of intussusception was not significantly different between those with identified mutations and those with no mutation detected, at 14.7 years and 16.4 years, respectively (log-rank test of difference, chi(2) = 0.58, with 1df; p = 0.45). Similarly no differences were observed between patient groups on the basis of the type or site of STK11 mutation. CONCLUSIONS: The risk of intussusception in PJS is not influenced by STK11 mutation status.

[Phenotype-genotype study in 154 French NF2 mutation carriers]. / Analyse phénotypique de 154 patients porteurs d'une mutation constitutionnelle du gène NF2.

INTRODUCTION: Germline mutations in the NF2 gene are responsible for 80 p.cent of neurofibromatosis type 2 typical cases. Mutations are mainly truncating mutations or deletions, missense mutations having been reported in few cases. An important phenotypic variability is observed among gene carriers. To assess whether the phenotypic variability of neurofibromatosis 2 could be linked to genotype, clinical data of 154 patients whose NF2 germline alteration had been identified in our laboratory have been collected. METHODS: A retrospective questionnaire was sent to the physicians in charge of these patients. Statistical analyses regarding genotypic and phenotypic data were performed by comparisons of average values and correlation tests. RESULTS: In French patients, type of mutation was correlated neither with patients' sex, nor with disease occurrence mode (de novo or inherited mutation). Disease associated with missense mutations occurred later, with a less severe symptomatology. Patients with nonsense or frameshift mutations were more frequently affected with meningiomas and spinal tumours, in addition to VIII nerve schwannomas, an observation that underlies the genetic determination of the number and type of NF2-related tumours. CONCLUSION: Results from the literature as well as from our study tend to show that only few correlations exist between genotype and phenotype in the NF2 disease. It also recognizes that missense mutations have a lower level of evolution, severity and mortality risk. Nonsense and frameshift mutations seem to be associated with a higher number of meningiomas and spinal tumours. Therefore, NF2 gene screening keeps its indications in both typical and moderate forms of the disease. Mutations are responsible of 80 p.cent of typical forms; in moderate forms, identification of a missense mutation seems linked to a lower disease evolution. In any case, assessment and supervision should be identical. Finally, in a small number of cases, the NF2 gene appears to be implicated in clinical forms different from those defined by NIH and it might be of interest to enlarge the clinical features suggestive of the disease.

Low compliance with colonoscopic screening in first-degree relatives of patients with large adenomas.

BACKGROUND: Little is known about compliance with colonoscopy as a screening method in first-degree relatives of patients with large adenomas. Aims To evaluate the compliance with screening colonoscopy among this population, and its determinants. METHODS: Data were obtained from the family part of the GEADE study, a study on genetic factors of colorectal adenomas. Index cases were 306 patients with adenomas > or = 10 mm. All living first-degree relatives aged 40-75 who could be contacted by the index case were asked to undergo a colonoscopy, unless they had had one in the previous 5 years. RESULTS: Among 674 eligible relatives, 56 had had a colonoscopy within the preceding 5 years and 114 underwent a screening colonoscopy resulting in a compliance with screening colonoscopy of 18%. This was not related to most characteristics of index cases. Compliance was significantly lower when the index case lived in the Greater Paris area than when he/she lived in other areas (12% vs. 21%). It was higher in siblings (18%) and offspring (23%) than in parents (9%) and in relatives under 55 years old (22%) than in relatives aged 55 and over (15%). CONCLUSIONS: Compliance with colonoscopy was low in first-degree relatives of patients with large adenomas. The reasons for this should be determined and appropriate strategies developed to increase compliance.

The location of constitutional neurofibromatosis 2 (NF2) splice site mutations is associated with the severity of NF2.

Neurofibromatosis 2 (NF2) patients with constitutional splice site NF2 mutations have greater variability in disease severity than NF2 patients with other types of mutations; the cause of this variability is unknown. We evaluated genotype-phenotype correlations, with particular focus on the location of splice site mutations, using mutation and clinical information on 831 patients from 528 NF2 families with identified constitutional NF2 mutations. The clinical characteristics examined were age at onset of symptoms of NF2 and number of intracranial meningiomas, which are the primary indices of the severity of NF2. Two regression models were used to analyse genotype-phenotype correlations. People with splice site mutations in exons 1-5 had more severe disease than those with splice site mutations in exons 11-15. This result is compatible with studies showing that exons 2 and 3 are required for self-association of the amino terminal of the NF2 protein in vitro, and that deletions of exons 2 and 3 in transgenic and knockout mouse models of NF2 cause a high prevalence of Schwann cell derived tumours.

[Turcot's syndrome confirmed by molecular biological tests]. / Syndrome de Turcot confirmé par biologie moléculaire.

INTRODUCTION: Turcot's syndrome is characterized clinically by the concurrence of a primary brain tumor and a familial adenomatous polyposis or a hereditary nonpolyposis colorectal cancer. OBSERVATION: We report a case of a 45-year-old woman who underwent in 1995 neuro-oncological treatment for an anaplastic astrocytoma (grade III according to the World Health Organization classification). Treatment included complete surgery, radiotherapy, a first-line nitrosourea-based chemotherapy regimen and a second-line platinium salt-based regimen. It was then noted that the patient's brother had colorectal cancer. A genetic study detected a germ-line mutation on the hMSH2 gene specific of HNPCC syndrome (Human Non Polyposis Colorectal Cancer). Colonoscopy was normal. Eight years after the diagnosis, the patient developed a gliomatosis cerebri and died. CONCLUSION: Relevant personal and familial history can provide the clue to the diagnosis of Turcot's syndrome. Molecular diagnosis may contribute to appropriate care of affected patients.

Concerted nonsyntenic allelic losses in hyperploid hepatocellular carcinoma as determined by a high-resolution allelotype.

Although the occurrence of loss of genetic material in hepatocellular carcinoma (HCC) has been documented both by cytogenetic analysis and by monitoring of allelic losses, a global overview of the extent and frequency of deletion occurring throughout the genome is not yet available. To contribute to this information, DNAs extracted from flow-sorted aneuploid nuclei from HCC and matched normal DNAs were typed for 275 microsatellite loci that were distributed along the autosomes. An average of 190 (69%) informative loci per case were generated on 48 HCC. Complete loss of heterozygozity in the tumor DNA was observed for 15.6% of the typed loci. The chromosome segments that were most frequently affected by deletion were: 8p (60%), 17p (48%), 1p (44%), 4q (42%), 16p (40%), 16q (39%), 6q (35%), 9p (30%), and 13q (29%). On average, 8 of the 39 chromosome segments studied per tumor carried at least one locus that demonstrated loss of heterozygosity (ie., the fractional allelic loss was 0.21). Groups of concerted nonsyntenic losses were observed for 16p and 1p and for 16p and 4q. The location of putative tumor suppressor genes on the most frequently deleted regions was confirmed and, in some cases, refined.

Detection of exon deletions and duplications of the mismatch repair genes in hereditary nonpolyposis colorectal cancer families using multiplex polymerase chain reaction of short fluorescent fragments.

Large genomic deletions within the mismatch repair MLH1 and MSH2 genes have been identified in families with the hereditary nonpolyposis colorectal cancer (HNPCC) syndrome, and their detection represents a technical problem. To facilitate their detection, we developed a simple semiquantitative procedure based on the multiplex PCR of short fluorescent fragments. This method allowed us to confirm in HNPCC families three known deletions of MLH1 or MSH2 and to detect in 19 HNPCC families, in which analysis of mismatch repair genes using classical methods had revealed no alteration, a deletion of exon 5 and a duplication of MSH2 involving exons 9 and 10. The presence of such duplications, the frequency of which is probably underestimated, must be considered in HNPCC families in which conventional screening methods have failed to detect mutations.

Peutz-Jeghers families unlinked to STK11/LKB1 gene mutations are highly predisposed to primitive biliary adenocarcinoma.

INTRODUCTION: Germline mutations of the STK11/LKB1 tumour suppressor gene (19p13.3) are responsible for Peutz-Jeghers syndrome (PJS), a rare genetic disorder, which is dominantly inherited. In addition to the typical hamartomatous gastrointestinal polyps and perioral pigmented lesions, PJS is also associated with the development of tumours in various sites. No specific follow up has yet been evaluated for gene carriers. Furthermore, genetic heterogeneity has been reported, which makes genetic counselling difficult. METHODS: We report here the analysis of the STK11/LKB1 locus in a series of 34 PJS families, combining the search for mutations and rearrangements in the coding sequence, allele specific expression tests, and linkage studies. RESULTS: Germline deleterious mutation of the STK11/LKB1 gene were identified in 70% of cases. The hypothesis of a second PJS locus was reinforced and PJS families could be divided into two groups on the basis of the presence or absence of an identified STK11/LKB1 alteration. Analysis of clinical data indicates that the cancer associated risk is markedly different in the two groups. PJS patients with no identified STK11/LKB1 mutation are at major risk for proximal biliary adenocarcinoma, an infrequent tumour in the general population. CONCLUSION: Up to 30% of PJS patients are caused by mutation in an unidentified gene that confers high susceptibility to cancer development.