Overexpression of the p53 protein and allele loss at 17p13 in ovarian carcinoma.

Mouse monoclonal antibodies PAb 240 and PAb 1801 which specifically immunoprecipitate p53 protein, were used to examine 27 fresh ovarian tumours (16 serous adenocarcinomas, six endometrioid carcinomas, one mucinous adenocarcinoma, one mucinous borderline tumour and three benign adenomas). Eleven out of 16 (69%) serous adenocarcinomas and one endometrioid tumour showed positive staining with one or both antibodies and none of the mucinous or benign tumours stained with either antibody. DNA from tumour and peripheral blood leukocytes was used to identify allelic deletions on chromosome 17p in tumours. 11/12 positively staining tumours showed less of heterozygosity (LOH) on 17p at the nearest informative locus to the p53 gene. In this series of ovarian tumours, LOH on 17p correlates closely with the aberrant expression of the p53 protein in a high proportion of advanced stage serous adenocarcinomas. This observation suggests that the p53 tumour suppressor gene is involved in the evolution of epithelial ovarian cancer (EOC) and may have prognostic significance.     

Expression and prognostic significance of Bcl-2 in ovarian tumours.

The expression of bcl-2 was studied in normal ovaries and in ovarian tumours by immunohistochemical analysis. Normal epithelium was strongly stained in all nine examined ovaries. In comparison, all tumour groups showed a substantially decreased tumour cell expression of the same order of magnitude. Thus, benign tumour cells were weakly stained in two and unstained in two samples, while the remaining eight showed strong expression. Of ten borderline samples, one was unstained and five had weakly and four strongly bcl-2 positive tumour cells. Finally, 24 of 50 malignant tumours showed strong staining, while weak or no expression in tumour cells was found in 16 and 10 samples respectively. The reduced staining deviated significantly from normal ovary for both borderline (P = 0.02) and malignant groups (P = 0.01). Tumour cell staining with the bcl-2 antibody was significantly reduced when tumour mass had to be left behind compared with those with no visible remaining tumour (P = 0.03 and 0.003 for weakly and strongly stained tumours respectively). The expression of bcl-2 in malignant tumour cells was inversely correlated with the expression of p53. Bcl-2 expression was correlated with survival with significantly reduced survival in weakly (P = 0.02) and unstained (P < 0.001) groups compared with those patients having strongly stained malignant tumour cells. This correlation between the presence of bcl-2 and survival was maintained in the subgroups of patients with advanced disease or with residual tumour bulk and was also the case in patients having p53-positive tumours. Our results indicate an inhibitory role of bcl-2 in development and progression of ovarian tumours.     

Expression of pro-apoptotic (p53, p21, bax, bak and fas) and anti-apoptotic (bcl-2 and bcl-x) proteins in serous versus mucinous borderline ovarian tumours

BACKGROUND: We examined the expression of apoptosis-related proteins in serous versus mucinous borderline ovarian tumours, in comparison with benign and malignant ovarian tumours. MATERIALS AND METHODS: Immunohistochemical expression of pro-apoptotic (p53, p21, bax, bak, fas) and anti-apoptotic proteins (bcl-2, bcl-x) was determined in 34 borderline (19 mucinous, 15 serous), 20 benign (10 mucinous, 10 serous) and 28 malignant ovarian tumours (9 mucinous, 19 serous). RESULTS: A difference in semi-quantitative p53 expression was found between benign and borderline tumours (P = 0.01), but not between borderline and malignant tumours. Increased p21 expression was found in borderline versus benign tumours (P = 0.004). Bcl-2 expression was lower in borderline than in benign (P = 0.01) and malignant tumours (P = 0.02). No difference in bax, bak, fas or bcl-x expression was observed among the three tumour types. Higher percentage of p21 positive cells was found in serous than in mucinous borderline tumours (P < 0.001). Bcl-2 expression was higher in serous than in mucinous forms of benign (P < 0.001), borderline (P < 0.001), and malignant tumours (P < 0.003). No difference in p53, bax, bak, fas or bcl-x expression was observed between serous and mucinous borderline ovarian tumours. CONCLUSION: Although p53 overexpression was a common feature of both mucinous and serous borderline tumours, p21 and bcl-2 overexpression appeared specific to serous tumours.     

Spontaneous apoptosis in ovarian carcinomas: a positive association with p53 gene mutation is dependent on growth fraction

Changes in cell survival contribute to tumour development, influence tumour biology and its response to chemotherapy. p53 gene alterations should negatively affect apoptosis by impaired p53-dependent apoptotic response. We looked for associations between spontaneous apoptosis, p53 gene mutation, p53 protein accumulation, growth fraction, bcl-2 expression and histological parameters in 64 ovarian, four tubal and three peritoneal carcinomas. Apoptotic cells were detected with the TUNEL method. p53 gene variants were detected by the single-strand conformation polymorphism and were sequenced directly. P53, Ki-67 and bcl-2 protein expressions were detected immunohistochemically. A weighed multiple logistic regression model was applied. Apoptotic index (AI) ranged 0.02-0.18 (mean 0.11); proliferation index (PI) ranged 3-90% (mean 54%). p53 gene mutations were present in 51, p53 protein accumulation in 46, and diffuse bcl-2 expression in 29 of 71 tumours. The AI was positively associated with the presence of p53 gene mutation (P = 0.011). However, the PI included into the analysis did positively influence the AI (P = 0.02) and diminished the association with p53 gene mutation (P = 0.082). The AI was negatively associated with good histological differentiation (P = 0.0006), the serous tumour type (P = 0.002), and diffuse bcl-2 expression (P = 0.025). Strong bcl-2 expression was associated with endometrioid tumour type (P = 0.002). FIGO stage and p53 protein accumulation were the only parameters that influenced overall survival time. Thus, our results suggest that histological tumour type and grade are major determinants of spontaneous apoptosis in ovarian carcinomas; p53 alterations do not adversely but rather positively affect spontaneous apoptosis by increasing growth fraction. This, in turn, suggests p53-independency of spontaneous apoptosis in ovarian carcinomas.     

Expression of apoptosis-related markers and clinical outcome in patients with advanced colorectal cancer

The clinical relevance of bax and bcl-2 protein expression has been investigated in 84 patients with recurrent or metastatic colorectal cancer submitted to a chemotherapy regimen including methotrexate and fluorouracil/leucovorin. Cytoplasmic immunostaining of bax and bcl-2 was present in 65.5% and 38%, respectively, of the tumours. No association was found between bax and bcl-2 or between p53 and bax or bcl-2 protein expression. Moreover, the biomarkers were unrelated to patient and tumour characteristics known to affect the clinical outcome of colorectal cancer patients. In general, the apoptosis-related markers did not appear indicative of short- and long-term clinical response nor of prognosis. Bcl-2-negative lesions were more frequent among patients who reached an objective clinical response, which is in agreement with previously reported data regarding other tumour types. When the interrelationship between p53 and bax expression was examined, a better response rate (40%) was found for patients whose tumours did not express p53 and bax, and a better prognosis (2-year probability of overall survival 75%) for patients with p53-positive and bax-negative tumours. In the present series of patients with advanced colorectal cancer submitted to systemic chemotherapy we did not find a clear association between expression of apoptosis-related markers and clinical outcome, even in the subset of patients in which the apoptotic index as determined by the TUNEL approach was investigated.     

Alteration of p53 gene in ovarian carcinoma: clinicopathological correlation and prognostic significance.

Inactivation of the tumour-suppressor gene p53 has been demonstrated in a variety of human tumours. We extracted DNA from paraffin-embedded tissues of 67 ovarian carcinoma samples (54 primary tumours, seven metastases and six tumours obtained after chemotherapy), and analysed allelic losses and mutations of the p53 gene using single-strand conformation polymorphism (SSCP) analysis of DNA fragments amplified by a polymerase chain reaction (PCR). Allelic loss was observed in 24 of 32 informative cases. The mutation was detected in 14 of 54 primary ovarian carcinomas: eight serous cystadenocarcinomas (SCA), 42%), five endometrioid adenocarcinomas (EA, 42%) and one mucinous cystadenocarcinoma (14%). The incidence of the alteration was higher in SCA and EA than in other histological types, but the difference was not statistically significant. The incidence of p53 gene abnormalities in ovarian carcinomas tended to be increased in patients with disease advanced (over FIGO stage II). Mutations were found in exons 5 and 7 only and consisted mainly of single nucleotide substitutions [9 or 14 (64%) in exon 7; 4 of 14 (29%) in exon 5]. In 13 of 14 cases, p53 gene mutations occurred concomitantly with losses of the normal allele. The status of the p53 gene in metastases and the tumours obtained after chemotherapy was identical to that in the primary tumours. The presence of p53 gene mutation did not correlate with histological grade, response to primary therapy and survival. These findings suggest that mutational alterations of the p53 gene are involved in the development of a significant proportion of some ovarian carcinomas (SCAs or EAs), especially in advanced stages. However, they may not be a marker predicting the biological behaviour or the outcome of the disease.     

Bcl-2 expression and response to chemotherapy in colorectal adenocarcinomas.

In the last year, a number of studies have reported the expression of bcl-2 in colorectal adenocarcinomas. However, the influence of bcl-2 expression on response to chemotherapy and outcome in patients with advanced colorectal adenocarcinoma has not been reported. We analysed bcl-2 expression in 231 colorectal tumours from patients that were treated by surgery alone or with 5-fluorouracil-based chemotherapy. Of 231 tumours, 149 (64.5%) overexpressed bcl-2. Bcl-2 expression was associated with low plasma CEA levels (P=0.013) and inversely associated with poor differentiation (P=0.049). However, bcl-2 expression did not significantly influence failure-free or overall survival in surgically treated patients. In the group of patients receiving 5-fluorouracil-based chemotherapy bcl-2 expression did not influence response to chemotherapy; nor did it effect failure-free or overall survival.     

Thymidilate synthase and p53 primary tumour expression as predictive factors for advanced colorectal cancer patients

The purpose of this work was to analyse the ability of p53 and thymidilate synthase (TS) primary tumour expression to retrospectively predict clinical response to chemotherapy and long-term prognosis in patients with advanced colorectal cancers homogeneously treated by methotrexate (MTX)-modulated-5-fluorouracil (5-FU-FA). A total of 108 advanced colorectal cancer patients entered the present retrospective study. Immunohistochemical p53 (pAb 1801 mAb) and TS (TS106 mAb) expression on formalin-fixed paraffin-embedded primary tumour specimens was related to probability of clinical response to chemotherapy, time to progression and overall survival. p53 was expressed in 53/108 (49%) tumours, while 54/108 (50%) showed TS immunostaining. No relationship was demonstrated between p53 positivity and clinical response to chemotherapy (objective response (OR): 20% vs 23%, in p53+ and p53- cases respectively) or overall survival. Percent of OR was significantly higher in TS-negative with respect to TS-positive tumours (30% vs 15% respectively; P < 0.04); simultaneous analysis of TS and p53 indicated 7% OR for p53-positive/TS-positive tumours vs 46% for p53-positive/TS-negative tumours (P < 0.03). Logistic regression analysis confirmed a significant association between TS tumour status and clinical response to chemotherapy (hazard ratio (HR): 2.91; 95% confidence interval (CI) 8.34-1.01; two-sided P < 0.05). A multivariate analysis of overall survival showed that only a small number of metastatic sites was statistically relevant (HR 1.89; 95% CI 2.85-1.26; two-sided P < 0.03). Our study suggests that immunohistochemical expression of p53 and TS could assist the clinician in predicting response of colorectal cancer patients to modulated MTX-5-FU therapy.     

p53 overexpression is associated with cytoreduction and response to chemotherapy in ovarian cancer

The aim of this study was to assess the association of p53 status with primary cytoreduction, response to chemotherapy and outcome in stage III-IV primary ovarian cancer patients. Immunohistochemical analysis of p53 was performed on formalin-fixed, paraffin-embedded specimens from 168 primary ovarian carcinomas by using the DO-7 monoclonal antibody. p53 nuclear positivity was found in 84 out of 162 (52%) malignant tumours. A higher percentage of p53 nuclear positivity was observed in patients with advanced stage of disease than in stage I-II (57% vs 23% respectively; P = 0.0022) and in poorly differentiated versus well/moderately differentiated tumours (59% vs 32% respectively; P = 0.0038). The multivariate analysis aimed to investigate the association of FIGO stage, grade and p53 status with primary cytoreduction in 136 stage III-IV patients showed that stage IV disease may influence the possibility to perform primary cytoreduction in ovarian cancer patients. p53-positivity also maintained a trend to be associated with poor chance of cytoreduction. In patients who underwent pathologic assessment of response, cases who did not respond to chemotherapy were much more frequently p53-positive than p53-negative (86% vs 14% respectively; P = 0.012). Moreover, patients with stage III disease and < 2-cm residual tumour were more likely to respond to treatment. In multivariate analysis, FIGO stage and p53 expression were independently correlated with pathologic response to chemotherapy. Time to progression and survival rates were shown not to be different in p53-positive versus p53-negative patients.     

Tumour stage,node stage,p53 gene status,and bcl-2 protein expression as predictors of tumour response to platin-fluorouracil chemotherapy in patients with squamous-cell carcinoma of the head and neck

The purpose of this study was to establish the relative contribution of tumour stage, node stage, p53 gene status, p53 expression, and bcl-2 protein expression to tumour response to platin-fluorouracil chemotherapy in 141 patients with squamous-cell carcinomas of the head and neck. Tumour response was measured at the primary site after three cycles of chemotherapy. Exons 2-10 and the coding part of exon 11 were sequenced on both strands. Bcl-2 or p53 expression was detected by immunohistochemistry. Predictor variables of objective response (reduction of at least 50% of tumour size) were tested in univariate and multivariate analyses. P53 mutations were found in 52 patients (37%). Tumour cells expressed p53 in 84 cases (59%) and bcl-2 in 25 cases (18%). T1 or T2 stage (adjusted odds ratio, 3.3; 95% confidence interval 1.3-8.7; P=0.01), N0 node stage (adjusted odds ratio, 2.7; 95% confidence interval 1.1-6.4; P=0.03), p53 wild-type gene (adjusted odds ratio, 4.0; 95% confidence interval 1.7-9.5; P=0.002), and bcl-2 protein expression (adjusted odds ratio, 20; 95% confidence interval 2.3-170; P=0.006), were positively associated with tumour response. P53 protein expression was not predictive of response. In conclusion, tumour stage, node stage, p53 gene status, and bcl-2 expression are independent predictors of tumour response to platin-fluorouracil in patients with squamous-cell carcinomas of the head and neck.     

Expression of Bcl-2 protein is decreased in colorectal adenocarcinomas with microsatellite instability

Bcl-2 is known to inhibit apoptosis and is thought to play a role in colorectal tumour development. Studies of the promoter region of bcl-2 have indicated the presence of a p53 responsive element which downregulates bcl-2 expression. Since p53 is commonly mutated in colorectal cancers, but rarely in those tumours showing microsatellite instability (MSI), the aim of this study was to examine the relationship of bcl-2 protein expression to MSI, as well as to other clinicopathological and molecular variables, in colorectal adenocarcinomas. Expression of bcl-2 was analysed by immunohistochemistry in 71 colorectal cancers which had been previously assigned to three classes depending upon their levels of MSI. MSI-high tumours demonstrated instability in three or more of six microsatellite markers tested, MSI-low tumours in one or two of six, and MSI-null in none of six. Bcl-2 expression in tumours was quantified independently by two pathologists and assigned to one of five categories, with respect to the number of cells which showed positive staining: 0, up to 5%; 1, 6-25%; 2, 26-50%; 3, 51-75%; and 4, > or =76%. Bcl-2 negative tumours were defined as those with a score of 0. Bcl-2 protein expression was tested for association with clinicopathological stage, differentiation level, tumour site, age, sex, survival, evidence of p53 inactivation and MSI level. A significant association was found between bcl-2 expression and patient survival (P = 0.012, Gehan Wilcoxon test). Further, a significant reciprocal relationship was found between bcl-2 expression and the presence of MSI (P = 0.012, Wilcoxon rank sum test). We conclude that bcl-2 expressing colorectal cancers are more likely to be MSI-null, and to be associated with improved patient survival.     

Biomarkers and outcome after tamoxifen treatment in node-positive breast cancers from elderly women

The predictive role of tumour proliferative rate and expression of p53, bcl-2 and bax proteins, alone and in association with tumour size, nodal involvement and oestrogen receptors (ER), was analysed on 145 elderly patients (> or =70 years of age) with histologically assessed node-positive breast cancers treated with radical or conservative surgery plus radiotherapy followed by adjuvant tamoxifen for at least 1 year. The 7-year probability of relapse was significantly higher for patients with tumours rapidly proliferating (hazard ratio (HR) = 2.0, P = 0.01), overexpressing p53 (HR = 4.4, P = 0.0001), weakly or not exhibiting bcl-2 (HR = 1.9, P = 0.02), without ERs (HR = 3.4, P = 0.0001) or with > or = 4 positive lymph nodes (HR = 2.3, P = 0.003) than for patients with tumours expressing the opposite patho-biological profile. Conversely, tumour size and bax expression failed to influence relapse-free survival. Adjustment for the duration of tamoxifen treatment did not change these findings. Oestrogen receptors, cell proliferation, p53 accumulation and bcl-2 expression were also predictive for overall survival. Within ER-positive tumours, cell proliferation, p53 accumulation, bcl-2 expression and lymph node involvement provided significant and independent information for relapse and, in association, identified subgroups of patients with relapse probabilities of 20% (low-risk group, exhibiting only one unfavourable factor) to 90% (high-risk group, exhibiting three unfavourable factors). Such data could represent the initial framework for a biologically tailored therapy even for elderly patients and highlight the importance of a patho-biological characterization of their breast cancers.     

Minichromosome maintenance proteins 2 and 5 in non-benign epithelial ovarian tumours: relationship with cell cycle regulators and prognostic implications

Minichromosome maintenance proteins (MCM) have recently emerged as novel proliferation markers with prognostic implications in several tumour types. This is the first study investigating MCM-2 and MCM-5 immunohistochemical expression in a series of ovarian adenocarcinomas and low malignant potential (LMP) tumours aiming to determine possible associations with clinicopathological parameters, the conventional proliferation index Ki-67, cell cycle regulators (p53, p27(Kip1), p21(WAF1) and pRb) and patients' outcome. Immunohistochemistry was applied in a series of 43 cases of ovarian LMP tumours and 85 cases of adenocarcinomas. Survival analysis was restricted to adenocarcinomas. The median MCM-2 and MCM-5 labelling indices (LIs) were significantly higher in adenocarcinomas compared to LMP tumours (P<0.0001 for both associations). In adenocarcinomas, the levels of MCM-2 and MCM-5 increased significantly with advancing tumour stage (P=0.0052 and P=0.0180, respectively), whereas both MCM-2 and MCM-5 increased significantly with increasing tumour grade (P=0.0002 and P=0.0006, respectively) and the presence of bulky residual disease (P<0.0001 in both relationships). A strong positive correlation was established between MCM-2 or MCM-5 expression level and Ki-67 LI (P<0.0001) as well as p53 protein (P=0.0038 and P=0.0500, respectively). Moreover, MCM-2 LI was inversely correlated with p27(Kip-1) LI (P=0.0068). Finally, both MCM-2 and MCM-5 were associated significantly with adverse patients' outcome in both univariate (> or =20 vs >20%, P=0.0011 and > or =25 vs <25%, P=0.0100, respectively) and multivariate (P=0.0001 and 0.0090, respectively) analysis. An adequately powered independent group of 45 patients was used in order to validate our results in univariate survival analysis. In this group, MCM-2 and MCM-5 expression retained their prognostic significance (P<0.0001 in both relationships). In conclusion, MCM-2 and MCM-5 proteins appear to be promising as prognostic markers in patients with ovarian adenocarcinomas.     

IL-6 production in ovarian carcinoma is associated with histiotype and biological characteristics of the tumour and influences local immunity

The presence of interleukin (IL)-6 in peritoneal carcinomatous fluid (PCF) and its effect on immune cells composition in PCF in patients with advanced ovarian carcinoma was studied. In 21 out of 30 ovarian carcinoma patients, PCF IL-6 levels were found to exceed those seen in PCFs of patients with gastrointestinal cancer. IL-6 activity was higher in serous/mucinous than in endometrioid and undifferentiated ovarian carcinoma PCF (P = 0.05). Ovarian carcinoma PCF IL-6 activities were correlated with serum C-reactive protein levels (r = 0.65, P = 0.0000, n = 25). Ovarian carcinoma PCF leucocyte profile differed from that in blood with respect to: (i) lower percentage of NK and CD8+ and (ii) higher percentage of B and CD45RO+, CD14+ and HLA-DR+ cells. The proportions of CD45RO+ in blood were correlated with IL-6 levels in PCF. Corresponding to PCF ovarian carcinoma tumours were stained for the presence of Ki-67 antigen and p53. The highest proportions of Ki-67+ cells and cells showing accumulation of p53 were seen in undifferentiated tumours. A low grade of p53 staining was seen in tumours associated with high IL-6 levels in PCF. It was evident that IL-6 production (i) depended on the histiotype of the tumour, (ii) influenced the local immune system in favour of accumulation of B, and T memory cells, and (iii) was higher in patients lacking p53 accumulation.     

The combined evaluation of p53 accumulation and of Ki-67 (MIB1) labelling index provides independent information on overall survival of ovarian carcinoma patients

Background: The prognostic implications of p53 accumulation, bcl-2immunoreactivity and tumour proliferative fraction in ovarian carcinomas arestill debated.Patients and methods: One hundred twelve ovarian carcinomas wereimmunostained for p53 protein, for bcl-2 and for the cell cycle-associatedKi-67 antigen. The immunostaining results were correlated with conventionalclinico-pathological variables, response to induction chemotherapy, andpatient survival.Results: p53 accumulation and bcl-2 immunoreactivity in more than10% of neoplastic cells were detected in 61 (54.5%) and 42(37.5%) cases, respectively. A positive correlation between p53accumulation and high (more than 30% neoplastic cells) MIB1 labellingindex (r = 0.235; P = 0.015) was ascertained, whereas no significantassociation was found between bcl-2 immunoreactivity and p53 accumulation orMIB1 labelling index. Both p53 accumulation and MIB1 immunoreactivitycorrelated significantly with a reduced overall survival, but the associationwas lost in multivariate analysis. However, patients with tumourssimultaneously showing p53 accumulation and MIB1 labelling index higher than30% had significantly reduced overall survivals, in both univariate andmultivariate analyses.Conclusion: The simultaneous evaluation of p53 accumulation and MIB1labelling index has independent prognostic implications in common epithelialmalignancies of the ovary, irrespective of the disease stage.     

Locally advanced breast cancer

In vitro studies suggest p53 and bcl-2 may be important in the apoptotic response to irradiation, and that rapidly proliferating cells are more sensitive to radiotherapy. The clinical relevance of biological factors in predicting radiotherapy response was investigated in 62 patients with locally advanced breast cancer. Immunocytochemical staining for p53 protein, BCL-2 protein and MIB 1 antigen on the primary tumour, showed that none of these factors significantly predicted radiotherapy response (BCL-2 p=0.45, p53 p=1.0, MIB 1 p=0.92) and appear to be of no clinical value. A semi-quantitative assessment of MIB 1 staining showed a reduction in positive cells following radiotherapy (p=0.04), consistent with a reduced proliferation associated with response.     

Expression of cyclooxygenase-2 and its relationship to p53 accumulation in ovarian adenocarcinomas

To investigate cyclooxygenase-2 (COX-2) expression and its relationship to p53 accumulation in ovarian adenocarcinomas, COX-2 and p53 protein expressions were examined by immunohistochemistry in 86 ovarian adenocarcinomas and six normal ovaries. In addition, COX-2 mRNA expression level was examined by semi-quantitative PCR in 36 ovarian adenocarcinomas. Neither COX-2 expression nor p53 accumulation were detected in normal ovarian surface epithelium or germinal inclusion cyst epithelial cells. In contrast, COX-2 protein expression was detected in 31.4% of adenocarcinomas, and p53 protein accumulation was found in 30.2% of adenocarcinomas. A significantly higher COX-2 expression rate was observed in endometrioid adenocarcinomas than in either mucinous (p=0.019) or clear cell (p=0.021) adenocarcinomas, and a significantly higher p53 accumulation rate was observed in serous adenocarcinomas compared to clear cell adenocarcinomas (p=0.015). p53 accumulation correlated with advanced clinical stage (stage I vs. stage II/III/IV: p=0.007), whereas no correlation was found between COX-2 expression and clinical stage. There was a significant positive correlation between COX-2 expression and p53 accumulation status (p=0.003). Log-rank testing showed that p53 accumulation was significantly correlated with poor patient survival (p=0.004), whereas no correlation was found between COX-2 expression and survival. COX-2 mRNA expression was detected in 72.2% of ovarian adenocarcinomas, and a significant correlation between COX-2 mRNA expression status and immunoreactivity (p=0.023) was observed. These results suggest that COX-2 expression might play an important role in ovarian cancer development and that COX-2 expression in ovarian adenocarcinomas is frequently associated with p53 protein accumulation. COX-2 overexpression in ovarian cancer cells might partly be caused by dysfunctional p53.     

Drug resistance in ovarian cancer — the role of p53

The aims were to determine the importance of p53 and bcl-2 expression on the response to chemotherapy with alkylating agents in patients with ovarian cancer. We have followed the response to chemotherapy in a series of 59 patients with ovarian adenocarcinoma designated as p53 and bcl-2 positive or negative by immunocytochemistry. Of these cases, 50 received either cisplatin + treosulfan or treosulfan alone. Immunocytochemistry for p53 was positive in 28/59 tumors. Patients were grouped according to their response to chemotherapy (stable or progressive disease) assessed at 6, 12, and 18 months. There was increasing divergence of p53+ and p53- tumors over time. Of those which were p53+, 25% showed progression at 6 months, 80% at 12 months and 89% progression at 18 months. In contrast, 23%, 50%, and 67% of p53-tumors showed progression at 6, 12 and 18 months respectively. For bcl-2, in 23/55 positive tumors there was progression in 35%, 78% and 94% compared with 25%, 57% and 59% in bcl-2 negative tumors at 6, 12 and 18 months respectively. Those tumors which were bcl-2 and p53 negative were most likely to progress, while those which were bcl-2 and p53 positive had the best prognosis. These differences did not translate into increased overall survival with minimum follow-up of 12 months. This data lends support to our suggestion that despite initially increased susceptibility to alkylating agents, enhanced genomic instability due to p53 inactivation may render tumors more likely to develop resistance to chemotherapy over time. This effect may be altered by bcl-2 function, lack of which will lead to a good response to chemotherapy as the tumor’s ability to undergo apoptosis will not be compromised.     

Comparative immunohistochemical studies of bcl-2 and p53 proteins in benign and malignant ovarian endometriotic cysts

BACKGROUND: A number of histologic and epidemiologic studies have suggested an association between endometriosis and ovarian carcinoma. Some reports have described a transition from endometriosis to atypical endometriosis to carcinoma. Using immunohistochemistry, the authors compared staining patterns in benign endometriotic cysts with ovarian tumors and the endometriotic cyst lining from which they arose, in an attempt to identify sequential or etiologic correlations. METHODS: One hundred thirteen formalin-fixed, paraffin-embedded sections were studied (30 benign ovarian endometriotic cysts, 24 endometriotic cysts containing endometrioid carcinomas, 19 endometriotic cysts harboring clear cell carcinomas, and 40 ovarian papillary serous cystadenocarcinomas). All sections were immunostained with anti-bcl-2 and anti-p53 antibodies using the streptavidin-biotin method. RESULTS: bcl-2 was reported to stain 23% of benign endometriotic cysts, 67% of endometrioid carcinomas, 73% of clear cell carcinomas, and 50% of papillary serous carcinomas. Approximately 42% of benign endometriotic lesions adjacent to the endometrioid carcinoma and 73% adjacent to clear cell carcinomas were found to stain for bcl-2 (p = 0.274 [not significant (NS)] and P = 0.008, respectively). p53 staining was negative in the benign endometriotic cyst group and was positive in 37-55% of the group with tumors. p53 staining was positive in 25% of the benign endometriotic lesions next to the endometrioid carcinoma and in 9% of the benign endometriotic lesions next to clear cell carcinoma (P = 0.014 and P = 0.239 [NS], respectively). CONCLUSIONS: The results of the current study suggest that alterations in bcl-2 and p53 may be associated with the malignant transformation of endometriotic cysts.     

Expression of apoptosis-related proteins (p53, p21WAF1, bcl-2, and bax) and sensitivity to chemotherapy in squamous cell carcinoma of the esophagus

Background. Chemotherapy is an important component of the multimodal approach to the treatment of advanced esophageal squamous cell carcinoma. Methods. We investigated the associations between p53, p21 (Waf1), bcl-2, and bax expression and response to chemotherapy (cisplatin + 5-fluorouracil + leucovorin) in 43 patients with advanced esophageal squamous cell carcinoma. The expression of p53, p21 (Waf1), bcl-2, and bax proteins was analyzed immunohistologically in pretreatment biopsy and post-treatment resected specimens. Results. The 23 patients who had objective evidence of either a complete response (CR) or a partial response (PR) to chemotherapy survived for significantly longer than the 20 patients who had no response (NR). The expression of p53, p21 (Waf1), bcl-2, and bax was detected in 26 (61%), 12 (28%), 6 (14%), and 19 (44%) of the pretreatment biopsy specimens, respectively. The response to chemotherapy was not independently associated with the expression of any of these proteins. However, in the 26 patients with p53-expressing tumors, the response rate was 80% in patients whose tumor also expressed p21, whereas it was 19% in those whose tumor did not coexpress p21. No change in p53 expression was observed before and after chemotherapy, except in 1 patient; however, p21 expression appeared to be induced by chemotherapy in 5 patients. Patient survival was also not independently associated with the expression of any of these proteins. However, patients with p53-negative or p21-positive tumors had a better response to chemotherapy and survived for longer than those with p53-positive and p21-negative tumors. Conclusion. p53 and p21 expression in biopsy specimens obtained before chemotherapy could be useful predictors of response and survival in patients with advanced esophageal squamous cell carcinoma. Received: April 14, 1999 / Accepted: November 8, 1999