xDEEP-MSI: Explainable Bias-Rejecting Microsatellite Instability Deep Learning System in Colorectal Cancer

The prediction of microsatellite instability (MSI) using deep learning (DL) techniques could have significant benefits, including reducing cost and increasing MSI testing of colorectal cancer (CRC) patients. Nonetheless, batch effects or systematic biases are not well characterized in digital histology models and lead to overoptimistic estimates of model performance. Methods to not only palliate but to directly abrogate biases are needed. We present a multiple bias rejecting DL system based on adversarial networks for the prediction of MSI in CRC from tissue microarrays (TMAs), trained and validated in 1788 patients from EPICOLON and HGUA. The system consists of an end-to-end image preprocessing module that tile samples at multiple magnifications and a tissue classification module linked to the bias-rejecting MSI predictor. We detected three biases associated with the learned representations of a baseline model: the project of origin of samples, the patient's spot and the TMA glass where each spot was placed. The system was trained to directly avoid learning the batch effects of those variables. The learned features from the bias-ablated model achieved maximum discriminative power with respect to the task and minimal statistical mean dependence with the biases. The impact of different magnifications, types of tissues and the model performance at tile vs patient level is analyzed. The AUC at tile level, and including all three selected tissues (tumor epithelium, mucin and lymphocytic regions) and 4 magnifications, was 0.87 ± 0.03 and increased to 0.9 ± 0.03 at patient level. To the best of our knowledge, this is the first work that incorporates a multiple bias ablation technique at the DL architecture in digital pathology, and the first using TMAs for the MSI prediction task.

Increased Risk of Colorectal Cancer in Patients With Multiple Serrated Polyps and Their First-Degree Relatives

BACKGROUND & AIMS

We investigated whether patients with multiple serrated polyps, but not meeting the World Health Organization criteria for serrated polyposis syndrome, and their relatives have similar risks for colorectal cancer (CRC) as those diagnosed with serrated polyposis.

METHODS

We collected data from patients with more than 10 colonic polyps, recruited in 2008-2009 from 24 hospitals in Spain for a study of causes of multiple colonic polyps. We analyzed data from 53 patients who met the criteria for serrated polyposis and 145 patients who did not meet these criteria, but who had more than 10 polyps throughout the colon, of which more than 50% were serrated. We calculated age- and sex-adjusted standardized incidence ratios (SIRs) for CRC in both groups, as well as in their first-degree relatives.

RESULTS

The prevalence of CRC was similar between patients with confirmed serrated polyposis and multiple serrated polyps (odds ratio, 1.35; 95% confidence interval [CI], 0.64-2.82; P = .40). The SIR for CRC in patients with serrated polyposis (0.51; 95% CI, 0.01-2.82) did not differ significantly from the SIR for CRC in patients with multiple serrated polyps (0.74; 95% CI, 0.20-1.90; P = .70). The SIR for CRC also did not differ significantly between first-degree relatives of these groups (serrated polyposis: 3.28, 95% CI, 2.16-4.77; multiple serrated polyps: 2.79, 95% CI, 2.10-3.63; P = .50). Kaplan-Meier analysis showed no differences in the incidence of CRC between groups during the follow-up period (log-rank, 0.6).

CONCLUSIONS

The risk of CRC in patients with multiple serrated polyps who do not meet the criteria for serrated polyposis, and in their first-degree relatives, is similar to that of patients diagnosed with serrated polyposis.

Value-based healthcare delivery in the digital era

Introduction

Mental disorders are a major cause of disability in Europe [1]. However, organizational structures and information systems are focused on delivery of care, rather than providing value [2]. In the digital era, we have the capacity to change priorities through the analysis of heterogeneous databases that could support patients’ and professionals’ decisions.

Objectives

to analyse the contradictions between the design and the theoretical structure of mental health services and the possibilities to evaluate the actual value of the delivered care.

Aims

To reflect on changing the trend using a different conceptualization of objectives and evaluating methods.

Methods

We used a tool provided to clinicians by the Madrid's Regional Health Service SERMAS (‘ConsultaWeb’) combining primary care, pharmacy and hospital data (n = 395,073 patients for the catchment area), and a set of hospital-based data (patients attended by psychiatrists at the ER, n = 13,877, and patients admitted to the Psychiatric Inpatient unit n = 3318), to explore some of the present professional information resources.

Results

Currently used healthcare databases only describe the diagnostic or therapeutic categories of patients and might be used to detect abnormal behaviours. However, they are neither able to show the functional status of patients nor designed to predict their clinical course.

Conclusions

A clearer definition of value in patient outcomes is needed. This might help to organize the healthcare delivery and to create a new information system that would allow to asses health outcomes.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

[Nodular regenerative hyperplasia associated with common variable immunodeficiency and other comorbidities]

BACKGROUND AND OBJECTIVE

Currently, there are not many data on the evolution of nodular regenerative hyperplasia (NRH) associated or not with underlying diseases and in particular that associated with common variable inmunodeficiency (CVID). Twenty cases of NRH are presented, and the differences between the cases associated with CVID and those related to other diseases are analysed.

METHODS

Retrospective and descriptive study over a period of 14 years.

RESULTS

Twelve out of the 20 patients were men; the median age was 51 years. CVID was the main illness associated with NRH. In patients with CVID and NRH, gastrointestinal haemorrhage was more common, all the patients had high gamma glutamyl transferase and alkaline phosphatase and none had altered albumin and bilirubin levels compared to the patients without CVID. On follow-up, 50% of patients with CVID (2/4) had died compared to 33.3% (5/15) without CVID.

CONCLUSIONS

NRH in patients with CVID seems to have more biochemical data of anicteric cholestasis and portal hypertension and could be associated with lower survival.

Prevalence of MLH1 constitutional epimutations as a cause of Lynch syndrome in unselected versus selected consecutive series of patients with colorectal cancer

BACKGROUND

The prevalence of MLH1 constitutional epimutations in the general population is unknown. We sought to analyse the prevalence of MLH1 constitutional epimutations in unselected and selected series of patients with colorectal cancer (CRC).

METHODS

Patients with diagnoses of CRC (n=2123) were included in the unselected group. For comparison, a group of 847 selected patients with CRC who fulfilled the revised Bethesda guidelines (rBG) were also included. Somatic and constitutional MLH1 methylation was assayed via methylation-specific multiplex ligation-dependent probe amplification of cases lacking MLH1 expression. Germline alterations in mismatch-repair (MMR) genes were assessed via Sanger sequencing and methylation-specific multiplex ligation-dependent probe amplification.

RESULTS

Loss of MLH1 expression occurred in 5.5% of the unselected series and 12.5% of the selected series (p<0.0001). No constitutional epimutations in MLH1 were detected in the unselected population (0/62); five cases from the selected series were positive for MLH1 epimutations (15.6%, 5/32; p=0.004).

CONCLUSIONS

Our results suggest a negligible prevalence of MLH1 constitutional epimutations in unselected cases of CRC. Therefore, MLH1 constitutional epimutation analysis should be conducted only for patients who fulfil the rBG and who lack MLH1 expression with methylated MLH1.

Prevalence and characteristics of MUTYH-associated polyposis in patients with multiple adenomatous and serrated polyps

PURPOSE

The present study aimed to determine the prevalence of MUTYH mutations in patients with multiple colonic polyps and to explore the best strategy for diagnosing MUTYH-associated polyposis (MAP) in these patients.

EXPERIMENTAL DESIGN

This study included 405 patients with at least 10 colonic polyps each. All cases were genetically tested for the three most frequent MUTYH mutations. Whole-gene analysis was performed in heterozygous patients and in 216 patients lacking the three most frequent mutations. Polyps from 56 patients were analyzed for the KRAS-Gly12Cys and BRAF V600E somatic mutations.

RESULTS

Twenty-seven (6.7%) patients were diagnosed with MAP, of which 40.8% showed serrated polyps. The sensitivity of studying only the three common variants was 74.1%. Of 216 patients without any monoallelic mutation in common variants, whole-gene analysis revealed biallelic pathogenic mutation in only one. G396D mutation was associated with serrated lesions and older age at diagnosis. There was a strong association between germinal MUTYH mutation and KRAS Gly12Cys somatic mutation in polyps. BRAF V600E mutation was found in 74% of serrated polyps in MUTYH-negative patients and in none of the polyps of MAP patients.

CONCLUSIONS

We observed a low frequency of MUTYH mutations among patients with multiple adenomatous and serrated polyps. The MAP phenotype frequently included patients with serrated polyps, especially when G396D mutation was involved. Our results show that somatic molecular markers of polyps can be useful in identifying MAP cases and support the need for the complete MUTYH gene analysis only in patients heterozygous for recurrent variants.

Risk of cancer in cases of suspected lynch syndrome without germline mutation

BACKGROUND & AIMS

Colorectal cancers (CRCs) with microsatellite instability (MSI) and a mismatch repair (MMR) immunohistochemical deficit without hypermethylation of the MLH1 promoter are likely to be caused by Lynch syndrome. Some patients with these cancers have not been found to have pathogenic germline mutations and are considered to have Lynch-like syndrome (LLS). The aim of this study was to determine the risk of cancer in families of patients with LLS.

METHODS

We studied a population-based cohort of 1705 consecutive patients, performing MSI tests and immunohistochemical analyses of MMR proteins. Patients were diagnosed with Lynch syndrome when they were found to have pathogenic germline mutations. Patients with MSI and loss of MSH2 and/or MSH6 expression, isolated loss of PMS2 or loss of MLH1 without MLH1 promoter hypermethylation, and no pathogenic mutation were considered to have LLS. The clinical characteristics of patients and the age- and sex-adjusted standardized incidence ratios (SIRs) of cancer in families were compared between groups.

RESULTS

The incidence of CRC was significantly lower in families of patients with LLS than in families with confirmed cases of Lynch syndrome (SIR for Lynch syndrome, 6.04; 95% confidence interval [CI], 3.58-9.54; SIR for LLS, 2.12; 95% CI, 1.16-3.56; P < .001). However, the incidence of CRC was higher in families of patients with LLS than in families with sporadic CRC (SIR for sporadic CRC, 0.48; 95% CI, 0.27-0.79; P < .001).

CONCLUSIONS

The risk of cancer in families with LLS is lower that of families with Lynch syndrome but higher than that of families with sporadic CRC. These results confirm the need for special screening and surveillance strategies for these patients and their relatives.

Comparison between universal molecular screening for Lynch syndrome and revised Bethesda guidelines in a large population-based cohort of patients with colorectal cancer

BACKGROUND

The selection of patients for genetic testing to rule out Lynch syndrome is currently based on fulfilment of at least one of the revised Bethesda criteria followed by mismatch repair (MMR) status analysis. A study was undertaken to compare the present approach with universal MMR study-based strategies to detect Lynch syndrome in a large series of patients with colorectal cancer (CRC).

METHODS

2093 patients with CRC from the EPICOLON I and II cohorts were included. Immunohistochemistry for MMR proteins and/or microsatellite instability (MSI) analysis was performed in tumour tissue. Germline MLH1 and MSH2 mutation analysis was performed in patients whose tumours showed loss of MLH1 or MSH2 staining, respectively. MSH6 genetic testing was done in patients whose tumours showed lack of MSH6 expression or a combined lack of MSH2 and MSH6 expression but did not have MSH2 mutations. PMS2 genetic testing was performed in patients showing isolated loss of PMS2 expression. In patients with MSI tumours and normal or not available MMR protein expression, all four MMR genes were studied.

RESULTS

A total of 180 patients (8.6%) showed loss of expression of some of the MMR proteins and/or MSI. Four hundred and eighty-six patients (23.2%) met some of the revised Bethesda criteria. Of the 14 (0.7%) patients who had a MMR gene mutation, 12 fulfilled at least one of the revised Bethesda criteria and two (14.3%) did not.

CONCLUSIONS

Routine molecular screening of patients with CRC for Lynch syndrome using immunohistochemistry or MSI has better sensitivity for detecting mutation carriers than the Bethesda guidelines.

Case-control study for colorectal cancer genetic susceptibility in EPICOLON: previously identified variants and mucins

Background

Colorectal cancer (CRC) is the second leading cause of cancer death in developed countries. Familial aggregation in CRC is also important outside syndromic forms and, in this case, a polygenic model with several common low-penetrance alleles contributing to CRC genetic predisposition could be hypothesized. Mucins and GALNTs (N-acetylgalactosaminyltransferase) are interesting candidates for CRC genetic susceptibility and have not been previously evaluated. We present results for ten genetic variants linked to CRC risk in previous studies (previously identified category) and 18 selected variants from the mucin gene family in a case-control association study from the Spanish EPICOLON consortium.

Methods

CRC cases and matched controls were from EPICOLON, a prospective, multicenter, nationwide Spanish initiative, comprised of two independent stages. Stage 1 corresponded to 515 CRC cases and 515 controls, whereas stage 2 consisted of 901 CRC cases and 909 controls. Also, an independent cohort of 549 CRC cases and 599 controls outside EPICOLON was available for additional replication. Genotyping was performed for ten previously identified SNPs in ADH1C, APC, CCDN1, IL6, IL8, IRS1, MTHFR, PPARG, VDR and ARL11, and 18 selected variants in the mucin gene family.

Results

None of the 28 SNPs analyzed in our study was found to be associated with CRC risk. Although four SNPs were significant with a P-value < 0.05 in EPICOLON stage 1 [rs698 in ADH1C (OR = 1.63, 95% CI = 1.06-2.50, P-value = 0.02, recessive), rs1800795 in IL6 (OR = 1.62, 95% CI = 1.10-2.37, P-value = 0.01, recessive), rs3803185 in ARL11 (OR = 1.58, 95% CI = 1.17-2.15, P-value = 0.007, codominant), and rs2102302 in GALNTL2 (OR = 1.20, 95% CI = 1.00-1.44, P-value = 0.04, log-additive 0, 1, 2 alleles], only rs3803185 achieved statistical significance in EPICOLON stage 2 (OR = 1.34, 95% CI = 1.06-1.69, P-value = 0.01, recessive). In the joint analysis for both stages, results were only significant for rs3803185 (OR = 1.12, 95% CI = 1.00-1.25, P-value = 0.04, log-additive 0, 1, 2 alleles) and borderline significant for rs698 and rs2102302. The rs3803185 variant was not significantly associated with CRC risk in an external cohort (MCC-Spain), but it still showed some borderline significance in the pooled analysis of both cohorts (OR = 1.08, 95% CI = 0.98-1.18, P-value = 0.09, log-additive 0, 1, 2 alleles).

Conclusions

ARL11, ADH1C, GALNTL2 and IL6 genetic variants may have an effect on CRC risk. Further validation and meta-analyses should be undertaken in larger CRC studies.

5-Fluorouracil adjuvant chemotherapy does not increase survival in patients with CpG island methylator phenotype colorectal cancer

BACKGROUND & AIMS

5-Fluorouracil (5-FU)-based adjuvant chemotherapy does not increase survival times of patients with colorectal tumors with microsatellite instability. We determined the response of patients with colorectal tumors with the CpG island methylator phenotype (CIMP) to 5-FU-based therapy.

METHODS

We analyzed a population-based cohort of 302 patients with colorectal cancer (CRC) for a median follow-up time of 50.7 months. CIMP status was determined by analysis of the CACNAG1, SOCS1, RUNX3, NEUROG1, and MLH1 promoters; tumors were considered to be CIMP positive if at least 3 promoters were methylated.

RESULTS

Tumors from 29.5% of patients (89/302) were CIMP positive; CIMP status did not influence disease-free survival (DFS; log-rank = 0.3). Of tumors of TNM stages II-III (n = 196), 32.7% were CIMP positive. Among patients with stages II-III CRC who did not receive adjuvant 5-FU chemotherapy, those with CIMP-positive tumors had longest times of DFS (log-rank = 0.04); In patients who received chemotherapy, those with CIMP-positive tumors had shorter times of DFS (log-rank = 0.02). In patients with CIMP-negative tumors, adjuvant 5-FU chemotherapy significantly increased time of DFS (log-rank = 0.00001). However, in patients with CIMP-positive tumors, adjuvant 5-FU chemotherapy did not affect time of DFS (log-rank = 0.7). Multivariate analysis showed a significant, independent interaction between 5-FU treatment and CIMP status (hazard ratio [HR], 0.6; 95% confidence interval [CI], 0.5-0.8). Among patients with CIMP-positive tumors, adjuvant chemotherapy was not an independent predictor of outcome (HR, 0.8; 95% CI, 0.3-2.0). In patients who did not receive adjuvant 5-FU chemotherapy, CIMP status was the only independent predictor of survival (HR, 2.0; 95% CI, 1.1-3.8).

CONCLUSIONS

Patients with CIMP-positive colorectal tumors do not benefit from 5-FU-based adjuvant chemotherapy.

EPCAM germ line deletions as causes of Lynch syndrome in Spanish patients

The standard genetic test for Lynch syndrome (LS) frequently reveals an absence of pathogenic mutations in DNA mismatch repair genes known to be associated with LS. It was recently shown that germ line deletions in the last exons of EPCAM are involved in the etiology of LS. The aim of this study was to evaluate the prevalence of EPCAM deletions in a Spanish population and the clinical implications of deletion. Probands from 501 families suspected of having LS were enrolled in the study. Twenty-five cases with MSH2 loss were identified: 10 had mutations of MSH2, five had mutations of MSH6, and 10 did not show MSH2/MSH6 mutations. These 25 cases were analyzed for EPCAM deletions using multiplex ligation-dependent probe amplification, and deletions were mapped using long-range PCR analysis. One subject with no MSH2/MSH6 mutations had a large deletion in the EPCAM locus that extended for 8.7 kb and included exons 8 and 9. The tumor exhibited MSH2 promoter hypermethylation. EPCAM deletion analysis followed by MSH2 methylation testing of the tumor is a fast low-cost procedure that can be used to identify mutations that cause LS. We propose that this procedure be incorporated into clinical genetic analysis strategies and present a decision-support flow diagram for the diagnosis of LS.

Methylation analysis of MLH1 improves the selection of patients for genetic testing in Lynch syndrome

Inactivation of MLH1 due to promoter hypermethylation strongly suggests a sporadic origin, providing exclusion criteria for Lynch syndrome. The aim of this study is to compare the utility of methylation analysis of MLH1 and BRAF V600E mutations for the selection of patients with MLH1 negative colorectal cancer for genetic testing. MLH1 methylation status was evaluated by MethyLight and methylation-specific MLPA (MS-MLPA) in tumor DNA from 73 colorectal cancer patients with loss of MLH1 protein expression. These tumors were analyzed for BRAF V600E mutations, and genetic testing for germline MLH1 mutations was performed in all corresponding patients. Ten patients had germline mutations in MLH1 and none of their tumors showed significant MLH1 methylation or BRAF V600E mutation. MLH1 genetic testing excluded patients by MethyLight in 47 patients (64%), by MS-MLPA in 49 (67%), and BRAF V600E mutation in only 25 patients (34%) (chi(2) P = 0.00001). Specificity was 75% for MethyLight, 78% for MS-MLPA and 40% for BRAF V600E mutation. The use of MethyLight or MS-MLPA instead of BRAF mutation resulted in a cost reduction of 41% and 45%, respectively, per every MLH1 mutation detected. Taken together, methylation analysis of MLH1 shows better performance characteristics than BRAF V600E mutation in the selection of patients for genetic testing of MLH1, especially when using MS-MLPA.

Utility of p16 immunohistochemistry for the identification of Lynch syndrome

PURPOSE

Immunohistochemistry for mismatch repair proteins has shown utility in the identification of Lynch syndrome, but majority of tumors with loss of MLH1 expression are due to sporadic hypermethylation of the MLH1 promoter. These tumors can also show epigenetic silencing of other genes, such as p16. The aim of our study is to evaluate the utility of p16 immunohistochemistry in the prediction of MLH1 germline mutations.

EXPERIMENTAL DESIGN

p16 immunohistochemistry was appropriately evaluated in 79 colorectal cancers with loss of MLH1 expression. Methylation of MLH1 and p16 were quantitatively studied using real-time PCR assay Methylight. BRAF V600E mutation in tumor tissue was also investigated. Genetic testing for germline mutation of MLH1 was made on 52 patients.

RESULTS

Loss of p16 expression was seen in 21 of 79 samples (26.6%). There was found statistically significant association between p16 expression and p16 methylation (P < 0.001), MLH1 methylation (P < 0.001), and BRAF mutation (P < 0.005). All tumors with loss of p16 expression showed hypermethylation of p16 (21 of 21), 95.2% (20 of 21) showed MLH1 methylation, and 71.4% (15 of 21) were mutated for BRAF V600E. Mutational analysis showed pathogenic germline mutations in 8 of the patients, harboring 10 tumors. All 10 of these tumors showed normal staining of p16 in the immunochemical analysis.

CONCLUSIONS

p16 immunohistochemistry is a good surrogate marker for p16 and MLH1 epigenetic silencing due to hypermethylation, and is useful as screening tool in the selection of patients for genetic testing in Lynch syndrome.

[Chronic hepatitis C virus infection and associated liver disease among the inmates of a Spanish prison]

OBJECTIVE

The objective of this study was to determine the prevalence and genotype distribution of chronic hepatitis C virus (HCV) infection in a penitentiary population. The secondary objective was to describe histological findings in liver of the biopsied population, and identify risk factors associated with liver fibrosis and inflammatory activity.

METHODS

Among 800 inmates, 730 accepted HCV antibody screening and PCR confirmation. Sociodemographic, behavioral, and incarceration-related variables were analyzed. Liver biopsy was offered to individuals with chronic HCV infection. Advanced liver disease was defined as fibrosis 3 and/or an inflammatory activity index score 8).

RESULTS

HCV antibodies were found in 279 inmates. PCR confirmed HCV infection in 250 inmates, yielding a prevalence of 34.2% (95% confidence interval [CI]: 30.8-37.8). Intravenous drug use was independently associated with HCV infection, odds ratio (OR) 51.7 (95% CI: 31-86). Genotypes were 1a 32.9%, 3 29.7%, 1b 18.4% and 4 17.1%. Fifty-one liver biopsies were performed; advanced liver disease was found in 7 patients (13.7%) based on fibrosis and in 31 patients (60.7%) based on the inflammatory activity index. High AST and ALT levels were associated with advanced liver disease established on both fibrosis and inflammatory activity (P<.05). Lengthy intravenous drug use was associated with inflammatory activity (P=.02; OR 1.2; 95% CI: 1.03-1.7).

CONCLUSIONS

Persistent HCV infection is highly prevalent among prison inmates and is associated with intravenous drug abuse. HCV genotype diversity is higher in prison inmates than in the general population. Higher transaminase levels are associated with advanced liver disease.

Acute liver failure in a patient with hairy cell leukemia

Acute liver failure as a manifestation of primary non-Hodkin's lymphoma is a rare phenomenon with a fatal prognosis. Hairy cell leukemia (HCL) is an uncommon chronic B-cell lymphoproliferative disorder, representing about 2 percent of all leukemies. We report a 78-year-old patient with a history of hairy cell leukemia since 10 years, presenting whith fulminant liver failure due to massive liver infiltration. He have reviewed several cases of infiltration of the liver by haematological malignancies, but we only have found after a review in MEDLINE between 1980 and 2006, one case of acute liver failure in a patient with hepatic invasion by hairy cell leukaemia.

Association of the ARLTS1 Cys148Arg variant with sporadic and familial colorectal cancer

ARLTS1 was recently identified in chromosome 13q14 as a tumor suppressor gene of the ADP-ribosylation factor family with pro-apoptotic characteristics. Additionally, one of its genetic variants (W149X) was hypothesized to be a polymorphism associated with familial cancer. We performed a large case-control association study within the EPICOLON project aimed at evaluating the sporadic and familial colorectal cancer (CRC) risk associated with ARLTS1 genetic variants. Whereas P131L and W149X did not seem to affect CRC risk, C148R did show, for the first time in CRC, statistically significant differences between cases and controls [odds ratio (OR) = 1.45, 95% confidence interval (95% CI) = 1.13-1.86, P = 0.003], sporadic cases and controls (OR = 1.59, 95% CI = 1.13-2.23, P = 0.007) and familial cases and controls (OR = 1.55, 95% CI = 1.10-2.19, P = 0.01) in agreement with a hypothetical moderate increase of the cancer risk linked to the C148R ARLTS1 variant, both in sporadic and familial CRC cases.

Performance of different microsatellite marker panels for detection of mismatch repair-deficient colorectal tumors

BACKGROUND

Colorectal tumors caused by failure of the DNA mismatch repair system commonly show microsatellite instability. Our goals were to compare the performance of two panels of markers (a panel previously recommended by the National Cancer Institute [NCI] and a pentaplex of mononucleotide repeats) and to devise the simplest diagnostic strategy for identification of patients with colorectal cancer characterized by defects in mismatch repair.

METHODS

We recruited 1058 patients who were newly diagnosed with colorectal cancer. DNA from fresh-frozen and paraffin-embedded tumors was tested for microsatellite instability, using the NCI-recommended panel of microsatellite markers and the pentaplex panel of mononucleotide repeats, respectively, as templates for polymerase chain reactions (PCRs). Microsatellite instability in fresh-frozen tumors was also assessed using the pentaplex panel of mononucleotides in a crossover analysis. The expression of mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2) in the tumors was determined immunohistochemically. The sensitivity and specificity with which the marker panels identified tumors with deficiencies in the expression of mismatch repair proteins were calculated. All statistical tests were two-sided.

RESULTS

The sensitivity and positive predictive value of the NCI panel were 76.5% (95% confidence interval [CI] = 61% to 92%) and 65.0% (95% CI = 49% to 81%), respectively; corresponding values for the mononucleotide pentaplex panel were 95.8% (95% CI = 89% to 103%) and 88.5% (95% CI = 79% to 98%), respectively. A panel consisting of the mononucleotide repeat markers BAT26 and NR24 alone had the same predictive value as the pentaplex panel of mononucleotide repeats.

CONCLUSIONS

The pentaplex panel of mononucleotide repeats performs better than the NCI panel for the detection of mismatch repair-deficient tumors. Simultaneous assessment of the instability of BAT26 and NR24 is as effective as use of the pentaplex panel for diagnosing mismatch repair deficiency.

Identification of MYH mutation carriers in colorectal cancer: a multicenter, case-control, population-based study

BACKGROUND & AIMS

Whereas it has conclusively been demonstrated that biallelic MutY human homolog (MYH) mutations confer a significant risk for colorectal cancer (CRC), the influence of monoallelic mutations remains controversial. Characterization of MYH-associated CRC is critical to identify individuals who might benefit from preventive strategies. This prospective, multicenter, case-control, population-based study was aimed at (1) establishing the CRC risk associated with specific germline MYH mutations and (2) devising a set of clinical criteria to identify MYH carriers among newly diagnosed CRC.

METHODS

Genotyping for Y165C and G382D was performed by TaqMan technology. Single-stranded conformation polymorphism analysis was performed in heterozygotes to screen for mutations in the entire gene. All individuals were re-screened for any additional pathogenic variant.

RESULTS

Biallelic and monoallelic MYH mutations were found in 8 (0.7%) and 19 (1.7%) of 1116 CRC patients, respectively. None of the 934 control subjects carried biallelic mutations, whereas 22 (2.3%) of them were monoallelic carriers. In a meta-analysis including all previous case-control studies, monoallelic MYH carriers were not at increased risk for CRC (odds ratio, 1.11; 95% confidence interval, 0.90-1.37), although a significant association was found with the Y165C mutation in either homozygotes or heterozygotes (odds ratio, 1.67; 95% confidence interval, 1.17-2.40). Furthermore, presence of more than 15 synchronous colorectal adenomas or CRC diagnosed before the age of 50 years was the most effective set of criteria for the identification of biallelic MYH mutation carriers.

CONCLUSIONS

This study proposes the first set of clinical criteria designed to identify CRC patients with biallelic MYH mutations, and it argues against an increased risk for monoallelic carriers.

Detection of BRAF V600E mutation in colorectal cancer: comparison of automatic sequencing and real-time chemistry methodology

Mutation V600E of BRAF, a kinase-encoding gene from the RAS/RAF/MAPK pathway, in colorectal carcinoma (CRC) suggests a sporadic origin of the disease, providing an exclusion criterion for hereditary nonpolyposis colorectal cancer. Here we describe detection of this mutation by real-time chemistry TaqMan MGB probes, confirmed by direct DNA sequencing as the gold standard. DNA was extracted from paraffin-embedded tissue from 112 tumors obtained from the EPICOLON study. Seventy-two tumors were CRC with defective DNA mismatch repair (MMR; microsatellite instability and/or loss of protein expression by immunohistochemical analysis), and 40 were proficient MMR controls. BRAF mutation was detected in 20/72 (27.8%) CRC with defective MMR and in 3/40 (7.5%) proficient MMR controls (P = 0.011). BRAF mutation was detected in 19/51 (37.3%) tumors with loss of MLH1 expression and in none of the tumors with loss of MSH2 expression (0/13). BRAF mutation was not found in cases with germline mutation of MLH1 (4/112) or MSH2 (3/112) genes. The sensitivity and specificity of our real-time chemistry were both 100% for detecting the V600E mutation. Because real-time chemistry methodology has advantages in cost, time, and labor, we consider it a valuable alternative to automatic direct sequencing, particularly for serial measurements.

Cyclooxygenase 2 expression in colorectal cancer with DNA mismatch repair deficiency

BACKGROUND

Cyclooxygenase 2 (COX-2) overexpression is a frequent but not universal event in colorectal cancer. It has been suggested that COX-2 protein expression is reduced in colorectal cancer with a defective mismatch repair (MMR) system, a phenomenon commonly associated with hereditary nonpolyposis colorectal cancer (HNPCC) but also present in up to 15% of sporadic tumors.

AIM

To assess COX-2 expression in a large series of fully characterized colorectal cancer patients with respect to the MMR system and to dissect the mechanisms responsible for altered COX-2 expression in this setting.

PATIENTS AND METHODS

MMR-deficient colorectal cancer were identified in a nationwide, prospective, multicenter study (EPICOLON project). Control MMR-proficient colorectal cancer patients were randomly selected. COX-2 expression was evaluated by immunohistochemistry. Personal and familial characteristics, as well as MSH2/MLH1 expression and germ line mutations, were evaluated.

RESULTS

One hundred fifty-three patients, 46 with MMR deficiency and 107 with MMR proficiency, were included in the analysis. Overall, tumor COX-2 overexpression was observed in 107 patients (70%). COX-2 overexpression was observed in 85 patients (79%) with a MMR-proficient system, but only in 22 patients (48%) with a MMR-deficient colorectal cancer (P < 0.001). The lack of COX-2 overexpression was independently associated with a MMR-deficient system (odds ratio, 3.89; 95% confidence interval, 1.78-8.51; P = 0.001) and a poor degree of differentiation (OR, 3.83; 95% CI, 1.30-11.31; P = 0.015). In the subset of patients with a MMR-deficient colorectal cancer, lack of COX-2 overexpression correlated with a poor degree of differentiation, no fulfillment of Amsterdam II criteria, absence of MSH2/MLH1 germ line mutations, presence of tumor MSH2 expression, and lack of tumor MLH1 expression. CpG island promoter hypermethylation of COX2 was observed in 6 of 18 (33%) tumors lacking COX-2 expression in comparison with 2 of 28 (7%) tumors expressing this protein (P = 0.04).

CONCLUSIONS

Up to half of MMR-deficient colorectal cancer do not show COX-2 overexpression, a fact observed almost exclusively in patients with sporadic forms. COX2 hypermethylation seems to be responsible for gene silencing in one third of them. These results suggest the potential utility of nonsteroidal anti-inflammatory drugs in HNPCC chemoprevention and may explain the lack of response of this approach in some sporadic tumors.

Analysis of HER2 by chromogenic in situ hybridization and immunohistochemistry in lymph node-negative breast carcinoma: Prognostic relevance

In patients with lymph node-negative breast carcinoma (LNNBC), the prevalence of HER2 overexpression and gene amplification and their prognostic value have not been extensively evaluated. We examined 162 patients with LNNBC with complete follow-up. Immunohistochemistry (IHC) for HER2, Ki67, and p53 was performed. HER2 gene status was analyzed by chromogenic in situ hybridization (CISH) and discordant cases by fluorescence in situ hybridization. HER2 overexpression was seen in 24.7% of cases (40/162) and amplification by CISH in 17.6% (28/159). Agreement between IHC and CISH was achieved in 147 (92.5%) cases. Amplification was seen in 21 (100%) of 21 (3+), 6 (35.3%) of 17 (2+), and 1 (0.6%) of 121 (0-1+) tumors. Fluorescence in situ hybridization detected 3 (1.8%) additional cases. HER2 overexpression and amplification were present in tumors of high grade, with necrosis and lymph-vascular invasion (LVI) (all P < .027). In addition, amplified tumors showed Ki67 of more than 20% and p53 overexpression (P < .05). By univariate analysis, shorter disease-free survival (DFS) and overall survival (OS) were seen for patients with tumors showing HER2 amplification, LVI, and Ki67 of more than 20% (P < .05) (Kaplan-Meier). However, the multivariate analysis (Cox regression) demonstrated only Ki67 as an independent prognostic factor for both DFS (P = .017) and OS (P = .010), and as a trend for HER2 gene status (OS, P = .087) and LVI (DFS, P = .11; OS, P = .063). We conclude that IHC is a reliable method for detecting HER2 expression that can be complemented by CISH in nondefinitive cases (2+). Moreover, CISH is a valuable tool for the assessment of HER2 gene status with potential prognostic value and, therefore, in clinical decision making for treatment of high-risk LNNBC.

Sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease) treated with 2-chlorodeoxyadenosine

Sinus histiocytosis with massive lymphadenopathy (SHML) or Rosai-Dorfman disease (RDD) is a rare but well-defined histiocytic proliferative disorder of unknown etiology that usually presents with cervical lymphadenopathy, fever, leukocytosis, and hypergammaglobulinemia in an otherwise healthy child. Although many patients undergo spontaneous remission, a subset of patients with systemic disease has a more serious course. For those patients with a poor outcome, steroids and chemotherapeutic agents such as etoposide or 6-mercaptopurine plus low dose methotrexate have been used. We present a child with a massive cervical lymphadenopathy treated with 2-chlorodeoxyadenosine (2-CdA, cladribine) after other approaches failed.

Mismatch repair status in the prediction of benefit from adjuvant fluorouracil chemotherapy in colorectal cancer

AIM

Some retrospective studies have shown a lack of benefit of 5-fluorouracil (5-FU) adjuvant chemotherapy in patients with mismatch repair (MMR) deficient colorectal cancer. Our aim was to assess if this molecular marker can predict benefit from 5-FU adjuvant chemotherapy. A second objective was to determine if MMR status influences short term survival.

METHODS

We included 754 patients with a median follow up of 728.5 days (range 1-1097). A total of 260 patients with stage II or III tumours received 5-FU adjuvant chemotherapy, according to standard clinical criteria and irrespective of their MMR status. A tumour was considered MMR deficient when either BAT-26 showed instability or there was loss of MLH1 or MSH2 protein expression.

RESULTS

At the end of the follow up period, 206 patients died and 120 presented with tumour recurrence. Sixty six (8.8%) patients had MMR deficient tumours. There were no significant differences in overall survival (MMR competent 72.1%; MMR deficient 78.8%; p = 0.3) or disease free survival (MMR competent 61.3%; MMR deficient 72.3%; p = 0.08). In patients with stage II and III tumours, benefit from 5-FU adjuvant chemotherapy was restricted to patients with MMR competent tumours (overall survival: chemotherapy 87.1%; non-chemotherapy 73.5%; log rank, p = 0.00001). Patients with MMR deficient tumours did not benefit from adjuvant chemotherapy (overall survival: chemotherapy 89.5%; non-chemotherapy 82.4%; log rank, p = 0.4).

CONCLUSIONS

Benefit from 5-FU adjuvant chemotherapy depends on the MMR status of tumours in patients with colorectal cancer. 5-FU adjuvant chemotherapy improves survival in patients with MMR competent tumours but this benefit from chemotherapy cannot be extended to patients with MMR deficient tumours.

Clinical performance of original and revised Bethesda guidelines for the identification of MSH2/MLH1 gene carriers in patients with newly diagnosed colorectal cancer: proposal of a new and simpler set of recommendations

Identification of individuals who should undergo hereditary nonpolyposis colorectal cancer (HNPCC) genetic testing is a critical and difficult issue. For this purpose, the National Cancer Institute outlined a set of recommendations, the Bethesda guidelines, which have recently been revised.

OBJECTIVE

To compare the clinical performance of original and revised Bethesda guidelines for the detection of MSH2/MLH1 gene carriers in patients with colorectal cancer.

METHODS

A total of 1,222 patients with newly diagnosed colorectal cancer were included in the EPICOLON study, a prospective, multicenter, nationwide epidemiology survey aimed at establishing the incidence of HNPCC in Spain (JAMA 2005; 293:1986-1994). Performance characteristics of the original and revised Bethesda guidelines were assessed with respect to the presence of MSH2/MLH1 germline mutations. Logistic regression analysis was performed to establish the most effective strategy.

RESULTS

Original or revised Bethesda guidelines were equivalent strategies in terms of sensitivity (100%vs 100%; ns), specificity (98.1%vs 97.9%; ns), and overall accuracy (98.1%vs 97.9%; ns), as well as positive (25.8%vs 24.2%) and negative predictive values (100%vs 100%). The most discriminating individual variables were criteria number 1 (i.e., fulfillment of the Amsterdam criteria; RR = 34.14; 95% CI = 6.85-170.16; p < 0.001) and number 2 (i.e., individuals with two HNPCC-related neoplasms; RR = 35.63; 95% CI = 4.83-262.6; p < 0.001) of the original guidelines, and criterion number 1 of the revised guidelines (i.e., colorectal cancer diagnosed under 50 yr of age; RR = 29.34; 95% CI = 3.81-225.96; p= 0.001). The aggregation of these three criteria was equivalent to both Bethesda guidelines in terms of sensitivity (100%) and negative predictive value (100%), but superior to the revised criteria regarding specificity (98.5%; p < 0.05), overall accuracy (98.5%; p < 0.05), and positive predictive value (30.8%).

CONCLUSIONS

Original and revised Bethesda guidelines are equivalent, highly effective criteria for the identification of MSH2/MLH1 gene mutation carriers in patients with newly diagnosed colorectal cancer. A new set of recommendations, based on a combination of some of their individual criteria, may provide additional advantages in terms of effectiveness.

Differential features of colorectal cancers fulfilling Amsterdam criteria without involvement of the mutator pathway

PURPOSE

Hereditary nonpolyposis colorectal cancer (HNPCC) is the commonest form of inherited colorectal cancer. Whereas it has been known that mismatch repair gene mutations are the underlying cause of HNPCC, an undetermined number of patients do not have these alterations. The main objectives of this study were to assess the relevance of clinically defined HNPCC patients without characteristic mutator pathway alterations and to identify their specific features.

EXPERIMENTAL DESIGN

This was a prospective, population-based, cohort that included 1,309 newly diagnosed colorectal cancer patients. Demographic, clinical, pathologic data and tumor DNA from probands as well as a detailed family history were collected. Microsatellite analysis and MLH1, MSH2, and MSH6 immunohistochemistry were done. Germ line MLH1 and MSH2 mutational analysis was done in all patients with evidence of MMR alterations.

RESULTS

Twenty-five patients (1.9%) fulfilled Amsterdam criteria of HNPCC but 15 (60%) of them did not have microsatellite instability and showed normal expression of MMR proteins. These patients presented mostly left-sided tumors without lymphocytic infiltrate; they were older, had fewer family members affected with colorectal or endometrial cancers, and more often fulfilled Amsterdam II criteria than HNPCC patients with microsatellite instability. Like unstable HNPCC patients, this group without mutator pathway alterations had a significant percentage of synchronous and metachronous adenomatous polyps and cancers.

CONCLUSIONS

We define an important group of HNPCC families with specific features, no evidence of mismatch repair deficiency, and an autosomal dominant trait with a lesser penetrance than HNPCC with deficiency.

[Perforation of the acalculous gallbladder in a renal transplant recipient with CMV infection]

We report the case of a renal transplant recipient who developed acute acalculous cholecyscitis resulting in gallbladder perforation. At admission CMV antigenemia was negative. Emergency laparatomy was performed and showed the gallbladder to be infarted with a perforation. The abdominal cavity contained two litres of sterile bilious fluid. The pathological report showed frequent endothelial cells contained intranuclear and intracitoplasmatic inclusion (fig. 1). Treatment with Ganciclovir iv was started after diagnosis, but a computerized tomography scan demonstrated severe acute pancreatitis (grade E. Baltazar). The patient developed multiorgan failure and died on 19th day after surgery. Necropsy showed cytomegalic inclusions in pancreas (fig. 2), gastrointerstinal tract, lung and graft. A necroticing pneumonia with Mycotic spores and hiphae was seen. Aspergillus was also observed in myocardium (fig. 3).

Accuracy of revised Bethesda guidelines, microsatellite instability, and immunohistochemistry for the identification of patients with hereditary nonpolyposis colorectal cancer

CONTEXT

The selection of individuals for hereditary nonpolyposis colorectal cancer (HNPCC) genetic testing is challenging. Recently, the National Cancer Institute outlined a new set of recommendations, the revised Bethesda guidelines, for the identification of individuals with HNPCC who should be tested for microsatellite instability.

OBJECTIVE

To establish the most effective and efficient strategy for the detection of MSH2/MLH1 gene carriers.

DESIGN, SETTING, AND PATIENTS

A prospective, multicenter, nationwide study (the EPICOLON study) in 20 hospitals in the general community in Spain of 1222 patients with newly diagnosed colorectal cancer between November 1, 2000, and October 31, 2001.

INTERVENTIONS

Microsatellite instability testing and MSH2/MLH1 immunostaining in all patients regardless of age, personal or family history, and tumor characteristics. Patients whose tumors exhibited microsatellite instability and/or lack of protein expression underwent MSH2/MLH1 germline testing.

MAIN OUTCOME MEASURES

Effectiveness and efficiency of both microsatellite instability testing and immunostaining, either directly or previous selection of patients according to the revised Bethesda guidelines, were evaluated with respect to the presence of MSH2/MLH1 germline mutations.

RESULTS

Two hundred eighty-seven patients (23.5%) fulfilled the revised Bethesda guidelines. Ninety-one patients (7.4%) had a mismatch repair deficiency, with tumors exhibiting either microsatellite instability (n = 83) or loss of protein expression (n = 81). Germline testing identified 11 mutations (0.9%) in either MSH2 (7 cases) or MLH1 (4 cases) genes. Strategies based on either microsatellite instability testing or immunostaining previous selection of patients according to the revised Bethesda guidelines were the most effective (sensitivity, 81.8% and 81.8%; specificity, 98.0% and 98.2%; positive predictive value, 27.3% and 29.0%, respectively) to identify MSH2/MLH1 gene carriers. Logistic regression analysis confirmed the revised Bethesda guidelines as the most discriminating set of clinical parameters (odds ratio, 33.3; 95% confidence interval, 4.3-250; P = .001).

CONCLUSION

The revised Bethesda guidelines constitute a useful approach to identify patients at risk for HNPCC. In patients fulfilling these criteria, both microsatellite instability testing and immunostaining are equivalent and highly effective strategies to further select those patients who should be tested for MSH2/MLH1 germline mutations.

Defective mismatch-repair colorectal cancer: clinicopathologic characteristics and usefulness of immunohistochemical analysis for diagnosis

The purpose of our study was to determine the usefulness of immunohistochemical analysis for the diagnosis of mismatch-repair (MMR) gene defective colorectal tumors and to describe their prevalence and clinicopathologic characteristics. We studied 172 cases. DNA was extracted from formalin-fixed, paraffin-embedded surgical samples, and microsatellite analysis was performed by polymerase chain reaction with BAT-26. The results were correlated with immunohistochemical analysis for hMLH1 and hMSH2. Microsatellite instability (MSI) was detected in 13 (7.6%) tumors, and all showed loss of protein expression of hMLH1 (11/13) or hMSH2 (2/13) (P < .000). Patients with MMR-defective tumors more frequently had poorly differentiated tumors (5/13 [38%] vs 18/159 [11.3%]; P = .02) located in the ascending colon (8/13 [62%] vs 30/159 [18.9%]; P < .0001) and a personal history of other neoplasms (4/13 [31%] vs 18/159 [11.3%]; P = .05). There were no differences in age, family history of cancer, or TNM stage. Immunohistochemical analysis seems to be a reliable method to detect most colorectal cancers with defective MMR genes.

Defective mismatch-repair colorectal cancer: clinicopathologic characteristics and usefulness of immunohistochemical analysis for diagnosis

The purpose of our study was to determine the usefulness of immunohistochemical analysis for the diagnosis of mismatch-repair (MMR) gene defective colorectal tumors and to describe their prevalence and clinicopathologic characteristics. We studied 172 cases. DNA was extracted from formalin-fixed, paraffin-embedded surgical samples, and microsatellite analysis was performed by polymerase chain reaction with BAT-26. The results were correlated with immunohistochemical analysis for hMLH1 and hMSH2. Microsatellite instability (MSI) was detected in 13 (7.6%) tumors, and all showed loss of protein expression of hMLH1 (11/13) or hMSH2 (2/13) (P < .000). Patients with MMR-defective tumors more frequently had poorly differentiated tumors (5/13 [38%] vs 18/159 [11.3%]; P = .02) located in the ascending colon (8/13 [62%] vs 30/159 [18.9%]; P < .0001) and a personal history of other neoplasms (4/13 [31%] vs 18/159 [11.3%]; P = .05). There were no differences in age, family history of cancer, or TNM stage. Immunohistochemical analysis seems to be a reliable method to detect most colorectal cancers with defective MMR genes.

Synchronous colorectal neoplasms in patients with colorectal cancer: predisposing individual and familial factors

PURPOSE

Patients with colorectal cancer have an increased risk for developing synchronous and metachronous neoplasms. However, besides those cases with inherited disorders predisposing to tumor multicentricity, it is unknown which patients are prone to this condition. This study was designed to identify individual and familial characteristics associated with the development of synchronous colorectal neoplasms in patients with colorectal cancer.

METHODS

During a one-year period, all patients with colorectal cancer attended in 25 Spanish hospitals were included. Exclusion criteria were colorectal cancer developed in the context of familial adenomatous polyposis or inflammatory bowel disease, refusal to participate in the study, incomplete family history, and inadequate examination of the colon and rectum. In addition to demographic, clinical, pathology, molecular (microsatellite instability status), and familial characteristics, presence of synchronous colorectal neoplasms (adenoma or carcinoma) were analyzed.

RESULTS

A total of 1,522 patients were included in the study. Synchronous colorectal neoplasms were documented in 505 patients (33.2 percent): adenoma (n = 411), carcinoma (n = 27), or both (n = 67). Development of these lesions was associated with male gender (odds ratio, 1.94; 95 percent confidence interval, 1.43-2.65), personal history of colorectal adenoma (odds ratio, 3.39; 95 percent confidence interval, 1.58-7.31), proximal location of primary tumor (odds ratio, 1.40; 95 percent confidence interval, 1.02-1.94), tumor TNM Stage II (odds ratio, 1.31; 95 percent confidence interval, 1.15-4.66), mucinous carcinoma (odds ratio, 1.89; 95 percent confidence interval, 1.19-2.99), and family history of gastric cancer (odds ratio, 2.03; 95 percent confidence interval, 1.17-3.52).

CONCLUSIONS

Based on individual and familial characteristics associated with synchronous colorectal neoplasms, it has been possible to identify a subgroup of patients with colorectal cancer prone to tumor multicentricity with potential implications on the delineation of preventive strategies.

Oncocytic Transformation in Pituitary Adenomas: Immunohistochemical Analyses of 65 Cases

Context.—Oncocytic change in pituitary adenomas has been evaluated by electron microscopy and more recently by immunohistochemistry. The clinical significance of this change is not well known, although some reports suggest a relationship with more aggressive behavior.

Objective.—To assess the frequency of oncocytic change in pituitary adenomas and to correlate this finding with clinicopathologic factors.

Design.—We studied oncocytic change in a series of 65 pituitary adenomas by immunohistochemistry. According to the percentage of oncocytic cells stained by antimitochondrial antibody, adenomas were classified in 3 groups: 50% or more, 10% to 49%, and 1% to 9% of oncocytic cells.

Results.—Eight cases (12.3%) showing at least 50% of oncocytic cells were classified as oncocytic adenomas: 6 were gonadotroph adenomas and 2 were null-cell adenomas. Among the remaining cases, 9 (14%; all gonadotroph adenomas) showed 10% to 49% oncocytic cells, and in 14 cases (21.5%; 5 gonadotroph adenomas, 6 somatotroph adenomas, 2 corticotroph adenomas, and 1 thyrotroph adenoma) between 1% and 9% were shown. Patients with adenomas that showed oncocytic change presented more frequently at a higher average age (P = .05), but no relationship with extrasellar extension or proliferative activity measured by Ki-67 was observed. In somatotroph adenomas, cases with oncocytic change showed higher percentages of Ki-67 (P = .05) but no correlation with extrasellar extension or cytokeratin staining (dot pattern versus perinuclear) was found.

Conclusion.—Adenomas with oncocytic change present more frequently in older patients, but they are not clinically more aggressive. In addition, somatotroph adenomas with oncocytic cells show similar cytokeratin pattern and higher proliferative activity, which is not correlated with local aggressiveness.

Tissue and tumor mosaicism of the myotonin protein kinase gene trinucleotide repeat in a patient with multiple basal cell carcinomas associated with myotonic dystrophy

We describe the third case (to our knowledge) of multiple basal cell carcinoma associated with myotonic dystrophy and carry out a genetic study of the tumor comparing it with healthy skin. We consider that our results show that this association might be not a purely random phenomenon and that the particular genetic characteristics of this disorder might have a role in the pathogenesis of the tumor.

Frequency of hereditary non-polyposis colorectal cancer and other colorectal cancer familial forms in Spain: a multicentre, prospective, nationwide study

BACKGROUND

Colorectal cancer is the third leading cause of cancer mortality in Western countries. Hereditary nonpolyposis colorectal cancer is the most common type of hereditary colorectal cancer, but its incidence remains controversial, ranging from 1 to 5%.

OBJECTIVE

This present prospective, multicentre, nationwide study was aimed at compiling prominent epidemiological and clinical data with respect to hereditary non-polyposis colorectal cancer and other familial colorectal cancer forms in Spain, where information is lacking.

METHODS

All patients with a de-novo diagnosis of colorectal cancer and who attended between November 2000 and October 2001 in 25 hospitals all over Spain were registered. Demographic, clinical and tumour-related characteristics of probands, and detailed family history, were obtained.

RESULTS

A total of 1872 colorectal cancer patients were included. Clinical diagnosis of hereditary non-polyposis colorectal cancer was established in 46 (2.5%) patients according to the Amsterdam II criteria. Comparison between patients fulfilling either the Amsterdam I or the Amsterdam II criteria revealed no differences with respect to demographic, clinical and tumour-related characteristics. A total of 504 (27.0%) patients had a family history of hereditary non-polyposis colorectal cancer-related neoplasm not fulfilling the Amsterdam criteria (familial colorectal cancer), while 360 (19.2%) patients fulfilled at least one of the Bethesda's criteria.

CONCLUSION

These clinicoepidemiological data provide a more accurate characterization of hereditary non-polyposis colorectal cancer and other familial colorectal cancer forms in Spain, with potential implications in preventive strategies.

Mesectodermal leiomyoma of ciliary body

A 37-year-old woman had a mass in her left ocular globe. Uveal melanoma was suspected and enucleation was performed. Microscopically, the lesion proved to be a typical case of mesectodermal leiomyoma of the ciliary body. According to some authors, the peculiar neural appearance of this tumor could be the reflection of its probable origin from mesectodermal smooth muscle. Immunohistochemical analysis showed reactivity for muscle-specific actin and negativity for desmin, S-100 protein, HMB-45, EMA, and GFAP. Our results do not support the proposed neuroectodermical origin of this tumor, since coexpression of muscular and neural markers was not observed.

[Toxic hepatitis associated with tamoxifen use. A case report and literature review]

Tamoxifen is an antiestrogenic drug that acts by binding to the estrogen receptor. The drug is used as a co-adjuvant treatment in advanced breast cancer expressing the oestrogen-receptor protein. Clinical trials of tamoxifen have shown its efficacy in reducing mortality and recurrence rates over a five-year treatment. Cases of tamoxifen-associated hepatotoxicity have been described, including cholestasis with or without cytolysis and steatohepatitis. We report the case of a female patient who developed hepatic alterations while undergoing continuous tamoxifen treatment. We also present an overview of similar cases published to date and comment on the advisability of continuing or suppressing this treatment in patients with hepatotoxicity or after a five-year treatment period.

Phyllodes tumor of the breast with actin inclusions in stromal cells: diagnosis by fine-needle aspiration cytology

The occurrence of hyaline inclusions in stromal cells in fibroepithelial tumors of the breast is very uncommon. These inclusions, characteristic of infantile digital fibromatosis, are comprised of actin filaments. This report illustrates a case of a benign phyllodes tumor of the breast with inclusion bodies, identified by fine-needle aspiration. Histologically, many of the stromal cells contained round intracytoplasmic inclusions, with positivity for smooth muscle actin.

Human immunodeficiency virus infection in pregnant women, transmission and zidovudine therapy

OBJECTIVE

To determine the rate of mother to child transmission of HIV infection in women treated with zidovudine (ZDV).

PATIENTS AND METHODS

A consecutive series of 52 HIV-positive pregnant women who either received antenatal care or delivered at our institution. Forty-three women were known to be HIV positive before delivery. Forty were treated with ZDV, 36 intravenously. Twelve had no antenatal care and one refused antenatal treatment. All neonates were treated with ZDV.

RESULTS

The HIV transmission rate in children born to mothers treated with ZDV was 6.6%. This compares with a transmission rate of 14% before we used ZDV. All three mothers who transmitted infection had low compliance, initiated therapy late in pregnancy or had advanced disease.

CONCLUSION

Our experience supports the idea that ZDV treatment has reduced HIV transmission rate.

[Validity of the declared tobacco consumption in pregnancy]

OBJECTIVES

To analyse the relationship between the stated consumption of tobacco by pregnant women who say they smoked before pregnancy and the levels of cotinine in their urine at the start and end of pregnancy.

DESIGN

Observational, longitudinal study.

PARTICIPANTS

During 1997.

STUDY GROUP

147 pregnant women at their first pre-natal visit to outclinics of the Hospital del Mar.

CONTROL GROUP

50 non-smoker pregnant women monitored during their pregnancy.

MEASUREMENTS AND MAIN RESULTS

The numbers of cigarettes per day that they said they smoked on their first monitoring visit to our centre and at the last attendance before giving birth were recorded. Cotinine levels in the urine samples taken on these visits were measured. Mean cotinine in pregnant women who said they had given up smoking was higher than in non-smokers. There was a statistically significant linear relationship between the number of cigarettes stated and cotinine levels at the first and last pregnancy monitoring visits, as well as between the variation in the number of cigarettes and cotinine levels at these two visits. The negative predictive value of what they said about their tobacco habit was 82.9%.

CONCLUSIONS

There was a certain under-declaration by pregnant smokers, although their statements of consumption and cotinine levels correlated closely. The under-declaration did not increase despite reiterated advice to stop smoking, which means that, despite its limitations, it could be a useful indicator for evaluating the effect of interventions aimed at stopping women smoking during pregnancy.