ABSTRACT
BACKGROUND: Comprehensive next-generation sequencing is widely used for precision oncology and precision prevention approaches. We aimed to determine the yield of actionable gene variants, the capacity to uncover hereditary predisposition and liquid biopsy appropriateness instead of, or in addition to, tumor tissue analysis, in a real-world cohort of cancer patients, who may benefit the most from comprehensive genomic profiling. METHODS: Seventy-eight matched germline/tumor tissue/liquid biopsy DNA and RNA samples were profiled using the Hereditary Cancer Panel (germline) and the TruSight Oncology 500 panel (tumor tissue/cfDNA) from 23 patients consecutively enrolled at our center according to at least one of the following criteria: no available therapeutic options; long responding patients potentially fit for other therapies; rare tumor; suspected hereditary cancer; primary cancer with high metastatic potential; tumor of unknown primary origin. Variants were annotated for OncoKB and AMP/ASCO/CAP classification. RESULTS: The overall yield of actionable somatic and germline variants was 57% (13/23 patients), and 43.5%, excluding variants previously identified by somatic or germline routine testing. The accuracy of tumor/cfDNA germline-focused analysis was demonstrated by overlapping results of germline testing. Five germline variants in BRCA1, VHL, CHEK1, ATM genes would have been missed without extended genomic profiling. A previously undetected BRAF p.V600E mutation was emblematic of the clinical utility of this approach in a patient with a liver undifferentiated embryonal sarcoma responsive to BRAF/MEK inhibition. CONCLUSIONS: Our study confirms the clinical relevance of performing extended parallel tumor DNA and cfDNA testing to broaden therapeutic options, to longitudinally monitor cfDNA during patient treatment, and to uncover possible hereditary predisposition following tumor sequencing in patient care.
Subject(s)
Genomics , Germ-Line Mutation , Neoplasms , Humans , Female , Liquid Biopsy , Neoplasms/genetics , Neoplasms/pathology , Male , Middle Aged , Cohort Studies , Germ-Line Mutation/genetics , Genomics/methods , Adult , Aged , Germ Cells/metabolism , High-Throughput Nucleotide Sequencing/methods , Genetic Predisposition to DiseaseABSTRACT
Mismatch repair (MMR) testing on all new cases of colorectal cancer (CRC) has customarily been preferably performed on surgical specimens, as more tissue is available; however, new clinical trials for the use of immune checkpoint inhibitors in the neoadjuvant setting require MMR testing on biopsy samples. This study aims at identifying advantages, disadvantages and any potential pitfalls in MMR evaluation on biopsy tissue and how to cope with them. The study is prospective-retrospective, recruiting 141 biopsies (86 proficient (p)MMR and 55 deficient (d)MMR) and 97 paired surgical specimens (48 pMMR; 49 dMMR). In biopsy specimens, a high number of indeterminate stains was observed, in particular for MLH1 (31 cases, 56.4%). The main reasons were a punctate nuclear expression of MLH1, relatively weak MLH1 nuclear expression compared to internal controls, or both (making MLH1 loss difficult to interpret), which was solved by reducing primary incubation times for MLH1. A mean of ≥ 5 biopsies had adequate immunostains, compared to ≤ 3 biopsies in inadequate cases. Conversely, surgical specimens rarely suffered from indeterminate reactions, while weaker staining intensity (p < 0.007) for MLH1 and PMS2 and increased patchiness grade (p < 0.0001) were seen. Central artefacts were almost exclusive to surgical specimens. MMR status classification was possible in 92/97 matched biopsy/resection specimen cases, and all of these were concordant (47 pMMR and 45 dMMR). Evaluation of MMR status on CRC biopsy samples is feasible, if pitfalls in interpretation are known, making laboratory-specific appropriate staining protocols fundamental for high-quality diagnoses.
Subject(s)
Colorectal Neoplasms , Humans , Retrospective Studies , Prospective Studies , Colorectal Neoplasms/genetics , BiopsyABSTRACT
CONTEXT: Colonic polyps occur in 30-40% of acromegalic patients, increasing the risk of colon carcinoma. Although debated, there is emerging evidence that metformin may play a protective role in diabetic and non-diabetic patients with colonic polyps and its use in chemoprevention is currently explored. OBJECTIVE: Evaluate the prevalence of colonic polyps in acromegalic patients treated or not with metformin and explore its possible protective role. DESIGN: Exploratory cross-sectional study in two tertiary Italian referral centres. MET: hods: Out of 153 acromegalic patients, we selected 58 patients (36-82 years; f: 33) who had at least one colonoscopy performed within the first 2 years of diagnosis. Presence of colonic polyps/cancer and related risk factors, current metformin and acetylsalicylic acid intake, disease duration, therapies for acromegaly, hormonal and metabolic parameters were assessed. RESULTS: An overall prevalence of 36% polyps was found. Based on the presence of polyps, we identified two groups, comparable for age, BMI, disease duration, glucose, insulin, HOMA-IR, HbA1c, GH and IGF-I levels. Of the patients with polyps (including three adenocarcinomas) only 24% were treated with metformin vs 57% of patients without polyps. Multivariate analysis confirmed a significant negative association between colonic polyps and metformin intake (OR: 0.22, 95% CI: 0.06-0.77, P = 0.01), whereas no significant association was found between polyps and age (P = 0.10), overweight/obesity (P = 0.54), smoking (P = 0.15), acetylsalicylic acid intake (P = 0.99), disease duration (P = 0.96), somatostatin analogues treatment (P = 0.70). CONCLUSIONS: These findings, though deriving from an exploratory study, could suggest a protective role of metformin on the development of colonic polyps in acromegaly, and need to be confirmed in an extended study population.
Subject(s)
Acromegaly/complications , Colonic Polyps/prevention & control , Hypoglycemic Agents/therapeutic use , Metformin/therapeutic use , Adult , Aged , Aged, 80 and over , Colonic Polyps/epidemiology , Colonic Polyps/etiology , Colonoscopy , Cross-Sectional Studies , Female , Humans , Incidence , Male , Middle Aged , RiskABSTRACT
Octreotide and lanreotide, the first-generation somatostatin analogs, successfully control hormone hyperproduction, and related syndromes, in patients with acromegaly and neuroendocrine tumors. However, their anti-tumor effect, rather evident in large number of pituitary adenomas in acromegalic patients, has been hypothesized for a long time in patients with neuroendocrine tumors as well, although a significant tumor shrinkage has rarely been observed. However, the recent publication of the CLARINET study has strengthened the evidence, already emerged with the PROMID trial, that the long-term treatment with the first-generation long-acting somatostatin analogs may exert an anti-tumor activity on G1 and G2 enteropancreatic neuroendocrine tumors, as well. After the publication, majority of international guidelines have updated their algorithms in line with these results and this class of drugs obtained the indication as anti-tumor agents in the majority of patients with neuroendocrine tumors.
Subject(s)
Antineoplastic Agents/therapeutic use , Neuroendocrine Tumors/drug therapy , Somatostatin/analogs & derivatives , Clinical Trials as Topic , Humans , Somatostatin/therapeutic useABSTRACT
Pancreatic adenocarcinoma (PC) is the third most common cancer associated with BRCA mutations. Most notice has been given to BRCA2, while the association between BRCA1 and PC is less widely reported. Recently, PALB2 has been implicated in both PC and breast cancer (BC) susceptibility. We selected 29 Italian PC patients from a case-control study of PC according to their personal and family history of both PC and breast/ovarian cancer (BC/OC) and tested them for presence of germline mutations in BRCA1, BRCA2 and PALB2. We identified no germline mutations or deletions in PALB2, but detected 7 BRCA mutations (4 in BRCA1 and 3 in BRCA2). These findings suggest that PALB2 does not play a major role in PC susceptibility in our population. As we found an almost equal frequency of germline mutations in BRCA1 and BRCA2, germline alterations in either of these genes may explain a subset of Italian families presenting both PC and BC/OC. Moreover, as we began the observation of these families from probands who are affected by PC, we provide here a direct assessment of the role of PALB2 and BRCA mutations in PC susceptibility.
Subject(s)
Adenocarcinoma/genetics , BRCA1 Protein/genetics , BRCA2 Protein/genetics , Gene Deletion , Germ-Line Mutation/genetics , Nuclear Proteins/genetics , Pancreatic Neoplasms/genetics , Tumor Suppressor Proteins/genetics , Adult , Aged , Aged, 80 and over , Breast Neoplasms/genetics , Case-Control Studies , Fanconi Anemia Complementation Group N Protein , Female , Genetic Predisposition to Disease , Humans , Italy , Male , Middle Aged , Ovarian Neoplasms/genetics , PedigreeABSTRACT
BACKGROUND: asparagine-glycine-arginine-human tumour necrosis factor (NGR-hTNF), an agent selectively damaging the tumour vasculature, showed a biphasic dose-response curve in preclinical models. Previous phase I trials of NGR-hTNF indicated 0.8 and 45 µg/m(2) as optimal biological and maximum-tolerated dose, respectively. PATIENTS AND METHODS: Two sequential cohorts of 12 colorectal cancer (CRC) patients who had failed standard therapies received NGR-hTNF 0.8 or 45 µg/m(2) in combination with capecitabine-oxaliplatin (XELOX). RESULTS: Median number of prior treatment lines was 3 in the low-dose and 2 in the high-dose cohort. Overall, 21 patients had been pretreated with oxaliplatin-based regimens. No grade 3-4 NGR-hTNF-related toxicities were observed. Grade 1-2 chills were reported in 43% and 40% of cycles in the low-dose and high-dose cohorts, respectively. In the low-dose cohort, one patient achieved a partial response and five had stable disease for a median of 4.6 months. In the high-dose cohort, six patients had stable disease for a median of 3.6 months. Three-month progression-free survival (PFS) rates were 50% and 33% in the low-dose and high-dose cohort, respectively. Three patients in low-dose cohort experienced PFS longer than PFS on last prior therapy. CONCLUSIONS: Both NGR-hTNF doses were safely combined with XELOX in pretreated CRC patients. Hint of activity was apparent only with low-dose NGR-hTNF.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Colorectal Neoplasms/drug therapy , Deoxycytidine/analogs & derivatives , Fluorouracil/analogs & derivatives , Organoplatinum Compounds/therapeutic use , Recombinant Fusion Proteins/therapeutic use , Salvage Therapy , Tumor Necrosis Factor-alpha/therapeutic use , Adult , Aged , Capecitabine , Deoxycytidine/administration & dosage , Deoxycytidine/therapeutic use , Disease-Free Survival , Dose-Response Relationship, Drug , Female , Fluorouracil/administration & dosage , Fluorouracil/therapeutic use , Humans , Male , Middle Aged , Organoplatinum Compounds/administration & dosage , Oxaliplatin , Oxaloacetates , Recombinant Fusion Proteins/administration & dosage , Treatment Outcome , Tumor Necrosis Factor-alpha/administration & dosageABSTRACT
Lynch syndrome is an inherited cancer syndrome caused by germline mutations in mismatch repair (MMR) genes MLH1, MSH2, MSH6 and PMS2. LS predisposes to high risk of early-onset colorectal, endometrial and other tumors. Patients with Lynch syndrome have also been shown to have an elevated risk for pancreatic cancer (PC). In this study, we aimed to estimate the frequency of suspected Lynch syndrome among a series of 135 PC patients. Further, we wanted to determine the frequency of MMR gene mutations in the suspected Lynch syndrome cases. We also aimed to verify the pathogenicity of any novel non-truncating variants we might detect with a functional assay. Based on personal and/or familial cancer history, 19 patients were classified as suspected Lynch syndrome cases. DNA material for mutation analysis was available for eleven of them. Four patients were found to carry a total of five MLH1 or MSH2 variants. Of these, MSH2-Q402X, MSH2-G322D, and MLH1-K618A had been previously reported, while the MSH2-E205Q and MSH2-V367I variants were novel. MSH2-Q402X is a known stop mutation and reported here for the first time here in association with PC. MLH1-K618A was found in the unaffected branch of a kindred, suggesting that it may be a polymorphism or a low penetrance variant. MSH2-G322D likely does not cause a MMR defect, although this variant has also been associated with breast cancer as indeed seen in our patient. The novel variants MSH2-E205Q and MSH2-V367I were found in the same patient. Both novel variants were however functional in the applied MMR assay. Our findings suggest that only a small subset of pancreatic cancer patients carry pathogenic MMR mutations.
Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Colorectal Neoplasms, Hereditary Nonpolyposis/genetics , Genetic Predisposition to Disease , MutS Homolog 2 Protein/genetics , Nuclear Proteins/genetics , Pancreatic Neoplasms/genetics , Adult , Base Sequence , Colorectal Neoplasms, Hereditary Nonpolyposis/complications , DNA Mismatch Repair/genetics , DNA Mutational Analysis , Female , Germ-Line Mutation , Humans , Immunohistochemistry , Italy , Male , Microsatellite Instability , Middle Aged , MutL Protein Homolog 1 , Pedigree , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
BACKGROUND: The anti-epidermal growth factor receptor (EGFR) antibody cetuximab is active in heavily pretreated patients with metastatic colorectal cancer (mCRC) both in monotherapy and in combination with chemotherapy (CT). This study assesses the antitumor activity of single-agent cetuximab in CT-naive patients. PATIENTS AND METHODS: Phase II clinical trial was used. Patients were EGFR positive by immunohistochemistry and were not candidate for radical surgery, even in the case of substantial tumor shrinkage. Cetuximab was administered weekly. RESULTS: Thirty-nine patients were treated and evaluated. The most common adverse event was skin toxicity (89% any grade; 48% grade 1; 31% grade 2; 10% grade 3). One patient had a complete response and three obtained partial responses (10% overall response rate). Thirteen patients had stable disease (34%). Twenty-two patients experienced progressive disease (56%). Overall median time to progression (TTP) was 2 months, and the responders individual TTP was 12, 9, 9, and 6 months. CONCLUSIONS: Even in chemo-naive patients, cetuximab as single agent is active only in a small fraction of mCRC, similarly to what has been reported for heavily pretreated patients. The extent of benefit when response occurs is, however, such that it is mandatory to intensify the search for the predictive markers of response to cetuximab therapy.
Subject(s)
Adenocarcinoma/drug therapy , Antibodies, Monoclonal/therapeutic use , Antineoplastic Agents/therapeutic use , Biomarkers, Tumor/analysis , Colorectal Neoplasms/drug therapy , ErbB Receptors/analysis , ErbB Receptors/drug effects , Skin Diseases/chemically induced , Adenocarcinoma/chemistry , Adenocarcinoma/secondary , Aged , Aged, 80 and over , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal/adverse effects , Antibodies, Monoclonal, Humanized , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/adverse effects , Biomarkers, Tumor/immunology , Cetuximab , Colorectal Neoplasms/chemistry , Colorectal Neoplasms/pathology , Disease Progression , Disease-Free Survival , Drug Administration Schedule , Drug Eruptions/etiology , ErbB Receptors/immunology , Female , Humans , Immunohistochemistry , Male , Middle Aged , Nail Diseases/chemically induced , Predictive Value of Tests , Pyoderma/chemically induced , Skin/drug effects , Treatment OutcomeABSTRACT
The aim of this study was to determine the diagnostic value of rectal bleeding for distal colorectal cancer (CRC), or large (> or =10 mm) adenomas among an average-risk population. A cross-sectional survey was conducted among individuals aged 55-64 years, who attended sigmoidoscopy (FS) screening in the context of a multicentre randomised trial of FS screening for CRC. Sensitivity, specificity and positive predictive value (PPV) of rectal bleeding for large distal adenomas or CRC were calculated. Rectal bleeding was reported by 8.8% of 8507 patients examined (15% of those with large adenomas and 29% of those with CRC). The risk of CRC was increased when bleeding was associated with an altered bowel habit: odds ratio (OR)=10.42; 95% Confidence Interval (CI): 4.08-26.59; the corresponding OR for isolated bleeding was 5.29 (95% CI: 2.28-12.30). Rectal bleeding carries an increased risk of distal neoplastic lesions. However, most lesions are detected among asymptomatic subjects. This finding suggests that screening represents the optimal strategy to detect CRC or large adenomas in the distal colon in the targeted age range.
Subject(s)
Colonic Neoplasms/diagnosis , Gastrointestinal Hemorrhage/etiology , Mass Screening/methods , Rectal Diseases/etiology , Colonic Neoplasms/prevention & control , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Risk FactorsABSTRACT
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.
Subject(s)
Adenoma/genetics , Adenomatous Polyposis Coli Protein/genetics , Colorectal Neoplasms/genetics , Mutation, Missense , Adult , Aged , Aged, 80 and over , Female , Gene Frequency , Humans , Italy , Male , Middle AgedABSTRACT
BACKGROUND: The need for colonoscopy in the care of patients with rectosigmoid adenoma 5 mm or less in diameter is still debatable. METHODS: We estimated the prevalence of proximal adenomas among 3052 consecutive subjects undergoing total colonoscopy. Rectosigmoid adenoma was classified as diminutive (5 mm), small (6 to 10 mm), or large (>/=11 mm). Advanced proximal adenoma was 10 mm in diameter or larger, or with a villous component, severe dysplasia, or infiltrating adenocarcinoma. RESULTS: Proximal adenoma was found in 212 of 2483 patients (8.5%, 95% CI [7.5, 9.7]) without distal neoplastic polyps, 49 of 214 (22.9%, 95% CI [17.6, 29.2]) with diminutive, 44 of 174 (25.3%, 95% CI [19.1, 32.5] with small, and 70 of 181 (38.7%, 95% CI [31.6, 46.2]) with large distal adenoma. Advanced proximal adenoma was found in 49 (2.0%, 95% CI [1.5, 2.6]), 8 (3.7%, 95% CI [1.7, 7.5]), 17 (9.8%, 95% CI [6.0, 15.4]), and 29 patients (16.0%, 95% [11.2, 22.4]), respectively. In patients with distal adenoma risk for proximal lesions increased with increasing age, size, and number of distal adenomas (p = 0.01). Size of distal adenoma was the strongest predictor of the presence of proximal advanced adenoma (multivariate analyses). CONCLUSIONS: In a clinical setting, the decision to perform colonoscopy should take into account proximal lesions of clinical interest, life expectancy, costs, and risks associated with the procedure. When detection of advanced proximal adenoma is the goal, presence of distal diminutive adenoma alone might not be an indication for total colonoscopy.
Subject(s)
Adenomatous Polyps/pathology , Colonoscopy/statistics & numerical data , Colorectal Neoplasms/pathology , Adenomatous Polyps/diagnosis , Adenomatous Polyps/epidemiology , Adolescent , Adult , Age Distribution , Aged , Cohort Studies , Colonoscopy/methods , Colorectal Neoplasms/diagnosis , Colorectal Neoplasms/epidemiology , Confidence Intervals , Female , Humans , Logistic Models , Male , Middle Aged , Multivariate Analysis , Prevalence , Prospective Studies , Referral and Consultation/statistics & numerical data , Retrospective Studies , Risk Assessment , Severity of Illness Index , Sex Distribution , Sigmoid Neoplasms/diagnosis , Sigmoid Neoplasms/epidemiology , Sigmoid Neoplasms/pathology , Sigmoidoscopy/methods , Sigmoidoscopy/statistics & numerical data , Unnecessary ProceduresABSTRACT
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.
Subject(s)
Adenoma/genetics , Colorectal Neoplasms/genetics , Genes, APC/genetics , Germ-Line Mutation/genetics , Neoplasms, Multiple Primary/genetics , Adult , Aged , Aged, 80 and over , Humans , Middle Aged , Polymorphism, Single-Stranded ConformationalABSTRACT
BACKGROUND: The association between distal hyperplastic polyps and proximal adenomas is still a matter of debate. We investigated this association while taking into account patient characteristics. METHODS: After exclusion of patients with inflammatory bowel diseases, familial adenomatous polyposis, or any cancer, 3088 eligible consecutive subjects aged 18 to 69 years underwent total colonoscopy in four gastroenterology units. The odds ratios (OR) of having proximal adenomas according to patient characteristics (age, sex, medical center, year of endoscopy, reasons for referral, and distal findings) were estimated in univariate and multivariate analyses. RESULTS: Patients with distal polyps of any type showed an adjusted OR of 2.5 (95% CI [1.9, 3.1] p < .001) of having proximal adenomas as compared with those without distal polyps. When distal adenomas and distal hyperplastic polyps were included in the multivariate model as independent factors, the presence of adenomas significantly increased the risk of proximal adenomas (OR = 2.8: 95% CI [2.2, 3.6] p < .001), whereas the presence of hyperplastic polyps did not (OR = 1.1: 95% CI [0.8, 1.5] p = .64). No association with number, size, or location of distal hyperplastic polyps was seen. CONCLUSIONS: Our data show that the presence of hyperplastic polyps should not be the sole indication for total colonoscopy because they are not associated with proximal adenomas when adjusting for patient characteristics and presence of distal adenomas.
Subject(s)
Adenoma/epidemiology , Colonic Polyps/epidemiology , Rectal Neoplasms/epidemiology , Sigmoid Neoplasms/epidemiology , Adult , Aged , Cohort Studies , Colon/pathology , Colonic Polyps/pathology , Colonoscopy , Female , Humans , Hyperplasia , Italy/epidemiology , Logistic Models , Male , Middle Aged , Prospective Studies , Rectal Neoplasms/pathology , Rectum/pathology , Retrospective Studies , Risk Factors , Sigmoid Neoplasms/pathologySubject(s)
Colorectal Neoplasms/pathology , Immunohistochemistry/methods , Keratins/analysis , Lymph Nodes/chemistry , Lymphatic Metastasis/diagnosis , Antibodies, Monoclonal , Colorectal Neoplasms/genetics , Colorectal Neoplasms/mortality , Colorectal Neoplasms/surgery , DNA, Neoplasm/genetics , Eosine Yellowish-(YS) , Flow Cytometry , Fluorescent Dyes , Follow-Up Studies , Hematoxylin , Humans , Neoplasm Staging , Ploidies , Prognosis , Retrospective Studies , Survival RateABSTRACT
Fifty-nine colonic adenomas and 6 hyperplastic colonic polyps were analyzed by single-strand conformation polymorphism analysis for mutations in the adenomatous polyposis coli gene (APC). Frameshifts and premature stop codons in at least one copy of APC were detected in 25 of these adenomas. Five adenomas carried 2 APC mutations. No mutations in APC were found in any of the 6 hyperplastic polyps. The detection of APC mutations increased with size and degree of dysplasia and in rectal as compared to colonic adenomas, although the association was not statistically significant. The frequency of detectable APC mutations was higher in tubulovillous and villous adenomas (10 of 13) than in tubular adenomas (15 of 45) (odds ratio, 6.67; 95% confidence limits, 1.39-41.83; P = 0.005). The significance of the association between the detection of APC mutations and a villous architecture was confirmed in multivariate analysis (relative risk, 6.67; 95% confidence limits, 1.54-28.8; P = 0.005). In conclusion, APC mutation plays a role in adenoma progression; its frequency is significantly higher in lesions with a more villous morphology.
Subject(s)
Adenoma, Villous/genetics , Adenoma, Villous/pathology , Colonic Polyps/genetics , Colonic Polyps/pathology , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Frameshift Mutation/genetics , Genes, APC/genetics , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Mutation/geneticsSubject(s)
Adenocarcinoma/chemistry , Colorectal Neoplasms/chemistry , DNA, Neoplasm/analysis , Female , Flow Cytometry , Humans , Male , Ploidies , PrognosisABSTRACT
To facilitate further mutational analysis of NM13-H1, a human metastasis suppressor gene, we have established its genomic organization. NM23-H1 is composed of five exons, spanning a genomic DNA fragment of 10 kb. Using oligonucleotide primers flanking each exon, PCR-SSCP analysis was performed on genomic DNAs of healthy individuals. A common polymorphism, a C to T transition, was detected 30 nucleotides upstream from the 5' splice site flanking exon 1. As NM23-H1 allele loss and altered expression have been reported in colorectal cancer, genomic DNAs of 20 colorectal tumors were analyzed for the presence of gene-specific mutations by PCR-SSCP: no abnormal sequences were detected within the coding and splice site regions of the NM23-H1 gene. This finding suggests that NM23-H1 mutations are rare events in human colorectal cancer.
Subject(s)
Chromosomes, Human, Pair 17 , Colorectal Neoplasms/genetics , Neoplasm Metastasis/genetics , Polymorphism, Genetic , Base Sequence , Cloning, Molecular , Colorectal Neoplasms/pathology , Cosmids , DNA Mutational Analysis , DNA Primers , DNA, Complementary/analysis , Exons , Gene Library , Humans , Molecular Sequence Data , Mutation , Polymerase Chain Reaction/methods , RNA Splicing , Restriction MappingABSTRACT
The purpose of this study was to investigate the correlation of flow cytometric (FCM) DNA content and cell cycle characteristics of Barrett's Esophagus (BE) with age and sex of the patients, length, histologic type and dysplasia of BE. Forty-one patients affected by histologically confirmed BE had multiple biopsies taken from the metaplastic epithelium and one biopsy taken from the gastric fundus, as control. The samples were either stored at -80 degrees C or immediately measured. Nuclei suspensions were obtained, stained with DAPI, measured with a high resolution flow cytometer (ICP22A, Ortho Instruments) and analyzed for the evaluation of the relative DNA content and the S- and G2 + M phases of the cell cycle. DNA histograms having two distinct G0/G1 peaks were classified as DNA aneuploid. The degree of DNA aneuploidy (DNA Index, DI), defined as the ratio of abnormal to normal DNA content, was obtained from the mixture of each BE sample with its control sample and trout erythrocytes. We found six patients with DNA aneuploid populations (14.6%), whose DNA Index values were 1.05 (in two), 1.8 (in one), and 2.0 (in three cases). DNA ploidy did not correlate with age and sex of the patients, length, histologic type, and dysplasia of BE. Among the 13 patients with dysplasia (6 indefinite, 4 low grade and 2 high grade with intramucous adenocarcinoma) only two (one indefinite and one low grade) showed DNA aneuploidy (15.4%). In addition, we found that the S-phase and the G2 + M-phase fractions in BE samples were both significantly higher than those of the controls (respectively, p = 0.01 and p = 0.0008).(ABSTRACT TRUNCATED AT 250 WORDS)