MSH2 missense mutations and HNPCC syndrome: pathogenicity assessment in a human expression system.

Hereditary Non-Polyposis Colorectal Cancer (HNPCC) is associated with germline mutations in one of several MisMatch Repair (MMR) genes. An increasing proportion (20-25%) of the reported MSH2 variants consists of single amino-acid substitution with uncertain disease-causing significance. The present study was undertaken to functionally characterize 3 MSH2 nontruncating variants: p.Gly162Arg (c.484G>C), p.Asp167His (c.499G>C) and p.Arg359Ser (c.1077A>T). Missense alterations, were assessed in a human system for expression/stability and for the ability to heterodimerize with MSH6 and correctly localize into the nucleus. Functional assays results were correlated with clinical and genetic features indicative of HNPCC as MicroSatellite-Instability (MSI), abnormalities of MMR gene expression in tumour tissue (IHC) and familial history. p.Gly162Arg and p.Arg359Ser variants showed a clearly decreased expression level of the MutSá complex and were associated with an abnormal subcellular localization pattern, which can be suggestive of an incorrect MSH2/MSH6 heterodimerization. Functional analysis results were supported by MSI and IHC data and by familial cancer history. The subcellular localization assay, performed in a human expression system, classifies as pathogenetic two MSH2 nontruncating alterations providing a useful tool in genetic testing programs.

A missense germline mutation in exon 7 of the MSH2 gene in a HNPCC family from center-Italy.

INTRODUCTION: Hereditary Non-Polyposis Colorectal Cancer (HNPCC) is an autosomal dominant inherited disease predisposing to the development of colorectal cancers and several other malignancies (endometrium, ovaries, stomach, small bowel, hepatobiliary and urinary tract). HNPCC is caused by germline mutations in any of the MisMatch Repair (MMR) genes. Mutations in MLH1 and MSH2 account for almost 90% of all identified ones. About 15% of mutations identified in MSH2 are missense ones. PATIENTS AND METHODS: We studied one family, fulfilling Amsterdam II criteria, referred to our Center for genetic counselling. The proband, and some of her relatives, have been investigated for microsatellite instability (MSI), immunohistochemical MMR protein staining and by direct sequencing and Multiplex Ligation-dependent Probe Amplification (MLPA). RESULTS: All patients carried the same novel MSH2 germline missense mutation (R359S) in exon 7, which determines the substitution of an Arginine, which is a basic amino acid, with a polar Serine residue (R359S). The mutation was associated with lack of expression of MSH2 protein and high microsatellite instability in tumour tissues. The same mutation has been detected in one healthy relative. CONCLUSIONS: The mutation here reported shows a high correlation with phenotype. The mutation is located in an evolutionary conserved domain. Taken together, our findings suggest evidence that the amino acid substitution can be interpreted as pathogenetic.

Assessing the pathogenicity of MLH1 missense mutations in patients with suspected hereditary nonpolyposis colorectal cancer: correlation with clinical, genetic and functional features.

Assessing the pathogenicity of missense mutations of MLH1 and MSH2 is critical to counsel patients with suspected hereditary nonpolyposis colorectal cancer (HNPCC). Approximately 32% of all MLH1 mutations and 18% of MSH2 mutations are missense variants which often have an uncertain genetic significance. To assess the pathogenicity of four MLH1 missense mutations which were found in five patients with suspected HNPCC, P648S (CCC --> TCC), L559R (CTG --> CGG), K618A (AAG --> GCG), Y646C (TAT --> TGT), we studied their ability to disrupt MLH1 protein function and their relationship with all those clinical, genetic and pathological features which are typical of this syndrome. Our results indicated that the P648S and L559R mutations were probably pathogenic because they disrupted MLH1 protein interaction with its partner PMS2 in vitro and abolished MLH1 expression in HCT116 cells. In addition these variants were associated with features often found in HNPCC patients: in particular high microsatellite instability, occurrence of high grade tumours and, in one case, strong family history. The pathogenicity of the K618A and Y646C mutations was questionable as their correlation with features typical of HNPCC was low and the outcome of the functional analysis was ambiguous. These observations suggested that a clinically usable assessment of the pathogenicity of MLH missense variants can be achieved through the analysis of multiple mutation characteristics among which loss of protein function, occurrence of microsatellite instability and family history seemed to have a predominant role.

Mutations of hMLH1 and hMSH2 in patients with suspected hereditary nonpolyposis colorectal cancer: correlation with microsatellite instability and abnormalities of mismatch repair protein expression.

PURPOSE: The relationship between germ-line mutations of hMSH2 and hMLH1, microsatellite instability (MSI), and loss of DNA mismatch repair (MMR) gene expression were studied to formulate an effective selection protocol for patients with suspected hereditary nonpolyposis colorectal cancer who should be offered genetic testing. PATIENTS AND METHODS: Patients eligible for germ-line analysis of hMLH1 and hMSH2 were selected. Tumor specimens were obtained to assess MSI and loss of MMR gene expression. RESULTS: Among 37 patients who participated in the study, two hMSH2 and two hMLH1 missense mutations (11%) were detected, none of which was found in a panel of 60 healthy volunteers. High MSI was found in five tumors (19%) and low MSI in 10 tumors (39%); 12 tumors (46%) were microsatellite stable. Four tumors demonstrated loss of hMLH1, and three tumors demonstrated loss of hMSH2 protein expression. CONCLUSION: No relationship was found between MMR gene mutations and MSI; low or no MSI was found in the four patients with germ-line mutations, and none of the five patients with high MSI demonstrated abnormalities of MMR genes. On the contrary, loss of hMLH1 or hMSH2 expression was found in the tumors from three of the four patients demonstrating germ-line mutations. These data suggest that germ-line mutations of the MMR gene can occur in people with MSI-negative tumors. Sensitive clinical criteria and the study of MMR gene expression may be useful to identify this subset of patients.

Molecular biology of sporadic gastric cancer: prognostic indicators and novel therapeutic approaches.

Both the availability of multiple treatment modalities and novel therapeutic targets make the correct prognostic stratification and the identification of truly predictive factors an issue of major debate in gastric cancer. Along with "classic" prognostic factors such as those related to the diffusion of the tumour at diagnosis (i.e., depth of gastric wall infiltration, locoregional lymph nodes or distant metastases) or those concerning the pathologic characteristics of the tumour, other, innovative, factors should be considered if a better definition of the characteristics of the tumour is to be given. These biological factors are often derived from the genetic process, which is thought to represent a crucial step to gastric cancer (DNA copy number changes, microsatellite instability, thymidilate synthase, E-cadherin, beta-catenin, mucin antigen, p53, c-erb B-2, COX-2, matrix metalloproteinases, VEGFR and EGFR). Some of those putative prognostic indicators can also be considered predictive of response to therapy as they are a molecular target either to chemotherapeutics (i.e., thymidilate synthase that is targeted by 5FU) or to a new class of antineoplastic molecules (i.e., c-erb B-2 targeted by trastuzumab, COX-2 by NSAIDs, matrix metalloproteinases, EGFR and VEGFR by specific inhibitors).

Clinical benefit of gemcitabine-cisplatin in advanced non-small cell lung cancer elderly patients.

BACKGROUND: Cisplatin-based chemotherapy seems to improve the control of non-small cell lung cancer (NSCLC)-related symptoms, but assessment of symptomatic gain in these patients is often difficult. This study was designed to test a method for the assessment of clinical benefit in elderly advanced NSCLC patients, after weekly cisplatin-gemcitabine chemotherapy. PATIENTS AND METHODS: Evaluation of clinical benefit was the primary end-point. Clinical benefit derived from the evaluation of eight parameters: PS, cough, dyspnea, pain and hemoptysis were considered primary parameters. Weight loss, asthenia and anorexia were secondary parameters. RESULTS: Twenty-nine patients aged > 65 years, symptomatic at study entry, were enrolled. Responses were calculated according to the intent-to treat principle. Fifteen patients were considered as clinical benefit responders for an overall clinical benefit response rate of 52% (95% C.I. = 33.5% to 70%). The median duration of clinical benefit was 9 months (range 2-36). Tumour objective responses, according to WHO criteria, were 14, for an overall response rate of 48% (95% C.I. = 31% to 65%). Ten patients (34%) obtained both clinical benefit and tumour response. The median survival-time was 10 months (range 1-36). Chemotherapy was well-tolerated with low incidence of WHO grade III-IV toxicities. CONCLUSION: Evaluation of clinical benefit in advanced, symptomatic, elderly NSCLC patients is feasible and could be used together with tumor response and quality of life questionnaires to assess the efficacy of chemotherapy. It could reasonably be extended to non-elderly NSCLC patients. Our results suggest that weekly cisplatin-gemcitabine seems to be able to improve the principal NSCLC-related symptoms in elderly patients.

Predictors of short-term survival and progression to chemotherapy in patients with advanced colorectal cancer treated with 5-fluorouracil-based regimens.

The aim of this study was to assess in patients with advanced colorectal cancer which factors were associated with short-term survival (6 months or less) and progression to first-line 5-fluorouracil (5-FU) chemotherapy. Three hundred twenty-one consecutive nonselected patients with advanced colorectal cancer were treated with conventional 5-FU-based regimens as first-line treatment from 1988 to 1999. Factors related to patient, tumor, or treatment were analyzed by univariate and multivariate logistic regression analysis by comparing short survivors (SS, those who survived or= 2) (p = 0.015), elevated (>or=5 microg/l) serum carcinoembryonic antigen (CEA) (p = 0.015), and more than one site of metastatic disease (p < 0.001). Progression to first-line chemotherapy (p < 0.001) was also a strong factor associated with short survival in multivariate analysis; factors predictive of progression were elevated CEA (p = 0.027) and diffuse metastatic disease (p = 0.029). Our data indicate the relevance of some clinical prognostic factors (younger age, poor performance status, elevated CEA, site of primary, number of metastatic sites, resistance to chemotherapy) as independent factors associated with poor survival and progression to first-line chemotherapy in patients with metastatic colorectal cancer treated with conventional 5-FU regimens. Patients identified by these factors as having a poor prognosis and low probability of response to treatment should be considered either for more aggressive regimens or supportive care only: conventional 5-FU treatments do not impact on response or survival.

Compliance with breast and cervical cancer screening programs in women: results from a population-based study.

AIMS AND BACKGROUND: Women's adherence to mammography and PAP test screening guidelines is a fundamental topic regarding women's health. The aim of the study was to evaluate the knowledge and compliance to breast and cervical cancer screening programs in women living in three Italian towns, where a public screening program, consisting of free mammography every two years and free PAP test every three years, is ongoing. METHODS: An anonymous survey was mailed to a random sample of women. Eight 120-min focus discussions with groups of women exploring perceptions, knowledge and practices were carried out after analysis of the returned surveys. RESULTS: Replies were received from 1345 women (response rate, 27%). Almost every woman knew of the screening program, but women's practice of mammography was age-dependent: up to 72% of the women performed it before the age of 50. Conversely, the age of the first PAP test was rather late: up to 70% of the women performed it at over 30 years of age. Women with a lower educational level reported being screened less than those with a higher level. During the group discussions, women's perceptions, knowledge and beliefs regarding cancer and screening, together with aspects of the health care system, appeared to strongly influence the preventive practices. Many women deplored being infrequently instructed by health professionals. CONCLUSIONS: Despite the limitations of the study due to the low response rate, we believe that health professionals should invest on encouraging factors and reduce the deterring factors to optimize screening practices.

Sub-cellular localization analysis of MSH6 missense mutations does not reveal an overt MSH6 nuclear transport impairment.

Nearly one-third of the identified MSH6 germline mutations deal with single amino acid substitutions. For an effective genetic counselling it is necessary to clearly elucidate by functional tools the specific sub-processes underlying the mismatch repair (MMR) misfunctioning in MSH6 non-truncating mutants. Since the MMR repair pathway occurs in the nucleus, we suppose the impairment of MutSα nuclear trafficking to be a possible Lynch syndrome susceptibility causative mechanism. In the present study the MMR status of the tumour, the main clinical features of mutation carriers and population data associated to the MSH6 missense variants, were complemented with computational data about tolerability predictions and amino acid substitution conservation. The selected panel of ten potentially pathogenic MSH6 mutations was analyzed in a homologous expression system for possible deleterious effects on nucleo-cytoplasmic shuttling through the assessment of the sub-cellular localization of the corresponding mutated proteins. Localization analysis results do not reveal an apparent role of MSH6 missense mutations in nuclear import impairment and provide the first hint to exclude the MSH6 nuclear translocation sub-process as a possible causative mechanisms of MMR misfunctioning.

BRCA1 expression in triple negative sporadic breast cancers.

OBJECTIVE: To study how to identify patients with "triple negative" sporadic breast cancers (BCs) having BRCA1 silenced or down-regulated due to epigenetic BRCA1 inactivation. STUDY DESIGN: We selected, from our database, patients diagnosed with BC between 1995 and 2001 with tumors exhibiting the "triple negative" phenotype. "Triple positive" tumors were used as controls. BRCA1 protein expression was determined by immunohistochemistry. Methylation specific polymerase chain reaction (PCR) and bisulfite sequencing on genomic DNA were used to assess BRCA1 promoter methylation. BRCA1 m-RNA expression analysis was conducted by real-time PCR. RESULTS: Forty-four triple negative and 68 controls (triple positive) were eligible for our analysis. BRCA1 promoter methylation was present in 31.8% of triple negative and in 20.6% of triple positive cases. BRCA1 was inactivated (absent BRCA1 m-RNA expression and lack of BRCA1 protein) in 21.4% of tumors with BRCA1 promoter methylation, as compared with 6% of non-methylated ones (p = 0.0453). CONCLUSION: BRCA1 inactivation due to promoter methylation could play an important role in some sporadic BC cases. Patients with this signature could represent the basis for prospective studies aiming to compare clinical response to different drugs.

CAT25 is a mononucleotide marker to identify HNPCC patients.

Mismatch repair mutations are the cause of generalized genomic instability and are particularly evident at microsatellite loci, which is known as microsatellite instability (MSI). MSI is present in 85% to 90% of colorectal cancers and occurs in hereditary non-polyposis colorectal cancer (HNPCC). The National Cancer Institute recommends the "Bethesda panel" for MSI screening. Recently, a novel T(25) mononucleotide marker was described, termed CAT25. This microsatellite marker displays a quasi-monomorphic pattern in normal tissues. The aim of our study was to evaluate the performance of CAT25 in HNPCC patients and to compare its reliability with the results of the Bethesda panel. We tested 55 tumor tissues from HNPCC patients using both the Bethesda panel and the CAT25 mononucleotide marker. One hundred healthy blood donors were used as controls. The CAT25 microsatellite was found to be altered in all 13 colorectal cancers classified as MSI-H using the standard Bethesda panel. Colorectal tumors that showed a stable Bethesda pattern did not show altered CAT25 repeats. Additionally, CAT25 showed a monomorphic allele pattern in all tissue samples. In our series, the concordance between the Bethesda panel and CAT25 in identifying colorectal cancers with high MSI reached 100%. Our results suggest that the CAT25 microsatellite represents a sensitive and specific marker for MSI and could be, at least, included in the panel of markers for the identification of HNPCC patients.

Identification of clinical prognostic factors in patients with unknown primary tumors treated with a platinum-based combination.

OBJECTIVE: The aim of this study was to evaluate patient and tumor characteristics in 102 patients with unknown primary tumors (UPT) prospectively treated with a combination of carboplatin, doxorubicin, and etoposide, to identify clinical variables predictive of response and survival. PATIENTS AND METHODS: The association between clinical characteristics and outcome was evaluated by univariate and multivariate analysis: chi(2) test and logistic regression analysis were used to study variables predictive of response, and survival analysis, comparison of survival curves and Cox multiple regression analysis to study variables predictive of survival. RESULTS: We obtained 26.5% objective responses (95% confidence interval: 18.2-36.1%) and a median survival of 9 months (95% confidence interval: 7-11 months). Several variables were associated with response to treatment and survival at univariate analysis. At multivariate analysis the number of tumor sites, bone/visceral involvement and epithelial tumor markers were significantly predictive of response; presence of pain, serum alkaline phosphatase, carboplatin AUC and response to treatment were significantly associated with survival. CONCLUSIONS: The identification of variables that can predict prognosis and response to treatment in patients with UPT may be useful to offer aggressive treatment to sensitive subsets of patients and provide therapeutic alternatives to those with a low probability of benefiting from standard treatment. In our patients the use of carboplatin AUC higher than 6 and response to treatment were the most important factors associated with prognosis, together with presence of pain and serum alkaline phosphatase. However, larger series and identification of new disease markers are necessary to better define predictive and prognostic variables in UPT patients.

Desmoplastic small round cell tumour: a description of two cases and review of the literature.

BACKGROUND: Desmoplastic small round cell tumour (DSRCT) is a recently described neoplasm, typically occurring in adolescent and young males. It usually shows an aggressive behaviour, presents in the abdomen, often with diffuse peritoneal implants. It has been demonstrated to be a chemosensitive tumour, generally with short-lasting response and poor survival gain from systemic chemotherapy. The authors report two additional cases of DSRCT and review the available medical literature. PATIENTS AND METHODS: Two young males with intra-abdominal DSRCT were treated with a first-line chemotherapy including carboplatin, doxorubicin and etoposide. RESULTS: Both of the patients obtained a partial response after first-line chemotherapy. The first patient started, subsequently, CD34+ stem cell mobilisation with high-dose cyclophosphamide (7 g/m(2)) in order to perform high-dose chemotherapy, but CD34+ cell count was insufficient to practice leukapheresis; he died 34 months after the diagnosis because of progression of the disease. The second patient underwent cytoreductive surgery, but progressed 2 months later despite second-line treatment; he died 16 months after the diagnosis. CONCLUSION: This experience confirms that DSRCT may be considered a chemosensitive tumour, highly aggressive, with short-lasting response to chemotherapy. Anyway, the recent literature suggests that multidisciplinary treatment including chemotherapy, surgery and radiation might be the proper approach to this rare malignancy.

Pain and its treatment in hospitalized patients with metastatic cancer.

GOALS: The aim of this prospective study was to assess the quality of pain management hospitalized cancer patients. PATIENTS AND METHODS: In a quantitative and qualitative evaluation from six oncology centers in Italy, all consecutive cancer patients complaining of pain and hospitalized during the same 2 weeks were requested to fill in a McGill pain questionnaire (MPQ), a present pain intensity scale (PPI), and a hospital anxiety and depression acale (HADS), and to answer a questionnaire focused (QF) on the quality of medical and nursing care. The healthcare provider's antalgic prescriptions were assessed by an index of pain management (IPM). MAIN RESULTS: Of 120 patients with pain admitted to oncology divisions (65 men and 52 women; mean age 57 years, range 21-79 years), 117 completed the questionnaires. The quantitative evaluation (PPI) showed a significant pain reduction between admission and discharge pain levels-from 2.65 to 1.50 ( p<0.001). While a significant reduction of anxiety (HADS) was also found-from 10.24 to 9.11 ( p<0.001)-depression did not improve (9.83 and 9.72). The most relevant information from qualitative evaluation (QF) was: in 37.6% of patients, pain level was higher overnight; 47% waited for spontaneous decrease of pain intensity before asking for nurse or physician intervention; 69% asked for nurse help when pain level was really high. The health care response to patients' pain was not completely satisfactory, since analgesic prescription was adequate in 56.52% but inadequate in 43.47%. CONCLUSIONS: Pain control in hospitalized cancer patients is not completely satisfactory. The physician's attitude is to underestimate and undertreat pain, while nurses are not adequately trained for timely intervention despite published guidelines for pain management. The findings of this study support the concern of inadequate knowledge and inappropriate attitudes regarding pain management, even in cancer patients hospitalized in medical oncology divisions.