Stevens-Johnson Syndrome and Fatal Pulmonary Toxicity to Combination Chemotherapy Containing Bleomycin: A Case Report

Bleomycin is a commonly used anticancer agent; in particular, it is an important component of multidrug regimens for germ cell tumors. The limiting toxicity of bleomycin is represented by pulmonary interstitial fibrosis; mucocutaneous side effects are common, but usually harmless. We describe a case of a young girl who developed Stevens-Johnson syndrome following the administration of bleomycin in a three-drug regimen containing vinblastine and cisplatin, for an ovarian immature teratoma. The severe dermatologic toxicity was kept under control, but a rapidly evolving respiratory insufficiency due to lung fibrosis developed soon thereafter and caused the patient's death.

The natural history of colorectal adenomas and early cancer

Adenomas represent the morphological precursors of the vast majority of colorectal cancers: although every adenoma has the capacity of malignant evolution, most adenomas stabilize their progression or even regress. Pathological factors are predictive of the natural history of adenomas in terms of potential and time interval for becoming malignant. Regression of adenomas is histologically well established, but it is thought to be a dynamic process, with cycling phases of regression and growth. Colorectal carcinoma invading the submucosa but not the muscular layer represents the earliest form of clinically relevant colorectal cancer. Grade of differentiation of carcinoma, lymphovascular invasion, and state of the resection margin predict the risk of metastasis. Microstaging of invasive cancer together with tumuor budding allow the metastatic risk to be further stratified into minimal, low, and high. Two distinct profiles are identifiable in the natural history of cancerous adenomas: blocking the growth of early cancer and allowing its progression towards advanced cancer. Thus, biomarkers to distinguish between progressive and non-progressive pT1 neoplasia are needed.

European guidelines for quality assurance in colorectal cancer screening and diagnosis: overview and introduction to the full supplement publication

Population-based screening for early detection and treatment of colorectal cancer (CRC) and precursor lesions, using evidence-based methods, can be effective in populations with a significant burden of the disease provided the services are of high quality. Multidisciplinary, evidence-based guidelines for quality assurance in CRC screening and diagnosis have been developed by experts in a project co-financed by the European Union. The 450-page guidelines were published in book format by the European Commission in 2010.  They include 10 chapters and over 250 recommendations, individually graded according to the strength of the recommendation and the supporting evidence. Adoption of the recommendations can improve and maintain the quality and effectiveness of an entire screening process, including identification and invitation of the target population, diagnosis and management of the disease and appropriate surveillance in people with detected lesions. To make the principles, recommendations and standards in the guidelines known to a wider professional and scientific community and to facilitate their use in the scientific literature, the original content is presented in journal format in an open-access Supplement of Endoscopy. The editors have prepared the present overview to inform readers of the comprehensive scope and content of the guidelines.

DNA-ploidy analysis within selected regions of colorectal adenomas containing carcinoma

In order to better understand the relationship of DNA ploidy, dysplasia, early cancer, and colorectal tumor progression, 11 colorectal adenomas containing carcinoma invading the submucosa were investigated using DNA flow cytometry. Multiple frozen samples were taken from the selected sectors corresponding to adenoma tissue with low-grade dysplasia, high grade dysplasia and early cancer. Sampling accuracy was performed under histologic examination by multiple cryostatic sections. Data were compared with previously reported results in non-cancerous adenomas and advanced carcinomas. Incidence of DNA aneuploidy among the dysplastic regions of the adenomas containing carcinomas resulted higher than that observed in non-cancerous adenomas (p=0.02). Furthermore, among the DNA aneuploid populations, the frequency of clones with high DNA Index (DI>1.3) was slightly higher in adenomas with cancer than in adenomas without cancer (p=0.07). We suggest that differences may exist in DNA aneuploidy evolution between these two types of lesions. In early cancer, the near-diploid clones were 57% with respect to 18% (p=0.01) in advanced cancer since in this latter case the majority of the DNA abnormal clones were in the near-hypertriploid region (82%). Thus, the acquisition of the invasive phenotype appears to be linked with the expansion and stabilization of high DNA aneuploid clones. Further analysis on a larger number of cases of adenomas containing carcinoma are necessary to validate these interpretations.

European guidelines for quality assurance in colorectal cancer screening and diagnosis. First Edition--Annotations of colorectal lesions

Multidisciplinary, evidence-based guidelines for quality assurance in colorectal cancer screening and diagnosis have been developed by experts in a project coordinated by the International Agency for Research on Cancer. The full guideline document covers the entire process of population-based screening. It consists of 10 chapters and over 250 recommendations, graded according to the strength of the recommendation and the supporting evidence. The 450-page guidelines and the extensive evidence base have been published by the European Commission. The chapter on quality assurance in pathology was supplemented by an annex describing in greater detail some issues raised in the chapter, particularly details of special interest to pathologists. The content of the annex is presented here to promote international discussion and collaboration by making the issues discussed in the guidelines known to a wider professional and scientific community.

European guidelines for quality assurance in colorectal cancer screening and diagnosis. First Edition--Quality assurance in pathology in colorectal cancer screening and diagnosis

Multidisciplinary, evidence-based guidelines for quality assurance in colorectal cancer screening and diagnosis have been developed by experts in a project coordinated by the International Agency for Research on Cancer. The full guideline document covers the entire process of population-based screening. It consists of 10 chapters and over 250 recommendations, graded according to the strength of the recommendation and the supporting evidence. The 450-page guidelines and the extensive evidence base have been published by the European Commission. The chapter on quality assurance in pathology in colorectal cancer screening and diagnosis includes 23 graded recommendations. The content of the chapter is presented here to promote international discussion and collaboration by making the principles and standards recommended in the new EU Guidelines known to a wider professional and scientific community. Following these recommendations has the potential to enhance the control of colorectal cancer through improvement in the quality and effectiveness of the screening process, including multi-disciplinary diagnosis and management of the disease.

CD31 and CD34 expression as immunohistochemical markers of endothelial transdifferentiation in human cutaneous melanoma

Introduction: Vasculogenic mimicry, as previously described in aggressive melanoma, is characterized by the de novo generation of intratumoral patterned vascular channels, composed of PAS-positive basement membrane in the absence of endothelial cells, providing additional microcirculation, in support to the classic tumoral angiogenesis. Methods: We investigated the immunohistochemical expression of two endothelial markers, CD31 and CD34, in tumoral cells of 60 melanomas (45 primary cutaneous and 15 metastatic) as possible evidence of vasculogenic mimicry. In addition we investigated the relationship between CD31 and CD34 expression and three pathological markers such as Clark’s level, and skin ulceration, predictive of melanoma’s aggressive behaviour, and mitotic index. Results: No cases of common melanocytic nevi immunoreacted with CD31 or CD34. Random CD31 immunoreactivity was present in 6% of Clark’s level I/II, 50% of Clark's level III and 80% Clark's level IV/V. CD34 was negative in Clark's level I/II but randomly stained the 20% and 55% of level III and IV/V respectively. 66% (10/15) of metastatic melanomas were CD31 positive showing a canalicular immunostaining pattern, conversely CD34 expression was never found. 7/8 cutaneous ulcerated melanomas immunostained for CD31 and 4/8 for CD34. CD31 immunostained 88% high/intermediate MI, and 53% of low MI melanomas. CD34 decorated the 29% of high/intermediate and 38% of low MI melanomas. Conclusions: CD31 and CD34 immunoreactivity closely parallel both the different morphologic steps of melanocytic tumor progression and the presence of histological parameters related to the aggressive behaviour. Their expression could be related to endothelial transdifferentiation of melanoma cells although a consequent functional role has not been demonstrated yet.

Somatic mutations of EGFR signal transducers and expression of tumor suppressor PTEN in biliary tract carcinoma

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Background: Biliary tract carcinomas express EGFR and are potential candidates to EGFR target therapies. We recently described somatic mutations of EGFR that can enhance MAPK or Akt activation (Clin Cancer Res, 2006). Some of them are identical to those previously reported to confer sensitivity to some tyrosine kinase inhibitors (TKIs) like erlotinib or gefitinib in lung cancer. Here we report a molecular analysis of EGFR transducers potentially involved in TKI response. Methods: In 49 samples of biliary tract carcinoma we performed mutational analysis of exons from 18 to 21 of EGFR, exons 9 and 20 of phosphatidylinositol 3’-kinase (PI3K), exon 2 of K-Ras, exon 15 of B-Raf and exons from 5 to 8 of PTEN. Nuclear PTEN expression was analyzed by immunohistochemistry and the expression in cancer cells was compared to that of normal cholangiocites. Results: Mutations of EGFR have been detected in 7 out of 49 samples (14.3%). One of them was a new stop-codon mutation. Five hotspot mutations of PI3K (codon 545, 546, 1048 and 1059) were found in 4 cases (8.2%); 3 cases (6.1%) had single mutations in K-Ras and 4 (8.2%) had the V599E mutation in B-Raf. In some samples, mutations of multiple trasducers were present simultaneously. PI3K mutations were significantly more frequent in EGFR mutated samples compared to wild type (28% vs. 4.7% respectively, p<0.05). A single F271L mutation of PTEN was observed (2%). We did not find loss of nuclear PTEN in biliary tract carcinoma cells; rather, a stronger labelling intensity (score 2+ or 3+) was present in biliary tract carcinoma compared to normal cholangiocites (score 1+). Moreover, the median percentage of PTEN labeled nuclei in tumor cells was 31.8%, but in samples with activating EGFR mutation was 60%, suggesting that a compensatory change in the level of the phosphatase might counteract the EGFR activition. Conclusions: These results corroborate our previous finding of EGFR pathway activation in EGFR mutated biliary tract carcinoma and suggest that an accurate analysis of the entire series of EGFR transducers may be done before planning treatments with TKIs.

No significant financial relationships to disclose.

Impact of surgery on the development of duodenal cancer in patients with familial adenomatous polyposis

PURPOSE

Precancerous duodenal lesions in patients with familial adenomatous polyposis can be detected with duodenoscopy and treatment may prevent the development of cancer. We proposed to determine the frequency, natural history, cumulative risk, and risk factors of the precancerous duodenal lesions in a series of patients diagnosed in northern Italy.

METHODS

A prospective, endoscopic, follow-up protocol was performed in 50 patients examined by gastroduodenoscopy at two years of interval or less. The presence and severity of precancerous lesions of the duodenal mucosa were evaluated by Spigelman score. Twenty-five patients (50 percent) had proctocolectomy and ileoanal anastomosis, 15 (30 percent) had colectomy and ileorectal anastomosis, and 5 (10 percent) had proctocolectomy and definitive ileostomy from 0 to 3 years before the admission to the surveillance program. All patients showed more than a thousand adenomas in the colorectal mucosa. No patients with attenuated polyposis were found.

RESULTS

At the first endoscopy, duodenal adenomas could be detected in 19 of 50 patients (38 percent), whereas at the end of the follow-up, 43 (86 percent) had duodenal lesions. The final mean Spigelman score increased during the follow-up period (P<0.001 respect to baseline values). No duodenal cancer could be detected. Eleven patients had or developed severe precancerous duodenal lesions (Stage IV) treated with endoscopic or surgical resection. The distribution of patients with Stage IV according to the surgery of the colon was: 2 of 25 treated with ileoanal anastomosis and 8 of 15 with ileorectal anastomosis (P=0.0024, Fisher's exact test).

CONCLUSIONS

Patients with familial adenomatous polyposis are at risk of significant neoplasia. The natural history of precancerous lesions might be related to surgical treatment of colorectal neoplasms.

Serum bile acids, programmed cell death and cell proliferation in the mucosa of patients with colorectal adenomas

BACKGROUND

Deoxycholic acid induced programmed cell death and an imbalance with cell proliferation may favour colorectal tumourigenesis according to 'in vitro' studies, but information is lacking on the relationships occurring 'in vivo' in humans.

AIMS

To evaluate whether serum deoxycholic acid is associated with programmed cell death and cell proliferation in colonic mucosa.

METHODS

In 10 patients with colorectal adenomas, we measured fasting serum levels of bile acids; and, in normal colonic mucosa, programmed cell death by the TUNEL technique and cell proliferation by immunohistochemical staining with anti-Ki67. Total and compartmental indices for both activities were calculated.

RESULTS

Among serum bile acids, only total deoxycholic acid (median: 0.89 micromol/L +/- 0.54 95% CI), showed a significant positive correlation with the total and basal compartments PCD Index (r = 0.68, p < 0.05). Total proliferation index showed no correlation with either total PCD Index, or bile acids. Within the median compartment of the crypt, cell proliferation was negatively associated with all unconjugated bile acids.

CONCLUSIONS

The positive association between deoxycholic acid and programmed cell death in the basal compartment of the crypt, and the negative association of cell proliferation and unconjugated bile acids in the median compartment, do not seem to support the co-carcinogenic effect of deoxycholic acid.

Malignant adenoma: diagnosis, staging, risk factors, lymph node involvement and problems of sampling

Colorectal adenoma containing invasive carcinoma corresponds to a carcinoma invading the submucosa and represents the earliest form of clinically relevant colon cancer. Despite the generally favourable course after endoscopic removal, a limited risk of developing lymph node metastases still exists and the correct histologic assessment of malignant polyps can help in defining the evolutive potential. At present, histopathologic parameters alone determine whether a high (35%) or low (7%) risk of nodal metastases exists and the most relevant diagnostic criteria are the grade of differentiation of invasive adenocarcinoma, vascular invasion, the level of invasion of carcinomatous cells and the status of the resection margin.

Somatic alterations of the androgen receptor CAG repeat in human colon cancer delineate a novel mutation pathway independent of microsatellite instability

The human androgen receptor gene contains a polymorphic CAG repeat region ranging from 8 to about 35 repeats in the normal human population. The repeat length is inversely related to the transactivation potential of the receptor. We have analyzed the repeat length in 50 sporadic colon cancer samples in comparison to surrounding healthy mucosa and have found somatic reductions of up to 10 repeats in 5 cases (10%), 3 of which were complex, probably involving both alleles. Alterations occurred in tumors with and without microsatellite instability indicating that they follow an independent mutation pathway. The similar repeat of the huntingtin gene did not show any somatic alterations in the same cases. No correlation to sex, tumor stage, location, or histology was evident. In the tumors that showed somatic reductions, the reduced allele was present in at least half of the cells and thus in most, if not all, of the tumor component of the sample. Somatic reductions of the androgen receptor CAG repeat thus occur frequently, through a pathway distinct from microsatellite instability and early during colon carcinogenesis. The receptor is expressed in most normal and neoplastic tissue samples analyzed. Apparent growth selection of cells bearing shortened AR alleles suggests that androgens contribute to colon carcinogenesis in a yet unknown way.

Preclinical mouse models for cancer chemoprevention studies

To aid in identifying the ability of chemopreventive agents to inhibit tumor development, new preclinical in vivo rodent models have recently been developed. Some of the models contain targeted mutations capable of increasing the incidence and progression of neoplastic lesions, whereas in other models dietary nutrients induce preneoplastic lesions in normal mice. These new preclinical models are assisting the analysis of genetic and environmental factors leading to neoplasia, and clinical studies to evaluate the chemopreventive efficacy of specific nutrients and pharmacological agents.

Programmed cell death, proliferating cell nuclear antigen and p53 expression in mouse colon mucosa during diet-induced tumorigenesis

Western-style diets (WDs) trigger and sustain the early phases of tumorigenesis in mouse colon, and when continued throughout the life span lead to the development of dysplastic crypts. In order to evaluate the roles both of cell proliferation and programmed cell death (PCD) in WD-induced tumorigenesis, immunohistochemical detection of proliferating nuclear antigen (PCNA), in situ end labeling (TUNEL) of DNA breaks, and p53 protein were carried out in mouse colonic mucosa during prolonged feeding of two WDs. PCNA Labeling Index of colonic crypts was significantly higher in WD-treated animals than in controls only at the beginning of the nutritional study, the gap rapidly bridged by increased cell proliferation spontaneously occurring in the colonic mucosa during aging. A transient early homeostatic activation of PCD at the base of the crypt also was observed in WD groups. No changes in PCD were seen in the upper third of the crypt or in surface epithelium throughout the study, indicating that PCD in that colonic crypt segment produces a constant flux of cell loss, uninfluenced by homeostatic fluctuations. A major finding was an irreversible, progressive, age-related decline of PCD at the crypt base in both control and treated animals that occurred during the second half of the rodents' life span. p53 protein was not immunohistochemically detected, suggesting that neither overexpression of wild-type nor mutated forms of the protein are involved in the above mentioned changes.

Small bowel tumors and polyposis syndromes

Tumors of the small bowel are uncommon and seldom suspected on a clinical basis. Together with the relative inaccessibility of the small bowel to endoscopic investigation, the rarity of these tumors undoubtedly delays the diagnosis. Small bowel tumors may be an interesting field of application for enteroscopy, which now can be readily performed with dedicated enteroscopic evaluation in patients with suspected small bowel neoplasia could improve prognosis and treatment. Enteroscopy may also play an important role in the surveillance of inherited polyposis syndromes, as in other precancerous condition of the small bowel. In Peutz-Jeghers syndrome it may reduce polyp-induced complications and improve planning for surgery; in familial adenomatous polyposis it may contribute to preventing upper gastrointestinal tract cancer.

K-ras2 activation and genome instability increase proliferation and size of FAP adenomas

The possible role of K-ras2 mutations and aneuploidy toward increase of proliferation and adenoma size in Familial Adenomatous Polyposis (FAP) adenomas is not known. The present study addresses these issues by investigating 147 colorectal adenomas obtained from four FAP patients. The majority of adenomas had size lower than or equal to 10 mm (86%), low grade dysplasia (63%), and were preferentially located in the right colon (60%). Normal mucosa samples were obtained from 19 healthy donors. Three synchronous adenocarcinomas were also investigated. K-ras2 mutation spectrum was analysed by PCR and Sequence Specific Oligonucleotide (SSO) hybridization, while flow cytometry (FCM) was used for evaluating degree of DNA ploidy and S-phase fraction. Overall, incidences of K-ras2 mutations, DNA aneuploidy and high S-phase values (>7.2%) were 6.6%, 5.4% and 10.5%, respectively. In particular, among the adenomas with size lower than 5 mm, K-ras2 mutation and DNA aneuploidy frequencies were only slightly above 1%. Statistically significant correlations were found between K-ras2 and size, DNA ploidy and size and K-ras2 and S-phase (p < 0.001). In particular, among the wild type K-ras2 adenomas, high S-phase values were detected in 8% of the cases versus 57% among the K-ras2 mutated adenomas (p = 0.0005). The present series of FAP adenomas indicates that K-ras2 activation and gross genomic changes play a role toward a proliferative gain and tumour growth in size.

Specific K-ras2 mutations in human sporadic colorectal adenomas are associated with DNA near-diploid aneuploidy and inhibition of proliferation

Recent studies indicate that p21ras proteins mediate their multiple cell functions through interactions with multiple effectors and that the number of new effectors is growing. We recently reported that K-ras2 mutations in human colorectal adenomas were associated with chromosome instability and proliferation changes. In the present study, we extend these previous observations. Hereditary and multiple (n > or = 5) adenomas and adenomas with early cancer were excluded. Dysplasia was moderate in 91 cases and high in 25, and the median adenoma size was 1.5 cm. K-ras2 spectrum analysis was done by sequence-specific oligonucleotide hybridization using nuclear suspensions provided by analysis and sorting of multiparameter flow cytometry. In particular, tissue inflammatory cells were separated for DNA diploid tumors, whereas DNA aneuploid epithelial subclones were analyzed separately. K-ras2 mutations and DNA aneuploidy were both detected in 29 of 116 (25%) cases. DNA aneuploid index was in the near-diploid region in the majority of cases. DNA aneuploidy was strongly associated with G-->C/T transversions. An association was also found between low S-phase values and G-->A transitions. These findings were confirmed using multivariate logistic regression analysis to account for the effects of size, dysplasia, site, type, age, and sex. These data suggest that specific K-ras2 mutations in a subgroup of human sporadic colorectal adenomas play a role in chromosome instability and, contrary to expectations, are associated with inhibition of proliferation.

Gastrointestinal stromal tumor, uncommitted type, with monosomies 14 and 22 as the only chromosomal abnormalities

Karyotypic analysis of a gastric stromal tumor with the histologic and immunohistochemical features of a malignant, uncommitted lesion revealed clonal monosomies of chromosomes 14 and 22. Such changes, together with loss of chromosomes 15 and 18, as well as structural rearrangements involved chromosome 1, have been previously reported in gastrointestinal stromal tumors with smooth muscle differentiation. We suggest that monosomies of chromosomes 14 and 22 are early events in the malignant transformation of the mesenchymal cell-originating gastrointestinal stromal tumors.

Correlation between 1p deletions and aneusomy in human colorectal adenomas

Human sporadic colorectal adenomas are characterized by a relatively high occurrence of aneuploidy. Similarly, 1p deletions have been reported to be an early event in colorectal tumorigenesis, while chromosome 7, 17 and 18 gain/losses were also found. The present study investigated 1p deletions, the numerical aberrations of chromosomes 1, 7, 17 and 18, and the nuclear DNA content as obtained by flow cytometry in a series of 34 human sporadic colorectal adenomas. From these adenomas, 51 intra-adenoma regions were microdissected according to 2 degrees of dysplasia and presence of foci of early cancer. Isolated epithelial nuclei were analyzed by fluorescence in situ hybridization interphase cytogenetics using centromeric probes for chromosomes 7, 17 and 18 and, in a double-target analysis, a centromeric probe for chromosome 1 simultaneously with a telomeric probe mapping to the 1p36 band. Aneuploidy incidence due to presence of numerical aberrations for at least one among the investigated chromosomes and/or abnormal flow-cytometric DNA content was 35%, while 1p deletion incidence was 38%. The correlation of 1p deletions with aneuploidy was statistically highly significant (p = 0.003), suggesting that loss of genes in this region may be implicated in chromosome instability.

Inherited and acquired risk factors in colonic neoplasia and modulation by chemopreventive interventions

The progressively abnormal development of epithelial cells prior to tumor development leads to widely differing chemopreventive approaches. The diversity of these approaches has resulted in different assays to measure the activities of the agents. To apply these assays to preclinical studies, we have developed rodent models in which different stages of evolution of colonic neoplasia are expressed. In one model mice carrying a truncated Apc allele with a nonsense mutation in exon 15 have been generated by gene targeting and embryonic stem cell technology (Apc 1638 mice). These mice develop multiple gastrointestinal lesions including adenomas and carcinomas, focal areas of high grade dysplasia (FAD) and polypoid hyperplasias with FADS. The incidence of inherited colonic neoplasms has now been modulated by a chemopreventive regimen. Colonic lesions significantly increased in Apc 1638 mice on a Western-style diet, compared to Apc 1638 mice on AIN-76A diet which has lower fat content and higher calcium and vitamin D. These studies have also been carried out in normal mice, and have demonstrated without any chemical carcinogen that a Western-style diet induced colonic tumorigenesis. Modulation of cell proliferation has also been induced by Western-style diets in other organs including mammary gland, pancreas and prostate. These findings are leading to the development of new preclinical models for evaluating the efficacy of many classes of chemopreventive agents.

Microsatellite instability is associated with the histological features of the tumor in nonfamilial colorectal cancer

Replication errors (RERs) at microsatellite loci were examined in 46 specimens of nonfamilial colorectal cancer. Somatic microsatellite alterations in at least two genetic loci, D11S904, D13S175, D2S123, and D10S197, consistent with a RER(+) phenotype were found in four cases (8.7%). Six additional cases (13%) showed alterations at a single locus. Mucinous differentiation was observed in 3 of 4 (75%) adenocarcinomas with a RER(+) phenotype and only in 19% (8 of 42) of RER(-) adenocarcinomas (P < 0.05). A distinct cap of inflammatory cells at the advancing edge of the tumor and Crohn's-like reaction in peritumoral stroma were histologically identified in 50 and 25% of RER(+) and in 5 and 0% of RER(-) tumors, respectively (P < 0.05). Also, the plexiform pattern of growth of carcinoma turned out to be significantly associated with the RER(+) phenotype (P < 0.05). Mucinous differentiation and stromal inflammatory reactions are frequent features of hereditary nonpolyposis colorectal cancer in which germ-line mutations of mismatch repair genes cause genetic instability. Our results indicate that a link exists between such histological features and somatic genetic instability consistent with a RER(+) phenotype also in nonfamilial colorectal cancer.

Apoptosis, cell replication, and Western-style diet-induced tumorigenesis in mouse colon

In this study, feeding Western-style diets (WDs) to mice for a duration of two years without any chemical carcinogen led to the development of gross colonic lesions that were histologically classified as dysplastic crypts and focal hyperplasias with or without atypical nuclei. To better understand early biological events contributing to the development of colonic neoplasia, grossly normal colonic mucosa was investigated; mitotic and apoptotic colonic epithelial cells, atypical mitosis, and atypical nuclei were studied. A significant and transient increase of mitotic activity in the basal and intermediate portions of the colonic crypts was seen in young mice after feeding them the WDs. This was accompanied by diffuse activation of apoptosis of the colonic epithelial cells. In the middle of the rodents' life span, after administration of both the WDs and control diet, the rodents developed a marked depletion of apoptotic epithelial cells in the mid-region of the colonic crypts; this was followed by the expansion of an epithelial cell population containing atypical nuclei, and the emergence of the gross lesions noted above. With this sequence of events, prolonged feeding of WDs to mice produced single-crypt dysplastic lesions and focal hyperplasias indicative of tumorigenesis.

Deletions at chromosome 1p by fluorescence in situ hybridization are an early event in human colorectal tumorigenesis

BACKGROUND & AIMS

Deletions at chromosome 1p have been observed frequently in human colorectal adenocarcinomas, suggesting that loss of genes in this chromosome arm is relevant for tumorigenesis. The aim of this study was to investigate whether 1p deletions are already present in adenomas within selected foci of dysplasia and early cancer using two-color fluorescence in situ hybridization.

METHODS

Fifty-one sectors characterized by low- and high-grade dysplasia and early cancer were microdissected from 34 adenomas, and isolated epithelial nuclei were subjected to hybridization with probes to the telomeric and centromeric regions of chromosome 1.

RESULTS

Deletions of 1p were detected in 13 of 34 adenomas (38%). In particular, low/moderate and high dysplasia and foci of early cancer had 1p deletion frequencies of 31%, 44%, and 50%, respectively.

CONCLUSIONS

Compared with classic cytogenetics, fluorescence in situ hybridization seems to be a particularly useful methodology to detect 1p deletions in human colorectal adenomas. The present findings indicate that loss of genes from the 1p chromosome arm may play an important role during the early steps of the colorectal carcinogenesis.

Inherited and acquired risk factors in colonic neoplasia and modulation by chemopreventive interventions

The progressively abnormal development of epithelial cells prior to tumor development leads to widely differing chemopreventive approaches. The diversity of these approaches has resulted in different assays to measure the activities of the agents. To apply these assays to preclinical studies, we have developed rodent models in which different stages of evolution of colonic neoplasia are expressed. In one model mice carrying a truncated Apc allele with a nonsense mutation in exon 15 have been generated by gene targeting and embryonic stem cell technology (Apc 1638 mice). These mice develop multiple gastrointestinal lesions including adenomas and carcinomas, focal areas of high grade dysplasia (FAD) and polypoid hyperplasias with FADS. The incidence of inherited colonic neoplasms has now been modulated by a chemopreventive regimen. Colonic lesions significantly increased in Apc 1638 mice on a Western-style diet, compared to Apc 1638 mice on AIN-76A diet which has lower fat content and higher calcium and vitamin D. These studies have also been carried out in normal mice, and have demonstrated without any chemical carcinogen that a Western-style diet induced colonic tumorigenesis. Modulation of cell proliferation has also been induced by Western-style diets in other organs including mammary gland, pancreas and prostate. These findings are leading to the development of new preclinical models for evaluating the efficacy of many classes of chemopreventive agents.

Intermediate biomarkers in the colorectal tumor progression

Intermediate biomarkers are biological alterations in tissue which signal a stage of carcinogenesis between initiation and the development of a malignant tumor. Proliferation biomarkers are those that most satisfy the requisites for premorphological intermediate markers in the colorectal tumor progression. Cell proliferation changes in histologically normal intestinal mucosa are early events directly and closely associated with the morphogenesis of colorectal neoplasia. The transition from the morphological stage and the latter's further progression can be reliably monitored through the use of differentiation and genomic markers. In particular the incidence and the degree of DNA aneuploidy are indicators of the risk of malignant transformation in colorectal adenomas. New "regression-related" biomarkers should be investigated for the planning of measures designed to bring about the regression of premalignant lesions.

Colorectal cancer in patients with ulcerative colitis. A prospective cohort study in Italy

BACKGROUND

The aim of this study was to assess the development of dysplasia or cancer in patients with ulcerative colitis and to determine the effectiveness of colonoscopy and biopsy follow-up in colon cancer surveillance.

METHODS

From 1980 to 1986, 65 patients who had ulcerative colitis for 7 years or more participated in a surveillance program of colonoscopy and biopsy. This cohort was followed until December 1992. Forty-nine patients (75.4%) had extensive colitis and 16 (24.6%) left-sided colitis. The mean disease duration was 17.2 years. Three hundred four colonoscopies were performed. During each endoscopy, random biopsies were performed.

RESULTS

Seven patients had definite dysplasia of the colorectal mucosa. Four of them had high grade lesions and underwent surgery. In all of these patients, colon cancer (3 Dukes' Stage A, 1 Dukes' Stage B) was found. No cancer was found in the other patients. Pedunculated adenomas were excised from 6 other patients during colonoscopy. When dysplasia was diagnosed, these patients were older than those who were dysplasia free, whereas the age at onset of colitis was significantly higher in the former (P < 0.01). Fifteen patients discontinued follow-up. Two of them developed colon cancer diagnosed at an advanced stage.

CONCLUSIONS

Dysplasia, especially of high grade, is a marker of colon cancer risk in patients with longstanding ulcerative colitis. Intensive colonoscopy and biopsy surveillance can lead to the diagnosis of colon cancer at a potentially curable stage. In this series, older age appeared to be an additional risk factor. A careful selection of patients with ulcerative colitis seems mandatory to minimize the cost and optimize the benefit of colon cancer surveillance programs.

K-ras-2 G-C and G-T transversions correlate with DNA aneuploidy in colorectal adenomas

BACKGROUND/AIMS

K-ras-2 mutations and DNA content heterogeneity represent early events of human colorectal tumor progression. The aim of the study was to investigate if specific K-ras-2 mutations in 58 human sporadic adenomas were correlated with DNA aneuploidization and cell proliferation.

METHODS

Multiparameter flow cytometry, based on scatter parameters and DNA content, was performed using 4,6-diamidino-2-phenilindole-2-hydrochloride-stained nuclei obtained from adenoma fragments with either mild-moderate or severe dysplasia. K-ras-2 polymerase chain reaction and spectrum analysis were performed using sorted DNA specific epithelial subclones.

RESULTS

We detected six G-A transitions, and four G-C and two G-T transversions. The DNA aneuploid subclones were 25 with DNA index values in the near diploid region (DNA index < 1.3) for the vast majority of cases (80%). DNA aneuploidy among the mutated adenomas with G-A transitions was 1 of 6 (17%) and 6 of 6 (100%) among G-C and G-T transversions. Although DNA aneuploidy and high S-phase values were also present among K-ras-2 wild-type adenomas, their statistical associations with K-ras-2 status were P < 0.005 and P < 0.05, respectively.

CONCLUSIONS

The present series of sporadic colorectal adenomas indicates that codon 12 G-C and G-T K-ras-2 transversion mutations and DNA aneuploidy are correlated. The underlying mechanisms that explain such association remain to be investigated.

Mucosal cell proliferation in patients with hyperplastic colorectal polyps

BACKGROUND

Morphologic, histochemical, and cytoproliferative characteristics differentiate hyperplastic polyps from adenomas. Even so, these polyps are indicators of populations with a high colorectal cancer risk. Since changes in mucosal cell proliferation are highly predictive biomarkers of the adenomacarcinoma sequence, this study examined the cytoproliferative profiles of mucosa bearing hyperplastic polyps, in a search for the significance of such lesions in bowel carcinogenesis.

METHODS

Proliferative activity demonstrated by immunohistochemical detection of the in vitro uptake of bromodeoxyuridine was evaluated in the rectal mucosa of 26 patients with hyperplastic polyps, 35 with adenomas < 1 cm, 60 with adenomas > 1 cm, 10 with adenomas + synchronous hyperplastic polyps, and 400 controls.

RESULTS

An upward shift of the major DNA synthesis zone to the intermediate and surface crypt compartments was found in all four patients groups. Significant hyperproliferation, on the other hand, was only observed in patients with large adenomas or hyperplastic polyps, or small adenomas and synchronous hyperplastic polyps.

CONCLUSIONS

These findings suggest that hyperplastic polyps are morphologic indicators of tumor initiation in the rectal mucosa and its ensuing hyperproliferation. Abnormalities in the distribution of proliferation in the mucosa do not appear to be specifically associated with the morphogenesis of hyperplastics polyps.

Clinical evaluation of push-type enteroscopy

BACKGROUND AND STUDY AIMS

Endoscopic exploration of the small bowel is potentially of prime importance in studying gastrointestinal bleeding of obscure origin, diarrhea and malabsorption, neoplasia, and other clinical conditions, but the method is still problematic because of the limited efficacy of sonde-type enteroscopes. This study evaluates the diagnostic yield of two push-type enteroscopes fitted with tip deflection and a biopsy channel.

PATIENTS AND METHODS

Seventy-two consecutive patients underwent enteroscopy using either an Olympus SIF-10 LY fiberscope or an Olympus SIF-100 video enteroscope. The depth of insertion was always checked by fluoroscopy, and ranged 30-120 cm beyond the ligament of Treitz.

RESULTS

Angiodysplasia was identified as the source in eight of 20 patients referred for gastrointestinal bleeding of obscure origin, and electrocoagulation was successfully performed in one case. A jejunal polyp was the cause of obscure bleeding in one patient. Radiological evidence of neoplasia/lymphoma located in the third portion of the duodenum or in the upper jejunum was ruled out in 10 of 12 patients. A normal jejunal appearance was found in two patients with lymphoma, subsequently confirmed by a normal enteroclysis. Duodenal or jejunal polyps were removed in seven of nine patients with familial polyposis. Endoscopic and histological alterations were found in nine of 24 patients with diarrhea or malabsorption. In addition, jejunal histology supplied the diagnosis in five patients with a normal endoscopic mucosal appearance. Only 18% of patients described slight, transient pain, and there were no complications. The tolerance and diagnostic efficacy were the same with both instruments.

CONCLUSIONS

Even though push-type enteroscope exploration is restricted to the jejunum, the instruments are safe and efficacious in clinical practice, and permit indepth study of small bowel anatomy and pathology.

Small rectosigmoid polyps as markers of proximal neoplasms

PURPOSE

The aim of this study was to determine the spatial distribution and histotype of small colorectal polyps and to determine the validity of distal-small colorectal polyps as markers of proximal neoplasms.

METHODS

In 366 patients who underwent total colonoscopy and removal of all polyps, the presence and features of polyps were recorded. The relationship between proximal neoplasms and distal polyps was investigated in 216 of 366 subjects who had no personal or familial history of colorectal neoplasia.

RESULTS

Of 366 patients, 96 were free from polyps. A total of 733 small colorectal neoplasms was removed from the remainder: 79.9 percent neoplastic and 20.1 percent hyperplastic, inflammatory, or hamartomatous. High-grade dysplasia was noted in 2.7 percent of the neoplastic polyps. One adenoma containing invasive carcinoma was observed. In the subset of 216 patients, proximal neoplasms were found in 11.4 percent of those with no distal polyps, 33.8 percent of those with distal-small colorectal polyps only (P < 0.01), and 58.8 percent of those with at least one polyp > 5 mm in diameter (P = 0.001). The proximal neoplasm percentage was the same in patients with at least one adenomatous-small polyp and those with only hyperplastic-small polyps.

CONCLUSIONS

A distal-small colorectal polyp, whether adenomatous or hyperplastic, may be a proximal neoplasm marker. Total colonoscopy is thus justified in all patients with distal polyps, regardless of their size and histotype.

Bromodeoxyuridine uptake and proliferating cell nuclear antigen expression throughout the colorectal tumor sequence

In vitro uptake of bromodeoxyuridine and expression of proliferating cell nuclear antigen (PCNA) were evaluated histochemically in rectal mucosa of control subjects and subjects with colorectal neoplasia in large intestine adenomas and adenocarcinomas. Both labeling indices progressively increased along the path of tumor progression, as did the difference between them (PCNA labeling indices were always greater than those of bromodeoxyuridine). The correlation between them was fairly close in the controls and in adenomas with low-grade dysplasia, whereas no significant linear relations were noted in adenomas with high-grade dysplasia or in adenocarcinomas. The progressive increase in PCNA would thus seem to be related to both hyperproliferation and neoplastic deregulation of PCNA synthesis. In the mucosa of subjects with colorectal neoplasia, PCNA labeling revealed hyperproliferation but not the surface-wards shift of the proliferative compartment detected by bromodeoxyuridine. PCNA expression, therefore, is not a sufficiently sensitive marker of the risk of tumor transformation in the intestinal mucosa.

Cell proliferation in colorectal adenomas containing invasive carcinoma

Immunohistochemical detection of the nuclear antigen recognised by the monoclonal antibody Ki67, DNA polymerase alpha, and the proliferating cell nuclear antigen (PCNA), and histochemical staining for the argyrophilic proteins associated with the nucleolar organizer regions (AgNOR) were carried out on histological sections from 107 colorectal adenomas containing invasive carcinoma (ACIC), including 7 with regional lymph node metastases. Separate evaluations were made for fields corresponding to adenoma with low-grade dysplasia, adenoma with high-grade dysplasia and early cancer. The same techniques were also employed in 20 cases of normal mucosa and 20 advanced carcinomas. The mean percentages of Ki67, DNA polymerase alpha, and PCNA-positive nuclei and the number of AgNOR per nucleus progressively increased along the sequence from normal mucosa via low-grade and high-grade dysplasia adenoma to advanced cancer, whereas the early cancer values were not significantly different from those in the low-grade dysplasia areas. No significant difference in PCNA positivity and number of AgNOR were noted in ACIC with and without lymph node metastases. It is suggested that the decrease in proliferative activity thus revealed in early cancer may be due to changes in the submucosa microenvironment caused by invasion, and that the metastatic potential of an early colorectal cancer cannot be correlated to such activity.

Histology, histochemistry, tumor and serum markers in gastrointestinal tract cancer

Integration of morphologic and molecular information is being pursued as a result of more extensive use of in situ hybridization techniques. Oncogenes, gene products, and viral genomes involved in the genesis and progression of gastrointestinal tumors have been located in specific histotypes or tumor sectors. The main advances in this area relate to cell-matrix interactions and the biologic mechanisms of tumor invasion. Some aspects of the morphogenetic sequences of gastric and colorectal adenocarcinomas and hepatocellular carcinoma have been elucidated. Studies of DNA ploidy have furnished results consonant with carcinogenesis models envisaging sequential genome alterations due to genetic instability of the transformed cell. The prognostic role of DNA content in gastrointestinal tumors, however, has not been unequivocally established. Research on tumor markers has been directed toward the tissue expression and distribution of apomucins with different molecular structures. Evaluation of tumor markers in body fluids has proved inadequate for the early detection and screening of gastrointestinal neoplasia. Some interesting results have been reported with regard to the monitoring of gastric and colorectal carcinomas by means of serum tumor markers.

Endoscopy to detect oral and oesophageal candidiasis in acquired immune deficiency syndrome

Cytologic evidence of candidiasis was sought on endoscopic oesophageal brushings from 116 patients with acquired immune deficiency syndrome (AIDS) to determine the reliability of oesophagoscopy and the possibility of predicting Candida spp. oesophagitis from concomitant oral candidiasis or oesophageal symptoms. Oesophageal candidiasis was present in 42 patients and constituted the first opportunistic infection in 19 patients. Sensitivity and specificity were, respectively, 98% and 96% for oesophagoscopy, 69% and 42% for oral candidiasis, 52% and 74% for oesophageal symptoms, and 83% and 35% for the presence of at least one of these last two parameters. Endoscopy also proved to be the examination of choice for diagnosis, and cytology was needed only when it was negative. Oral candidiasis and oesophageal symptoms were not sufficient to predict oesophageal candidiasis. Endoscopy would seem to be indispensable to the diagnosis of oesophageal candidiasis and its differentiation from other forms, thus preventing any empirical resort to unwarranted forms of treatment. It is also indicated for staging purposes in asymptomatic patients, since oesophageal candidiasis is one indicator of the transition to full-blown AIDS.

Cell proliferation in colorectal tumor progression: an immunohistochemical approach to intermediate biomarkers

Cell renewal in the large intestine mucosa is normally tied to a rigidly compartmentalized model. Immunohistochemical identification of cells in S phase through uptake of bromodeoxyuridine is the method of choice for detailed compartmental mapping of proliferation, while immunohistochemical detection of proliferation-associated antigens (Ki-67, PCNA, DNA polymerase alpha) provides information in advanced tumor cases. Mucosal hyperproliferation due to inflammation may be transient (self-limited colitis, Crohn's disease, acute radiation damage) or lasting (ulcerative colitis). Progressive shifting of the proliferation zone to the crypt surface (Stage II abnormality) is a late feature of irradiated rectal mucosa and subgroups of ulcerative colitis patients at high risk for cancer. Hyperproliferation and Stage II abnormality coexist in the mucosa of patients with colorectal neoplasia, but are mutually independent and correlated to different clinical and pathological features of the disease. These cytokinetic abnormalities are highly predictive markers of the adenoma-carcinoma sequence, but are not associated with de novo adenocarcinoma. Proliferation increases progressively in the subsequent steps of this sequence, except in early cancer.

Correlations between rectal mucosa cell proliferation and the clinical and pathological features of nonfamilial neoplasia of the large intestine

An in vitro study of proliferative activity as shown by immunohistochemical detection of the uptake of bromodeoxyuridine was run on rectal biopsies from 400 patients with nonfamilial large bowel neoplasia: 200 adenoma; 150 adenocarcinoma; 50 adenoma plus adenocarcinoma. The controls were 400 subjects with negative personal and family histories of colorectal neoplasia. The number and height distribution of bromodeoxyuridine positive cells were determined by dividing the crypt into five longitudinal compartments. The total labeling index and the labeling index of each compartment were higher in all three groups compared with the controls. In subjects with adenoma, total labeling index and labeling index values were correlated with tumor size and decreased in function of the duration of the polyp-free colon state. The major zone of DNA synthesis had shifted to the intermediate and surface crypt compartments in all three groups. This stage II abnormality was more marked in adenoma patients with a high degree of dysplasia and in those with adenoma plus adenocarcinoma. Hyperproliferation and the proliferative compartment shift are cytokinetic abnormalities that coexist in the flat rectal mucosa of patients with colorectal neoplasia. Nonetheless, they are independent, controlled by different factors, and are expressions of different biological aspects of large bowel carcinogenesis.

Needle biopsy of submucosal lesions of the gastrointestinal tract

Needle biopsy of submucosal lesions is an important addition to the diagnostic capabilities of gastrointestinal endoscopy. A series of 22 cases is described employing a guillotine needle to diagnose submucosal lesions, 4 of which were infiltrating adjacent carcinomas. The specimens obtained were sufficient for firm histological diagnosis in 20 cases. There were no complications apart from minor bleeding in 1 case.

Late cytokinetic abnormalities in irradiated rectal mucosa

Late cytokinetic changes of the colonic crypt epithelium after radiation therapy were investigated. A monoclonal antibody to bromodeoxyuridine (anti-BrdU MAb) was used in tissue specimens previously incubated with BrdU to show S-phase cells by immunohistochemical technique. Endoscopic rectal biopsies were taken from 30 patients previously treated with radiotherapy for gynaecological cancer and from 50 patients with comparable but untreated neoplasms, as controls. Number and height distribution of S-phase cells were evaluated by dividing each crypt column into 5 equal longitudinal compartments. No statistically significant differences were found in total Labelling Index (LI) between controls and irradiated mucosa, whereas LI per crypt compartment, percentage of labelled compartments and percentage of BrdU-positive cells in the middle and superficial portions of the crypt were significantly higher in patients submitted to radiation therapy. This kinetic abnormality corresponds to a progressive shift of the major zone of DNA synthesis to the upper third of the crypt as a late reaction to radiation and represents an early step in the histogenesis of colorectal cancer. These results lend support to the view that there is a higher risk of colorectal carcinoma after pelvic irradiation.

[Lipoma of the small intestine. A clinical case]

The paper reports a case of a 45-year-old female with long-standing anemia, recurrent abdominal pain and subocclusive crises. Following a negative endoscopy of the upper tract of the large intestine, barium enema and angiography, the patient underwent total colonoscopy. Massive bleeding from the ileal valve suggested an ileal pathology: a small intestine enema confirmed a polypoid proliferation 60 cm above the Bahuino valve with related ileal invagination 25 cm long. The patient underwent surgery and pathological findings revealed a 7 cm-wide ileal lipoma near a small angiodysplasia. The latter seemed to be the cause of bleeding. The diagnosis of small intestine tumours is made difficult by the fact that the only important signs are abdominal pain, intestinal bleeding and subocclusive crises, which are common symptoms in many pathologies. The authors stress the importance of a thorough endoscopic examination and selective angiography.