Biomedical subjects

J Melamed

Publications and source records attributed to J Melamed.

At least 37 records · Page 2Linked to original sources

PubMed1998

The role of bladder neck biopsy in men undergoing radical retropubic prostatectomy with preservation of the bladder neck.

PURPOSE: Radical retropubic prostatectomy is often performed with preservation of the bladder neck. We examine the incidence of benign and malignant prostatic tissue at the bladder neck margin in men undergoing radical retropubic prostatectomy with preservation of the bladder neck for clinically localized prostate cancer. MATERIALS AND METHODS: The study included 100 cases of radical retropubic prostatectomy with preservation of the bladder neck performed by a single surgeon (H. L.). A 2 mm. thick circumferential specimen was excised from the bladder neck, divided into 4 quadrants (anterior, posterior, right and left) and submitted for frozen section examination. The permanent sections from these bladder neck biopsies and the entire surgical specimens were analyzed by a single pathologist (J. M.). RESULTS: The frozen section diagnosis from the bladder neck biopsies were adenocarcinoma, benign prostatic tissue and no prostatic tissue in 3, 38 and 59 cases, respectively. The permanent section diagnosis of the bladder neck biopsies was adenocarcinoma, benign prostatic tissue and no prostatic tissue in 4, 57 and 39 cases, respectively. The sensitivity specificity, and positive and negative predictive values for examination of the surgical specimen to identify benign prostatic tissue was 67, 90, 90 and 65%, respectively. The bladder neck was re-biopsied because of the findings of adenocarcinoma and benign prostatic tissue in 3 and 8 cases, respectively. The initial bladder neck biopsy resulted in pathological down staging to pT2c in only 1 case. Repeat resection of the bladder neck in all cases with 10% or less benign prostatic tissue showed no prostatic tissue, whereas 50% of the cases with more than 10% benign prostatic tissue demonstrated residual benign prostatic tissue. Serum prostate specific antigen was undetectable immediately after radical retropubic prostatectomy in all cases with benign prostatic tissue only. CONCLUSIONS: Preservation of the bladder neck during radical retropubic prostatectomy does not significantly compromise total extirpation of the malignant process. Benign prostatic tissue at the bladder neck margin is relatively common. Examination of the surgical specimen has limited sensitivity, and negative and positive predictive values for the presence of benign prostatic tissue at the bladder neck margin. The impact of benign prostatic tissue as it relates to future malignant transformation is unknown. Submitting frozen section specimens from the bladder neck is reasonable for the younger man who may be at risk from benign prostatic tissue at the bladder neck margin.

Adenocarcinoma↗

PubMed1998

Initial clinical evaluation of radiolabeled MX-DTPA humanized BrE-3 antibody in patients with advanced breast cancer.

To evaluate radiometal-labeled humanized BrE-3 (huBrE-3) monoclonal antibody as a radioimmunolocalization and therapeutic agent in breast cancer patients, tumor localization, pharmacokinetics, radiation dosimetry, and immunogenicity of (111)In-labeled combined 1-p-isothiocyanatobenzyl 3-methyl- and 1-p-isothiocyanatobenzyl 4-methyldiethylenetriamine pentaacetic acid (MX-DTPA) huBrE-3 were studied. Seven women with BrE-3 antigen-positive, metastatic breast carcinoma underwent (111)In huBrE-3 infusion (5 mCi; 50 mg), followed by serial gamma camera imaging and plasma sampling. Region of interest analysis of images was used to make radiation absorbed dose estimates for (111)In huBrE-3. Data were extrapolated to 90Y huBrE-3. Human anti-human antibody (HAHA) response was measured in serum samples obtained up to 3 months after infusion. Patients tolerated infusions well. Seventy-six percent of 105 known sites of disease were identified on planar and single-photon emission computed tomography scans. For six of seven patients, a biexponential model fit the plasma time-activity curve best with an average T1/2alpha=10.6+/-8.5 (SD) h and average T1/2beta=114.2+/-39.2 h. Radiation absorbed dose estimates for (111)In huBrE-3 for whole body averaged 0.53+/-.08 rads/mCi. Dose estimates for 90Y huBrE-3 for marrow averaged 8.4+/-11.9 rads/mCi, and for tumors, 70+/-31.5 rads/mCi. Liver radioactivity uptake averaged 19.7+/-8.8% injected dose at 24 h after infusion, translating into an average radiation absorbed dose 21.1+/-12 rads/90Y mCi administered. Only one of seven patients demonstrated a low level of HAHA response. Although the plasma half-lives are longer and marrow dose higher for radiolabeled huBrE-3 compared with the murine construct, the excellent tumor localization, good tumor dosimetry, and low immunogenicity support the use of 90Y-huBrE-3 antibody for radioimmunotherapy of breast cancer.

Adult↗

PubMed1997

Allelic loss on chromosome 13q in human prostate carcinoma.

To clarify the role in prostate tumorigenesis played by loss of the three known or putative tumor suppressor loci on the centromeric portion of chromosome 13q, we examined 80 clinically localized and 15 advanced prostate carcinomas for allelic loss at microsatellite markers mapped to this region, including markers tightly linked to the BRCA-2, retinoblastoma (Rb), and DBM (deleted in B-cell malignancy) loci. Among the 80 clinically localized cases, 24 showed allelic loss at one or more 13q loci. In all cases with loss, the Rb and/or DBM loci were lost. No cases were found with loss of Rb without loss of DBM or loss of DBM without loss of Rb, implying a role for both the Rb and DBM loci in clinically localized prostate cancer. Loss of the BRCA-2 locus was less common (4 of 55 informative cases) and was always associated with loss of Rb and/or DBM loci. Thus, the BRCA-2 locus does not appear to play as important a role in clinically localized prostate cancer as the Rb and/or DBM loci. Allelic loss on 13q was extremely common in the clinically advanced cases; it was present in 14 of the 15 cases. The rate of allelic loss at each of the three tumor suppressor loci was increased significantly in the advanced cases (P < 0.01, Fisher's exact test). Thus, loss of heterozygosity on 13q is very common in prostate cancer and occurs at all three known or putative tumor suppressor loci on the centromeric portion of chromosome 13q.

Alleles↗

PubMed1996

Morphological and biological characteristics of mammogram-detected invasive breast cancer.

Thirty-nine mammographically detected, (M-detected) small invasive carcinomas of the breast (< or = 5 mm) were compared with 78 consecutive clinical cancers (> or = 10 mm) for a variety of morphological and biological markers of prognostic importance. There were more tubular carcinomas in the M-detected group (12.8% v 3.8%), but this did not reach statistical significance. Incidences of other histological types were similar. The types of associated in situ component were similar in the two groups. M-detected cancers were of lower overall grade (P < .001), lower architectural and nuclear grades (P = .0164 and P < .0001 respectively), and had fewer mitotic cells (P < .0001). None showed positive lymph nodes (P < .0001). Estrogen and progesterone receptor expression was similar in both groups. M-detected cancers expressed p53 nuclear protein less frequently than clinical cancers (P = .0398), had lower levels of microvessel density (P = .0001), and were more often diploid (P = .0131). S-phase of diploid tumors in the two groups was similar, but S-phase of aneuploid tumors was lower in the M-detected group (P = .0057). Ki67 expression was lower in M-detected cancers (P < .0001). In conclusion, M-detected small breast cancers, although invasive, represent an evolutionary phase of breast cancer that generally lacks morphological and biologic markers of aggressive behavior. The presence or absence of these markers, collectively, may explain the influence of tumor size on survival in patients with breast cancer.

Breast Neoplasms↗

PubMed1996

A placebo- and active-controlled randomized trial of prophylactic treatment of seasonal allergic rhinitis with mometasone furoate aqueous nasal spray.

BACKGROUND: Topical nasal corticosteroids have become a mainstay of treatment for the symptoms of seasonal allergic rhinitis (SAR). It is likely that topical corticosteroids, by blocking an initial influx of inflammatory cells in the nasal mucosa induced by aeroallergens, may have a preventive effect on nasal allergy symptoms when administered before the pollen season. OBJECTIVE: This study was designed to assess the efficacy and safety of an 8-week course of mometasone furoate nasal spray (MFNS), 200 micrograms once daily, in the treatment of SAR compared with beclomethasone dipropionate aqueous nasal spray (BDP), 168 micrograms twice daily, and placebo vehicle, when treatment is initiated before the anticipated onset of the ragweed season. METHODS: Three hundred forty-nine patients with SAR to ragweed pollen from nine centers in the Northeast and Midwest of the United States were randomized to one of the three intranasal study medications (MFNS, 200 micrograms once daily, BDP, 168 micrograms twice daily, or placebo vehicle), starting 4 weeks before the estimated start of the ragweed season. RESULTS: The proportion of "minimal symptom" days (total nasal symptom score < or = 2) was statistically significantly higher in both the MFNS and BDP groups when compared with the placebo vehicle group (p < 0.01). The two active treatment groups were not statistically significantly different from each other. MFNS and BDP displayed a similar safety profile that did not differ from placebo. CONCLUSIONS: This suggests that MFNS, 200 micrograms (once daily), is a useful therapy in the prophylactic treatment of SAR.

Administration, Intranasal↗

PubMed1996

Tilarin in combination with astemizole.

This multicentre double-blind, placebo controlled study had a practical objective, based on the expectation that many patients with seasonal allergic rhinitis will be prescribed oral antihistamine monotherapy by their primary care physician, whereas allergy specialists are more likely to prescribe combination therapy including antiinflammatories. The specific question was, "Will the addition of nedocromil sodium 1% nasal spray to astemizole tablets improve control of symptoms of seasonal allergic rhinitis induced by ragweed pollen, as compared to astemizole therapy alone?'. Following a one-week baseline, planned to coincide with the start of the local ragweed pollen season, patients (aged 12-64) were randomly assigned to four weeks' double-blind test treatment with either nedocromil sodium 1% nasal spray four times daily (QID) + astemizole (n = 146) or placebo nasal spray + astemizole (n = 148) or double-dummy (nasal spray + capsules) placebo (n = 71). Patient diary cards were kept throughout the five weeks, and clinic visits were made before and after baseline and after one and four weeks' treatment. During the 10-day peak pollen period, the diary card rhinitis symptom summary score (0-4 severity scale) was significantly reduced in patients receiving either astemizole alone (p < 0.001) or the combination therapy (p < 0.001) as compared with placebo. Direct comparison of the active treatments further showed that symptoms were significantly less severe (p < 0.01) with the combined therapy than with astemizole alone, and this despite significantly greater reliance on permitted rescue medications (p < 0.05 for pseudoephedrine usage) in the astemizole group. Clinical assessments of rhinitis made during the peak pollen visit, after the first week of test treatment, were also significantly (p < 0.05 - p < 0.01) in favour of combined therapy with nedocromil sodium 1% nasal spray + astemizole rather than astemizole alone, and at the same time this preference was confirmed by physician (p = 0.011) and patient (p = 0.003) opinions of symptom control. In conclusion, this antiinflammatory + antihistamine treatment proved superior to antihistamine alone for effective management of allergic rhinitis. The combined therapy worked quickly and was well-tolerated, with no serious adverse events or untoward effects on blood or urine variables.

Administration, Intranasal↗

PubMed1995

Chromosome 12 abnormalities in malignant ovarian germ cell tumors.

We analyzed 3 cases of malignant ovarian germ cell tumors (MOGCTs), comprising 1 dysgerminoma and 2 immature teratomas, by banded chromosome analysis and by in situ hybridization (ISH) using a chromosome 12p painting probe. We found evidence of 12p abnormalities in two of them. A possible common genetic pathway of origin of a subset of MOGCTs with testicular germ cell tumors (TGCTs) is discussed.

Aneuploidy↗

PubMed1995

Kaposi's sarcoma of internal organs. A multiparameter study of 86 cases.

BACKGROUND: During the past decade, Kaposi's sarcoma (KS), one of the most common acquired immune deficiency syndrome-defining diseases, has been the subject of sustained research. However, basic questions about its etiology, histogenesis, growth, and dissemination remain unanswered. Even its nature, whether hyperplasia or neoplasia, is still controversial. Most studies and concepts to date have been based on dermatologic KS. The present study, in contrast, examines by various parameters a series of patients with KS of internal organs. MATERIALS AND METHODS: The series includes 86 cases (39 surgical specimens and 47 autopsies) of visceral and disseminated KS. The study is focused on the gross distribution of lesions, the mode of dissemination, the histologic patterns, and the cellular immunophenotypes, which are investigated with the use of 18 monoclonal antibodies. RESULTS: The involvement of various organs, multiplicity of lesions, and progression of tumors were recorded. Seven histologic patterns forming a spectrum of cellular differentiation were distinguished. Immunophenotypes characteristic for different histologic patterns were recognized. Although some cell markers such as those recognized by antibodies against Factor VIII R-Ag, Actin, and Ulex europaeus were restricted to the well differentiated KS cells, others including CD34 and CD31 demonstrated a strong affinity for the entire spectrum of KS cell differentiation. CONCLUSION: The present study of KS of internal organs revealed that poor grades of histologic and immunophenotypic differentiation correlated with invasion and dissemination, which are fundamental characteristics of malignant tumors.

Acquired Immunodeficiency Syndrome↗

PubMed1995

Sinus histiocytosis mimicking metastatic melanoma in lymph nodes of a patient with a large joint prosthesis: case report and review of the literature.

Malignant melanoma metastases to regional lymph nodes may be mimicked by several non-neoplastic processes, including sinus histiocytosis induced by fragments shed from joint prostheses. A patient who had an elective lymph node dissection for malignant melanoma and was found to have "post-prosthesis lymph node histiocytosis" resembling metastatic disease is described. Knowledge of the patient's past history of a total shoulder joint replacement along with the use of polarized light microscopy to identify birefringent particles of prosthetic debris allows for an accurate histologic diagnosis.

Aged↗

PubMed1995

Chromosomal abnormalities in choriocarcinomas of the female.

We have studied six cases of choriocarcinomas in the female by conventional cytogenetic analysis and by in situ hybridization using a 12p painting probe, and found evidence for chromosome 12 abnormalities in two of them. Abnormalities of chromosome 12 are a common occurrence in genitourinary tumors of the female, but their significance is not known. We discuss the present findings in relation to those in malignant ovarian germ cell tumors (MOGCTs).

Choriocarcinoma↗

PubMed1995

Minor symptoms are not predictive of elevated theophylline levels in adults on chronic therapy.

BACKGROUND: Theophylline toxicity is associated with significant morbidity and mortality. While a relationship of the serum theophylline level to symptoms associated with toxicity has been described in acutely intoxicated or elderly patients, this relationship may not be valid in younger patients receiving chronic theophylline therapy. OBJECTIVE: This study was designed to define the predictive value and prevalence of minor symptoms of theophylline toxicity in ambulatory asthmatic adults receiving chronic theophylline therapy with elevated serum theophylline levels. METHODS: We conducted a retrospective study to determine the prevalence of symptoms in patients with elevated theophylline levels ( > 20 mg/L or 110 mumol/L). A prospective study was performed to ascertain the sensitivity, specificity, and predictive value of symptoms as an indication of elevated the theophylline level. In addition, we describe a patient who had a seizure in association with an elevated theophylline level in the absence of any preceding symptom of theophylline toxicity. RESULTS: We reviewed the result of 483 theophylline measurements in 450 asthmatic patients. In 46 instances the theophylline levels was > 20 mg/L. Only three of these patients were symptomatic. Ninety patients were prospectively studies with a total of 111 theophylline measurements of which 13 exceeded 20 mg/L. None of the symptoms (ie, nausea or gastrointestinal upset; headache or palpitations, irregular heart beat, tremor, or shakiness) was a sensitive predictor of an elevated theophylline level. CONCLUSIONS: Elevation of the theophylline level is frequently associated with lack of symptoms in young ambulatory asthmatic adults receiving chronic theophylline therapy. The question of whether cardiac or neurologic electrophysiologic abnormalities might exist in the absence of symptoms is an issue that needs to be addressed. Clinicians should continue to monitor serum levels on a regular basis and prescribe this drug conservatively.

Adolescent↗

PubMed1994

Hepatoid adenocarcinoma in the urinary bladder. Unusual localization of a newly recognized tumor type.

A tumor mass resected from the anterior bladder wall of a 68-year-old woman displayed unusual histologic features: sheets of hepatoid cells merging focally with a secondary glandular pattern of adenocarcinoma. Intracytoplasmic hyaline globules and bile production within the solid areas supported the impression of hepatocytic differentiation. Immunoreactivity for alpha-fetoprotein (AFP) and alpha-1-antitrypsin and a striking canalicular immunostaining pattern for carcinoembryonic antigen and epithelial membrane antigen all indicate hepatocellular differentiation within this bladder tumor. This represents a case of a hepatoid adenocarcinoma located in the urinary bladder. The use of the term "hepatoid" in the literature is reviewed and the reported cases are grouped into two distinct categories of tumors: (1) germ cell tumors with focal hepatoid areas and (2) true hepatoid adenocarcinomas that meet histologic and immunohistochemical criteria for hepatocellular differentiation. AFP-producing tumors without any other feature of hepatocellular differentiation should not be considered as hepatoid tumors. This classification of hepatoid tumors is likely to be important in elucidating the histogenesis and clinicopathologic features of these unusual neoplasms.

Adenocarcinoma↗

PubMed1994

Expression of transforming growth factor-alpha and the epidermal growth factor receptor in human prostate tissues.

Cells respond to certain soluble factors that bind to cell surface receptors possessing intrinsic tyrosine kinase activity. Overexpression of these molecules has been associated with tumor progression. Enhanced prostatic cancer cell growth in vitro has been reported in the presence of certain growth factors. To characterize the patterns of expression of the epidermal growth factor receptor (EGFr) and transforming growth factor-alpha (TGF alpha), we studied tissue from 107 prostate specimens using immunohistochemistry. We observed that epithelial cells of normal (n = 4) and benign prostatic (n = 56) tissues express EGFr but were unreactive for TGF alpha, while stroma cells in these tissues express TGF alpha but not EGFr. However, coexpression of EGFr and TGF alpha was identified in 22 of 46 prostatic adenocarcinomas studied. These results suggest that the major mode of action of EGFr/TGF alpha in normal and benign prostate is that of a paracrine or juxtacrine loop, the ligand being expressed in the stroma cells and the receptor in the epithelial cells. Since a subset of prostatic carcinomas coexpressed the ligand and the receptor in their tumor cells, it is suggested that an independent autocrine signaling mechanism may occur and grant a selective advantage for the growth of prostate cancers.

Adenocarcinoma↗

PubMed1994

Association of P53 nuclear overexpression and tumor progression in carcinoma in situ of the bladder.

We investigated the prevalence and clinical relevance of p53 nuclear overexpression, as detected by antibody PAb1801 and immunohistochemistry, in 33 patients with carcinoma in situ of the bladder. Median followup was 124 months. Disease progressed in 16 patients (48%) during followup. The association between p53 nuclear overexpression and tumor progression was assessed by multivariate analysis, controlling for possible confounding variables, such as patient age and sex, presence of associated stage Ta bladder tumor and adjuvant bacillus Calmette-Guerin therapy. Patients were stratified into 2 groups according to the per cent of tumor cells displaying p53 nuclear overexpression: group 1-18 with less than 20% tumor cells positive and group 2-15 with 20% or more tumor cells positive. Disease progressed in 3 patients (16.7%) in group 1 and in 13 (86.7%) in group 2 (p < 0.0001). Detection of p53 nuclear overexpression in 20% or more tumor cells was the only independent marker of tumor progression in univariate and multivariate analyses (p = 0.004, adjusted relative risk 8.6, 95% confidence interval 2 to 40). Death specifically from bladder cancer was also associated with this altered pattern of p53 expression (p = 0.01, Fisher's exact test). We conclude that p53 nuclear overexpression is an early event in bladder cancer, occurring in 48% of cases of carcinoma in situ of the bladder. Our results also suggest that p53 nuclear overexpression offers significant clinical information and may be a useful tool in the selection of therapy for patients with carcinoma in situ of the bladder.

Aged↗

PubMed1994

Clinical and pathobiological effects of neoadjuvant total androgen ablation therapy on clinically localized prostatic adenocarcinoma.

Neoadjuvant total androgen ablation therapy leads to involutional changes in prostatic carcinoma and may have the potential to downstage operable prostate cancers. We studied 27 clinically localized prostatic carcinomas after 3 months of combined treatment with a luteinizing hormone-releasing hormone agonist, goserelin acetate, and the antiandrogen flutamide, followed by radical retropubic prostatectomy, for changes in the serum prostate-specific antigen (PSA) level, changes in prostatic volume, therapy-induced histopathologic changes, DNA ploidy, and proliferative activity. Ten hormonally untreated, grade-matched prostatic adenocarcinomas served as controls. The mean pretherapy serum PSA level was 17.5 ng/ml, and posttherapy PSA levels were all < 4.0 ng/ml, with 18 men having undetectable levels. The mean reduction in prostatic volume following hormonal therapy was 37% (range 16-52%). Pathologic staging confirmed 20 pT2N0, six pT3N0, and one pT3N1. All prostates showed residual adenocarcinoma (extremely focal in seven cases [26%] with loss of glandular architecture, cytoplasmic vacuolization, and nuclear pyknosis. High-grade adenocarcinoma was nondiploid in 25% of hormonally treated prostates and 80% of 10 untreated controls. Immunostaining for proliferating cell nuclear antigen showed > 10% nuclear reactivity in 33% of treated carcinomas and 90% of untreated carcinomas. In conclusion, 3 months of neoadjuvant androgen ablation for localized prostatic carcinoma significantly lowers serum PSA and prostatic volume and produces involutional changes in residual carcinomas that mimic high-grade disease. However, pretreated carcinomas have predominantly a diploid DNA content and low proliferative activity as opposed to untreated carcinomas. Thus, grading of pretreated adenocarcinomas by conventional methods may be misleading. Preoperative total androgen ablation has a profound effect on a subset of prostatic carcinoma cells, possibly by facilitating programmed cell death.

Adenocarcinoma↗

PubMed1994

Evaluation of nedocromil sodium 2% ophthalmic solution for the treatment of seasonal allergic conjunctivitis.

During peak ragweed season, 86 patients with seasonal allergic conjunctivitis participated in a 9-week, multicenter, double-masked, placebo-controlled, group-comparative study testing the efficacy and safety of bid nedocromil sodium, 2% ophthalmic solution. The clinical effectiveness of nedocromil sodium was measured by analyzing the means of patient daily symptom scores and eye examinations after 1, 3, 5, and 8 weeks of treatment. The use of nedocromil sodium during peak ragweed pollen season reduced symptom scores with statistically significant treatment differences as compared with the placebo for itchy eyes, tearing, overall eye condition, and symptom summary score. Clinician assessments also favored the use of nedocromil sodium as indicated by significant improvements in tearing, conjunctival injection, and conjunctival edema. No significant side effects were reported by the patients, allergists, or ophthalmologists. We conclude that nedocromil sodium, 2% ophthalmic solution, administered bid is more effective in the relief of symptoms of seasonal allergic conjunctivitis than placebo and causes no major side effects.

Adolescent↗

PubMed1994

Renal myxoma. A report of two cases and review of the literature.

Renal myxomas are rare neoplasms. Seven cases have been reported, of which only two are convincingly diagnosed as myxoma; the remaining cases exhibit features of sarcoma, fibroepithelial polyp, or myxolipoma. We report two additional cases; one in a 52-year-old man and another in a 68-year-old woman. They were discovered incidentally by radiological examination. The resected kidney in both patients contained a well-demarcated gelatinous intraparenchymal tumor, which consisted of occasional slender spindle cells scattered in an abundant myxoid stroma, closely resembling myxomas of other sites. The tumor cells showed immunoreactivity for vimentin but not for S-100 protein, epithelial membrane antigen (EMA), CAM 5.2, HHF-35, or smooth muscle actin. Ultrastructural features were of fibroblast-like cells with an elaborate network of cytoplasmic processes. The differential diagnosis of myxoid tumors of the kidney includes myxoid variants of renal sarcomas and carcinomas, renomedullary interstitial cell tumors, and fibroepithelial polyps. It is important to recognize the existence of a renal myxoma, to avoid confusing this benign tumor with the malignant neoplasms with secondary myxoid features that may involve the kidney.

Aged↗

PubMed1993

p53 expression in precancerous gastric lesions: an immunohistochemical study of PAb 1801 monoclonal antibody on adenomatous and hyperplastic gastric polyps.

To determine the chronology of p53 mutation in the gastric carcinogenic sequence, we studied p53 overexpression in premalignant lesions, including 17 adenomatous polyps (10/17 surrounded by intestinal metaplasia and 11/17 harboring foci of adenocarcinoma or severe dysplasia), and 18 hyperplastic polyps (4/18 with focal adenomatous changes). Immunohistochemistry with PAb 1801 monoclonal antibody was performed on archival material; p53 nuclear staining was seen in 10/17 adenomas, but was limited to the foci of adenocarcinoma in three cases. Five adenomas with foci of severe dysplasia or carcinoma were nonreactive. Intestinal metaplasia, normal gastric mucosa, and 14/18 hyperplastic polyps were nonreactive. p53 Reactivity observed in four hyperplastic polyps was limited to adenomatous foci. These results suggest that p53 overexpression occurs in dysplastic epithelium of precancerous gastric lesions. Its absence in chronic atrophic gastritis with intestinal metaplasia suggests it is a relatively late event in the gastric carcinogenic sequence.

Adenocarcinoma↗