KRAS mutation testing for predicting response to anti-EGFR therapy for colorectal carcinoma: proposal for an European quality assurance program

Novel therapeutic agents targeting the epidermal growth factor receptor (EGFR) have improved outcomes for patients with colorectal carcinoma. However, these therapies are effective only in a subset of patients. Activating mutations in the KRAS gene are found in 30-40% of colorectal tumors and are associated with poor response to anti-EGFR therapies. Thus, KRAS mutation status can predict which patient may or may not benefit from anti-EGFR therapy. Although many diagnostic tools have been developed for KRAS mutation analysis, validated methods and standardized testing procedures are lacking. This poses a challenge for the optimal use of anti-EGFR therapies in the management of colorectal carcinoma. Here we review the molecular basis of EGFR-targeted therapies and the resistance to treatment conferred by KRAS mutations. We also present guideline recommendations and a proposal for a European quality assurance program to help ensure accuracy and proficiency in KRAS mutation testing across the European Union.

Reconstructing the genealogy of a BRCA1 founder mutation by phylogenetic analysis

Estimating the age of founder mutations may contribute to improve our knowledge of population genetics and evolutionary history of diseases. Previous haplotype analysis suggested that the BRCA1*1499insA mutation was a founder allele, probably originated in Tuscany (Italy). Here, we collected additional pedigrees carrying this mutation, and applied a phylogenetic method for estimating mutation age. A chromosome segment of about 25 cM, including 37 short tandem repeats (STRs) on both sides of the BRCA1 gene (DeCode map), was typed in 50 subjects (28 mutation carriers) from 14 unrelated families. The time to the most recent common ancestor (MRCA) of the mutation carriers was estimated by the length of the shared haplotype between all possible pairs of individuals. A function relating the length of the shared haplotype to the time to the MRCA was obtained by a computer simulation. This approach gives results comparable with those of other existing mutation-dating methods, but does not depend explicitly on population-specific parameters such as allele frequencies, provides narrower confidence intervals (CI), and allows one to build an extended genealogical tree of all mutation carriers. The 1499insA mutation shared by the investigated subjects was estimated to be present in an individual living about 30 generations ago (95% CL 22-56), or 750 years (95% CL 550-1,400).

Correlation of recurrence rates and times with posttreatment human papillomavirus status in patients treated with loop electrosurgical excision procedure conization for cervical squamous intraepithelial lesions

The aim of the present study was to assess recurrence rates and times in patients with squamous intraepithelial lesion (SIL) of the uterine cervix treated with loop electrosurgical excision procedure (LEEP) conization, in order to define categories of patients who have a different risk of recurrence and who need a different surveillance protocol. This study was carried out on 119 consecutive patients who underwent LEEP. All patients were followed up with cervical smear and colposcopy after 3, 6, and 12 months in the first-year posttreatment, and every 6-12 months afterwards. Human papillomavirus (HPV) testing was performed at the time of LEEP and repeated 3-6 months later. The histologic examination of LEEP specimens revealed stage IA1 squamous cell cervical cancer in 4 (3.4%) cases, high-grade SIL in 75 (63%) cases, and low-grade SIL in 40 (33.6%) cases. The four patients with stage IA1 cervical cancer were not included in the further analyses. Disease recurred in none of the 50 patients with negative posttreatment HPV testing, in 4 (9.3%) of the 43 patients with positive posttreatment HPV testing and negative surgical margins, and in 8 (36.4%) of 22 patients with positive posttreatment HPV testing and positive margins. The combined evaluation of surgical margin status and posttreatment HPV testing could allow to subdivide patients treated with LEEP into categories at different risk of recurrence, requiring new tailored surveillance procedures.

Endoscopic management of symptomatic choledocholithiasis in pregnancy without the use of radiations

We report a case of 26-year-old woman at 10th week of gestation with cholestatic jaundice due to a common bile duct (CBD) stone managed by endoscopical retrograde cholangiopancreatography (ERCP). The procedure was successfully carried out without the use of ionizing radiations and under trans-abdominal ultrasonographical (US) control. A few cases are reported in literature in which ERCP was performed without fluoroscopy examination. We believe that ERCP with US guidance is an effective and safe procedure to treat symptomatic choledocholithiasis in pregnant women.

Contrast-enhanced MR imaging in patients with BI-RADS 3-5 microcalcifications

PURPOSE

The aim of this study was to evaluate the role of magnetic resonance imaging (MRI) in patients with microcalcifications classed as Breast Imaging Reporting and Data Systems (BI-RADS) 3-5.

MATERIALS AND METHODS

Fifty-five patients with mammographic microcalcifications classified as BI-RADS categories 3, 4 or 5 underwent MRI and biopsy with stereotactic vacuum-assisted biopsy (VAB). Our gold standard was microhistology in all cases and histology with histological grading in patients who underwent surgery. Patients with a microhistological diagnosis of benign lesions underwent mammographic follow-up for at least 12 months. MRI was performed with a 1.5-Tesla (T) unit, and T1 coronal three-dimensional (3D) fast low-angle shot sequences were acquired before and after injection of paramagnetic contrast agent (0.1 mmol/kg). MRI findings, according to the Fisher score, were classified into BI-RADS classes. In patients with cancer who underwent surgery, we retrospectively compared the extension of the mammographic and MRI findings with histological extension.

RESULTS

Histology revealed 26 ductal in situ cancers (DCIS) and ductal microinvasive cancers (DCmic), three atypical ductal hyperplasias (ADH) and 26 benign conditions. Histological grading of the 26 patients with cancer revealed four cases of G1, 11 cases of G2 and 11 cases of G3. If we consider mammographic BI-RADS category 3 as benign and BI-RADS 4 and 5 as malignant, mammography had 77% sensitivity, 59% specificity, 63% positive predictive value (PPV), 74% negative predictive value (NPV) and 67.2% diagnostic accuracy. If we consider MRI BI-RADS categories 1, 2 and 3 as benign and 4 and 5 as malignant, MRI had 73% sensitivity, 76% specificity, 73% PPV, 76% NPV and 74.5% diagnostic accuracy. As regards disease extension, mammography had 45% sensitivity and MRI had 84.6% sensitivity.

CONCLUSION

Mammography and stereotactic biopsy still remain the only techniques for characterising microcalcifications. MRI cannot be considered a diagnostic tool for evaluating microcalcifications. It is, however, useful for identifying DCIS with more aggressive histological grades. An important application of MRI in patients with DCIS associated with suspicious microcalcifications could be to evaluate disease extension after a microhistological diagnosis of malignancy, as it allows a more accurate presurgical planning.

Methyl group metabolism gene polymorphisms as modifier of breast cancer risk in Italian BRCA1/2 carriers

BRCA1 and 2 are major cancer susceptibility genes but their penetrance is highly variable. The folate metabolism plays an important role in DNA methylation and its alterated metabolism is associated with cancer risk. The role of allele variants 677T and 1298C (MTHFR gene) and 2756G (MS gene) has been investigated as potentially modifying factors of BRCA gene penetrance, evaluated as age at first diagnosis of cancer, in 484 BRCA1/BRCA2 carriers and in 108 sporadic breast cancer cases as a control group. The genotype analysis has been performed by means of PCR/RFLP's. The analysis of association between a particular genotype and disease risk was performed using Cox Regression with time to breast or ovarian cancer onset as the end-point. The presence of 677T allele confers an increased risk of breast cancer in BRCA1 carriers (P = 0.007) and the presence of 1298C allele confers an increased risk of breast cancer in sporadic cases (P = 0.015).

MMTV-like sequences in human breast cancer: a fluorescent PCR/laser microdissection approach

The hypothesis that a retrovirus homologous to the mouse mammary tumour virus (MMTV) is involved in human breast cancer aetiology has fascinated scientists from many years, but it has never been convincingly demonstrated. Renewed interest in this hypothesis developed when an MMTV env gene-like sequence was found in 38% of human breast cancer tissues. Whereas some subsequent studies confirmed these findings, others did not. The main reasons for this discrepancy, among others, are the different sensitivities and technical details of current molecular approaches to the detection of these sequences. This study is an attempt to find sensitive and reproducible conditions capable of detecting MMTV env-like sequence in human samples. To this end, we first developed a fluorescence nested-PCR (FN-PCR) method that was able to detect very low copies of the viral genome, and then screened a panel of 45 frozen breast cancer samples obtained by laser microdissection. The MMTV env gene-like sequence was found in 15 (33%) of the human breast cancers analysed, whereas the same sequence was detectable neither in normal tissues nor in other types of tumour. Sequence analysis revealed 96% homology with the MMTV genome, but no other significant similarities with the human genome. The combined use of frozen material, microdissected cell populations and FN-PCR provides a novel, sensitive, robust, non-radioactive and fast methodology for the molecular detection of human-MTV. This approach might be successfully used in large molecular studies that aim to investigate the hypothesis of a retroviral aetiology of human breast cancer.

The sodium-iodide symporter expression in placental tissue at different gestational age: an immunohistochemical study

BACKGROUND

Iodide (I(-)) is crucial for foetal thyroid function. Foetal iodide results from maternal circulating iodide and from deiodination of iodothyronines within the placenta. The Na(+)/I(-) symporter (NIS) localized in placental cells appears to be involved in iodide exchange. Low NIS expression has been reported in trophoblast cells from the first trimester and pregnancy at term.

AIMS

The aim of this study was to examine NIS expression by immunohistochemistry in the major components of human ovular tissue and placenta.

MATERIALS AND METHODS

Formalin-fixed and paraffin-embedded specimens of placental tissue from the first trimester and at term were analysed. NIS expression was quantified as percentage of NIS-positive cells/total cells. NIS expression was also evaluated by real-time polymerase chain reaction (RT-PCR) in five first-trimester and five at-term placental specimens.

RESULTS

In the first-trimester specimens heterogeneous NIS immunoreactivity was found in cyto-syncytiotrophoblast cells, with a range of NIS-positive cells from 5% to 80% (mean +/- SD 21.85 +/- 23.95), in mesenchymal and endothelial cells from 1% to 40% (14.5 +/- 11.16), in decidual cells from 5% to 40% (10.38 +/- 11.98) and in endometrial glands from 3% to 40% (21.86 +/- 13.93). In specimens from placenta at term, NIS-positive cyto-syncytiotrophoblast cells were between 5% and 40% (mean 17.85 +/- 18.15), mesenchymal and endothelial cells between 1% and 40% (13.67 +/- 12.16), decidual tissue between 5% and 30% (16.43 +/- 9.08), and endometrial glands between 3% and 40% (16.67 +/- 15.27). No significant differences in NIS expression were observed between the first trimester and placenta at term. A similar level of mRNA expression for the NIS gene was obtained by RT-PCR both in ovular material of the first trimester and in placenta at term.

CONCLUSIONS

We found NIS to be expressed in various placental and ovular components and its expression to remain constant during pregnancy.

Large needle aspiration biopsy and galectin-3 determination in selected thyroid nodules with indeterminate FNA-cytology

Thyroid fine-needle aspiration biopsy (FNA)-cytology is widely used for the preoperative characterisation of thyroid nodules but this task is difficult for follicular lesions, which often remain undefined. We propose a strategy for improving the preoperative characterisation of selected follicular thyroid proliferations, which is based on large needle aspiration biopsy (LNAB) and galectin-3 expression analysis. Eighty-five thyroid specimens were obtained by LNAB (20-gauge needles) from thyroid nodules with indeterminate follicular FNA-cytology. Aspirated material was processed as a tissue microbiopsy to obtain cell blocks for both cyto/histo-morphological evaluation and galectin-3 expression analysis, by using a purified monoclonal antibody to galectin-3 and a biotin-free immunoperoxidase staining method. Preoperative diagnosis was compared to the final histology. LNAB and cell-block technique allow a preliminary distinction between nodules with a homogeneous microfollicular/trabecular structure, as frequently observed in tumours, and lesions with mixed normo-micro-macrofollicular architecture, as observed in goitre. Furthermore, LNAB provides optimal substrates for galectin-3 expression analysis. Among 85 cases tested, 14 galectin-3-positive cases were discovered preoperatively (11 thyroid cancers and three adenomas confirmed at the final histology), whereas galectin-3-negative cases were 71 (one carcinoma and 70 benign proliferations at the final histology). Sensitivity, specificity and diagnostic accuracy of this integrated morphologic and phenotypic diagnostic approach were 91.6, 97.2 and 95.3%, respectively. In conclusion, LNAB plus galectin-3 expression analysis when applied preoperatively to selected thyroid nodules candidate to surgery can potentially reduce unnecessary thyroid resections.

Small cell lung cancer

Small cell lung cancer accounts for 13-15% of all lung cancer worldwide. There has been a decrease in the number of cases, with no clear explanation, except probably to changing in smoking habits in the last two decades. In the early eighties, it became clear that SCLC was an extremely sensitive tumor as to radiation as to chemotheraputic agents. With cisplatinum etoposide combinations or cyclophosphamide, anthracycline and vincristine/etyoposide regimens responses were observed in 50-70%, with 20-30% complete remissions in extensive disease. For limited stage patients chemotherapy associated with thoracic radiation was able to produce a cure rate of 10-20%. The addition of prophylactic brain irradiation to limited stage cases has reduced mortality by a factor of nearly 5%. But despite these early good results no breakthrough came later on, and in the last decade or so, we are still facing this plateau. New agents have recently been included in the therapeutic armamentarium, such as gemcitabine, irinotecan, paclitaxel. This fact has allowed many patients to receive a relatively active second line therapy, but the overall survival remains unchanged. Targeted therapies are undergoing some evaluations, but the data are too premature and so far quite discouraging. At the present time there is a urgent need to improve clinical research in this somehow forgotten disease.

Current concepts on the pulmonary surfactant in infants

Surfactant has been a main topic of neonatology in the last 20 years. Many studies have been conducted since the discovery of its role in the pathogenesis of respiratory distress syndrome and the knowledge on its composition and metabolism has become complex. In this article we review the current concepts of its metabolism, ways of acting, properties of its proteins and activities other than the ability of reducing surface tension within the lung as a basis to understand the development of disease in case of its deficiency.

Reexamination of the Helfrich-Hurault effect in smectic-A liquid crystals

The Helfrich-Hurault effect is a phase transition that occurs in samples of cholesteric or smectic liquid crystals subject to external electric or magnetic fields. In this paper we analyze the Helfrich-Hurault effect of smectic-A liquid crystals in an electrostatic field taking into account the complete electromechanical coupling. A comparison is made with the results already obtained for the partially coupled case where one takes into account only the effect of the field on the crystal configuration and considering that field unaffected.

Coherent population trapping spectra in presence of ac magnetic fields

Experimental and theoretical investigations are reported on the effects induced by an alternating magnetic field on coherent population trapping resonances. We show that the ac magnetic field produces sidebands of these resonances in such a way that the spectrum observed is similar to those observed via the FM spectroscopic technique. Because of the very narrow linewidth of the resonances, sidebands are resolved even for ac field frequencies as low as a fraction of a kHz. The theoretical model developed, which takes into account a very simple atomic structure, fits the experimental data quite well.

Early diagnosis of bacterial infection in the neonate

The diagnosis of neonatal bacterial infection remains one of the greatest and most tantalizing challenges to neonatologists. At birth it must be based on the history of pregnancy and take into account a number of now well-defined risk factors. In addition, if promptly started, antibiotic therapy can reduce its sequelae and improve the prognosis. However, the number of tests that obstetricians can rely on for the diagnosis of infection is quite limited. Tests of maternal inflammation indicators have a low specificity, culture tests are not immune from the risk of contamination, and the measurement of interleukins in the amniotic fluid and maternal blood serum is not yet routine. Observation of clinical signs therefore remains crucial to neonatologists, at the same time that new and more sophisticated laboratory tests enable them to establish a diagnosis of infection at an increasingly earlier stage. In recent years, several infection markers have been investigated, such as procalcitonin and especially C-reactive protein (CRP). Currently, the measurement of plasma concentrations of interleukins (IL), IL-6 and IL-8 in particular, appears to be one of the most sensitive and specific infection indicators in newborns. Cytokine levels are increased even before infants develop any clinical symptoms and routine laboratory tests turn positive. However, owing to their short half-life, their sensitivity decreases after 12-24 h from the onset of inflammation, increasing the risk of false negatives. Ideally, they should then be used in combination with other inflammation indicators, such as CRP. The measurement of cytokines and other new inflammatory markers might be helpful in the early diagnosis of both early-onset infection (assay in umbilical cord blood) and late-onset infection (serial assays performed during the stay in the neonatal intensive care unit). In spite of their time-consuming techniques, culture tests remain of the utmost importance to plan a targeted treatment; blood culture, in particular, is crucial to the diagnosis of sepsis.

Neonatal seizures in preterm infants: clinical outcome and relationship with subsequent epilepsy

OBJECTIVE

Neonatal seizures are considered an acute manifestation of disturbance of the neonatal brain. Some of them can be considered as neonatal epilepsy. Our goal was to evaluate perinatal risk factors, electroencephalogram (EEG) findings and ictal semeiological characteristics of our newborns with neonatal seizures in order to identify which clinical variables were the most early predictive factors of poor neurodevelopmental outcome and of epilepsy.

METHODS

Among all preterm infants consecutively admitted to the neonatal intensive care unit (NICU) of the University Hospital of Parma in the period between January 1999 and June 2003, 28 preterm infants with gestational age<or=36 weeks were selected according to the presence of repetitive neonatal seizures, need of chronic anticonvulsant therapy, more than one EEG performed during the neonatal period, and at least one imaging examination (cerebral ultrasound and/or cerebral magnetic resonance imaging (MRI). These patients were prospectively followed up for at least 6 months to evaluate the clinical outcome. Independent variables considered for analysis included perinatal risk factors, etiology of convulsions, EEG activity and type of seizures.

RESULTS

The background EEG activity was the strongest predictive factor of the neurodevelopmental outcome, but status epilepticus (SE) also represented a significant variable associated with poor prognosis and subsequent epilepsy.

CONCLUSIONS

EEG activity was predictive of the developmental outcome and allowed identification of the infants with SE, a condition often related to neonatal epilepsy (71.4%, p<0.05).

[Assessment of the presence of mutations of the epidermal growth factor receptors in tumors of various histologies]

Recent reports from US and Japan have established that mutations in the tyrosine kinase (TK) domain of the epidermal growth factor receptor (Egfr) occur in a subset of patients with lung cancer that respond to therapy with gefitinib, a TK inhibitor. To gain further insights into the role of Egfr in carcinogenesis of lung and tumors of diverse histology, that are currently under investigation with drugs of the same class, we have taken in examination a panel of tumors consisting in 110 pulmonary adenocarcinomas, 40 pulmonary squamous carcinomas, 40 gastric adenocarcinomas and 40 colorectal adenocarcinomas. The sequence analysis of exon 19 and 21 of the Egfr has allowed the identification of 10 cases exhibiting specific deletions in exon 19 and 1 case with point mutation in a conserved residue in exon 21. All Egfr mutations occur specifically in lung adenocarcinomas while tumors of different histology result unaffected. The rate of mutation affecting these other tumors is either very rare, involves different domains of the receptor or other tyrosine kinases. The molecular analysis of the Egfr gene can help identify patients that will benefit from gefitinib therapy.

[Perinatal risk factors for infection in the newborn. Multicenter clinico-epidemiologic investigation]

The neonate, in particular if preterm, has a specific immunological system that makes him/her more susceptible to infections which are still a major cause of mortality and morbidity. The early onset infective patterns are often vertically transmitted from the mother to the fetus in the perinatal period. Some mother conditions like genitourinary infections, pre-delivery fever, PROM, pPROM, preterm delivery, abortions, fetal demise are important neonatal risk factors. The role of these factors as causes of early onset neonatal infections was evaluated by an Italian multicentric epidemiologic investigation supported by the MIUR. Mothers admitted to obstetrician hospitals for parturition were studied in a case control retrospective analysis. Mothers presenting with the selected risk factors were the cohort of cases while the admissions without risk factors next to each case represented the controls. The following risk factors were considered for analysis: 2nd trimester abortion, PROM, pPROM, preterm delivery and fetal demise. Eight hospitals entered the multicentric research and 29610 patients have been analyzed: 2466 PROM, 478 pPROM, 946 preterm delivery, 244 abortions, 133 fetal demise. Every woman received a microbiological screening by cervico-vaginal and rectal swab and/or urine culture. As much as 3892 cases from the University Hospitals of Parma and Torino concern, the cervicovaginal swab was positive in 76.5% pPROM, in 50.6% PROM and 50.5% preterm deliveries. The positivity of the swabs showed statistical relevance in cases compared to controls. In cases presenting with abortion the frequency of positive cultures (44.1%) was higher than the controls, but it did not reach statistical relevance. Conversely, positivity of cultures was lower in cases with fetal demise than control group but without statistical difference. In the cohort of 675 women selected from our Institute (University of Parma) the overall rate of positivity of cervico-vaginal swabs was about 44% and only one germ was isolated in 94.6% cases: 49,8% Gram positive and negative, 14.1% Streptococcus hemolyticus B group, 34.7% Candida. The rate of cultural tests performed before delivery was statistically higher in cases than controls (74.3% vs 23.2%, p < 0.001). Furthermore 14.3% newborns from mothers in the case group and 2.3% newborns from mothers in the control group were admitted to the neonatal care unit. Among them 8.4% and 1.2% respectively needed antibiotics while 0.4% and 0.2% respectively presented with early onset infection. Ear swabs were performed in 48,8% of infants born to mothers from the case group and in 26.9% of infants born to mothers from the control group, in 6.5% and in 2.9% respectively were the skin swabs performed as well. No statistical difference was met. The choice to perform cultural examinations was statistically higher in cases than controls, but the positivity rate was similar in both groups, perhaps because of a more specific choice in the control group.

CONCLUSION

our data confirm the relationship between infections and preterm delivery, PROM, pPROM and support the hypothesis that infections might be the cause of these conditions and not simply an association. A prompt maternal microbiological control during pregnancy and delivery, especially in women presenting with known risk factors, gives the possibility to do early diagnostic-therapeutic interventions and to minimize the frequency and severity of early sepsis in newborns.

Genetic alterations in hereditary breast cancer

Genetic linkage studies have led to the identification of highly penetrant genes as the possible cause of inherited cancer risk in many cancer-prone families. Most women with a family history of breast/ovarian cancer have tumors characterized by alterations in particular genes, mainly BRCA1 and BRCA2, but also CHK2, ATM, STK11 and others. This paper examines the BRCA1 and BRCA2 genes, focusing on the Italian pattern of mutations. The function of these two genes, classified as tumor suppressors, is linked with key metabolic mechanisms such as DNA damage repair, regulation of gene expression and cell cycle control. The pathological BRCA allelic variants may cause alteration of protein function, transcriptional activity and DNA repair; accumulation of the defects leads to widespread chromosome instability that may be directly responsible for cancer formation. In fact, mutations in BRCA1 and BRCA2, conferring a highly increased susceptibility to breast and ovarian cancer, do not lead to cancer by themselves. The current consensus is that these are 'caretaker' genes, which, when inactivated, allow other genetic defects to accumulate. The nature of these other molecular events may define the pathway through which BRCA1 and BRCA2 act. The BRCA mutation spectrum is complex, and the significance of most nucleotide alterations is difficult to understand. Moreover, the mutation pattern seems to be related to ethnicity. The Italian Consortium of Hereditary Breast and Ovarian Cancer has reviewed 1758 families; 23% have been found to be carriers of pathogenetic mutations in BRCA1 or BRCA2. Founder mutations have been described in geographically restricted areas of Italy; a regional founder effect has been demonstrated in Italy for the mutations BRCA1 5083del19 and BRCA2 8765delAG, and a probable new founder mutation has been characterized in Tuscany. The presence of founder mutations has practical implications for genetic testing.