Chromosome changes in desmoid tumors developed in patients with familial adenomatous polyposis.

Chromosome analyses were performed on benign desmoid tumors obtained from two female patients with familial adenomatous polyposis (FAP), one of whom was diagnosed as having Gardner syndrome (GS). The modal chromosome number was 46 in both specimens, and detailed Q-banding analysis in Case 1 (GS) revealed a clonal abnormality of an interstitial deletion of the long arm of chromosome 5, del(5)(q21q31). The deleted region included an assigned locus for an FAP major gene (5q21-q22). All of the metaphases analyzed in this case showed an extra segment of bright fluorescence on the short arm of chromosome 15, but this unusual chromosome (15p+) was observed in both peripheral lymphocyte and skin fibroblast cultures from the patient, indicating that the 15p+ was constitutional in nature. In Case 2, no clonal rearrangements were identified and most cells had a normal karyotype. However, two cells showed rearrangements involving a 17q with non-identical breakpoints, one of which was observed as a solitary chromosome change. Based on the present findings in Case 1 and those reported so far, the chromosomal defect on 5q might be one of the causal genetic events primarily associated with the development of both benign desmoid tumors and colorectal adenomas and carcinomas in FAP patients.     

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.     

p53 gene mutations in colorectal tumors from patients with familial polyposis coli.

The p53 gene has been elucidated as a tumor suppressor gene, and inactivation of this gene caused by deletion or point mutations may play a crucial role in the development of human malignancies. In colorectal carcinomas with an allelic deletion of the p53 gene, the remaining p53 gene was mutated with considerable frequency. It is most difficult to detect point mutations or small deletions of the gene because the mutations occur in diverse regions, although four hot spots have been observed [J.M. Nigro et al., Nature (Lond.), 342: 705-708, 1989]. The polymerase chain reaction and denaturing gradient gel electrophoresis facilitate detection of mutations in the hot spots of the p53 gene. Using these methods, we detected mutations in three adenomatous polyps and one carcinoma from familial polyposis coli patients and three carcinomas of sporadic cases. The DNA sequence analysis confirmed mutations of the p53 gene in 2 adenomas (13 base-pair deletions in one and a point mutation in the other) and 1 carcinoma (point mutation) from familial polyposis coli patients. These results suggest that the p53 gene mutations may be involved in the formation not only of carcinomas but also of adenomas which occur in familial polyposis coli patients.     

APC gene mutations and colorectal adenomatosis in familial adenomatous polyposis

Correlations between germline APC mutation sites and colorectal pathophenotypes, as evaluated by the direct count of adenomas at colectomy, were investigated analysing colectomy specimens from 29 FAP patients carrying one mis-sense (codon 208) and 14 frame-shift or non-sense APC mutations (codons 232, 367, 437, 623, 876, 995, 1061, 1068, 1075, 1112, 1114, 1309, 1324, 1556). The mis-sense mutation at codon 208 was associated with a relatively mild colorectal pathophenotype. The mutation at codon 367, subject to alternative splicing, was associated with attenuated FAP. The mutation at codon 1309 was associated with the profuse colorectal adenomatosis. For 13 mutations, predicted to result in null alleles or truncated APC proteins, we correlated density and distribution of colorectal adenomas with the predicted functional effects of the mutation. The most severe colorectal pathophenotype was significantly associated with the truncating mutation at codon 1309, which is located downstream to the I beta-catenin binding domain but upstream II beta-catenin-binding domain. Mutations between codons 867 and 1114, which affect the I beta-catenin binding domain, as well as mutations occurring in exons 6 and 9, predicted to result in null alleles, were associated with a less severe colorectal pathophenotype. Overall, the highest number of adenomas was detected in the right colon, followed by the left colon, transverse colon sigma and rectum. However, the highest density of adenomas was observed in the left colon, followed by the right colon, sigma, transverse colon and rectum. Colorectal carcinomas, observed in only five patients, were all in the left colon.     

Assessment of endostatin gene therapy for familial adenomatous polyposis-related desmoid tumors

Constitutive activation of the Wnt signaling pathway is a hallmark of many cancers, including familial adenomatous polyposis (FAP)-related desmoid tumors. Endostatin is a well-known antiangiogenic protein that has been described recently as a potential inhibitor of this signaling pathway. Here, we show that endostatin directly induces apoptosis and inhibits the Wnt signaling pathway in colorectal cancer cell lines bearing mutations on the adenomatous polyposis coli (APC) gene as a model of FAP-related malignant cells. We then explore the relationship between apoptosis and inhibition of this pathway and show that they are not correlated. These results seem to contradict a well-recognized study, showing that reintroduction of the APC cDNA in APC-deficient cells leads to apoptosis. To reconcile our conclusions with the literature, we further show that a truncated fragment of APC capable of inhibiting the Wnt signaling pathway in SW480 cells is incapable of inducing apoptosis in these cells, confirming that APC-mediated apoptosis is uncoupled to the inhibition of the Wnt signaling pathway. Finally, we show that endostatin directly induces cell death on primary FAP-related desmoid tumor cells in culture. This phenomenon is also independent of the inhibition of the Wnt signaling pathway. Considering the current lack of effective treatment against desmoid tumors, we advocate that endostatin gene therapy represents an attractive new therapeutic approach for this disease.     

Evaluation of management of desmoid tumours associated with familial adenomatous polyposis in Dutch patients

Background:

The optimal treatment of desmoid tumours is controversial. We evaluated desmoid management in Dutch familial adenomatous polyposis (FAP) patients.

Methods:

Seventy-eight FAP patients with desmoids were identified from the Dutch Polyposis Registry. Data on desmoid morphology, management, and outcome were analysed retrospectively. Progression-free survival (PFS) rates and final outcome were compared for surgical vs non-surgical treatment, for intra-abdominal and extra-abdominal desmoids separately. Also, pharmacological treatment was evaluated for all desmoids.

Results:

Median follow-up was 8 years. For intra-abdominal desmoids (n=62), PFS rates at 10 years of follow-up were comparable after surgical and non-surgical treatment (33% and 49%, respectively, P=0.163). None of these desmoids could be removed entirely. Eventually, one fifth died from desmoid disease. Most extra-abdominal and abdominal wall desmoids were treated surgically with a PFS rate of 63% and no deaths from desmoid disease. Comparison between NSAID and anti-estrogen treatment showed comparable outcomes. Four of the 10 patients who received chemotherapy had stabilisation of tumour growth, all after doxorubicin combination therapy.

Conclusion:

For intra-abdominal desmoids, a conservative approach and surgery showed comparable outcomes. For extra-abdominal and abdominal wall desmoids, surgery seemed appropriate. Different pharmacological therapies showed comparable outcomes. If chemotherapy was given for progressively growing intra-abdominal desmoids, most favourable outcomes occurred after combinations including doxorubicin.     

K-ras gene mutation in colorectal adenomas and carcinomas from familial adenomatous polyposis patients.

Colorectal adenomas and carcinomas from familial adenomatous polyposis (FAP) patients were screened for the presence of K-ras gene mutations at codon 12 using an in vitro amplification step (polymerase chain reaction) followed by dot blot analysis using oligonucleotide probes specific for different mutations at codon 12. We examined 28 colorectal adenomas and two colorectal carcinomas from 12 FAP patients and observed a mutation at codon 12 in seven adenomas and in both carcinomas. The frequency of K-ras gene mutations in colorectal tumours from FAP patients is similar to those in cases of sporadic adenomas and sporadic colorectal carcinomas indicating that the mechanisms involved in their development may be similar.     

Giant desmoid tumor of the abdominal wall associated with familial adenomatous polyposis

In this paper a case of vast desmoid tumor of the abdominal wall associated with familial adenomatous polyposis is reported. Desmoid tumors represent a particular type of fibrous neoplasms with a higher prevalence in females. They are extremely rare in the sporadic form, while they are found in about 10% of patients affected by familial adenomatous polyposis. Despite their benign histology and the absence of metastatic potential, they can be considered as fibrosarcomas with a low level of malignancy because of their locally invasive nature. The treatment of choice is surgical excision, as wide as possible, aimed at preventing recurrences, which are frequent in this tumor type. The usefulness of complementary therapies such as radiotherapy, hormone or chemotherapy, is not entirely clear.     

Abdominal desmoid in familial adenomatous polyposis presenting as a pancreatic cystic lesion

A 17-year-old male with familial adenomatous polyposis (FAP) presented with chest pain and significant weight loss. An abdominal CT scan detected a cystic pancreatic lesion of unknown etiology. The patient therefore underwent surgical resection of the distal pancreas, which included the lesion, because of the known association of pancreatic cancer with FAP. Histopathological examination of the resected specimen showed a benign pancreatic cyst and fibrous plaque with desmoid fibromatosis adherent to the surface of the pancreas, serosa of the stomach, and colon. The fibrous plaque was histologically identical to the fibrous mesenteric plaque known to occur in FAP and associated mesenteric fibromatosis. We present pathologic evidence that the pancreatic cyst formation was induced by FAP-associated desmoid invasion. Desmoid growth should be considered in the differential diagnosis of a pancreatic cystic mass lesion in patients with FAP or its Gardner syndrome variant. This case report provides the first pathologic evidence for benign epithelial cyst formation in the pancreas caused by fibromatosis invasion of that organ as a part of FAP.     

Genetic changes and histopathological types in colorectal tumors from patients with familial adenomatous polyposis

Loss of heterozygosity (LOH) and K-ras mutation were analyzed in 111 colorectal polyps and 26 invasive carcinomas from 40 patients with familial adenomatous polyposis of distinct histopathological types. LOH, being less than 2% in moderate adenomas, was detected on chromosome 5q (20%) in severe adenomas, on 5q (26%) and 17p (38%) in intramucosal carcinomas, and on 5q (52%), 17p (56%), 18 (46%), and 22q (33%) in invasive carcinomas. LOH on chromosome 5q occurred most frequently in the region close to the APC gene both in adenomas and carcinomas, and a loss of the normal allele of the APC gene was demonstrated in 3 cases. K-ras mutation markedly increased in the step of development from moderate (11%) to severe (36%) adenomas. These results suggest the following mechanisms for the development of colon tumors in patients with familial adenomatous polyposis: (a) the heterozygous mutant/wild-type condition at the APC gene causes formation of mild or moderate adenoma; (b) the loss of the normal allele in the APC gene leads to a change from moderate to severe adenoma; (c) LOH on chromosome 17p contributes to the conversion of adenoma to intramucosal carcinoma; (d) LOH on other chromosomes, such as 18 and 22q, are involved in the progression of intramucosal carcinoma to invasive carcinoma; and (e) K-ras mutation may also affect the development of moderate to severe adenoma.     

Nuclear accumulation of beta-catenin without an additional somatic mutation in coding region of the APC gene in hepatoblastoma from a familial adenomatous polyposis patient

The APC (adenomatous polyposis coli) gene status in a familial adenomatous polyposis (FAP) patient who developed hepatoblastoma was analyzed by the yeast color assay. Although a single base insertion at codon 462 resulting in truncation of its product was documented in hepatoblastoma cells, no additional somatic mutation was detectable in the whole coding sequence of the APC gene. The nuclear accumulation of beta-catenin without mutation in the exons 2-4 of the beta-catenin gene, however, was observed in the tumor cells by immunohistochemistry. The similar nuclear accumulation of beta-catenin without an additional somatic mutation in its gene, in the absence of somatic mutation in cluster region of the APC gene, has been previously reported in the single FAP case. Moreover, review in the hepatoblastoma cases in the FAP families showed a relatively later onset of the disease when compared with the sporadic cases. These observations suggest that accumulation of beta-catenin without an additional somatic mutation in the APC gene might be a possible mechanism for tumorigenesis of hepatoblastoma in the FAP families.     

Common genetic evolutionary pathways in familial adenomatous polyposis tumors

Cancer cells progress through the accumulation of genetic alterations. Familial adenomatous polyposis (FAP) tumors provide an excellent model to unravel the molecular steps underlying malignant transformation. Global genomic damage was assessed in 56 adenomas and 3 carcinomas from six FAP patients and compared with that of sporadic adenomas and carcinomas. Evolutive trees were traced after application of maximum likelihood clustering and split decomposition methods to the analysis of comprehensive genetic profiles generated by diverse molecular approaches: arbitrarily primed PCR, comparative genomic hybridization, and flow cytometry. Overall, genomic damage as assessed by arbitrarily primed PCR was lower in familial adenomas than in sporadic adenomas and carcinomas. Comparative genomic hybridization data also show a low number of alterations in the majority of FAP adenomas. Tumors of the same patient were likely to share specific genetic alterations and may be grouped into one or two clusters. Putative common pathways were also identified, which included tumors of up to three different patients. According to our data, FAP tumors accumulate specific genetic alterations and in a preferred order that is characteristic of each individual. Moreover, the particular genetic background and environmental conditions of a FAP patient restrain the molecular evolution portrait of synchronous tumors.     

Frequent mutations of the beta-catenin gene in mouse colon tumors induced by azoxymethane

The beta-catenin gene is frequently mutated at codons 33, 41 and 45 of the glycogen synthase kinase-3beta phosphorylation motif in human colon cancers in patients without APC mutations. Frequent mutations at codons 32 and 34, as well as 33 and 41, have been detected in rat colon tumors induced by azoxymethane (AOM), with the second G of CTGGA sequences being considered as a mutational hot-spot. In the present study, exon 3 of the beta-catenin gene in mouse colon tumors induced by AOM was amplified by PCR and mutations were detected by the single strand conformation polymorphism method, restriction enzyme fragment length polymorphism and direct sequencing. All 10 colon tumors tested were found to have beta-catenin mutations, four in codon 34, three in codon 33, two in codon 41 and one in codon 37, nine being G:C-->A:T transitions. However, no mutations were found in codon 32 of the mouse beta-catenin gene. On immmunostaining, beta-catenin was observed in the cytoplasm and nucleus of the tumor cells. The cytoplasmic staining was homogeneous, while both homogeneous and heterogeneous patterns were noted for the nuclei. Highly frequent mutations of the beta-catenin gene in AOM-induced mouse colon tumors suggest that consequent alterations in the stability and localization of the protein may play an important role in this colon carcinogenesis model.     

Loss of expression of the DCC gene during progression of colorectal carcinomas in familial adenomatous polyposis and non-familial adenomatous polyposis patients.

We have previously observed that the frequency of loss of heterozygosity (LOH) on chromosome 18q was low in adenomas and intramucosal carcinomas, whereas invasive carcinomas exhibited a high frequency in familial adenomatous polyposis patients (M. Miyaki et al., Cancer Res., 50: 7166-7173, 1990). In the present study, LOH at the DCC locus on chromosome 18q and the expression of DCC gene into mRNA were analyzed in colorectal tumors with distinct histopathological types. The carcinomas that showed 18q LOH also lost the DCC locus. The expression of DCC gene into mRNA was examined at the level of 233-base pair fragments of nucleotide 986-1218 in DCC complementary DNA. In a moderate-to-severe adenoma, 5 carcinoma-in-adenomas, and 4 intramucosal carcinomas, the level of expression was as high as in normal colorectal mucosa, whereas it was greatly reduced or not detectable in most (13 of 16) invasive carcinomas. Among these invasive carcinomas, 7 of 11 showed 18q LOH, but 4 showed no LOH. These results suggest that the DCC gene is included in the allelic deletion on chromosome 18q, and that the progression of colorectal carcinoma from early stage to advanced stage accompanies the inactivation of the DCC gene through LOH and other mechanisms.     

Gynecological malignancies, brain tumors, and familial adenomatous polyposis.

The syndrome of familial adenomatous polyposis has a wide spectrum of clinical manifestations including adenomatous polyps of the colon and small bowel, adenocarcinoma of ampulla of Vater, tumors of the central nervous system, bone lesions, and various soft tissue tumors. The one common denominator is colonic polyposis. It is not known whether this phenotypic heterogeneity is due to various genotypes, or if the entire clinical spectrum is due to one genetic defect. We are reporting the association of gynecologic malignancies with familial adenomatous polyposis as an additional variant of this disease. This report is on two sisters from a family with familial polyposis coli who developed adenomatous polyposis of the colon, central nervous system tumors, and cancers of the ovary and uterus. The gynecological malignancies add another variant to this clinical syndrome.     

Sulindac inhibits beta-catenin expression in normal-appearing colon of hereditary nonpolyposis colorectal cancer and familial adenomatous polyposis patients.

Sulindac reduces colorectal cancer risk in genetically susceptible humans and animals. The molecular mechanisms underlying these effects are incompletely understood. Many studies suggest an important role for induction of apoptosis involving the mitochondrial pathway and the death receptor pathway. Alternatively, mechanisms involving the APC-beta-catenin-Wnt pathway have been suggested, possibly mediated by p21. We determined the effects of sulindac on apoptosis and expression of death receptor (DR)-4 and DR5, beta-catenin, and p21 in normal-appearing colorectal epithelium. Biopsies were obtained before and after sulindac treatment during two chemoprevention studies. Patients (n = 18) with hereditary nonpolyposis colorectal cancer (HNPCC) received 150 mg sulindac bd for 4 weeks in a placebo-controlled crossover design. Patients (n = 6) with familial adenomatous polyposis (FAP) received 150 mg sulindac bd for 6 months. Apoptosis was assessed by M30 staining and expression patterns of DR4, DR5, beta-catenin, and p21 were studied immunohistochemically. In HNPCC patients, apoptotic indices were similar following placebo and sulindac. Also in FAP patients, apoptotic indices were not different after sulindac compared with pretreatment values. Expression of DR4 and DR5 was observed in all samples with no consistent differences between placebo/baseline and sulindac. Intensity of membranous beta-catenin staining was lower in HNPCC samples following sulindac compared with placebo (P < 0.001). Similar results were obtained in FAP samples (P < 0.01). p21 expressions before and after sulindac treatment were similar in both patient groups. In conclusion, sulindac inhibits beta-catenin expression in normal colorectal epithelium from HNPCC and FAP patients without affecting apoptotic indices and DR4, DR5, and p21 expression.     

Rectal cancers in patients with familial adenomatous polyposis

Patients with familial adenomatous polyposis may develop rectal cancer at their initial presentation (primary) or after colectomy and ileorectal anastomosis (secondary). Little is known about whether differences in presentation impact survival. We hypothesize that patients with secondary rectal cancer have better oncologic outcomes. Patients with rectal cancer in the context of familial adenomatous polyposis were classified into 3 groups: known rectal cancer at presentation, incidental rectal cancer unrecognized before proctocolectomy, and rectal cancer diagnosed after ileorectal anastomosis. Primary endpoint was 5-year survival. There were 58 patients, 39 with primary rectal cancer, 5 of which were incidental, and 19 with secondary rectal cancer. Median ages at diagnosis were 32 years (range 14–56) for primary cancer, 35 years (range 22–56) for incidental cancer and 49 years (range 24–66) for secondary cancer (p = 0.001). 76 % of those with primary rectal cancer had symptoms, similar to those with incidental cancer (60 %) but more than secondary cancer (21 %) (p < 0.001). 47 % of primary cancers were advanced (stages III and IV) compared to 20 % of incidental cancers and 32 % of secondary cancers. There was no local recurrence in any patient, but 9 patients had distant recurrences (16 % overall). Overall 5-year survival of patients with primary cancer was 72.4 %, incidental cancer was 100 %, and secondary cancer was 69.7 % (p = 0.031). More patients with primary rectal cancer have advanced disease but survival is similar to those with cancer diagnosed on surveillance. More patients with primary rectal cancer have a restorative resection when compared to other groups.     

Oxidative stress in familial adenomatous polyposis.

The prooxidant/antioxidant imbalance in familial adenomatous polyposis (FAP) is suggested by (i) the intimate connection between APC and prostaglandin H synthase-2 genes, (ii) the increase of the free radical-generating enzyme xanthine oxidase, and (iii) the decrease of antioxidant defences. In this research work we evaluated lipid peroxidation measuring the thiobarbituric acid (TBA) reactive products and we studied the activities of superoxide dismutase (SOD) and catalase as well as the levels of ascorbate and tocopherols in the peripheral blood cells from a total of 27 FAP patients and 83 normal controls. TBA-reactive products were determined according to a previously published method. SOD and catalase activities were determined by the spectrophotometric monitoring of the inhibition of pyrogallol autoxidation and the hydrogen peroxide decomposition rate, respectively. Ascorbate levels were determined by a modified 2,4-dinitrophenylhydrazine method and tocopherol levels by a modified Emmerie-Engle method. The levels of TBA-reactive products were higher in FAP patients than in normal controls. Although no statistically significant differences in SOD and catalase activities were observed between FAP patients and normal controls, we found that ascorbate and tocopherol levels were significantly lower in FAP patients than in normal controls, as assessed by the Mann-Whitney test. Hence, this finding of an imbalance in the prooxidant/antioxidant status may contribute towards new strategies for prevention and therapy in FAP patients.     

Gastroduodenal polyps in familial adenomatous polyposis.

A retrospective review of the medical records of 30 patients with familial adenomatous polyposis who underwent oesophagogastroduodenoscopy was performed to evaluate the spectrum of gastroduodenal polyps. Twenty-five patients (83%) had gastroduodenal polyps. Eighteen patients (60%) had gastric polyps and 21 patients (70%) had duodenal polyps. Five patients (17%) had gastric and 20 patients (67%) had duodenal adenomatous polyps. Three patients (10%) died from an upper gastrointestinal tract adenocarcinoma. Three of nine patients with periampullary adenomas had a normal-appearing papilla of Vater. Since gastroduodenal polyps are common in familial adenomatous polyposis, oesophagogastroduodenoscopy should be performed at the time of diagnosis. Biopsy of polyps as well as biopsy of a normal-appearing papilla of Vater should be performed. Due to their malignant potential, if identified, gastroduodenal adenomatous polyps should be destroyed.