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L Varesco

Publications and source records attributed to L Varesco.

At least 19 recordsLinked to original sources
PubMed2006

Impact of surgery on the development of duodenal cancer in patients with familial adenomatous polyposis.

PURPOSE: Precancerous duodenal lesions in patients with familial adenomatous polyposis can be detected with duodenoscopy and treatment may prevent the development of cancer. We proposed to determine the frequency, natural history, cumulative risk, and risk factors of the precancerous duodenal lesions in a series of patients diagnosed in northern Italy. METHODS: A prospective, endoscopic, follow-up protocol was performed in 50 patients examined by gastroduodenoscopy at two years of interval or less. The presence and severity of precancerous lesions of the duodenal mucosa were evaluated by Spigelman score. Twenty-five patients (50 percent) had proctocolectomy and ileoanal anastomosis, 15 (30 percent) had colectomy and ileorectal anastomosis, and 5 (10 percent) had proctocolectomy and definitive ileostomy from 0 to 3 years before the admission to the surveillance program. All patients showed more than a thousand adenomas in the colorectal mucosa. No patients with attenuated polyposis were found. RESULTS: At the first endoscopy, duodenal adenomas could be detected in 19 of 50 patients (38 percent), whereas at the end of the follow-up, 43 (86 percent) had duodenal lesions. The final mean Spigelman score increased during the follow-up period (P<0.001 respect to baseline values). No duodenal cancer could be detected. Eleven patients had or developed severe precancerous duodenal lesions (Stage IV) treated with endoscopic or surgical resection. The distribution of patients with Stage IV according to the surgery of the colon was: 2 of 25 treated with ileoanal anastomosis and 8 of 15 with ileorectal anastomosis (P=0.0024, Fisher's exact test). CONCLUSIONS: Patients with familial adenomatous polyposis are at risk of significant neoplasia. The natural history of precancerous lesions might be related to surgical treatment of colorectal neoplasms.

Adenoma↗
PubMed2005

Attenuated familial adenomatous polyposis and Muir-Torre syndrome linked to compound biallelic constitutional MYH gene mutations.

Attenuated familial adenomatous polyposis and Muir-Torre syndrome linked to compound biallelic constitutional MYH gene mutations.Peculiar dermatologic manifestations are present in several heritable gastrointestinal disorders. Muir-Torre syndrome (MTS) is a genodermatosis whose peculiar feature is the presence of sebaceous gland tumors associated with visceral malignancies. We describe one patient in whom multiple sebaceous gland tumors were associated with early onset colon and thyroid cancers and attenuated polyposis coli. Her family history was positive for colonic adenomas. She had a daughter presenting with yellow papules in the forehead region developed in the late infancy. Skin and visceral neoplasms were tested for microsatellite instability and immunohistochemical status of mismatch repair (MMR), APC and MYH proteins. The proband colon and skin tumors were microsatellite stable and showed normal expression of MMR proteins. Cytoplasmic expression of MYH protein was revealed in colonic cancer cells. Compound heterozygosity due to biallelic mutations in MYH, R168H and 379delC, was identified in the proband. The 11-year-old daughter was carrier of the monoallelic constitutional mutation 379delC in the MYH gene; in the sister, the R168H MYH gene mutation was detected. This report presents an interesting case of association between MYH-associated polyposis and sebaceous gland tumors. These findings suggest that patients with MTS phenotype that include colonic polyposis should be screened for MYH gene mutations.

Adenomatous Polyposis Coli↗
PubMed2004

Familial adenomatous polyposis: genetics and epidemiology.

Familial adenomatous polyposis (FAP) is a rare genetic disease characterised by the development of hundreds to thousands of adenomatous polyps along the colon-rectum leading to cancer at a young age, if left untreated. In 1991, the gene responsible for the vast majority of FAP cases, the adenomatous polyposis coli (APC) gene, was identified. In 5-30% of FAP patients, no APC mutation is identifiable by current genetic testing. In 2003, it was shown that 'APC-negative' FAP patients may carry biallelic mutations in a different gene, the MYH gene. Genetics of FAP will be discussed in relation to its present clinical applications. If the hereditable mutation(s) is/are known in a family, it is possible to plan endoscopic surveillance only for those who actually inherited the mutation(s). Also, genetic testing may be of help in the diagnosis of atypical adenomatous polyposis cases and in the clinical management of affected individuals.

Adenomatous Polyposis Coli↗
PubMed2003

Multiple approach to the exploration of genotype-phenotype correlations in familial adenomatous polyposis.

PURPOSE: Familial adenomatous polyposis (FAP), caused by a mutation in the APC gene, is a colorectal cancer predisposition syndrome associated with several other clinical conditions. The severity of the FAP is related to the position of the inherited mutation in the APC gene. We analyzed a large series of FAP patients to identify associations among major clinical manifestations and to correlate the mutation site with specific disease manifestations. MATERIALS AND METHODS: APC mutations were identified in 953 FAP patients from 187 families. We used unconditional logistic regression models and a method involving generalized estimating equations to investigate the association between genotype and phenotype. We used multiple correspondence analysis to represent the interrelationships of a multiway contingency table of the considered variables. RESULTS: APC germline mutations were located between codons 156 and 2011 of the APC gene. Mutations spanning the region between codons 543 and 1309 were variable, but strongly associated with congenital hypertrophy of retinal pigment epithelium. Mutations between codons 1310 and 2011 were associated with a six-fold risk of desmoid tumors relative to the low-risk reference region (159 to 495). Mutations at codon 1309 were associated with early development of colorectal cancer. Mutations between codons 976 and 1067 were associated with a three- to four-fold increased risk of duodenal adenomas. The cumulative frequency of extracolonic manifestations was highest for mutations between codons 976 and 1067, followed by mutations between 1310 and 2011. CONCLUSION: Analysis of the relation between APC mutation site and phenotype identifies subgroups of FAP patients at high risk for major extracolonic disease, which is useful for surveillance and prevention.

Adenoma↗
PubMed2002

Prevalence of the E1317Q variant of the APC gene in Italian patients with colorectal adenomas.

Loss of APC is an initial, rate-limiting event in inherited and sporadic colorectal tumorigenesis. Rare germline APC mutations have been identified in patients with multiple colorectal adenomas. Recently, the E1317Q APC variant has been associated with a predisposition to the development of multiple colorectal adenomas. In this study, the prevalence of the E1317Q variant was examined in 182 patients with single or multiple colorectal adenomas, and in 235 controls. In all, E1317Q was identified in two of 182 patients with adenomatous polyps (1.1%) and in two of 235 controls (0.8%) (p = 0.59). The risk of harboring adenoma(s) among subjects bearing the E1317Q variant was 1.29 (95% CI 0.09-18.0). No difference in the prevalence of E1317Q between cases with single (2.0%) or multiple colorectal adenomas (0.7%) and controls (0.8%) was found. None of the subjects with a family history of colorectal cancer carried the E1317Q variant. In conclusion, our results confirm that only a very small fraction of colorectal adenomas may be associated with the presence of E1317Q.

Adenoma↗
PubMed2001

Genotype and phenotype factors as determinants of desmoid tumors in patients with familial adenomatous polyposis.

Desmoids represent the most important cause of death, after colorectal cancer, in patients affected with familial adenomatous polyposis (FAP), an inherited disease due to mutations in the APC gene. The aims of our study were to estimate the risk of developing desmoids in FAP patients and to evaluate the association between desmoids and different risk factors. The occurrence of desmoids, colorectal cancer and other extra-colonic manifestations were assessed in 897 FAP patients, 653 of whom were also investigated for APC mutations. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were computed using an unconditional multiple logistic regression model. Desmoids developed in 107 patients (11.9%), with a cumulative risk of 20.6%. Females had a significantly higher risk than males (OR = 2.1; 95% CI 1.4-3.1). Family history of desmoids (OR = 8.75; 95% CI 5.66-13.51), osteomas (OR = 2.9; 95% CI 1.8-4.8) and epidermoid cysts (OR = 1.8; 95% CI 1.1-3.2) was also significantly associated with the occurrence of disease. Subjects with APC mutations beyond codon 1444 had a 12-fold increased risk, compared with patients with mutations located upstream. Mutations beyond codon 1309 conferred a 17-fold higher risk, compared with mutations upstream codon 452. Multivariate analysis identified as independent predictors mutation beyond codon 1444 (OR = 6.2; 95% CI 2.5-15.8), family history of desmoids (OR = 5.8; 95% CI 3.1-10.6), female gender (OR = 2.1; 95% CI 1.1-3.8) and the presence of osteomas (OR = 1.9; 95% CI 1.1-3.4). Our results indicate that integrating genetic and clinical data is helpful in defining subgroups of patients at higher risk for desmoids, who may benefit from specific prevention programs.

Adenomatous Polyposis Coli↗
PubMed2001

Cloning and characterization of a senescence inducing and class II tumor suppressor gene in ovarian carcinoma at chromosome region 6q27.

Cytogenetic, molecular and functional analysis has shown that chromosome region 6q27 harbors a senescence inducing gene and a tumor suppressor gene involved in several solid and hematologic malignancies. We have cloned at 6q27 and characterized the RNASE6PL gene which belongs to a family of cytoplasmic RNases highly conserved from plants, to man. Analysis of 55 primary ovarian tumors and several ovarian tumor cell lines indicated that the RNASE6PL gene is not mutated in tumor tissues, but its expression is significantly reduced in 30% of primary ovarian tumors and in 75% of ovarian tumor cell lines. The promoter region of the gene was unaffected in tumors cell lines. Transfection of RNASE6PL cDNA into HEY4 and SG10G ovarian tumor cell lines suppressed tumorigenicity in nude mice. When tumors were induced by RNASE6PL-transfected cells, they completely lacked expression of RNASE6PL cDNA. Tumorigenicity was suppressed also in RNASE6PL-transfected pRPcT1/H6cl2T cells, derived from a human/mouse monochromosomic hybrid carrying a human chromosome 6 deleted at 6q27. Moreover, 63.6% of HEY4 clones and 42.8% of the clones of XP12ROSV, a Xeroderma pigmentosum SV40-immortalized cell line, transfected with RNASE6PL cDNA, developed a marked senescence process during in vitro growth. We therefore propose that RNASE6PL may be a candidate for the 6q27 senescence inducing and class II tumor suppressor gene in ovarian cancer.

Animals↗
PubMed2001

Phenotype-genotype correlations in an extended family with adenomatosis coli and an unusual APC gene mutation.

PURPOSE: Genotype-phenotype correlations in familial adenomatous polyposis are only partially understood and, in particular, little is known about the biomolecular characteristics of desmoid tumors, which are one of the most serious and frequent manifestations of familial adenomatous polyposis. In the present study, we describe a family with familial adenomatous polyposis, with peculiar clinical characteristics (i.e., frequency and severity of desmoid neoplasms) associated with an unusual mutation of the adenomatosis polyposis coli gene. If confirmed by other investigations, these findings might help to understand the biologic mechanisms by which specific adenomatosis polyposis coli mutations predispose to desmoid tumors. METHODS: The family with familial adenomatous polyposis, living in southern Italy, was studied from 1985 to the end of 1999; at this date, 15 individuals have been affected by histologically verified familial adenomatous polyposis, 11 of whom had desmoid tumors. A total of 19 family members were studied for adenomatosis polyposis coli gene mutations; 13 of them tested positive and 6 negative. The analytical procedure-previously described-consisted of the extraction of peripheral blood cell DNA, amplification of exon 15 by polymerase chain reaction, single-strand conformation polymorphism analysis, and direct sequencing of the DNA fragment containing the mutation. RESULTS: The main clinical features of the family were 1) a high frequency of desmoid tumors and, consequently, a high penetrance of the desmoid trait in all branches of the family and in 11 (73.3 percent) of 15 affected individuals and 2) severity of desmoids in at least 4 family members, 2 of whom died for causes related to the presence of these tumors. The molecular basis of the disease was an uncommon mutation of the adenomatosis polyposis coli gene, consisting of a large deletion of 310 base pairs at codon 1,464, with duplication of the breakpoint (4,394ins15del310), leading to a stop codon at position 1,575. CONCLUSIONS: The present study shows that a truncating mutation in the adenomatosis polyposis coli gene at the beginning of the region frequently associated with desmoids induced a familial adenomatous polyposis phenotype featured by a high penetrance of the desmoid trait, with severe disease in several affected members of both sexes. The study may help to understand the biologic mechanisms of genotype-phenotype correlations in adenomatosis coli.

Adenomatous Polyposis Coli↗
PubMed2001

Numerous colonic adenomas in an individual with Bloom's syndrome.

Bloom's syndrome (BS) is a rare recessive disorder caused by germline mutation of the BLM gene. Individuals with BS manifest growth retardation, immunodeficiency, and a predisposition to cancer. In this report, we describe an individual with BS and multiple colonic adenomas reminiscent of familial adenomatous polyposis coli (FAP). Molecular studies revealed APC mutations in 4 of 6 adenomas, including 2 adenomas with the identical APC mutation and microsatellite instability in 1 of 6 adenomas. These results demonstrate similar pathways to colorectal neoplasia in BS as in the normal population and suggest that individuals with BS may be particularly susceptible to colorectal neoplasia.

Adenoma↗
PubMed2000

Genotype and phenotype factors as determinants for rectal stump cancer in patients with familial adenomatous polyposis. Hereditary Colorectal Tumors Registry.

OBJECTIVE: To identify factors influencing the occurrence of cancer in the rectal remnant in patients with familial adenomatous polyposis (FAP) after colectomy and ileorectal anastomosis (IRA). SUMMARY BACKGROUND DATA: The risk for rectal cancer in patients with FAP after colectomy and IRA remains a major concern. METHODS: Between 1955 and 1997, 371 patients (206 men, 165 women) from the Registry of Hereditary Colorectal Tumors underwent colectomy and IRA as a primary surgical procedure. Survival was estimated using the Kaplan-Meier method. Cox proportional hazard models were fitted to assess the relative excess risk of rectal cancer and to control for confounding factors. A multivariate analysis was performed to assess the relation between cancer risk in the rectum and sex, age, number of rectal polyps, colon cancer, and APC germline mutation. RESULTS: Median follow-up was 81 months. Eighty-nine patients (24%) had colon cancer at the time of surgery. The APC mutation was found in 200 patients. In 27 patients, cancer developed in the retained rectum 1 to 26 years after surgery. The incidence of rectal carcinoma appears to increase with time: at 10, 15, and 20 years after surgery, the cumulative risk was 7.7%, 13.1%, and 23.0%, respectively. Multivariate analysis identified as independent predictors the presence of colon cancer at IRA and a mutation occurring between codons 1250 and 1464; both factors increased the risk nine times. CONCLUSIONS: The presence of cancer at IRA and APC mutation type are the most important risk factors for the future development of cancer in the rectal remnant in patients with FAP.

Adenomatous Polyposis Coli↗
PubMed1999

TbetaR-I(6A) is a candidate tumor susceptibility allele.

We have previously described a type I transforming growth factor (TGF)-beta receptor (TbetaR-I) polymorphic allele, TbetaR-I(6A), that has a deletion of three alanines from a nine-alanine stretch. We observed a higher than expected number of TbetaR-I(6A) homozygotes among tumor and nontumor DNA from patients with a diagnosis of cancer. To test the hypothesis that TbetaR-I(6A) homozygosity is associated with cancer, we performed a case-control study in patients with a diagnosis of cancer and matched healthy individuals with no history of cancer and who were identical in their gender and their geographical and ethnic background to determine the relative germ-line frequencies of this allele. We found nine TbetaR-I(6A) homozygotes among 851 patients with cancer. In comparison, there were no TbetaR-I(6A) homozygotes among 735 healthy volunteers (P < 0.01). We also observed an excess of TbetaR-I(6A) heterozygotes in cancer cases compared to controls (14.6% versus 10.6%; P = 0.02, Fisher's exact test). A subset analysis revealed that 4 of 112 patients with colorectal cancer were TbetaR-I(6A) homozygotes (P < 0.01). Using mink lung epithelial cell lines devoid of TbetaR-I, we established stably transfected TbetaR-I and TbetaR-I(6A) cell lines. We found that, compared to TbetaR-I, TbetaR-I(6A) was impaired as a mediator of TGF-beta antiproliferative signals. We conclude that TbetaR-I(6A) acts as a tumor susceptibility allele that may contribute to the development of cancer, especially colon cancer, by means of reduced TGF-beta-mediated growth inhibition.

Activin Receptors, Type I↗
PubMed1999

Clinical features and genotype-phenotype correlations in 41 Italian families with adenomatosis coli.

BACKGROUND: Familial Adenomatous Polyposis in an autosomal dominant disease in which the large bowel is carpeted by polyps of various dimensions appearing during the second or third decade of life. Several extracolonic manifestations complete the clinical spectrum of Familial Adenomatous Polyposis. If untreated, the disease leads invariably to colorectal cancer. The gene responsible for the disease, adenomatous Polyposis Coli, has been localized at chromosome 5q21. AIMS: To describe the clinical features of 156 Familial Adenomatous Polyposis patients (from 41 families) and to analyze possible correlations between genotype and phenotype. PATIENTS AND METHODS: Familial Adenomatous Polyposis was defined as the presence of 100 or more polyps in the large bowel. In 17 families (41%), the proband was the only affected individual (single cases). Adenomatous Polyposis Coli gene mutations were studied on DNA extracted from peripheral white blood cells and evaluated by polymerase chain reaction single strand conformation polymorphism, followed by direct sequencing of samples showing abnormal banding at single strand conformation polymorphism. RESULTS: The large majority of Familial Adenomatous Polyposis patients underwent surgery; colectomy with ileorectal anastomosis was the most frequent approach, however, cancer of the rectal stump developed in 11.6% of patients submitted to colectomy and ileorectal anastomosis. Adenomas were rare in the stomach (8.8%), but their frequency increased in the duodenum (33.8%) and jejunum (55.0%, chi 2 for trend 23.7, p < 0.001). Desmoid tumours were diagnosed in 17 patients (10.9% of the total) and in 6 families. Mutations of the Adenomatous Polyposis Coli gene were studied in 20 out of 25 families (80%) and on a total of 75 individuals. The most frequent alterations were 1 to 5 bp deletions leading to stop codons and truncated proteins. Desmoid tumours, presence of duodenal or jejunal adenomas were associated with an ample range of mutations, from codon 215 to codon 1464. In contrast, particularly severe polyposis (mean age at appearance of polyps 11-16 years, and of cancer development 27-32 years) was associated with a "hotspot" mutation site at codons 1303-1309. CONCLUSIONS: In patients with Familial Adenomatous Polyposis, subtotal colectomy with ileorectal anastomosis is still the treatment of choice. Adenomatous lesions seem to show a "gradient" distribution from the stomach to the large bowel. Desmoid tumours are relatively common, though their incidence is limited to some of the families. Constitutional mutations can be detected in 80% of the investigated families. Genotype-phenotype correlations showed a hot-spot at codons 1303-1309, frequently associated with severe polyposis.

Adenomatous Polyposis Coli↗
PubMed1998

Novel germline APC variants in patients with multiple adenomas.

Chain-terminating germline APC mutations are responsible for adenomatous polyposis coli (APC). In the present work, we tested the hypothesis that germline APC mutations may be present in some patients with a milder phenotype, i.e., multiple synchronous colorectal adenomas. Eighteen patients with 3 or more colorectal adenomas at endoscopy (within a 6-month period) were ascertained from a series of subjects undergoing endoscopic examination. Their blood DNAs were analysed for the presence of germline mutations in the APC coding region by single-strand polymorphism analysis. Ten unrelated polyp-free subjects and 101 unrelated APC patients were used as controls in the molecular analyses. Five of the eighteen patients carried novel germline APC variants or rare polymorphisms. These were various in site (from the splice acceptor site of intron 7 to the end of exon 15) and type (splice-site, missense, and chain-terminating mutations). Only one of ten polyp-free individuals carried a silent APC variant and none of these variants was found in the 101 APC controls. A first- or second-degree family history of colorectal cancer was reported by 4 of the 5 patients carrying a germline APC variant. In conclusion, novel APC germline variants were detected in patients with multiple synchronous adenomas. This suggests that the development of sporadic adenomas, in some instances, is associated with the presence of minor germline variants of the APC gene and that the spectrum of germline APC functional mutations may be larger than previously thought.

Adenoma↗
PubMed1998

The familial adenomatous polyposis region exhibits many different haplotypes.

In the present study, we used five different polymorphic markers to construct the haplotype at the adenomatous polyposis coli (APC) locus in families with familial adenomatous polyposis (FAP) and in the normal Italian population. Non-ambiguous haplotypes were reconstructed from 246 normal chromosomes and 65 FAP chromosomes. In the control population, the four polymorphisms intragenic to APC gave rise to 16 haplotypes, the most common of which (II and XV) accounted for over 50% of all chromosomes. In FAP patients, 13 haplotypes were found but their distribution was not statistically different from normal subjects. Eighty complete chromosomal haplotypes (many fewer than the theoretical maximum of 208) for the five polymorphic sites assayed were observed in the control population, 35 being found in the FAP patients. We compared the distribution of these haplotypes within the two groups; no statistically significant differences between normal and FAP chromosomes were found. The elevated heterogeneity of FAP chromosomes was clearly confirmed by the observation that 19 patients who carried one or other of the two most common APC mutations (nt 3183 and nt 3927) showed 18 different haplotypes. On the basis of these results, we were not able to identify a founder FAP chromosome. Various mechanisms are presented to explain this observation.

Adenomatous Polyposis Coli↗
PubMed1998

Chain-terminating mutations in the APC gene lead to alterations in APC RNA and protein concentration.

APC mutations introduce premature stop codons into the open reading frame of the gene, leading to the formation of truncated tumor suppressor proteins. Both RNA and protein levels are likely to be profoundly altered by such nonsense mutations. To test this hypothesis, Western blotting and RT-PCR strategies were used to characterize mutant and normal APC protein and APC RNA concentrations in lymphoblastoid cell lines from 22 unrelated polyposis patients carrying different APC mutations. Variable levels of truncated APC peptides were observed in 14 of 14 cell lines with APC mutations within exon 15. No truncated APC protein was detected in six of eight cell lines with APC mutations located 5' of exon 15. Mutations located in exon 15 showed mutant RNA underrepresentation in four of eight cell lines, whereas mutations located 5' of exon 15 showed RNA reduction in five of six cell lines. These findings indicate that a two- to threefold decrease in RNA concentration is common when APC alleles carry chain-terminating mutations. They also suggest that the severe decrease of truncated APC protein observed in some cell lines is due to mechanisms acting at the protein level.

Adenomatous Polyposis Coli Protein↗