p53 status has no prognostic significance in glioblastomas treated with radiotherapy

Mutation of the tumor suppressor gene TP53 and accumulation of the p53 protein are common events in the range of cerebral astrocytic tumors, including glioblastomas, but it is uncertain whether these events are associated with prognosis. Evidence suggests that the response of various tumors to radiotherapy may be influenced by the status of p53 which is involved in control of the cell cycle and apoptosis. This study tests the hypothesis that p53 governs survival in patients (n = 62) with glioblastomas who have received radiotherapy. Analysis of TP53 and p53 immunohistochemistry were undertaken using standard methods. TP53 mutations were present in 27% tumors, while 50% were p53-immunopositive (LI > 3%). A strong correlation (p < 0.0001) was found between a high p53 LI (> 50%) and the presence of a mutation, but p53 status at the level of gene or protein was unrelated to survival. Radiation-induced apoptosis that is independent of p53, and the presence in glioblastomas of genetic abnormalities that are also involved in the cellular response to radiation, such as deletions and mutations of pRb, are possible explanations of this result.     

p53 expression in breast cancer related to prognostic factors

In this article the results of molecular marker p53 examinations were presented in relation to the following established breast cancer prognostic factors: age, histologic type, histologic grade, lymph node involvement, tumor size as well as estrogen a progesterone receptor status. Twenty one percent of these primary breast cancer specimens exhibited the overexpression of p53 protein. Significant associations were found between p53 overexpression and younger age, high histologic grade and low content of estrogen and progesterone receptors. Identification of p53-positive breast carcinomas potentially represents a clinically useful indicator of breast cancer aggressiveness.     

p53 expression is of independent predictive value in lymph node-negative breast carcinoma

OBJECTIVES: To compare the diagnostic accuracy of the most widely available tests for diagnosis of Helicobacter pylori infection after antibiotic treatment. METHODS: A total of 59 H. pylori-positive, duodenal ulcer patients (mean age, 40.7 +/- 11.7 yr; 40 male and 19 female) were treated for 2 wk with either amoxicillin-metronidazole (n = 36) or omeprazole-amoxicillin-tinidazole (n = 23), and after 4 wk, were tested for H. pylori infection by [14C]urea breath test (UBT), serum IgG antibody level, and multiple antral biopsies for rapid urease testing, histology, Warthin-Starry stain, and polymerase chain reaction to detect H. pylori DNA. Infection status was established by a concordance of test results. RESULTS: H. pylori was eradicated in 47 patients (80%). UBT and rapid urease testing had the best sensitivity and specificity, although not statistically different to Warthin-Starry stain and polymerase chain reaction. Serology and histology had little diagnostic value in this setting due to high proportion of false-positive results. CONCLUSIONS: Noninvasive UBT is as accurate in predicting H. pylori status after antibiotic treatment as rapid urease testing and Warthin-Starry stain. Especially for duodenal ulcer patients, UBT could be considered the gold standard to confirm eradication of H. pylori.     

p53 nuclear protein expression is an independent prognostic marker in clinically localized prostate cancer patients undergoing radical prostatectomy

Immunohistochemical (IHC) staining for p53 protein nuclear expression was evaluated in archival paraffin-embedded radical prostatectomy specimens from 139 patients with clinically localized prostate cancer followed up from 1 to 8 (mean, 4) years. Elevated nuclear p53 protein expression was detected in 85 (61%) of 139 patients, being heterogeneous and focal in the majority of specimens. Only four specimens displayed homogeneous nuclear accumulation of p53 protein. Disease progression, most commonly prostate-specific antigen elevation, was noted in 46 (33%) patients, with 39 (85%) having positive p53 protein IHC stains. Conversely, 93 (67%) of 139 have not recurred, with 46 (49%) having positive p53. Of all 54 p53-negative patients, 47 (87%) have had no disease recurrence. An increased p53 protein IHC stain was associated with a higher pathological stage (T1 and T2, 51% versus >/=T3, 69%) and Gleason score 2-4, 17%; 5-7, 72%; and 8-10, 87.5%). Despite these associations, p53 IHC staining was an independent predictor of disease-free survival in a multivariate analysis of p53, age, race, stage, and grade. This study revealed that a majority of clinically localized prostate cancers heterogeneously express elevated nuclear levels of p53 protein in at least a subset of malignant cells, and that this expression is an independent predictor of disease progression in prostate cancer patients after radical prostatectomy.     

Analysis of p53 gene mutation by polymerase chain reaction-single strand conformation polymorphism provides independent prognostic information in node-negative breast cancer

Controversy continues regarding the prognostic utility of detection of p53 gene abnormalities in node-negative breast cancer. To resolve this, we used a rapid and nonisotopic PCR-single strand conformation polymorphism method to screen for mutations in exons 4-8 of the p53 gene in primary tumors from 422 node-negative breast cancer patients. The prevalence of p53 mutation in the exons tested was 18%. p53 mutation was significantly associated with several markers of poor prognosis including larger tumor size, high tumor grade, low hormone receptor content, increased expression of MIB-1 (Ki-67), amplification of the HER-2/neu oncogene, and accumulation of the p53 protein. After a median duration follow-up period of 74 months, the parameters of tumor diameter > or =20 mm, HER-2/neu oncogene amplification, and p53 mutation were found to be associated with a statistically significant shortened duration of disease-free and overall survival, but not the parameters of tumor grade, hormone receptor levels, or p53 expression. The poor prognosis associated with p53 mutation was observed primarily in patients with a tumor diameter of > or =20 mm. In multivariate analysis, p53 mutation was a risk factor for increased risk of recurrence and death from breast cancer independent of tumor size, hormone receptor levels, HER-2/neu amplification, and MIB-1 expression. We conclude that a relatively simple and rapid single strand conformation polymorphism method of determining p53 mutation status in node-negative breast cancers can provide independent prognostic information.     

K-ras and p53 mutations are an independent unfavourable prognostic indicator in patients with non-small-cell lung cancer

We examined 159 consecutive cases of non-small-cell lung cancer (NSCLC) for a mutation at codon 12 of the K-ras gene and for a mutation of the p53 gene occurring in exons 5-8. Eleven (6.9%) had mutations of the K-ras (ras+) and 57 (35.8%) had mutations of the p53 (p53+). There were 95 cases (59.7%) with ras- p53-, seven cases (4.4%) with ras+/p53-, 53 cases (33.3%) with ras-/p53+ and four cases (2.5%) with ras+/p53+. The ras+ group had a worse prognosis than the ras group in all cases and in 107 early-stage cases (stage I-II, P<0.05). The p53+ group had a worse prognosis in 107 early-stage cases (P<0.01), but there was no statistically significant difference when 52 advanced-stage cases (stage III-IV) or all patients were considered. Both ras and p53 mutations were unfavourable prognostic factors in 94 cases with adenocarcinoma, but there was no statistical significance in 57 cases with squamous cell carcinoma. According to Cox's model, the pathological stage, ras mutation and p53 mutation were found to be independent prognostic factors. Our results suggest that ras and p53 mutations were independent unfavourable prognostic markers especially in the early stage of NSCLC or in adenocarcinoma.     

Association among p53 gene mutation, nuclear accumulation of the p53 protein and aggressive phenotypes in breast cancer

In order to reveal whether differences in the type and site of p53 gene mutations influence the function of the gene and tumor phenotype, we examined nuclear accumulation of the p53 protein immunohistochemically, loss of the other p53 allele by restriction-fragment-length polymorphism analysis, and histological grade of atypia in 52 breast-cancer tissue specimens in which the position and pattern of the mutation were identified. When mis-sense point mutations or deletions of 3n bases (n = 1, 2, ...), which did not cause a frameshift downstream, occurred within codons 110-180 or 234-285, containing highly conserved regions, the p53 protein was almost always (92%) accumulated in nuclei in a majority of the cancer cells. When these mutations occurred outside these regions, only 46% of the cases showed nuclear accumulation of the protein in a majority of cancer cells. In tumors with non-sense point mutations or deletion of 3n + 1 or 3n + 2 bases (n = 0, 1, 2, ...), which caused a downstream frameshift, nuclear accumulation of the p53 protein was absent in 93% of cases. Irrespective of the mutation site or pattern, a majority of cases showing p53 mutation revealed loss of heterozygosity on 17p13 (83%), which suggested they do not carry wild-type p53 allele, and the highest histological grade of atypia (90%). Regardless of differences in their protein-expression pattern, a majority of the p53 gene mutations were suggested to function in a recessive mode and to be involved in the development of histologically aggressive breast cancer.     

Expression of c-met is a strong independent prognostic factor in breast carcinoma

BACKGROUND: The c-met protooncogene encodes the met protein, the receptor for scatter factor/hepatocyte growth factor, a growth factor that modulates the motility and stable interaction of the epithelial cells. This study assesses the expression of met receptor in breast carcinoma and its prognostic value with respect to survival. METHODS: Immunofluorescence was used to evaluate 91 archival breast carcinoma specimens using a polyclonal antibody to the cytoplasmic domain of the receptor. Cases were scored by two pathologists on a percentage basis and then converted to binary scores (positive or negative) on the basis of a bimodal distribution. RESULTS: Strong expression of met was found in 20 invasive ductal breast tumor specimens (22%). The 5-year survival of patients whose tumors showed decreased met expression was 89%, in contrast to a 52% 5-year survival rate in patients whose tumors expressed met (P = 0.008). This trend also was observed in patients without lymph node metastases at presentation, in whom met negative patients had a 95% 5-year survival compared with only 62% for met positive patients (P = 0.006) Multivariate analysis using the Cox proportional hazards model showed met expression to be an independent predictor of survival, with a predictive value nearly equivalent to that associated with lymph node status. CONCLUSIONS: The authors conclude that expression of met in patients with invasive ductal carcinoma of the breast is a strong, independent predictor of decreased survival and may be a useful prognostic marker with which to identify a subset of patients with more aggressive disease.     

p53 protein expression in breast cancer as related to histopathological characteristics and prognosis

Reaction of Klebsiella aerogenes urease with diethylpyrocarbonate (DEP) led to a pseudo-first-order loss of enzyme activity by a reaction that exhibited saturation kinetics. The rate of urease inactivation by DEP decreased in the presence of active site ligands (urea, phosphate, and boric acid), consistent with the essential reactive residue being located proximal to the catalytic center. The pH dependence for the rate of inactivation indicated that the reactive residue possessed a pKa of 6.5, identical to that of a group that must be deprotonated for catalysis. Full activity was restored when the inactivated enzyme was treated with hydroxylamine, compatible with histidinyl or tyrosinyl reactivity. Spectrophotometric studies were consistent with DEP derivatization of 12 mol of histidine/mol of native enzyme. In the presence of active site ligands, however, approximately 4 mol of histidine/mol of protein were protected from reaction. Each protein molecule is known to possess two catalytic units; hence, we propose that urease possesses at least one essential histidine per catalytic unit.     

p53 mutations and overexpressions in Japanese breast cancer

In this paper, we explore the use of a variety of familial transmission tests (and case-control analyses) to screen for allelic associations in simulated marker data of a quality (2 cM map) that will feasibly arise from genomic scans within the next 5-10 years. We demonstrate a form of the transmission-disequilibrium test extended to multiallele systems. The methods used were log-linear and related models implemented largely using standard statistical packages.     

p53 mutation and tamoxifen resistance in breast cancer

A substantial portion of patients with estrogen receptor-positive breast cancer fail to respond to estrogen depletion or to the antiestrogen tamoxifen. The molecular changes that lead to tamoxifen resistance and estrogen-independent growth are unknown. To test the hypothesis that a p53 mutation could result in tamoxifen resistance and estrogen-independent growth, the MCF-7 cell line was transfected with p53 cDNA which was mutated at codon 179 (histidine to glutamine). MCF-7 is an estrogen receptor-positive, estrogen-dependent, tamoxifen-sensitive cell line with only wild-type p53. The presence of transfected mutant p53 cDNA was verified by the PCR, and overexpression of p53 protein was assessed by Western blotting. Five separate mutant-transfected clones were selected and tested in subsequent growth experiments. In monolayer culture, there was no consistent evidence of estrogen-independent growth or tamoxifen resistance in the mutant transfectants compared with vector-only controls or the parental cell line. In soft agar growth experiments, four of five mutant transfectants remained sensitive to tamoxifen in a dose-dependent manner. In the presence of wild-type p53, mutant 179 p53 protein does not result in estrogen-independent growth or tamoxifen resistance. These results do not exclude the possibility that other p53 mutational types could result in tamoxifen resistance, or that loss of the remaining wild-type allele may be necessary to result in this phenotype.     

The prognostic value of NCAM, p53 and cyclin D1 in resected non-small cell lung cancer

Expression of the neural cell adhesion molecule, NCAM, in frozen sections has been associated with decreased postoperative survival in non-small cell lung carcinoma. Of the various isoforms of NCAM described, the highly sialylated isoform plays a role in the migration of embryonal cells from the neural crest and is expressed by highly malignant tumours such as small cell lung carcinomas. We investigated the clinical significance of expression of this NCAM isoform as a prognostic factor in a series of 96 non-small cell lung carcinomas resected with curative intent. We also evaluated the effect of microwave pre-treatment of formalin-fixed, paraffin-embedded sections on the NCAM immunostaining and related the outcome to the postoperative clinical course of disease. In addition, in an attempt to extend our search for possible molecular markers of unfavourable prognosis in lung cancer, we evaluated increased immunostaining for p53 and cyclin D1 in the same series. We did not find a significant relation between expression of NCAM or its highly sialylated isoform and the length of postoperative survival. The numbers of positive cases (9 and 14, respectively) were relatively low. Increased p53 and cyclin D1 immunostaining (50 and 55 of the 96 tumours) failed to show a significant relation with postoperative survival. In our material, tumour stage was the only significant prognostic factor.     

p53 protein expression in benign and malignant breast lesions

OBJECTIVE: To investigate p53 protein expression in imprints from benign and ductal breast carcinoma cases in relation to the histologic grade of malignancy and clinical stage. STUDY DESIGN: The study group consisted of 60 cases of primary ductal breast carcinomas and 20 benign lesions. For the demonstration of p53 protein expression, an immunocytochemical avidin-extravidin complex technique was applied. Monoclonal antibody p53 was used as the primary antibody, diaminobenzidine as the chromogen and hematoxylin as the counterstain. RESULTS: Forty-five percent of breast cancer cases showed positive expression of p53. A statistically significant difference in p53 protein expression was observed between grade 1, 2 and 3 carcinomas and stage I, II and III cases. All benign lesions were negative for p53 protein expression. CONCLUSION: Immunocytochemical p53 protein expression in cytologic material is a simple method that can be applied in routine cytologic laboratories for the identification of genetic alterations in primary ductal breast cancer.     

Expression of p53 protein and p53 gene transcripts in rabbit carotid arteries after balloon denudation

A case of sinusitis caused by the basidiomycete Schizophyllum commune is reported in a 36-year-old female with a history of allergic rhinitis and dermatitis. The patient presented with sudden nasal obstruction, purulent nasal discharge, headache and general discomfort. Computer tomography revealed extensive opacity of the left maxillary sinus as well as erosion of the nasal wall and maxillary bone. Mycological examinations of nasal discharges and material aspirated during anthrostomy showed hyaline, septate hyphae with rare spicules. Primary isolation yielded a white, woolly mould which demonstrated clamp connections and basidiocarp primordia but these characteristics were lost in subculture. Identification was confirmed by vegetative compatibility studies. The patient was treated with itraconazole to avoid possible postsurgical dissemination. Three months after cessation of therapy, no recurrence of infection had occurred.     

p53 protein expression in extrahepatic bile duct cancer

p53 mutations, a tumor suppressor gene located on chromosome 17p, are the most common genetic alterations found in human cancers. Although the p53 expression or mutation has been investigated in a variety of cancers there have been very few studies in extrahepatic bile duct cancers. In this study, we investigated the immunohistochemical expression of p53 in formalin fixed paraffin embedded archival specimens of 36 extrahepatic bile duct cancers in which p53 expression was found in eighteen (50%) cases. There was no significant difference in age, gender, size of tumor, histologic grade, extent of tumor involvement, lymph node metastasis and tumor resectability according to p53 immunoreactivity. Comparison of survival duration according to p53 expression showed no significant difference. In conclusion, we reported 50 percent of p53 expression in extrahepatic bile duct cancers by immunohistochemical staining and we found no prognostic significance of p53 expression in dinicopathologic parameters.     

Expression of p53 protein and proliferative activity in multiform glioblastoma

The aim of the study of 41 multiform glioblastomas was the analysis of p53-protein immunoreactivity in neoplastic cells and evaluation of relationship of this biologic marker to tumour proliferation activity. Positive p53 expression was observed in 24 (58.5%) tumours, the negative one in 17 tumours (41.5%). Proliferation indexes of PCNA, anti-Ki6 and AgNORs showed high values in the multiform glioblastoma p53 positive group, but without statistical differences in comparison with the group of p53-negative glioblastomas. Significant differences were observed in survival time of patients with p53 positive tumours in comparison with p53-negative ones. In 15 patients with p53-positive multiform glioblastomas survival time was less than 6 months (62.5%) on the contrary with only 4 patients with similar survival time in p53-negative glioblastoma group (23.5%). Our results suggest that p53 expression in multiform glioblastoma cells, generally considered as the indirect index of p53 suppressor gene, reflects aggressive stadium of neoplastic disease and significantly worsens the prognosis.     

The prognostic significance of accumulation of p53 protein in stage III non-small cell lung cancer treated by radiotherapy

In the present study the prognostic significance of accumulation of nuclear p53 protein on survival and freedom from local progression was investigated. Formalin-fixed, paraffin-embedded sections obtained by bronchoscopy or mediastinoscopy were used to examine the expression of nuclear p53 protein using immunohistochemistry. In 37 cases (57%), overexpression of the p53 protein was detected. No relation was found between p53 expression and other pretreatment variables. Response to radiotherapy was found in 11 p53-negative cases (65%) versus 10 p53-positive cases (42%). Freedom from local progression was significantly better in the p53-negative cases as compared with the p53-positive cases. The p53-negative cases who responded to radiotherapy showed an excellent freedom from local progression rate after 2 years of 100%, whereas all p53-positive cases without response to radiotherapy showed local progression within 24 months. Overall survival between p53-negative and -positive cases did not differ, however the disease-specific survival was found to be worse in the p53-positive cases as compared to the negative cases (median survival 8.4 vs. 14.4 months (P < 0.05)). No correlation was found between p53 expression and the frequency of distant metastases. In conclusion, the results of this study suggest that p53 protein expression may be of prognostic value on freedom from local progression in non-small cell lung carcinoma.     

MIB-1 labelling index is an independent prognostic marker in primary breast cancer

The proliferative activity of a tumour is considered to be an important prognostic factor in primary breast cancer. We have investigated the prognostic value of the MIB-1 labelling index in 341 patients with primary breast cancer and compared the results with the S-phase fraction in 220 patients of the same cohort. All patients were treated in one hospital and had a median follow-up of 128 months. No correlation between MIB-1 labelling and S-phase fraction could be demonstrated. MIB-1 had prognostic value for disease-free survival in the whole group of patients (P < 0.001) and in the node-negative subgroup (P < 0.001). In multivariate analysis, MIB-1 was an independent prognostic factor (P = 0.004) besides axillary lymph node status (P = 0.001). In univariate analysis high S-phase fraction was associated with decreased overall survival (P = 0.04); however, not in multivariate analysis. Moreover, S-phase fraction had a borderline prognostic significance for post-relapse survival in multivariate analysis (P= 0.08). Thus, in conclusion, the growth fraction of a tumour as determined by the MIB-1 labelling index is an important prognostic factor in patients with primary breast cancer.     

Immunohistochemical detection of p53 and Bcl-2 in colorectal carcinoma: no evidence for prognostic significance

To evaluate the prognostic significance of immunohistochemically detected p53 and Bcl-2 proteins in colorectal cancer, tissue sections from 238 paraffin-embedded colorectal carcinomas were immunostained for p53 (MAb DO-7 and CM-1 antiserum) and Bcl-2 (MAb Bcl-2:124). Staining patterns were assessed semiquantitatively and correlated with each other and with sex, age, tumour site, Dukes' classification, tumour differentiation, mucinous characteristics, lymphocyte and eosinophilic granulocyte infiltration, and patient survival. In our series, 35% of carcinomas showed no nuclear staining and 34% (DO-7) to 40% (CM-1) showed staining in over 30% of tumour cell nuclei. A majority of carcinomas that had been immunostained with CM-1 showed cytoplasmic staining, but this was not observed with DO-7. With respect to Bcl-2, 51% of tumours were completely negative, 32% displayed weak and 15% moderate staining; only 3% showed strong positive staining. No evidence was found for reciprocity between Bcl-2 expression and nuclear p53 accumulation. From 13 cases containing tumour-associated adenoma, four were Bcl-2 negative in premalignant and malignant cells, in another four cases these cells showed similar staining intensities and in the remaining cases only the malignant colorectal cells were Bcl-2 negative. Therefore, our data indicate that Bcl-2 is dispensable in the progression towards carcinoma. Except for an association between nuclear p53 accumulation and mucinous tumours (P = 0.01), no significant correlation was found between the clinicopathological parameters mentioned above and immunostaining pattern of (nuclear or cytoplasmic) p53 or Bcl-2.     

Expression of p53 protein in colorectal cancer and its relationship to cell proliferative activity and prognosis

The expression of p53 protein in 66 cases of colorectal cancer and its relationship to cell proliferative activity, lymph node metastasis as well as prognosis were investigated by means of AB-PAP immunohistochemical technique. The results showed that 62.1% of colorectal cancer was positive. The cell proliferative activity and the frequency of lymph node metastasis in p53-positive cases were significantly higher than those of p53-negative cases (P < 0.05). The survival rate in patients with p53-positive tumors was significantly shorter than those with p53-negative tumors (P < 0.05). Our results suggest that the abnormal expression of p53 and cell proliferation associated with mutations are involved in both human carcinogenesis and lymph node metastasis of colorectal cancer. Examination of p53 expression is of value in understanding the degree of malignancy, and evaluating prognosis of the disease.