Genetic testing among high-risk individuals in families with hereditary nonpolyposis colorectal cancer.

Hereditary nonpolyposis colorectal cancer (HNPCC) is frequently associated with constitutional mutations in a class of genes involved in DNA mismatch repair. We identified 32 kindreds, with germline mutations in one of three genes hMSH2, hMLH1 or hMSH6. In this study, we purposed to evaluate how many high-risk individuals in each family underwent genetic testing: moreover, we assessed how many mutation-positive unaffected individuals accepted colonoscopic surveillance and the main findings of the recommended follow-up. Families were identified through a population-based registry, or referred from other centres. Members of the families were invited for an education session with two members of the staff. When a kindred was consistent with HNPCC, neoplastic tissues were examined for microsatellite instability (MSI) and immunohistochemical expression of MSH2, MLH1 and MSH6 proteins. Moreover, constitutional mutations were searched by SSCP or direct sequencing of the whole genomic region. Of the 164 subjects assessed by genetic testing, 89 were gene carriers (66 affected - that is, with HNPCC-related cancer diagnosis - and 23 unaffected) and 75 tested negative. Among the 23 unaffected gene carriers, 18 (78.3%) underwent colonoscopy and four declined. On a total of 292 first degree at risk of cancer, 194 (66.4%) did not undergo genetic testing. The main reasons for this were: (a) difficulty to reach family members at risk, (b) lack of collaboration, (c) lack of interest in preventive medicine or 'fatalistic' attitude towards cancer occurrence. The number of colorectal lesions detected at endoscopy in gene carriers was significantly (P<0.01) higher than in controls (noncarriers). We conclude that a large fraction of high-risk individuals in mutation-positive HNPCC families does not undergo genetic testing, despite the benefits of molecular screening and endoscopic surveillance. This clearly indicates that there are still barriers to genetic testing in HNPCC, and that we are unable to provide adequate protection against cancer development in these families.

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.

Microsatellite instability and MLH1 and MSH2 germline defects are related to clinicopathological features in sporadic colorectal cancer.

Clinical and pathological features were evaluated to predict tumor microsatellite instability (MSI) and germline mutations in MLH1 and MSH2 DNA mismatch repair genes in two patient groups with sporadic colorectal cancer (CRC): 38 young patients (age /=60 years). Nine (25.7%) young patients out of 35 and five (16%) old patients out of 31 exhibited MSI in their cancers. MSI+ cancers were related to proximal cancer and mucinous carcinoma independently of the age at cancer onset. Three (7.9%) out of 38 young patients had mutations in MLH1 and MSH2 genes that led to truncated protein products; they were all at age <35 years and showed MSI in their tumors, with mucinous histotype in two cases. In conclusion, histopathological and clinical features of CRC allow identification of cancers showing DNA microsatellite instability. MSI in CRC at very early onset (age <35 years) appears useful to predict germline MMR gene defects.

Evaluation of the replication error phenotype in relation to molecular and clinicopathological features in hereditary and early onset colorectal cancer.

Mutations affecting human mismatch repair (MMR) genes (MLH1, MSH2, PMS1, PMS2, and MSH6) cause tumour predisposition in hereditary nonpolyposis colorectal cancer (HNPCC) syndrome, and an association has been demonstrated with the replication error (RER) phenotype in most colorectal and some extracolonic neoplasms. A pathogenetic model for RER+ tumours through inactivation of suppressor genes has been hypothesised, and TGF beta RII, BAX and IGFIIR genes have recently been proposed as targets of such inactivating mutations. In this study, a series of 47 tumours developed in patients with known MLH1/MSH2 status and a family history of HNPCC and/or early onset colorectal cancer were characterised for the RER phenotype through microsatellite analysis. The RER phenotype, displayed by 17 tumours, was then correlated with the presence of insertions/deletions at the TGF beta RII, IGFIIR and BAX gene stretches, confirming that the TGF beta RII inactivation may be particularly critical for the RER-associated tumorigenesis. RER+ colorectal cancers (CRCs) developed more frequently in patients from HNPCC families (72.7%) than in those from families not fulfilling the Amsterdam criteria (33.3% in suspected HNPCC and 20.8% in early onset CRC patients). A consistent fraction of either Amsterdam and non-Amsterdam patients developed RER- CRCs, pointing to the involvement of other genes not related to the MMR system. The RER phenotype was associated with younger age at diagnosis in familial cases, and there was a trend for an association with proximal CRC localisation and early Dukes' stages. The RER status was also correlated with the presence and type of MLH1 and MSH2 alteration.

High prevalence of activated intraepithelial cytotoxic T lymphocytes and increased neoplastic cell apoptosis in colorectal carcinomas with microsatellite instability.

Microsatellite instability (MSI) characterizes colorectal carcinomas (CRCs) in hereditary nonpolyposis colorectal cancer (HNPCC) syndrome and a proportion of sporadic CRCs. These MSI+ CRCs share several clinicopathological features, including a reputation for better survival rates than MSI- cases and a pronounced stromal inflammatory reaction of still undefined nature. In the present study, the presence, spatial distribution, and activation status of infiltrating cytotoxic effectors were investigated comparatively in 18 MSI+ and 37 MSI- CRCs by immunohistochemistry. The frequency of apoptosis was also evaluated by morphology and in situ end-labeling. MSI+ cases carried significantly higher numbers of cytotoxic lymphocytes infiltrating within neoplastic epithelial structures, as shown by immunostaining for CD3 (15.1 +/- 6.2 versus 4.6 +/- 4.1, P < 0.001), CD8 (13 +/- 6.4 versus 3.7 +/- 3.8, P < 0.001), and TIA-1 (11.2 +/- 6.5 versus 1.9 +/- 1.7, P < 0.001). These cytotoxic effectors were globally more activated in MSI+ than in MSI- tumors, as revealed by the expression of granzyme B (5.3 +/- 4.5 versus 0.6 +/- 1.3, P < 0.001). In MSI+ CRCs, the number of intraepithelial activated cytotoxic lymphocytes was significantly correlated with the proximal location of the tumor, a poorly differentiated phenotype, and the presence of peritumor lymphoid nodules. Multivariate analysis revealed that MSI was the major determinant of the presence of activated cytotoxic intraepithelial lymphocytes. Moreover, MSI+ CRCs also showed a significantly higher percentage of tumor cells undergoing apoptotic cell death (4.1 +/- 2.1 versus 2.6 +/- 1.1, P < 0.0001, by the TUNEL method), often located in close proximity of activated cytotoxic lymphocytes. These results are consistent with the presence of anti-tumor cytotoxic immune responses in most of MSI+ CRCs, a phenomenon that may at least in part contribute to the survival advantage ascribed to these patients.

Evaluation of the risk for metachronous colorectal neoplasms following intestinal polypectomy: a clinical, endoscopic and pathological study.

BACKGROUND/AIMS: Surveillance programs are recommended for patients with previous intestinal polypectomy because of the high rate of adenomatous recurrences and risk of subsequent colorectal cancer. The parameters to identify patients at higher risk and the length and schedules of follow-up have not yet been established. We considered some clinical, endoscopic and pathological parameters in order to assess the probability of developing new colorectal neoplasms and eventually to schedule proper surveillance programs. METHODOLOGY: Patients with removed adenomas were enrolled into a clinico-endoscopic follow-up, comprehensive of two colonoscopies the first at 1 year and the second at 3 years. We evaluated the risk of new neoplasms dividing the patients into four groups according to the number and size of the adenomas removed and the parameters considered. RESULTS: Of 164 patients enrolled 156 completed the study. We had an overall 21.3% of adenomatous recurrences at 1 year and 12.8% at 3 years. Most of the adenomas removed were tubular and small in size (< 1 cm). The percentage of patients who had adenomas with advanced pathological features was 1.82% at 1 year and 0.64% at 3 years. The increase in number and size of the adenomas removed on the initial colonoscopic examination was the only one parameter statistically significant, X(2)1 (trend) 5.11; p<0.05 at the first follow-up and X(2)1 (trend) 4.87; p<0.05 at the second follow-up. CONCLUSIONS: Patients with previous single adenoma showed few recurrences of extremely benign histological features. Since they do not require short-term endoscopic examination, it would be reasonable to defer the next colonoscopy for at least another 5 years. During follow-up, patients with multiple polyps had adenomas with advanced pathological features so it was useful to follow-up at 1 year. The tendency for advanced pathological features of removed polyps was not seen at 3 years, suggesting the importance of long-term follow-up, but with longer intervals.

Lack of PMS2 gene-truncating mutations in patients with hereditary colorectal cancer.

Hereditary non-polyposis colorectal cancer (HNPCC) is a genetically heterogeneous disease for which PMS2 gene, a member of the human PMS gene family, is believed to have a marginal role. To better define the contribution of PMS2 to hereditary colorectal cancer, we investigated this gene in 22 unrelated Italian patients that, despite a positive family history and/or early onset and development of tumors with microsatellite instability (MSI), did not carry constitutional mutations of MLH1 and MSH2 genes. No mutations with clear-cut pathogenetic significance were detected in the coding regions of PMS2 gene, but only 8 polymorphisms (7 common and 1 rare, 3 silent and 5 missense) and 3 unique molecular variants (2 missense substitutions and one 3-nucleotide deletion) were seen. Lack of PMS2 truncating mutations in our study does not disagree with its supposed marginal involvement in hereditary colorectal cancer, but at the same time points out the need to investigate the phenotypic molecular and clinical characteristics more specifically associated with PMS2 mutations.

Risk factors for endometrial cancer according to familial susceptibility.

Endometrial cancer (EC) shares some environmental or genetic risk factors with colorectal cancer (CRC). It represents a risk factor for CRC. Furthermore, EC is the most frequent extracolonic neoplasm in HNPCC (hereditary nonpolyposis colorectal cancer) and, in this syndrome, it has the same inheritance pattern as CRC. Neoplastic family history and clinical features were evaluated in women with EC in a health care district (Pordenone Province) in Northeastern Italy from 1990 to 1995, to examine the proportion of patients with hereditary cancer and the relation with clinical characteristics of EC. We interviewed 215 patients with EC (average age 61 years, range 35-88) in relation with some risk factors (age, weight, diabetes, menstrual and reproductive pattern, synchronous and metachronous neoplasms) and we obtained their family pedigree. Twenty-nine patients (13.5%) had a CRC family history, 66 (30.7%) showed an aspecific cancer aggregation in their families and more than half (120, 55.8%) had a negative cancer family history. Family pedigrees were consistent with a dominant inherited cancer pattern in 8 patients (3.7%) belonging to the CRC-related family history group. A different pattern of family history distribution emerged in relation with age (< 55 vs. > or = 55, p < 0.001) and body mass index (BMI) (< 26 vs. > or = 26, p = 0.002). Patients with a CRC pedigree were more numerous in the younger group, in the group with lower BMI and in pre-menopausal women.

MLH1 and MSH2 constitutional mutations in colorectal cancer families not meeting the standard criteria for hereditary nonpolyposis colorectal cancer.

Genetic diagnosis of hereditary nonpolyposis colorectal cancer (HNPCC) may have a significant impact on the clinical management of patients and their at-risk relatives. At present, clinical criteria represent the simplest and most useful method for the identification of HNPCC families and for the selection of candidates for genetic testing. However, reports of mismatch repair (MMR) gene mutations in families not fulfilling the minimal diagnostic criteria point out the necessity to identify additional clinical parameters suggestive of genetic predisposition to colorectal cancer (CRC) related to MMR defects. We thus investigated a series of 32 Italian putative HNPCC individuals selected on the basis of one of the following criteria: 1) family history of CRC and/or other extracolonic tumors; 2) early-onset CRC; and 3) presence of multiple primary malignancies in the same individual. These patients were investigated for the presence of MLH1 and MSH2 mutations by single-strand conformation polymorphism analysis. Pathogenetic truncating mutations were identified in 4 (12.5%) cases, 3 of them involving MSH2 and 1 MLH1. In addition, 2 missense MLH1 variants of uncertain significance were observed. All pathogenetic mutations were associated with early age (<40 years) at onset and proximal CRC location. Our results support the contention that constitutional MMR mutations can also occur in individuals without the classical HNPCC pattern. Moreover, evaluation of the clinical parameters associated with MMR mutations indicates that early onset combined with CRC location in the proximal colon can be definitely considered suggestive of MMR-related hereditary CRC and should be included among the guidelines for referring patients for genetic testing.

Hereditary nonpolyposis colorectal cancer: an approach to the selection of candidates to genetic testing based on clinical and molecular characteristics.

OBJECTIVE: Identification of clinical and molecular characteristics associated with constitutional MLH1 and MSH2 mutations and definition of a stepwise strategy for the selection of colorectal cancer (CRC) patients amenable to MLH1 and MSH2 genetic testing. METHODS: 90 unrelated CRC patients were initially selected on the basis of either familial or early onset occurrence of CRC. They were screened for the presence of constitutional MLH1 and MSH2 mutations and for microsatellite instability (MSI). RESULTS: 16 pathogenetic mutations (9 MLH1 and 7 MSH2) were identified in 41% of Amsterdam hereditary nonpolyposis colorectal cancer (HNPCC) families, 5% of suspected HNPCC families, and 14% of sporadic early-onset CRC patients. The presence of the mutations correlated with MSI, with early age of onset and proximal location of the tumor, and with the presence of some extracolonic tumors of the HNPCC spectrum and/or multiple tumors in the family. CONCLUSIONS: Evaluation of clinical and molecular characteristics is useful for the identification of candidates to MLH1 and MSH2 mutational analysis and allows the application of a rational approach to genetic testing.

Characterization of MSH2 and MLH1 mutations in Italian families with hereditary nonpolyposis colorectal cancer.

Mismatch repair genes MSH2 and MLH1 are considered to be the two major genes that are responsible for hereditary nonpolyposis colorectal cancer (HNPCC). Germline heterozygous inactivating mutations of MSH2 and MLH1 have been identified previously in a substantial fraction of individuals who are predisposed genetically to colorectal carcinoma (CRC) and other tumors of the HNPCC spectrum. With the aim of determining the relevance of these two genes in the Italian population, we submitted to mutational analysis a set of 17 HNPCC families, all of which fulfilled the "Amsterdam criteria." A combination of different techniques, including reverse transcription-polymerase chain reaction (RT-PCR) of long fragments and single-strand conformation polymorphism (SSCP) on cDNA and genomic DNA, allowed the identification of ten molecular variants, seven of which are predicted to inactivate mismatch repair function. The mutated predisposing gene was MSH2 in two families and MLH1 in five other families. All of the mutations were characterized by DNA sequencing and appeared to involve different molecular mechanisms, such as short in-frame and out-of-frame deletions, splicing errors, and nonsense mutations. This study also demonstrates that, in the Italian population, a considerable fraction of HNPCC families (at least 41%) is linked to MSH2 and MLH1 mutations.

Gastroduodenal involvement in staging of nodal non-Hodgkin lymphomas: a clinical and endoscopic prospective study of 235 patients.

OBJECTIVES: The gastrointestinal tract is often the site of involvement of non-Hodgkin lymphomas (NHL). The aim of this endoscopic prospective study was to verify the prevalence of the gastroduodenal involvement in patients in staging for NHL and to assess its impact on the choice of therapeutic strategies. METHODS: Two hundred and thirty-five consecutive patients were included in the study. Upper gastrointestinal endoscopy was performed, and biopsy samples were taken on every mucosal lesion and on macroscopically illness-free duodenal and gastric mucosa. The samples were submitted to histological examination, and the clinical stage of NHL was reevaluated. RESULTS: Sixty-one of the 235 patients exhibited histological involvement of gastric (40), duodenal (7), or both (14) mucosae. Endoscopic lesions were recorded in 51 patients, but the involved mucosa appeared macroscopically normal in 10 patients (16.3%). In 13 patients, the gastroduodenal involvement modified the clinical stage from I and II to III, indicating a different therapeutic approach. No difference was detected in the frequency of gastrointestinal involvement among the high, intermediate, and low grades of lymphoma malignancies. Thirty-five positive patients underwent a further endoscopic examination after the chemotherapy treatment. Although clinical remission was expected in all cases, 42.8% of them subsequently exhibited NHL. CONCLUSIONS: Upper digestive endoscopy plus biopsy sampling plays a necessary diagnostic role, not only when major clinical signs (hemorrhage) are present, but also in earlier stages of NHL (I and II), when a reevaluation of the therapeutic strategy may be indicated. In stages III and IV of illness, it may also prove useful in evaluating the efficacy of chemotherapy.

Nonsteroidal antiinflammatory drugs for cancer pain: comparison between misoprostol and ranitidine in prevention of upper gastrointestinal damage.

PURPOSE: The prophylactic strategy of nonsteroidal antiinflammatory drug (NSAID)-induced upper gastrointestinal (UGI) damage has largely been studied in arthritic patients, but not in cancer patients. The efficacy of misoprostol and ranitidine in the prevention of gastroduodenal damage in patients taking diclofenac for their cancer pain has been compared in this study. PATIENTS AND METHODS: Patients who needed high-dose (200 to 300 mg/d) diclofenac for cancer pain and without mucosal lesions at baseline gastroduodenal endoscopy were randomized to receive misoprostol (200 micrograms twice daily; M group) or ranitidine (150 mg twice daily; R group). UGI endoscopy was repeated after 4 weeks. RESULTS: Twenty-three patients treated with misoprostol and 26 treated with ranitidine concluded the study. The M group showed a significantly (P < .02) lower incidence of gastroduodenal lesions (two patients; 8.7%) than the R group (10 patients; 38.5%). Gastric ulcers occurred in one (4%) misoprostol-treated patient and in six (23%) ranitidine-treated patients. Six of seven patients with ulcers were asymptomatic. Seventy-one percent and 86% of ulcers occurred in patients older than 60 years and in those who received greater than 3.1 mg/kg of diclofenac, respectively. CONCLUSION: Misoprostol was significantly more effective than ranitidine in the prevention of gastroduodenal lesions in cancer patients receiving diclofenac.

Percutaneous endoscopic gastrostomy as a decompressive technique in bowel obstruction due to abdominal carcinomatosis.

BACKGROUND AND STUDY AIMS: Percutaneous endoscopic gastrostomy (PEG) is a simple method of achieving nonsurgical gastric decompression in patients suffering from metastatic abdominal tumors and upper gastrointestinal tract obstruction. The aim of this prospective study was both to evaluate the efficacy of PEG for intestinal decompression in patients with disseminated abdominal cancer and to compare two catheters with different diameters. PATIENTS AND METHODS: Over a one-year period, 22 consecutive female patients (mean age 53.7, range 29-73) were referred to us and a PEG was successfully placed in 21. In four patients with unsatisfactory endoscopic trans-illumination of the anterior abdominal wall, an ultrasound unit was used to identify an adequate site for PEG placement. RESULTS: All patients experienced substantial symptomatic relief after a few days: vomiting and nausea completely resolved, and abdominal pain persisted in one patient only. No gastrostomy-related additional morbidity was noticed. We randomly inserted a 15-French or a 20-French tube: no statistically significant difference was noticed between the two in the symptomatic relief provided. CONCLUSIONS: Our data support the hypothesis that PEG is an effective, safe, and well-tolerated method of achieving gastric decompression in cancer patients; ultrasound guidance was an interesting option in positioning a tube in difficult situations; a standard nutritional tube, namely 15 or 20 French in diameter, may be large enough to obtain excellent clinical results.

DNA flow cytometric evaluation of cell cycle distribution in ulcerative colitis: a proposed method for assessing severity of disease.

The assessment of disease severity in ulcerative colitis depends mainly on subjective variables, and an objective method of assessing mucosal inflammation is needed. Determination of the synthetic phase of the cell cycle is an accurate expression of inflammatory activity in the colonic mucosa. The aim of the study was to find out if the proliferative index or the synthetic phase (S phase) of the colonic mucosa of patients with ulcerative colitis, as evaluated by DNA flow cytometry, is a reliable and reproducible marker of disease activity. Sixty consecutive patients with ulcerative colitis of different degrees of activity were entered into the study and submitted to colonoscopy plus multiple rectal biopsies. Disease severity was defined for each patient by means of a clinical, endoscopic, and histological score. Flow cytometry was used to calculate the proliferative index and the S phase of the cell cycle. A statistically significant correlation (p < 0.001) was found between all indices of severity. It is suggested that flow cytometric evaluation of the cell cycle in the rectal mucosa may be an efficient method of assessing severity of disease and efficacy of medical treatment in ulcerative colitis.

Effect of short- and long-term treatment with omeprazole on cell cycle distribution in the gastric mucosa. Results of a flow cytometric study.

Omeprazole may exert an effect on gastric mucosal proliferation by inhibiting gastric acid secretion and increasing serum gastrin levels. It may also influence the kinetics of endocrine cells and the oxyntic mucosa. The aim of the present study was to evaluate the cell cycle in different gastric compartments following short- (1 month) and long-term (6 months) administration of two different dosages of omeprazole by means of a flow cytometric method. We also determined serum gastrin levels at the same time. No differences in cell cycle distribution of the antrum, body, and fundus were found in the two different dosage groups after 1 month of therapy, considering the synthetic phase (S-phase) of the cell cycle. A statistically significant increase in S-phase was reported after long-term therapy in the mucosa of the fundus and body of the stomach in both groups. Gastrin levels showed no clear correlation with cell cycle distribution variables. We postulate a proliferative adaptation of the oxyntic mucosa to long-term drug administration not mediated by gastrin influence.