A morpho-molecular prognostic model for hepatocellular carcinoma

Background:

Hepatocellular carcinoma (HCC) is the third common cause of cancer-related deaths and its prognostication is still suboptimal. The aim of this study was to establish a new prognostication algorithm for HCC.

Methods:

In all, 13 biomarkers related to the etiopathogenesis of HCC were evaluated by immunohistochemistry using tissue microarrays containing 121 primary HCC resection cases, and validated in subsequent cohort of 85 HCC cases. The results were compared with Affymetrix Gene Chip Human Genome U133Plus microarray data in a separate cohort of 228 HCC patients.

Results:

On immunohistochemical evaluation and multivariate Cox regression analysis p53, alpha fetaprotein (AFP), CD44 and CD31, tumour size and vascular invasion, were significant predictors for worse survival in HCC patients. A morpho-molecular prognostic model (MMPM) was constructed and it was a significant independent predictor for overall survival (OS) and relapse-free survival (RFS) (P<0.000). The OS and RFS of HCC^low was higher (104 and 78 months) as compared with HCC^high (73 and 43 months) (P<0.0001for OS and RFS). Hepatocellular carcinoma patients with higher stage (III+IV), >5 cm tumour size, positive vascular invasion and satellitosis belonged to HCC^high group. The validation group reproduced the same findings. Gene expression analysis confirmed that 7 of the 12 biomarkers were overexpressed in >50% of tumour samples and significant overexpression in tumour samples was observed in AFP, CD31, CD117 and Ki-67 genes.

Conclusion:

The MMPM, based on the expression of selected proteins and clinicopathological parameters, can be used to classify HCC patients between good vs poor prognosis and high vs low risk of recurrence following hepatic resection.

In vivo diagnosis of esophageal cancer using image-guided Raman endoscopy and biomolecular modeling

The aim of this work was to evaluate the biochemical foundation and clinical merit of multimodal image-guided Raman endoscopy technique for real-time in vivo diagnosis of cancer in the esophagus during clinical endoscopic examinations. A novel fiber-optic Raman endoscopy system was utilized for in vivo esophageal Raman measurements at 785 nm laser excitation within 0.5 second under the multimodal wide-field endoscopic imaging (white light reflectance (WLR) imaging, narrow-band imaging (NBI) and autofluorescence imaging (AFI) guidance. A total of 75 esophageal tissue sites from 27 patients were measured, in which 42 in vivo Raman spectra were from normal tissues and 33 in vivo Raman spectra were from malignant tumors as confirmed by histopathology. The biomolecular modeling (non-negativity-constrained least-squares minimization (NNCLSM) utilizing six basis reference spectra from the representative biochemicals (i.e., actin, collagen, DNA, histones, triolein and glycogen) were employed to estimate the biochemical compositions of esophageal tissue. The resulting diagnostically significant fit coefficients were further utilized through linear discriminant analysis (LDA) and leave-one tissue site-out, cross validation method to develop diagnostic algorithms for esophageal cancer diagnosis. High-quality in vivo Raman spectra in the range of 800-1800 cm-1 can be acquired from normal and cancerous esophageal mucosa in real-time under multimodal endoscopic imaging guidance. Esophageal cancer tissue showed distinct Raman signals mainly associated with cell proliferation, lipid reduction, abnormal nuclear activity and neovasculation. The fit coefficients for actin, DNA, histones, triolein, and glycogen were found to be most significant for construction of the LDA diagnostic model, giving rise to an accuracy of 96.0% (i.e., sensitivity of 97.0% and specificity of 95.2%) for in vivo diagnosis of esophageal cancer. This study demonstrates that multimodal image-guided Raman endoscopy technique in conjunction with biomolecular modeling has promising potential for the real-time, in vivo diagnosis and detection of esophageal cancer during clinical endoscopic examination.

Near-infrared Raman spectroscopy for early diagnosis and typing of adenocarcinoma in the stomach

Background

The aim of this study was to evaluate the feasibility of using near-infrared (NIR) Raman spectroscopy for early diagnosis and typing of intestinal and diffuse adenocarcinoma of the stomach.

Methods

A dispersive-type NIR Raman system was used for tissue measurements. One hundred gastric tissue samples from 62 patients who underwent endoscopy or gastrectomy were used (70 normal tissue specimens and 30 adenocarcinomas). Principal components analysis (PCA) and multinomial logistic regression (MNLR) were used to develop diagnostic algorithms for tissue classification.

Results

High-quality Raman spectra ranging from 800 to 1800 cm−1 were acquired from gastric tissue within 5 s. There were significant differences in Raman spectra between normal stomach and the two gastric adenocarcinoma subtypes, particularly in the spectral ranges 850–1150, 1200–1500 and 1600–1750 cm−1, which contain signals related to proteins, nucleic acids and lipids. PCA–MNLR achieved predictive accuracies of 88, 92 and 94 per cent for normal stomach, and intestinal- and diffuse-type gastric adenocarcinomas respectively.

Conclusion

NIR Raman spectroscopy can detect gastric malignancy and identify the subtype of gastric adenocarcinoma.

Diagnostic potential of near-infrared Raman spectroscopy in the stomach: differentiating dysplasia from normal tissue

Raman spectroscopy is a molecular vibrational spectroscopic technique that is capable of optically probing the biomolecular changes associated with diseased transformation. The purpose of this study was to explore near-infrared (NIR) Raman spectroscopy for identifying dysplasia from normal gastric mucosa tissue. A rapid-acquisition dispersive-type NIR Raman system was utilised for tissue Raman spectroscopic measurements at 785 nm laser excitation. A total of 76 gastric tissue samples obtained from 44 patients who underwent endoscopy investigation or gastrectomy operation were used in this study. The histopathological examinations showed that 55 tissue specimens were normal and 21 were dysplasia. Both the empirical approach and multivariate statistical techniques, including principal components analysis (PCA), and linear discriminant analysis (LDA), together with the leave-one-sample-out cross-validation method, were employed to develop effective diagnostic algorithms for classification of Raman spectra between normal and dysplastic gastric tissues. High-quality Raman spectra in the range of 800–1800 cm⁻¹ can be acquired from gastric tissue within 5 s. There are specific spectral differences in Raman spectra between normal and dysplasia tissue, particularly in the spectral ranges of 1200–1500 cm⁻¹ and 1600–1800 cm⁻¹, which contained signals related to amide III and amide I of proteins, CH₃CH₂ twisting of proteins/nucleic acids, and the C=C stretching mode of phospholipids, respectively. The empirical diagnostic algorithm based on the ratio of the Raman peak intensity at 875 cm⁻¹ to the peak intensity at 1450 cm⁻¹ gave the diagnostic sensitivity of 85.7% and specificity of 80.0%, whereas the diagnostic algorithms based on PCA-LDA yielded the diagnostic sensitivity of 95.2% and specificity 90.9% for separating dysplasia from normal gastric tissue. Receiver operating characteristic (ROC) curves further confirmed that the most effective diagnostic algorithm can be derived from the PCA-LDA technique. Therefore, NIR Raman spectroscopy in conjunction with multivariate statistical technique has potential for rapid diagnosis of dysplasia in the stomach based on the optical evaluation of spectral features of biomolecules.

Lymphocytic gastritis-like T cell lymphoma: molecular evidence of an unusual recurrence

This report describes a patient with a gastric biopsy specimen showing histomorphological and immunohistochemical appearances indistinguishable from those usually present in lymphocytic gastritis, a rare condition of unknown aetiology with a distinctive phenotype. The patient had a history of a biopsy confirmed T cell non-Hodgkin lymphoma at two anatomical sites (bladder and stomach), which was subsequently treated. Molecular analysis of the T cell receptor (TCR) gamma chain gene rearrangements showed a distinct monoclonal T cell population in the bladder and gastric biopsies. The same analysis in the lymphocytic gastritis-like biopsy sample showed a monoclonal population with identical base pair size to that identified in the other specimens. This report highlights the importance of TCR gene rearrangement analysis in the diagnosis of unusual gastric inflammation, and the use of capillary electrophoresis based polymerase chain reaction in the follow up of lymphoproliferative disorders.

Dietary isothiocyanates, glutathione S-transferase -M1, -T1 polymorphisms and lung cancer risk among Chinese women in Singapore

Chinese populations consume a diet relatively high in isothiocyanates (ITCs), a derivative of cruciferous vegetables known to have cancer-protective effects. This class of compounds is metabolized by the glutathione S-transferase family of enzymes, which are also involved in the detoxification of tobacco-related carcinogens such as polycyclic aromatic hydrocarbons and alkyl halides. We evaluated the association between dietary isothiocyanate intake, GSTM1 and GSTT1 polymorphisms, and lung cancer risk in 420 Chinese women: 233 histologically confirmed lung cancer patients and 187 hospital controls. Among these, 58.8% of cases and 90.3% of controls were lifetime nonsmokers. An allele-specific PCR method was used to detect the presence or absence of the GSTM1 and GSTT1 genes in DNA isolated from peripheral blood. Higher weekly intake of ITCs (above the control median value of 53.0 micromol) reduced the risk of lung cancer to a greater extent in smokers [adjusted odds ratio (OR), 0.31; 95% confidence interval (CI), 0.10-0.98] than nonsmokers (OR, 0.70; 95% CI, 0.45-1.11). The inverse association was stronger among subjects with homozygous deletion of GSTM1 and/or GSTT1. Among nonsmokers with GSTM1-null genotype, higher intake of ITCs significantly reduced the risk of lung cancer (OR, 0.54; 95% CI, 0.30-0.95), an effect not seen among those with detectable GSTM1 (OR, 1.07; 95% CI, 0.50-2.29). Our results, in a Chinese female population, are consistent with the hypothesis that ITC is inversely related to the risk of lung cancer, and we show that among nonsmokers this effect may be primarily confined to GST-null individuals. Conjugation and elimination of ITCs is enhanced in GST-non-null relative to -null individuals, such that the GST metabolic genotype modifies the protective effect of ITCs on lung cancer development.

Inhibition of angiopoietin-1 expression in tumor cells by an antisense RNA approach inhibited xenograft tumor growth in immunodeficient mice

Angiopoietin-1 (Ang1) is an angiogenic growth factor that functions through activation of its endothelium-specific tyrosine kinase receptor Tie2; it mediates the interaction between endothelial and surrounding cells to promote the remodeling, maturation and stabilization of blood vessels. Although Ang1 is expressed constitutively in many adult tissues, its role in tumor growth and metastasis is not clear. Here we describe experiments in which Ang1 expression was inhibited in HeLa cells by an antisense RNA approach. The modified HeLa cells produced significantly less Ang1 protein both in cultured cells and in tumors formed when these cells were injected into immunodeficient mice. The Ang1 antisense tumors grew much more slowly, with significantly reduced tumor angiogenesis compared with control tumors. Furthermore, they also had substantially increased tumor cell apoptosis and decreased tumor necrosis. Our results indicate that the perturbation of Ang1 expression in tumors could be an effective method to control tumor growth by inhibiting tumor angiogenesis and that antisense RNA is an efficient way to inhibit Ang1 protein production in tumor cells.

Cytochrome P4501A2 (CYP1A2) activity and lung cancer risk: a preliminary study among Chinese women in Singapore

There is increasing evidence for the role of heterocyclic and other arylamines in carcinogenesis, including lung carcinogenesis. Chinese women have a high rate of lung cancer despite a low smoking prevalence, and studies in this population may provide useful information on risk factors other than smoking. Hepatic CYP1A2 and NAT2 are involved in the metabolism of carcinogenic arylamines, and NAT2 also catalyzes the detoxification pathway for these compounds. In this study, we examined the effect of CYP1A2 activity using a urinary caffeine metabolic ratio assay for 54 Chinese women with newly diagnosed lung cancer (including 28 adenocarcinomas) and 174 hospital controls. Among them, NAT2 genotype was available for 47 cases and 98 controls. There was no effect of CYP1A2 activity on overall risk of lung cancer in the study population [odds ratio (OR) 0.8, 95% confidence interval (CI) 0.4-1.6, adjusted for age at diagnosis, smoking and cruciferous vegetable intake]. For adenocarcinomas, the OR was 1.5, 95% CI 0.6-3.4. After further adjustment for NAT2 acetylator genotype, the OR for adenocarcinoma was 1.8 (95% CI 0.7-4.8). When the combined NAT2/CYP1A2 status was examined, women with slow NAT2 and rapid CYP1A2 activity were at highest risk (adjusted OR 6.9, 95% CI 1.3-37.6) relative to women with rapid NAT2 and slow CYP1A2 activity, for lung adenocarcinoma. While larger studies are needed to confirm or refute these results, they are consistent with a role for heterocyclic arylamines in lung carcinogenesis in this primarily non-smoking population.

Fumes from meat cooking and lung cancer risk in Chinese women

Chinese women are recognized to have a high incidence of lung cancer despite a low smoking prevalence. Several studies have implicated domestic exposure to cooking fumes as a possible risk factor, although the exact carcinogens have yet to be identified. Heterocyclic amines are known carcinogens, which have been identified in cooked meat, and also in fumes generated during frying or grilling of meats. We conducted a case-control study of 303 Chinese women with pathologically confirmed, primary carcinomas of the lung and 765 controls to examine the association between exposure to meat cooking and lung cancer risk. Data on demographic background, smoking status, and domestic cooking exposure, including stir-frying of meat, were obtained by in-person interview while in hospital. The response rates among eligible cases and controls were 95.0 and 96.9%, respectively. The proportion of smokers (current or ex-smokers) among cases and controls was 41.7 and 13.1%, respectively. Adenocarcinomas comprised 31.5% of cancers among smokers and 71.6% among nonsmokers. When cases were compared with controls, the odds ratio (OR) for lung cancer (all subtypes) among ex-smokers was 4.3 [95% confidence interval (CI) 2.7-6.8] and that among current smokers was 5.0 (95% CI, 3.4-7.3). Among smokers, women who reported that they stir-fried daily in the past had a significantly increased risk of lung cancer (adjusted OR, 2.0; 95% CI, 1.0-3.8) and among these women, risk was enhanced for those who stir-fried meat daily (OR, 2.7; 95% CI, 1.3-5.5). Women who stir-fried daily but cooked meat less often than daily did not show an elevated risk (OR, 1.0. 95% CI, 0.5-2.4). Risk was further increased among women stir-frying meat daily who reported that their kitchen was filled with oily fumes during cooking (OR, 3.7; 95% CI, 1.8-7.5). These cooking practices on their own did not increase risk among nonsmokers in our study population. Our results suggest that inhalation of carcinogens, such as heterocyclic amines generated during frying of meat, may increase the risk of lung cancer among smokers. Further studies in different settings are warranted to examine this possibility, which may also help to explain the higher risk observed among women smokers compared with men.

NAT2 slow acetylator genotype is associated with increased risk of lung cancer among non-smoking Chinese women in Singapore

Among non-smokers, the factors resulting in lung carcinogenesis are poorly understood. We conducted a hospital-based case-control analysis of 294 Chinese women, of whom 217 were non-smokers, to evaluate the role of polymorphic N-acetyltransferase (NAT2) as a susceptibility factor for the disease. The proportion of slow acetylator genotypes among non-smoking cases (n = 92) and controls (n = 125) was 38.0 and 24.0%, respectively [odds ratio (OR) 2.0, 95% confidence interval (CI) 1.1-3.7]. No effect of NAT2 genotype was seen among smokers. Among non-smokers, the effect was marked for adenocarcinomas (OR 2.1, 95% CI 1.1-4.0). As NAT2 activity is known to modify risk of arylamine-induced carcinogenesis, our results suggest that exposure to arylamines in the environment may play a role in risk of lung cancer among non-smokers.

Soft tissue chondroma in the finger: a case report and review of the literature

Soft tissue chondromas are rare. A fairly benign condition, it is an uncommon occurrence in the hand. It usually presents as an enlarging mass and local surgery is the treatment of choice. We report a case of a patient in our local population presenting with a soft tissue chondroma in a digit.

An unusual case of multiple recurrence of a glomangioma

Glomus tumour is a benign lesion arising from the glomus apparatus of the skin and subcutaneous tissue. Glomangioma is the angiomatous variant, which is uncommon. We report a very rare presentation of a glomangioma with multiple recurrences. We advocate preoperative angiography to delineate the extent of the lesion to facilitate complete excision.

Effects of physical barriers in prevention of adhesions: an incisional hernia model in rats

BACKGROUND

Adhesion formation between viscera and mesh is almost inevitable following incisional hernia repair with prosthetic mesh. Such adhesions may lead to intestinal obstruction and enterocutaneous fistulae formation and make further laparotomies extremely difficult. Sodium carboxymethylcellulose (SCMC) and Interceed TC7 (oxidized regenerated cellulose) as physical barriers have been shown to be effective in reducing postoperative adhesions.

MATERIALS AND METHODS

To evaluate the effects of SCMC and Interceed TC7, we used an incisional hernia model in rats. A ventral abdominal defect (15 x 25 mm) was created in each of 36 male rats which were then divided into three equal groups. In Group I (control) the defect was repaired with polypropylene mesh (PPM) only; in Group II the defect was repaired after a layer of Interceed TC7 was laid over the viscera with Interceed TC7-covered PPM; in Group III the defect was repaired after a layer of SCMC was laid over the viscera with SCMC-coated PPM. Six of the animals from each group were sacrificed at Postoperative Day 7 and the adhesions were scored. The remaining 6 were sacrificed at Day 30 and histological evaluation was made in addition to the adhesion score.

RESULTS

Animals in the SCMC-treated group developed significantly less adhesions (P = 0.0002) compared with control and Interceed TC7-treated groups. However, histological analysis revealed poor fibroblast proliferation with impaired wound healing in the SCMC group.

CONCLUSION

SCMC prevented adhesion formation but seriously impaired wound healing, and Interceed TC7 was ineffective in preventing adhesion in this model.

Haemangioendothelioma in an infant's wrist

A rare case of an epitheloid haemangioendothelioma presenting as an aggressive soft tissue mass in the wrist of an infant is presented. The management of the lesion presents particular difficulties because of its diffuse involvement of surrounding muscles, tendons and neurovascular bundle and the importance of preserving hand function. The epitheloid haemangioendothelioma rarely occurs extravascularly with less than 15 such cases reported in the literature.

Effect of cisapride on functional dyspepsia in patients with and without histological gastritis: a double-blind placebo-controlled trial

In the present double-blind placebo-controlled study the effect of cisapride on functional dyspepsia was evaluated in patients with and without histological gastritis. Patients with functional dyspepsia and whose symptoms persisted after a 2 week run-in period with antacid treatment were randomized to receive cisapride (10 mg) or matching placebo three times daily for 4 weeks. Symptoms of epigastric pain, bloating, nausea, belching, early satiety and heartburn were graded on a four-point scale based on patients' feedback and diary card recording. A global response was also formulated by the investigators. One hundred and four patients entered the study and 76 completed the trial, comprising 36 patients with histological gastritis and 40 patients without gastritis. Symptom scores in both gastritis and non-gastritis groups were significantly improved by both cisapride and placebo; however, the improvement was not statistically different between the two treatment groups. Cisapride produced a good or better global response in 58% of subjects with histological gastritis and in 53% of subjects without gastritis compared with 47% and 52%, respectively, of patients on placebo; this difference was not statistically significant. Gastric histology did not influence the effect of cisapride on the symptoms of functional dyspepsia.

An immunohistochemical study of p53 protein in ovarian mucinous neoplasms

p53 gene mutations are among the most common genetic lesions in human cancers. While previous studies have established the presence of p53 protein in ovarian carcinomas some have not shown the alteration of the p53 gene to be a feature in benign or borderline ovarian epithelial neoplasms. In this study we examined both benign and borderline malignant/malignant mucinous neoplasms for p53 protein accumulation by the means of an anti-human p53 protein monoclonal antibody on paraffin sections. Our results show that p53 protein accumulation is associated to a similar degree with both malignant mucinous cystadenocarcinomas and mucinous cystademonas of borderline malignancy. This suggests that p53 mutations may play an important and early role in the malignant transformations of one-third or more of mucinous ovarian neoplasms. Furthermore, among the mucinous cystadenomas of borderline malignancy where p53 staining was present, staining could be found in the morphologically benign areas thus indicating that, despite their innocuous appearance, such epithelial cells might have already taken a very important step in their evolution to frank malignancy.

Extraskeletal Ewing's sarcoma presenting with pulmonary embolism

Small round cell tumours with the morphologic characteristics of Ewing's sarcoma arise rarely in soft tissues of the extremities, retroperitoneum, chest and orbit. Patients usually present with symptoms arising from the swelling at the primary site. We report on a patient with a retroperitoneal extraskeletal Ewing's sarcoma who presented with massive tumour embolism to the pulmonary vasculature. To our knowledge, this is the first report of extraskeletal Ewing's sarcoma presenting with pulmonary tumour embolism.

An immunohistochemical study of p53 protein in cervical intraepithelial neoplasia and squamous cell carcinoma

p53 mutations are known to occur frequently in human cancers where they are considered to be an important event in the stepwise progression towards malignant transformation. It is therefore interesting to compare p53 expression in the uterine cervix for non-neoplastic/metaplastic squamous epithelium, cervical intraepithelial neoplasia (CIN) and invasive squamous cell carcinoma. One hundred and nineteen biopsied and resected specimens of the uterine cervix were stained with an anti-human p53 protein monoclonal antibody by the streptavidin-biotin immunoperoxidase method. Histologically these could be categorized into non-neoplastic/dysplastic conditions, including condyloma (34 cases), CIN 1-3 (66 cases) and invasive squamous cell carcinoma (19 cases). Fifty eight per cent (11/19) of the invasive squamous cell carcinomas and 11% (7/66) of the CIN stained positively for p53. Except for 3 cases of invasive squamous cell carcinoma, there was only sporadic intranuclear staining of less than 5% of the cells. No staining was observed in all non-neoplastic/metaplastic squamous epithelial cells. The pattern of p53 staining is significantly different for all 3 categories. However it is undetermined as to whether the positive immunoperoxidase staining is a direct consequence of p53 gene mutation or otherwise.

p53 expression in hepatocellular carcinoma in a population in Singapore with endemic hepatitis B virus infection

AIMS

To study the expression and clinical significance (if any) of p53 protein in hepatocellular carcinomas (HCC) arising in a population with endemic hepatitis B virus (HBV) infection.

METHODS

Immunohistochemical staining was performed on formalin fixed, paraffin was embedded histological sections of 46 HCC cases using an antihuman p53 monoclonal antibody; serial sections were also stained for hepatitis B surface antigen (HBsAg), hepatitis B core antigen (HBcAg) and alpha fetoprotein (AFP). Nuclear p53 staining was assessed according to intensity (absent, weak or strong) and extent (< 5%, 6-25%, 26-50%, and > 50%) of positive cells. Tissue HBsAg, HBcAg and AFP were recorded as absent or present.

RESULTS

The p53 protein was expressed in 35% (16 of 46) of HCCs; the positive rate in grade III/IV tumours (13 of 31; 42%) was higher than in grade I/II tumours (three of 15; 20%) but this was not statistically significant. HBsAg positive tumours showed almost the same proportion of p53 staining (11 of 29; 38%) as HBsAg negative ones (five of 17; 29%).

CONCLUSIONS

The p53 protein was expressed in 35% of HCC cases. There was no statistically significant correlation between HBV infection and p53 protein expression. Similarly, there was no definite correlation between p53 positivity and tumour size, histological grade or vascular invasion.

An immunohistochemical study of p53 protein in the different histological subtypes of gastric carcinoma

p53 mutations are known to occur frequently in human cancers, including gastric carcinomas. Previous studies of its incidence in gastric carcinomas had shown a varying incidence ranging from a low of 4% to as high as 57%. In this study, 42 cases of gastric carcinomas were analyzed for p53 using a commercially available mouse monoclonal antibody in routinely formalin-fixed paraffin-embedded tissue sections. These included 22 intestinal-type (7 well/moderately differentiated and 15 poorly differentiated), 16 diffuse-type and 4 mixed. Altogether, 60% of our cases stained positively for p53. Overall, well/moderately differentiated intestinal-type carcinomas stained more frequently for p53 than poorly differentiated intestinal-type carcinomas (p < 0.075). A comparison between the incidence in diffuse-type (69%) and intestinal type (55%) was unremarkable. p53 staining was also present in 3 of the 4 early cases studied. The results suggest that p53 mutations play an important role in carcinogenesis in gastric carcinoma and further implies that p53 mutation may be an early occurrence during tumor transformation.

An immunohistochemical study of p53 protein in gallbladder and extrahepatic bile duct/ampullary carcinomas

BACKGROUND

p53 mutations are known to occur frequently in human cancers, including gallbladder carcinoma. However, there has been no study of p53 expression in extrahepatic bile duct/ampullary carcinoma. Furthermore, gallbladder carcinoma is associated with cholelithiasis, whereas no such association is known for extrahepatic bile duct carcinoma, suggesting that they could arise from different pathogenetic mechanisms.

METHODS

Twenty-four gallbladder carcinomas and 35 extrahepatic bile duct/ampullary carcinomas were stained with an anti-human p53 protein monoclonal antibody by the streptavidin-biotin immunoperoxidase method. Both the extent and intensity of p53 protein staining were noted.

RESULTS

Ninety-two percent of the gallbladder carcinomas stained for p53 protein compared with only 66% of the extrahepatic bile duct/ampullary carcinomas. The statistical significance was maintained even when the comparison was restricted to strong p53 staining in moderately to poorly differentiated adenocarcinomas (P < 0.05). Of the gallbladder carcinomas, poorly differentiated adenocarcinomas stained more strongly than well to moderately differentiated adenocarcinomas; the converse was true for extrahepatic bile duct/ampullary adenocarcinomas.

CONCLUSION

The majority of gallbladder and extrahepatic bile duct/ampullary carcinomas stain for p53 protein. The incidence and pattern of staining is different, however, and supports the contention that these could be different tumors with differing etiologies and pathogenetic mechanisms.

p53 expression in pseudoepitheliomatous hyperplasia, keratoacanthoma, and squamous cell carcinoma of skin

BACKGROUND

Expression of p53 protein has been described in a variety of human malignant tumors. Recent reports have also demonstrated its presence in benign and reactive lesions. The significance of p53 expression is unclear.

METHODS

This study examines the p53 expression in proliferative lesions of skin, including 6 pseudoepitheliomatous hyperplasia, 33 keratoacanthoma, and 45 squamous cell carcinoma, and to evaluate its significance.

RESULTS

p53 expression was observed in all of the six cases of pseudoepitheliomatous hyperplasia, 78.8% of keratoacanthoma, and 75.5% of squamous cell carcinoma. The staining pattern of pseudoepitheliomatous hyperplasia and keratoacanthoma was generally less intense and extensive compared with that of squamous cell carcinoma. A keratoacanthoma with nuclear atypia that showed strong and extensive p53 staining was also encountered. The perilesional skin in sun-exposed sites often showed the presence of p53-positive keratinocytes. Control skin taken from the buttock was negative for p53 protein. Conversely, p53 was often expressed in carcinomas arising from sun-exposed as well as sun-protected sites. p53 positivity involved mainly the undifferentiated cells at the base of the epidermis or periphery of tumor cords. Differentiated keratinized cells were not stained. p53-positive fibroblasts were also noted in the inflammatory and granulation tissues of pseudoepitheliomatous hyperplasia.

CONCLUSIONS

p53 expression in skin is common and appears to be an early event in a series of genetic alterations reflecting underlying actinic damage, which may lead to but does not necessarily indicate neoplastic or malignant transformation. Because p53 staining is seen in proliferative and undifferentiated cells and ceases to be expressed when the cells differentiate, it appears that the expression of p53 protein, mutant or wild-type, is an indicator of immaturity and proliferative capacity of the cell rather than one of neoplasia or malignancy.

Clinical importance of p53 protein in gall bladder carcinoma and its precursor lesions

AIMS

To study the expression and importance (if any) of p53 protein in gall bladder carcinoma and its precursor lesions.

METHODS

Immunohistochemical staining was performed on formalin fixed, paraffin wax embedded histological sections with an anti-human p53 monoclonal antibody (DO-7; Dako Corporation M7001) (24 carcinomas, one adenocarcinoma in situ, six dysplasias, three adenomas and four cases of chronic cholecystitis). Invasive, in situ, and dysplastic areas as well as normal-looking epithelium were sought. Nuclear staining was assessed according to intensity and extent of positive cells. Both variables were graded on a scale of 1-3 and aggregate p53 scores were obtained (range: 0, 2-6). Only p53 scores of > or = 3 were regarded as significant.

RESULTS

Clinically important amounts of p53 were expressed in 92% of invasive carcinomas, 86% of carcinoma in situ, and 28% of dysplastic areas. None of the adenomas contained clinically important amounts of p53. Normal epithelium, present in all the cases, did not express p53 except in one case of moderately differentiated adenocarcinoma (p53 score 3). In general, there was no difference in the prevalence of p53 protein expression between dysplasias associated with, and those unassociated with invasive disease. There was a tendency for higher grade carcinomas to express more p53 protein.

CONCLUSIONS

The distribution of p53 protein in invasive carcinomas and the adjacent dysplastic and preinvasive lesions suggests that it is more commonly expressed than previously thought. The fact that p53 protein is also expressed in cases of dysplasia and carcinoma in situ unassociated with invasive malignancy lends further support to the contention that p53 gene mutations may have a role in the pathogenesis of gall bladder cancer. Expression of p53 protein may possibly be an indication of likely disease progression from dysplasia, to carcinoma in situ, to invasive disease.

HLA-DR antigen expression in colonic adenomas and adenocarcinomas

Previous studies have shown that malignant transformation is sometimes associated with the aberrant expression of HLA class II antigens. The functional significance of such aberrant expression is not known. Since HLA-DR antigen is expressed in normal colonic mucosa, it would be interesting to see if malignant transformation could result in the aberrant suppression of this antigen. Sixteen colonic adenocarcinomas, 29 colonic adenomatous polyps and 23 samples of normal colonic mucosa, including 9 cases of colonic mucosa adjacent to carcinoma, were stained immunohistochemically for HLA-DR antigen. The intensity and distribution of the antigen staining in the cytoplasm and luminal surface of the epithelial elements were analysed semiquantitatively. The lymphoplasmacytic infiltrate in the lamina propria was also evaluated. Cytoplasmic HLA-DR antigen expression was found to be significantly diminished in moderately and poorly differentiated adenocarcinomas but not in adenomas or well-differentiated adenocarcinomas. This suggests that the change in HLA-DR expression is not intrinsic to the neoplastic process but may merely be due to the fact that malignant cells, as they become less differentiated, tend to show alterations in their antigenic phenotype.

An immunohistochemical study of ras oncoprotein expression in gastric carcinoma

BACKGROUND

Previous studies have shown that ras oncoprotein is overexpressed in gastric carcinoma. It is unsettled whether there is differential expression of this oncoprotein in the two major subtypes of gastric carcinoma--intestinal type and diffuse type.

METHODS

Forty-four cases of gastric carcinomas (24 intestinal type, 18 diffuse type, and 2 mixed according to the Lauren classification) were analyzed for ras oncoprotein expression using commercially available antibodies in routinely formaldehyde-fixed, paraffin-embedded tissue sections.

RESULTS

Altogether, 13 cases stained unequivocally, and these appeared as granular cytoplasmic staining in tumor cells. Only five were intestinal-type carcinomas; the remaining eight were diffuse type and included two intramucosal carcinomas. When the comparison between the two subtypes was limited only to the poorly differentiated carcinomas, the difference was statistically significant (P < 0.05). ras Oncoprotein also was strongly expressed in normal duodenal mucosa as well as areas of gastric intestinal metaplasia.

CONCLUSIONS

These results suggest that the strong expression of ras oncoprotein in gastric intestinal metaplasia may be merely a reflection of metaplastic change to an intestinal epithelial phenotype. The differential expression of ras oncoprotein between diffuse-type and poorly differentiated intestinal-type gastric carcinoma implies that these are two distinct subtypes of gastric carcinoma.

Papillary carcinoma arising in a thyroglossal cyst

Carcinoma arising in a congenital thyroglossal cyst is rare, with less than 150 cases reported worldwide. This is a case report of a papillary carcinoma arising within a thyroglossal cyst in a 51 year old woman. Management of this condition remains controversial. Most of these tumours arise from ectopic thyroid tissue within the cyst. Prognosis is good as metastasis is uncommon. Sistrunk procedure is adequate if histology does not reveal extracystic extension.

Histogenesis of true splenic cysts: a histological and immunohistochemical study

Three true splenic cysts were studied histologically and immunohistochemically using antibodies against Ber-EP4, CEA, factor-VIII related antigen and several cytokeratins of varying molecular weights. Two cysts were lined by cuboidal and columnar cells with extensive squamous metaplasia. The columnar cells have the immunophenotype of mesothelial cells being positive for keratin but negative for Ber-EP4 and CEA. The third cyst occurred in a wandering spleen and was lined by hobnail columnar cells with cilia resembling tubal epithelium of Fallopian tube. The immunophenotype was that of epithelial cells being positive for both keratin and Ber-EP4. It is likely that true splenic cysts originate from invagination of the capsular mesothelial lining. The frequent occurrence of stratified squamous epithelium is attributed to squamous metaplasia secondary to haemorrhage and irritation. On the other hand, the presence of tubal epithelium in true splenic cysts is more likely to be due to the innate potentiality of mesothelial cells to differentiate along Mullerian line and may be a manifestation of the secondary Mullerian system. The cyst lining cells were negative for factor-VIII related antigen and thus offered no support for an origin from endothelium.

Helicobacter pylori and gastric cancer: correlation with gastritis, intestinal metaplasia, and tumour histology

This study aimed to examine the association between Helicobacter pylori, histological gastritis, and intestinal metaplasia in gastric cancers of different histological types. A total of 169 gastrectomy specimens received in one pathology department were studied. Altogether 156 were adenocarcinomas (intestinal type 87, diffuse type 50, mixed type 19). Gastritis occurred in 137 of 163 body specimens (84%) and in 126 of 131 antral specimens (96%). Its presence was unrelated to tumour histology. Atrophic gastritis was more common in both body and antral mucosa in intestinal type compared with diffuse type carcinoma. This was also true for intestinal metaplasia of the body, but not of the antral mucosa. H pylori was present in 101 of 163 (62%) body specimens and 56 of 131 (43%) antral specimens. In intestinal type carcinoma, H pylori was found in 52/84 (62%) body specimens and in 24/70 (34%) antral specimens, while the corresponding figures for diffuse type carcinoma were 29/48 (60%) and 17/38 (45%) respectively. Tumour histology therefore had no influence on the occurrence of H pylori. Tumour site had no effect on the presence or absence of gastritis, atrophic changes, intestinal metaplasia, or H pylori. While both H pylori and gastritis are associated with gastric cancer, the association is unrelated to tumour histology and may not be a causal one.

Expression of HLA-DR antigen in different histological types of gastric polyp

AIMS

To study the expression of HLA-DR antigen in the different histological types of gastric polyps.

METHODS

Ninety five cases of gastric polyps were histologically classified and examined for the presence of Helicobacter pylori, and for degree and type of inflammation. Further sections were stained immunohistochemically for HLA-DR antigen expression in the epithelium using a monoclonal antibody that was reactive to formalin-fixed paraffin wax embedded tissue.

RESULTS

HLA-DR antigen was expressed in all of the inflammatory polyps studied (20/20), and in most hyperplastic (12/16) and adenomatous (4/6) polyps. Only a few fundic gland polyps (8/51) stained positively for HLA-DR antigen. Gastric polyps seem to have a greater tendency to express HLA-DR antigens than non-polypoid gastric mucosa, even after considering the factors that may affect HLA-DR antigen expression, such as inflammation and the presence of H pylori.

CONCLUSIONS

Growth disturbances/polyp formation may be associated with increased HLA-DR antigen expression.

Effects of polyphenolic natural products on the lipid profiles of rats fed high fat diets

Male Wistar rats were fed a high fat diet (HFD) containing 2.5% cholesterol and 16% lard supplemented with polyphenolic natural products namely quercetin, morin or tannic acid (100 mg/rat/day) for 4, 7 and 10 wk. Rats fed HFD without the supplements served as control. The effects of these compounds on blood lipid profiles, enzymes, liver fat and aorta of the rat were studied. In rats fed HFD containing tannic acid, plasma total cholesterol (TC), low density lipoprotein cholesterol (LDLC) and triglyceride (TG) were reduced by 33.3%, 29.6% and 65.1%, respectively, at week 10. High density lipoprotein cholesterol (HDLC) concentration was not altered. Fat deposition was also decreased in the liver of these rats. Morin significantly reduced plasma TG (65.1%) and liver fat only at week 7 while at week 10 it reduced plasma TC and LDLC by 30.9% and 29.3% respectively. The plasma HDLC concentration was increased by 47.3% at week 4 but no effect was seen at weeks 7 and 10. In the rats fed HFD containing quercetin, plasma HDLC was increased by 28.6% at week 7 but at week 10, plasma LDLC was increased by 21.2%. Quercetin did not cause any significant changes on the plasma TC, TG and liver fat at weeks 4, 7 and 10. Plasma alanine aminotransferase, alkaline phosphatase and bilirubin in control and treated groups were not significantly different. However, hepatic lipase activity in rats fed tannic acid was significantly lower. Aortae of all groups of rats showed no abnormalities. The present report indicates that tannic acid and morin are effective in reducing plasma and liver lipids when supplemented with a high fat diet in rats.

HLA-DR antigen expression in intestinal-type and diffuse-type gastric carcinoma

The expression of the HLA-DR antigen, a Class II HLA antigen, was analyzed in 41 cases of gastric carcinoma (23 intestinal-type and 18 diffuse-type according to a modified Lauren classification) using a monoclonal antibody that is reactive to this antigen in routinely formalin-fixed, paraffin-embedded tissue sections. Seventeen cases of intestinal-type gastric carcinoma and two cases of diffuse-type gastric carcinoma were positive for the HLA-DR antigen. The staining in intestinal-type carcinoma generally was stronger and more extensive than in diffuse-type carcinoma, which showed only weak and focal staining. The difference in the frequency and pattern of staining between intestinal and diffuse-type gastric carcinoma supports the concept that these are two distinct subtypes of gastric carcinoma.

Association of Helicobacter pylori with HLA-DR antigen expression in gastritis

AIMS

To assess the association between Helicobacter pylori-associated gastritis and HLA-DR antigen (class II antigen) expression.

METHODS

Fifty endoscopic gastric biopsy specimens were studied for the presence of H pylori, degree and type of inflammation, and for HLA-DR antigen expression in the epithelium. The cases were chosen to represent different categories: inflamed gastric mucosa with (n = 13) and without (n = 20) H pylori, and non-inflamed mucosa (n = 17).

RESULTS

The antigen was aberrantly expressed in the antral mucosal epithelium in 11 of 12 cases (92%) with acute-on-chronic gastritis when H pylori was also present. It was present in the antrum in only seven of 18 H pylori negative cases (39%) with acute-on-chronic/chronic gastritis. One of three cases of acute gastritis and three of seven cases of chronic gastric erosions (non-inflamed category) showed positive staining. Generally, there was more staining in the antral than body mucosa and in the surface/foveolar epithelium than in the glands. No aberrant HLA-DR antigen expression was found in the 10 cases of normal gastric mucosa examined.

CONCLUSIONS

These findings suggest that H pylori may have a role in the induction of class II HLA antigen expression in chronic gastritis and lend support to the view that these organisms may be responsible for part of the inflammatory response.

Paraneoplastic optic neuropathy in nasopharyngeal carcinoma--report of a case

A 31-year-old Chinese man developed left optic neuritis with left sectorial field loss as a remote effect of nasopharyngeal carcinoma. The field defect showed interesting fluctuations in response to the dosage of systemic steroid therapy. Neuropathologic findings from an exploratory craniotomy did not show any gross tumour mass around the left optic nerve nor any histological evidence of tumour infiltration. This case illustrates that "optic neuritis" could be a paraneoplastic effect of nasopharyngeal carcinoma.

Malignant glandular triton tumor

A case of left brachial plexus-related malignant peripheral nerve sheath tumor showing neoplastic, glandular, and rhabdomyoblastic elements in a 39-year-old Chinese man is reported. The authors suggested that this tumor be termed a malignant glandular triton tumor in view of the presence of the adenocarcinomatous component. The patient had extensive local recurrence comprising mainly the Schwann spindle cells within a year after complete piecemeal removal and died 15 months later after the initial presentation. The natural behavior of this tumor, as in other reported cases of malignant triton tumor, is extremely aggressive, unlike malignant schwannoma or glandular malignant schwannoma. The histogenesis of this tumor is likely to be from primitive neural crest cells, Schwann's cell precursors, or metaplastic malignant Schwann's cells.

Modulation of MHC gene expression in human breast carcinoma cells by hormones

Products encoded by the class I Major Histocompatibility Complex (MHC) genes serve as restriction molecules which enable T cells to generate an immune response to specific antigens. Recently, many investigators have demonstrated the importance of class I antigens in enabling the host to regulate tumor growth in vivo. In this report, we have studied the regulation of HLA genes by hormones in human breast cancer cell lines. Eight lines were studied. Using HLA locus-specific DNA probes, the level of HLA-A and HLA-B specific mRNAs were found to be underrepresented in six of these cell lines when compared to an epithelial cell line derived from a normal lactating breast. Moreover, the expression of class I MHC mRNA in these cells correlated well with the level of chloramphenicol acetyltransferase (CAT) activity detected after the introduction of exogenous HLA-CAT DNA-constructs. It was also found that HLA expression in some of the breast carcinoma cell lines could be modulated by the addition of hormones. Hence, HLA mRNA expression in the cell line MCF-7 was enhanced by the addition of estrogen; but was down-regulated in the presence of dexamethasone. Conversely, for T-47D cells, HLA expression was suppressed by progesterone. These results indicate that hormones could have an influence on the expression of HLA genes and may therefore indirectly be involved in the regulation of tumor growth by the host's immune system.

Spindle and epithelioid cell nevus of tongue at an unusual site

A case of spindle and epithelioid cell nevus of the tongue is presented. It shows unusual and distinctive desmoplasia and cells containing melanosomes identified by histochemical and electron microscopic techniques. We believe this is the second case, but the first fully documented report, of this unusual nevus of tongue reported in the literature.

Intestinal and diffuse carcinoma of the stomach among the ethnic and dialect groups in Singapore

This study attempts to determine the relative prevalence of intestinal-type and diffuse-type carcinomas (using a modified Lauren classification of gastric carcinomas) and to evaluate its significance in relation to the difference in stomach cancer risks among the different ethnic and Chinese dialect groups in Singapore. Of the 648 cases of primary adenocarcinoma of the stomach studied, 405 (62.5%) were of the intestinal type, 206 (31.8%) of the diffuse type, and 37 (5.7%) of the mixed type. Men had higher proportions of intestinal-type carcinoma than women. The intestinal-diffuse carcinoma ratio increased progressively with age. Although the relative intestinal-diffuse carcinoma ratios in women appeared to reflect the relative incidence rates of stomach cancer of the different ethnic and dialect groups, the ratios in men were inconsistent. Indian men had a higher intestinal-diffuse carcinoma ratio than Chinese men despite a lower incidence of stomach cancer. Hokkien men had the highest incidence of stomach cancer and the lowest intestinal-diffuse carcinoma ratio among the Chinese dialect groups. The use of the ratio as an indicator of relative risks for gastric cancer between populations of different genetic makeup is inconsistent and unreliable.

Thrombotic complication of umbilical arterial catheterization and its sequelae

Umbilical arterial catheterization caused major complications including 5 deaths in 25 of 230 infants who underwent autopsy at the Kandang Kerbau Hospital in a two-and-a-half year period beginning May 1982. Arterial thrombosis developed in 25 of 129 (19.3%) autopsies with a history of umbilical arterial catheterization. Pathological sequelae of thrombosis occurred in 14 cases (peripheral gangrene 1, renal 6, gastrointestinal 3 and both renal and gastro-intestinal 4). The sequelae were clinically unsuspected in the majority. Early deaths were uncommon in the group with thrombosis. Comparison of neonatal factors revealed no significant differences between the group with sequelae and those without. Infants with indwelling umbilical arterial catheter should be actively monitored for complications.

Haemorrhagic chronic radiation cystitis--following treatment of pelvic malignancies

Haemorrhagic chronic radiation cystitis is not an uncommon clinical entity, and should be suspected in patients with painless gross haematuria who have a past history of radiotherapy to the pelvic region. A series of 29 patients with haemorrhagic chronic radiation cystitis were managed in the University Department of Surgery, Singapore General Hospital over a 5 years period from 1979 to 1983. Cystodiathermy was the mainstay of treatment and was successful in controlling haematuria in 27 patients. Two patients developed uncontrolled haematuria, urinary tract infection, septicaemia and died giving mortality of 6.9%. Excellent control of haemorrhage can be obtained with cystodiathermy in the majority of patients. Intravesical instillation of steroid or silver nitrate is used for the more intractable cases, after cystodiathermy. Urinary diversion with or without cystectomy are desperate measures to salvage the severe case and mortality is high.