p53 accumulation in ovarian carcinomas and its prognostic implications

P53 and TLR4 expression are prognostic markers informing progression free survival of advanced stage high grade serous ovarian cancer

OBJECTIVE

New prognostic biomarkers, and bio-signatures, are urgently needed to facilitate a precision medicine-based approach to more effectively treat patients with high-grade serous ovarian cancer (HGSC). In this study, we analysed the expression patterns of a series of candidate protein biomarkers.

METHODS

The panel of markers which included MyD88, TLR4, MAD2, PR, OR, WT1, p53, p16, CD10 and Ki67 was assessed using immunohistochemistry in a tissue microarray (TMA) cohort of n = 80 patients, composed of stage 3-4 HGSCs. Each marker was analysed for their potential to predict both overall survival (OS) and progression-free survival (PFS).

RESULTS

TLR4 and p53 were found to be individually predictive of poorer PFS (Log Rank, p = 0.017, p = 0.030 respectively). Cox regression analysis also identified high p53 and TLR4 expression as prognostic factors for reduced PFS (p53; HR=1.785, CI=1.036-3.074, p = 0.037 and TLR4; HR=2.175, CI=1.112-4.253, p = 0.023). Multivariate forward conditional Cox regression analysis, examining all markers, identified a combined signature composed of p53 and TLR4 as prognostic for reduced PFS (p = 0.023).

CONCLUSION

Combined p53 and TLR4 marker assessment may help to aid treatment stratification for patients diagnosed with advanced-stage HGSC.

P53 Expression, Dna Ploidy and Mitotic Index as Prognostic Factors in Patients with Epithelial Ovarian Carcinoma

Aims and Background

Biological variables linked to genomic instability were examined and related to survival in 52 patients affected by ovarian carcinoma and nine patients with low malignant potential tumors (LMP).

Methods

DNA ploidy was measured by image cytometry in isolated neoplastic cells; the mitotic index was measured in Feulgen-toluidine blue-stained sections and p53 was investigated by immunohistochemistry.

Results

Twenty-five tumors (4 LMP) were peridiploid (ploidy <2.25c), 22 tumors (4 LMP) were hyperdiploid (2.25c>ploidy<2.9c) and 14 (1 LMP) had high ploidy (≥2.9c). Ml ranged from 0.3 to 24.2 with a mean of 1.8 for LMP and 6.8 for carcinomas (P <0.001). Widespread p53 overexpression was detected in 49% of carcinomas and in none of the LMP tumors.

Conclusions

Survival analysis performed in patients with carcinomas indicated that, of the examined biological variables, only Ml was moderately associated with survival in a subgroup of early-stage patients.

Cell Cycle Control of Ovarian Granulosa Cells in Tumors and Cysts

Ovarian granulosa cell tumors (GCTs) behave unpredictably. Stage I patients suffer recurrences many years after treatment, and histopathologic evaluation of the primary GCT offers few clues. p21IPl/wafl (Waft), the principle downstream effector of the p53-dependent pathway of growth control, inhibits cyclin-dependent kinases responsible for conversion of GI to S in the cell cycle. This study hypothesizes that immunohistochemistry for these proliferation-related markers will help discern granulosa cell growth control and may predict the GCTs' clinical behavior. Paraffin sections from a surgical series of 43 GCTs (34 primary and 9 recurrent: 19 diffuse and 18 typical adult; 6 juvenile type) and 12 benign cysts (8 follicular and 4 corpora luteal) were immunostained for Waft and p53. Ki67 (MIB-1 clone) proliferation index is the percent of nuclei immunoreactive on a count of at least 400. The 43 GCTs stained as follows: 40% Waft + (11 St = < 10%, 4 S2 = 10-50%, and 2 S3 = > 50% of nuclei) and 28% p53 + (2 W = weak, 8 S 1, 2 S2). All p53 + GCTs stained with Waf 1; the number of immunoreactive nuclei correlated (P < .00001). Juvenile more often than adult type GCTs exhibited Waf 1 (6/6) and p53 staining (5/6) (P < .001). No difference in pS3 or Waft staining was present in primary compared with recurrent GCTs. Ki67 proliferation index for GCTs ranged from 1 to 50% (mean, 13.8%; median, 10.9%) and associated with both p53 and Waft (P < .000 1). The 12 benign cysts stained as follows: 100% Waft + (6 S1, 5 S2, 1 S3) and 75% p53+ (4 W, 4 S1, 1 S2). Of the 43 patients, 41 were available for follow-up study: 15 suffered recurrences after 16-133 (mean 59.3, median 55) months, and 26 were disease-free 21-369 (mean 78.2, median 57.5) months after diagnosis. Waft staining of the primary GCT does not help predict recurrence. All GCTs immunoreactive for p53 produce Waft, suggesting detection of an active wild type p53 rather than overproduction of mutant p53. Waft is produced by granulosa cells in all benign functional cysts, suggesting a physiologic role in the ovulation sequence. Waf t's association with proliferation in GCTs suggests possible physiologic feedback. Proliferation (correlated with histopathologic grading) in GCTs may signify appropriate feedback control; thus it is not a predictor of aggressive clinical behavior.

Granulosa Cell-Specific Brca1 Loss Alone or Combined with Trp53 Haploinsufficiency and Transgenic FSH Expression Fails to Induce Ovarian Tumors

BRCA1 mutations are associated with ovarian cancer. Previous studies reported that murine granulosa cell (GC) Brca1 loss caused ovarian-uterine tumors resembling serous cystadenomas, but the pathogenesis of these tumors may have been confounded by ectopic Brca1 expression and altered estrous cycling. We have used Tg.AMH.Cre conferring proven ovarian and GC-specific Cre activity to selectively target Brca1 disruption, denoted Brca1(GC-/-). Furthermore, ovary-specific Brca1(GC-/-) was combined with global Trp53 haploinsufficiency (Trp53(+/-)) and transgenic follicle-stimulating hormone (Tg.FSH) overexpression as a multi-hit strategy to investigate additional genetic and hormonal ovarian tumorigenesis mechanisms. However, 12-month-old Brca1(GC-/-) mice had no detectable ovarian or uterine tumors. Brca1(GC-/-) mice had significantly increased ovary weights, follicles exhibiting more pyknotic granulosa cells, and fewer corpora lutea with regular estrous cycling compared to controls. Isolated Brca1(GC-/-) mutation lengthened the estrous cycle and proestrus stage; however, ovarian cystadenomas were not observed, even when Brca1(GC-/-) was combined with Trp53(+/-) and overexpressed Tg.FSH. Our Brca1(GC-/-) models reveal that specific intra-follicular Brca1 loss alone, or combined with cancer-promoting genetic (Trp53 loss) and endocrine (high serum FSH) changes, was not sufficient to cause ovarian tumors. Our findings show that the ovary is remarkably resistant to oncogenesis, and support the emerging view of an extragonadal, multi-hit origin for ovarian tumorigenesis.

The consequence of oncomorphic TP53 mutations in ovarian cancer

Ovarian cancer is the most lethal gynecological malignancy, with an alarmingly poor prognosis attributed to late detection and chemoresistance. Initially, most tumors respond to chemotherapy but eventually relapse due to the development of drug resistance. Currently, there are no biological markers that can be used to predict patient response to chemotherapy. However, it is clear that mutations in the tumor suppressor gene TP53, which occur in 96% of serous ovarian tumors, alter the core molecular pathways involved in drug response. One subtype of TP53 mutations, widely termed gain-of-function (GOF) mutations, surprisingly converts this protein from a tumor suppressor to an oncogene. We term the resulting change an oncomorphism. In this review, we discuss particular TP53 mutations, including known oncomorphic properties of the resulting mutant p53 proteins. For example, several different oncomorphic mutations have been reported, but each mutation acts in a distinct manner and has a different effect on tumor progression and chemoresistance. An understanding of the pathological pathways altered by each mutation is necessary in order to design appropriate drug interventions for patients suffering from this deadly disease.

Mitotic count reflects prognosis of gallbladder cancer particularly among patients with T3 tumor

The surgical strategy for gallbladder cancer (GBC) depends on the extent of the disease. Thus, the identification of useful prognostic markers exerting strong prognostic impact for each T stage would be beneficial in the development of rational therapeutic strategies. The purpose of this study was to identify useful prognostic markers of GBC for each T stage. CD8⁺ tumor-infiltrating lymphocytes (TIL), Ki-67 labeling index (LI), p53 nuclear expression and mitotic count (MC) were investigated as candidate prognostic markers. In total, 86 patients with invasive GBC were included. Of the prognostic markers examined, only MC showed a correlation with reduced survival (P=0.0383) in the univariate analysis of overall T stage. In the univariate analysis of T2 stage (n=31), only high p53 expression correlated with survival showing a positive correlation (P=0.0154). In the univariate analysis of T3 stage (n=40), the only factor showing a significant correlation with survival was MC (P=0.0113). Multivariate analysis, including N and M as factors, identified only MC as an independent prognostic factor in T3 stage GBC (P=0.0419). In conclusion, this study demonstrated the strong prognostic impact of MC in GBC, particularly in patients with T3 tumor.

A cytohistological study of p53 overexpression in ovarian neoplasms

Background:

The present study was undertaken to evaluate the diagnostic accuracy of imprint cytology in ovarian neoplasms, investigate the biological significance of p53 expression in malignant ovarian tumors and correlate it with histological type, grade and stage of tumor.

Material and Methods:

A total of 50 cases including 25 prospective and 25 retrospective cases were studied. Imprint cytology was performed on 25 ovarian tumors and compared with histopathological diagnosis. p53 immunohistochemistry was performed on all 50 cases.

Results:

On immunohistochemistry, all the benign tumors were negative for p53 while 42% of primary ovarian malignant tumors were positive. p53 expression was found to have a diagnostic value in differentiating benign from malignant tumors. p53 overexpression did not show any significant correlation with prognostic factors as stage of disease, grade of differentiation and type of tumor.

Conclusion:

The present study confirms the importance of p53 tumor suppressor gene expression as documented by immunohistochemistry in the differentiation of malignant and benign ovarian tumors.

Dys-psychological Stress Effect on Expressions of P53 and NFκBp65 in Human Ovarian Carcinoma In Vivo

OBJECTIVE

To investigate the dys-psychological stress effect on the growth of subcutaneous xenotransplanted tumor in nude mice bearing human epithelium ovarian carcinoma, and the influence on P53 and NFκBp65 expressions.

METHODS

The subcutaneous tumor xenografts were established by implanting human epithelium ovarian carcinoma tissues into nude mice and the dys-psychological stress model was established with restraint. The mice were randomized into the following four treatment groups with each group six mice respectively: tumor group (group A), normal saline intraperitoneal injection; tumor with stress group (group B), normal saline intraperitoneal injection; tumor therapy group (group C), cisplatin intraperitoneal injection; and tumor therapy with stress group (group D), cisplatin intraperitoneal injection. The expressions of P53 and NFκBp65 in tumor tissues were determined by Western blotting.

RESULTS

The expressions of P53 and NFκBp65 in each restraint group were enhanced compared with the control groups (P<0.05).

CONCLUSION

The dys-psychological stress may induce the high expressions of P53 and NFκBp65 proteins and further promote tumor growth.

P53 and bcl-2 assessment in serous ovarian carcinoma

The study objective was to determine the prognostic value of assessment of staining of p53 and bcl-2 in a well-selected group of serous ovarian carcinomas. Immunohistochemical detection was used to identify both p53 and bcl-2 positive tumors. One hundred thirty-two tumors were analyzed for positivity of staining, grade of staining intensity, and for p53 alone, percent expression rates. These were analyzed alongside traditional clinicopathologic parameters for their ability to predict overall survival (OS), disease-free survival (DFS), and response to chemotherapy (CR). Univariate COX analysis revealed percent p53 expression (P = 0.012) and p53 grade (P = 0.01) to be significant predictors of DFS. Neither the p53 nor bcl-2 measurement parameters were found significant for OS or prediction of CR. On multivariate analysis, incorporating clinicopathologic parameters, p53 parameters did not retain independent significance for any outcome measure. As in primary reported studies, bcl-2 was not found to be of clear independent prognostic value in this group of ovarian tumors. If mutation of p53 and its consequent overexpression is an early event in ovarian tumorigenesis, then p53 assessment may prove useful prognostically in the assessment of either low-grade ovarian carcinomas, as a possible indicator for progression, or in early-stage ovarian tumors, as a marker of tumor aggression or likelihood of recurrence. p53 analysis of a larger group of stage I ovarian tumors would be desirable to further explain the potential association with DFS.

Human papilloma virus (HPV) status, p16INK4a, and p53 overexpression in epithelial malignant and borderline ovarian neoplasms

This investigation is the first to evaluate simultaneously human papilloma virus (HPV) status, p16(INK4a), and p53 immunoreactivity in epithelial ovarian neoplasms. The results were analyzed and correlated with histological type, histological grade, and survival of patients. Subtypes considered are papillary serous and mucinous. Polymerase chain reaction (PCR) analysis, performed in our previous study, had already demonstrated a small number of HPV-positive epithelial ovarian neoplasms. No significant correlation was found between the presence of HPV DNA and subtypes of ovarian neoplasms; thus, HPV cannot be considered responsible for epithelial ovarian neoplasm. Since p16 immunoreactivity was present in many other HPV-negative cases of epithelial ovarian neoplasms, this study suggests that p16 overexpression in some neoplasms of the female genital tract is not related to HPV carcinogenesis. A higher p53 expression rate observed between borderline and malignant serous tumors and between serous and mucinous neoplasms can confirm a recent dualistic model of ovarian carcinogenesis. According to this theory, low-grade serous carcinomas (serous intraepithelial carcinomas, serous borderline neoplasm, and ovarian mucinous neoplasms) (type I tumors) develop from mutations of KAS and BRAF, while high-grade serous carcinomas (type II tumors) develop from mutation of p53. In malignant neoplasms, for univariate analysis, patient survival seems to be related to p53, strong and diffuse p16 overexpression, and the stage of development of neoplasms at the diagnosis. In multinomial logistic regression, used to evaluate the role of staging, grading, p16 and p53 immunopositivity as predictor variables of unfavorable outcome of the disease, only p16 positivity was significantly related to the poor prognosis of the cancer.

A new prognostic model comprising p53, EGFR, and tumor grade in early stage epithelial ovarian carcinoma and avoiding the problem of inaccurate surgical staging

Epithelial ovarian carcinoma rarely occurs because of a single event. Therefore, no single biological tumor factor will give accurate prognostic information for all ovarian cancer patients. On the other hand, a combination of two or more independent factors may yield an improved overall prognostic index. Because FIGO stage is included in most of the previously presented models, inaccurate surgical staging in patients with apparently early disease has been a problem. In a series of 226 patients with epithelial ovarian carcinomas in FIGO stages IA-IIC, a number of clinicopathological factors (age, FIGO stage, histopathologic type, and tumor grade) were studied in relation to the biological factors p53 and epidermal growth factor receptor (EGFR), important regulators of the apoptosis and mitosis. Immunohistochemical techniques were used. All patients received adjuvant radiotherapy or chemotherapy after the primary surgery. Expression of p53 was significantly associated with the tumor grade and disease-free survival (DFS). EGFR expression was also associated with DFS. In a Cox multivariate analysis, tumor grade, p53 status, and EGFR status were all independent and significant prognostic factors with regard to DFS. A prognostic model was proposed using these factors. A low-risk group, an intermediate-risk group, and a high-risk group were defined. DFS amounted to 89% in the low-risk group (grades 1-2, p53-negative, and EGFR-negative), 66% in the intermediate-risk group (grade 3, p53-negative, and EGFR-negative or grades 1-2, p53-positive or EGFR-positive) and 39% in the high-risk group (grade 3, p53-positive, and EGFR-positive).

Analyses of p53 expression pattern and BRCA mutations in patients with double primary breast and ovarian cancer

OBJECTIVE

To analyze the somatic pattern of p53 expression and BRCA germline mutation status in Israeli patients with both ovarian (OvCa) and breast cancer (BrCa).

METHODS

The study group comprised 43 Israeli patients with OvCa, all of whom had previous primary BrCa. p53 immunohistochemistry (IHC) on all available archival tissues and genotyping for the three predominant Jewish germline BRCA1-2 mutations were carried out. Samples from 64 patients with solitary OvCa and 61 with solitary BrCa were similarly analyzed as controls.

RESULTS

p53 expression pattern and the immunopositivity rate were similar in the ovarian and breast tumors within the study group and in the two control groups: positive p53 staining was detected in 68% of ovarian tumors in the study group compared with 71.9% in the controls, and in 19.4% of the BrCa tissues versus 21.3% in the controls. Within the study group, advanced stage OvCa had a higher rate of p53 expression (84%) compared to early stage disease (38.5%) (P = 0.006). This difference was not apparent in the solitary OvCa control group. OvCa in BRCA1-2 mutation carriers from the study group were more likely to display positive p53 staining (79%), especially in tumors diagnosed before the age of 60 (90%) compared with the OvCa of noncarriers (60%), but this difference was statistically insignificant. The p53 expression rate in BrCa samples from the study group was not associated with BRCA1-2 mutation status.

CONCLUSIONS

Positive p53 expression, detected by IHC, in OvCa patients with previous primary BrCa is significantly higher in advanced stage disease in BRCA1-2 mutation carriers. There is a higher positive p53 expression somatically in OvCa in BRCA1-2 carriers in whom OvCa was diagnosed before the age of 60 years, although this trend is not statistically significant. These observations suggest that somatic p53 inactivation may be an important event in ovarian tumorigenesis in this subset of patients.

Pathophysiological Dynamics of Human Ovarian Surface Epithelial Cells in Epithelial Ovarian Carcinogenesis

Epithelial ovarian cancer is responsible for almost half of all the deaths from female genital tract tumors. Major impediments to the clinical treatment of this disease are the relatively asymptomatic progression and a lack of knowledge regarding defined precursor or malignant lesions. Most epithelial ovarian cancers are thought to arise from the transformation of ovarian surface epithelial cells, a single continuous layer of flat-to-cuboidal mesothelial cells surrounding the ovary. To improve our understanding of the pathogenesis of epithelial ovarian cancer, it is necessary to study the biological characteristics of normal ovarian surface epithelial cells. However, this approach has been hampered by the inability to purify and culture such human cells. During the past decade, procedures to isolate and culture human ovarian surface epithelial cells have been developed, and, subsequently, using viral oncogenes, several immortalized cells have been established. This new experimental system is being employed to improve our understanding of the genetic changes leading to the initiation of epithelial ovarian cancer and to identify events in the cancer's development. This review mainly describes the biological dynamics of ovarian surface epithelial cells in the pathogenesis of epithelial ovarian cancer, focusing on humans and excluding small animal models.

Independence of the prognostic value of tumor suppressor protein expression in ovarian adenocarcinomas: A multivariate analysis of expression of p53, retinoblastoma, and related proteins

Accurate estimation of prognosis of ovarian cancer is difficult. For this report, in a group of 73 patients with ovarian adenocarcinomas, clinical factors and protein expression status of p53, retinoblastoma (Rb), and related proteins were evaluated for potential prognostic values. Clinical factors included FIGO stage, age, histopathologic type, and protein expression of p53, Rb, MDM2, p14ARF, p21WAF(1)/CIP(1) was determined by an immunohistochemical technique. Univariate Cox proportional hazard regression analysis was used to determine the significant prognostic value of FIGO stage (P < 0.0001), p53 status (0.0021), and patient age (P = 0.0255), and we report here, for the first time, the significant (P = 0.0072) prognostic value of Rb status. Histopathologic type and MDM2, p14ARF, p21WAF(1)/CIP(1) status did not show any prognostic value. To examine further the independence of prognostic values, we next applied multivariate analysis: We found that FIGO stage (P < 0.0001) and p53 status (P = 0.0108) were independent prognostic factors, while age and Rb status were not. Independence of prognostic value of p53 has heretofore been controversial, but we found a definite independent prognostic value for p53 status in ovarian adenocarcinomas. We also found that selection of appropriate antibodies for immunohistochemistry was essential to obtain significant results. We used five kinds of antibodies for p53 immunolocalization, and correlation with prognosis was obtained by three of these with different grades of statistical significance.

A review of p53 expression and mutation in human benign, low malignant potential, and invasive epithelial ovarian tumors

BACKGROUND

In the current study, the authors present pooled data from studies that investigated p53 protein expression and/or mutation in human epithelial ovarian tumors.

METHODS

The English literature in the MEDLINE, PubMed, and Ingenta databases was searched to the end of the year 2000 to identify relevant studies. Data were pooled across eligible studies, and the prevalence of p53 expression and mutation among benign, low malignant potential (LMP), and invasive tumors was determined. Prevalence estimates by tumor histology, International Federation of Gynecology and Obstetrics (FIGO) stage, and grade also were calculated.

RESULTS

The pooled prevalence estimate for p53 overexpression among epithelial ovarian carcinomas was 51% (95% confidence intervals [95% CI], 50-53%) compared with 17% (95% CI, 15-20%) among LMP tumors and 7% (95% CI, 5-10%) among benign tumors. p53 mutation prevalence estimates were 45% (95% CI, 42-47%), 5% (95% CI, 2-9%), and 1% (95% CI, 0-5%), respectively, for invasive, LMP, and benign tumors. The prevalence of these p53 abnormalities was found to be associated positively with increasing tumor grade and stage. Differences based on histologic subtype also were found.

CONCLUSIONS

Although these pooled estimates might appear to offer support for various hypotheses regarding the role of p53 in ovarian carcinoma, the limitations inherent in these data hamper the interpretation of the significance of any of the findings. Future studies will require innovative methods to address the limitations of many previous investigations and more comprehensive investigation into defective tumor suppression mechanisms.

Correlation of p53 immunostaining in primary and residual ovarian cancer at the time of positive second-look laparotomy and its prognostic role: a Southwest Oncology Group ancillary study

OBJECTIVE

The objective of this study was to verify the correlation between p53 immunostaining at initial diagnosis and at positive reassessment after completing platinum-based chemotherapy and to assess prognostic differences between patients whose tumors display positive immunostaining versus those that have negative immunostaining at such reassessment.

METHODS

This study made use of samples from patients entered into a prospective randomized study of the Southwest Oncology Group (SWOG 8835) that treated patients with minimal residual disease at second-look laparotomy with either intraperitoneal (ip) mitoxantrone or fluorodeoxyuridine (FUDR). Unstained slides from tumor obtained at the initial diagnosis and at reassessment were retrospectively requested from individual institutions. The degree of nuclear staining was determined using the anti-p53 mouse monoclonal antibody Pab1801 and previously published techniques, with a cutoff of 10% or more staining of tumor cell nuclei for a positive result. Cox model regression analysis was performed for overall survival and progression-free survival, with p53 status, ip treatment, and baseline CA125 as independent variables.

RESULTS

p53 determination was feasible in 22 patients both at diagnosis and at the second-look samples; 9 additional patients had only either sample available. Since concordance between the 10 negative and 12 positive immunostained samples was 100%, all 31 patients were considered in the Cox model. The death hazard ratio of p53-positive versus p53-negative patients was 4.18 (two-sided P value of 0.006).

CONCLUSION

p53 immunostaining at second-look laparotomy correlates with the immunostaining at diagnosis. In this series confined to patients with minimal residual disease after initial therapy subjected to second-line intraperitoneal treatment, it appears to identify a poor prognostic (positive) subset for survival.

Mutations of TP53 do not correlate with the sensitivity to paclitaxel--a study using 27 gynaecological cancer cell lines

The correlation between inactivation of the TP53 gene through mutation or the presence of high-risk human papillomavirus (HPV) DNA and intrinsic paclitaxel sensitivity was studied in 27 gynaecological cancer cell lines. IC(50) values, as a measure of drug sensitivity, were determined using a 96-well clonogenic assay. TP53 mutations were investigated with polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct DNA sequencing. HPV status was studied with PCR using HPV consensus primers. TP53 mutations were found in 7/11 vulvar SCC cell lines. Only 2/9 endometrial and 1/7 ovarian cancer cell lines carried TP53 mutations. One vulvar and one endometrial cancer cell line were HPV-positive; both carrying HPV type-16 DNA. Thus, TP53 was functionally normal in 3/11 vulvar, 6/9 endometrial and 6/7 ovarian cancer cell lines. The IC(50) values for paclitaxel were 0.60-2.9, 0.49-2.3 and 0.40-3.4 nM in the vulvar, endometrial and ovarian cancer cell lines, respectively. No correlation could be demonstrated between inactivation of the TP53 gene and paclitaxel sensitivity in vitro; the cell lines were evaluated as one group or according to their anatomical origin or histology. Previous reports have given inconclusive results, partly due to the cell types used, i.e. normal, cancerous or transformed cells. Our results support the view that paclitaxel sensitivity of tumour-derived cancer cell lines is not related to the TP53 status.

Increased MCL-1 expression is associated with poor prognosis in ovarian carcinomas

To investigate the potential role of the BCL-2 gene family (BAX, BCL-2, MCL-1, and BCL-XL) in ovarian cancer development and progression, mRNA expression levels of these genes were measured using semi-quantitative PCR in epithelial ovarian tumor tissues and normal ovaries. The immunohistochemical expression of MCL-1 in ovarian tumors was also examined. The expression levels of BAX and MCL-1 mRNA were significantly higher in ovarian cancers and in adenomas than in normal ovaries (P < 0.05). In contrast, the BCL-2 mRNA expression level in ovarian cancers was significantly lower than in ovarian adenomas and in normal ovaries (P < 0.05). Expression of BCL-XL mRNA was no different between normal ovaries and ovarian tumors. Log-rank testing showed that low BAX mRNA expression and high MCL-1 mRNA expression significantly correlate with poor survival for patients with stage III ovarian carcinomas (BAX, P = 0.05; MCL-1, P = 0.02). Immunohistochemical analysis showed that diffuse-positive expression of MCL-1 protein in mucinous carcinomas was significantly higher than in mucinous low malignant potential (LMP) tumors (P = 0.03). In ovarian cancer cases, diffuse-positive expression of MCL-1 protein significantly correlates with advanced clinical stage, high histologic grade, and poor survival (stage, P < 0.01; grade, P = 0.01; survival, P = 0.01). These results suggest that increased MCL-1 expression may play an important role in replacing the functions of increased BAX and decreased BCL-2 in ovarian carcinoma cells, thereby promoting cell survival, and resulting in a poor prognosis for patients with ovarian cancer.

Immunohistochemical analysis of gynecologic tumors

Ancillary techniques such as immunohistochemistry (IHC) enable the surgical pathologist to extract additional information from fixed, deparaffinized tissue specimens and to provide data critical to optimal clinical management of the patient. In this review of applications of IHC to the analysis of gynecologic malignancies, the usefulness of immunohistochemical analysis of neoplasms of the cervix, endometrium, and ovary is summarized. In the uterine cervix, dysplasia is associated with qualitative and quantitative alterations in the expression of the Ki-67 antigen expression, as well as an ability to detect human papillomavirus. Endometrial endometrioid adenocarcinomas display a highly characteristic immunophenotype, with coexpression of cytokeratin and vimentin and demonstration of foci of high molecular weight cytokeratin expression; in addition, IHC analysis of estrogen and progesterone receptor and p53 expression can provide important prognostic information about this tumor. Stromal tumors of the endometrium may display a partial smooth muscle immunophenotype, but novel markers such as CD10 provide new tools for the identification of these tumors. The immunophenotypes of the normal ovarian surface epithelium (OSE) and corresponding tumors display significant overlap with, but important distinctions from, mesothelium, and important new markers such as the Wilms tumor gene product can prove useful in the identification of carcinomas of the OSE. Important prognostic markers for carcinomas of the OSE include the HER-2/neu gene product and p53, alterations of which can both be assessed by IHC techniques. Finally, the recent availability of markers of ovarian stroma, including Melan-A and inhibin-alpha, has provided a means for the positive identification of ovarian stromal tumors, which can manifest protean histological appearances.

Prognostic significance of cell cycle proteins and genomic instability in borderline, early and advanced stage ovarian carcinomas

Disturbed cell cycle-regulating checkpoints and impairment of genomic stability are key events during the genesis and progression of malignant tumors. We analyzed 80 epithelial ovarian tumors of benign (n = 10) and borderline type (n = 18) in addition to carcinomas of early (n = 26) and advanced (n = 26) stages for the expression of Ki67, cyclin A and cyclin E, p21WAF-1, p27KIP-1 and p53 and correlated the results with the clinical course. Genomic instability was assessed by DNA ploidy measurements and, in 35 cases, by comparative genomic hybridization. Overexpression of cyclin A and cyclin E was observed in the majority of invasive carcinomas, only rarely in borderline tumors and in none of the benign tumors. Similarly, high expression of p53 together with undetectable p21 or loss of chromosome arm 17p were frequent events only in adenocarcinomas. Both borderline tumors and adenocarcinomas revealed a high number of chromosomal gains and losses. However, regional chromosomal amplifications were found to occur 13 times more frequently in the adenocarcinomas than in the borderline tumors. The expression pattern of low p27 together with high Ki67 was found to be an independent predictor of poor outcome in invasive carcinomas. The results provide a link between disturbed cell cycle regulatory proteins, chromosomal aberrations and survival in ovarian carcinomas.

New insights into p53 regulation and gene therapy for cancer

Due to its critical involvement in cell cycle control and apoptotic signaling, the transcription factor p53 has become the most important tumor suppressor currently under investigation. TP53 is the most frequently mutated gene in human cancers and is thought to play a crucial role in malignant transformation. Therefore, p53 appears to be an appealing target for gene therapy. Adenoviral-based p53 gene transfection is now being introduced in large clinical trials. Viral cell entry was found to be the rate-limiting step of gene delivery and thus of therapeutic efficiency. Attachment of adenoviruses to the target cell surface is mediated through the coxsackie-adenovirus receptor, and internalization is achieved via interactions with integrins of the alpha v beta(3) and alpha v beta(5) class. The assumption that the restitution of the p53-dependent apoptotic pathway results in a higher responsiveness of solid tumors to cytostatic agents remains a major matter of debate. Combinations of p53-based gene therapy with other components involved in apoptosis, such as tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)/APO2L, or agents neutralizing tumor-promoting antiapoptotic signals, such as humanized anti-growth factor antibodies, should further improve the effectiveness of cancer treatment in the future.

Loss of heterozygosity at chromosomes 3, 6, 8, 11, 16, and 17 in ovarian cancer: correlation to clinicopathological variables

Tumor specimens from 78 epithelial ovarian cancer patients were examined for loss of heterozygosity (LOH) at 11 microsatellite markers at chromosomes 3p14.2, 6q27, 8p12, 11p15.5, 11q23.1-q24, 16q24.3, and 17p13.1, to evaluate the involvement, possible clustering, and prognostic significance of these lesions in the progression of the disease. The LOH analysis was performed on polymerase chain reaction (PCR)-amplified DNA from sections of paraffin-embedded tumor and normal tissue pairs. In addition to primary tumors, specimens of metastatic tissues were studied from 19 patients. In the combined results from primary and metastatic tumors, LOH frequencies varied between 31% (6q27) and 69% (17p13.1). Only LOH at chromosomal regions 3p14.2 (D3S1300), 11p15.5 (D11S1318), 11q23.3-q24 (D11S1340 and D11S912), 16q24.3 (D16S476 and D16S3028), and 17p13.1 (D17S938) was associated with an adverse disease course. Our results indicate that LOH at 17p13.1 occurs independently from the other chromosomal sites studied, and is an early event in ovarian tumorigenesis. The LOH at 16q24.3, 11q23.3/q24, and 11p15.5 seems to occur later. The LOH at 11p15.5 and 11q23.3 was associated with reduced cancer-specific survival time; therefore, the studied markers could be located close to genes with influence on patient survival. Of the studied chromosomal regions, the most important tumor suppressor genes involved in the evolution of ovarian cancer appear to be located on chromosomes 11, 16, and 17. The genetic heterogeneity observed in primary and metastatic specimens demonstrates that there are multiple pathways involved in the progression of ovarian cancer.

Topoisomerase II alpha: prognostic predictor and cell cycle marker in surface epithelial neoplasms of the ovary and peritoneum

Immunohistochemistry for Topoisomerase II alpha (TopoIIa), a nuclear protein important for the separation of chromosomes and deoxyribonucleic acid replication, provides insight into the molecular events in the cell cycle and the response to chemotherapeutic agents, which target TopoIIa. We test the hypothesis that the percentage of TopoIIa immunoreactive nuclei (TopoIIaI) aids in the treatment and prognostic evaluation of ovarian and primary peritoneal surface epithelial neoplasms (SENs) and correlates with established cell cycle control markers: p53, p21WAF1/CIP1 (p21), and Ki67. Paraffin sections from a retrospective surgical series of 108 SENs were immunostained with anti-TopoIIa, anti-p53, anti-p21, and anti-Ki67. The TopoIIaI, the Ki67 proliferation index (Ki67PI), and the immunoreactivity score for p53 and p21 (IMS: S1, S2, S3 < 10%, 10 to 50%, > 50% of strong staining cells, respectively) were evaluated manually. TopoIIaI and Ki67PI ranged from 5 to 84% and 4 to 88% (mean/median: 31/30 and 44/46%), respectively, and were correlated (coefficient 0.62, p < 10(-11)). IMS of 108 SENs was as follows: p53 50% + (2S1, 52S3) and p21 66% + (38S1, 12S2, 21S3). The TopoIIaI associated directly with p53 (p < 10(-5) and inversely with p21 (p < 0.005) IMS. TopoIIaI correlated with SEN architectural/nuclear grade (p < 10(-5)/10(-7)), but not histologic type. Sixty-seven patients had disease at last follow-up, 55 were dead from disease at 2 to 67 months (mean/median 24/21), and 14 were alive with disease at 31 to 230 months (mean/median 73/59). Forty-one patients were disease free at 5 to 228 months (mean/median 75/54). TopoIIaI correlated with presence of disease (p < 0.01) and poor survival (p < 1 x 10(-9), even when only 93 invasive SEN cases are considered (p < 0.005). TopoIIaI correlates with poor prognosis and other cell cycle control markers. The patients in this retrospective series of SEN were treated primarily with platinum-based chemotherapy. These data may suggest further prospective studies in which patients with SENs exhibiting high TopoIIaI are treated with chemotherapy targeted against TopoIIa (e.g., etoposide). In this retrospective series, high SEN TopoIIaI predicted poor survival when treated with platinum-based chemotherapy, which does not target TopoIIa.

Effect of cisplatin-based chemotherapy on emergence of cisplatin resistance, and its correlation with intracellular glutathione levels and accumulation of p53 protein in human ovarian cancer

Forty-seven ovarian cancer cases in which 20 were previously treated with cisplatin (cisPt) based chemotherapy, were checked for in vitro chemosensitivity using MTT assay. The drugs included in the study were cisPt, adriamycin (ADR), epirubicin (EPR) and etoposide (ETO). The logarithemic concentrations (0.1, 1.0, 10.0 and 100.0 micrograms/ml) of these drugs were used in the MTT assay. The IC50 values for these drugs in the above tumor samples were calculated. The effect of pretreatment with cisPt based chemotherapy on the emergence of drug resistance, expression of p53 protein (detected using immunohistochemical method by employing monoclonal antibody to p53) and intracellular glutathione (GSH) levels was also studied. Our results demonstrated the superiority of EPR in terms of its efficacy as compared to the other drugs used in the study. EPR was effective in both, previously cisPt-exposed and cisPt-unexposed ovarian cancer cases indicating its importance as a second line chemotherapy in the refractory ovarian carcinoma cases. Pre-exposure to cisPt based chemotherapy appears to result in the emergence of cisPt resistance, elevated intracellular GSH levels as well as p53 positivity. A statistically significant correlation was also observed between ADR and EPR resistance and p53 positivity (P < 0.01 and 0.05 respectively).

p53 and bcl-2 in epithelial ovarian carcinoma: their value as prognostic indicators at a median follow-up of 60 months

OBJECTIVE

p53 is the most common tumor suppressor gene involved with human malignancies. Mutations in p53 are present in approximately 50% of human malignancies. bcl-2 is a protooncogene. Expression of its protein product is related to better prognosis in several malignancies.

METHODS

One hundred and three patients with epithelial ovarian carcinoma were studied. Immunohistochemical staining using the pAb1801 monoclonal antibody to p53 and the anti-bcl-2 124 monoclonal antibody to bcl-2 was performed. Image analysis was used to measure percentage positive nuclear area staining of mutant p53. In addition to bcl-2 and p53, FIGO stage, grade, histology, and level of cytoreduction were analyzed as prognostic factors. Univariate as well as Cox regression analysis was performed.

RESULTS

One hundred and three patients were followed for a mean of 60 months. Twenty patients had FIGO stage I disease, 4 stage II, 59 stage III, and 20 stage IV. Immunohistochemical staining for mutant p53 was not significantly related to DNA index (P = 0.99) but was related to increasing FIGO stage (P < 0.001) and increasing histologic grade (P = 0.039). Using Cox regression analysis, increased mutant p53 staining was an independent predictor of survival in these patients (P = 0.0032), along with stage (P < 0. 0001) and level of cytoreduction (P < 0.0001). Although by itself bcl-2 was not an independent prognostic indicator (P = 0.18), the combination of p53 and bcl-2 was independently predictive of survival (P = 0.038).

CONCLUSION

This study confirms the authors' earlier report on the importance of p53 as a prognostic indicator of survival in ovarian carcinoma. Cox regression analysis reveals mutant p53 staining to be a better independent indicator of prognosis and survival in patients with ovarian carcinoma than the combination of bcl-2 and p53.

Emergence of cisplatin-resistant cells from the OVCAR-3 ovarian carcinoma cell line with p53 mutations, altered tumorigenicity, and increased apoptotic sensitivity to p53 gene replacement

Resistance to chemotherapy commonly compromises the treatment of many advanced cancers. Evidence suggests a correlation between chemoresistance and more aggressive tumor growth, possibly through accumulation of additional genetic defects in drug-treated or resistant cells. To study this process in a human ovarian cancer model, we examined OVCAR-3 cells for acute sensitivity to cisplatin (cDDP) and subsequent emergence of drug-resistant clones following chronic cDDP exposure. Clonal cells (OVCAR-3/C-1) that displayed 20-fold reduced sensitivity to cisplatin but retained equivalent sensitivity to paclitaxel, as compared with the parental population, were isolated. The cDDP-resistant clone had growth kinetics similar to those of parental population, but when transplanted into the peritoneal cavity of nude mice, they acquired the ability to grow with the development of both ascites and solid tumor masses; such growth was not detectable after transplantation of the drug-sensitive parental cell line. C-1 cells had a p53 gene mutation (codon 266) that was not detected in the parental OVCAR-3 cell line, and infection of C-1 cells with p53-adenovirus (rAd-p53) caused greater apoptosis and gene transduction than that observed in the similarly infected parental population. rAd-p53 induced high levels of p21WAF1, p27Kip1, activated caspase 3 and apoptosis in C-1 cells, without causing major changes in bax or bcl-XL levels. Together, the results suggest that alterations in tumor growth and gene mutations characterize cDDP-resistance in OVCAR-3 cells, and viral replacement of one of these defective genes (p53) may provide an effective treatment for elimination of drug-resistant cells.

Incidence of P53 and K-ras alterations in ovarian mucinous and serous tumors

Clarification of the pathogenic relationships existing among ovarian cystadenomas, tumors of low malignant potential (LMP) and various adenocarcinoma types, a series of 29 mucinous and 19 serous ovarian tumors including adenomas, LMP tumors and adenocarcinomas were examined. P53 protein was detected by the streptavidin-biotin method and point mutation of K-ras codon 12 was detected by polymerase chain reaction-restriction fragment length polymorphism analysis. P53 overexpression was observed more frequently in serous adenocarcinomas (5/8, 63%) than in mucinous adenocarcinomas (2/9, 22%) and was correlated with the malignant potential of serous tumors. Furthermore, the proportion of P53-positive cells was significantly higher in serous adenocarcinomas than in mucinous adenocarcinomas. P53 overexpression may therefore be closely related to the early events of carcinogenesis in serous tumors. Although mutation of the K-ras oncogene appears to be an important event in the early tumorigenesis of mucinous tumors, mutation of the K-ras oncogene in serous tumors may be dependent on morphology. Different complex pathways of oncogene and/or tumor suppressor gene abnormalities may be involved in the development of mucinous and serous adenocarcinomas.

Immunoreactivity of p53, Ki-67, and Bcl-2 in oncocytic adenomas and carcinomas of the thyroid gland

To analyze relevant factors of neoplastic transformation in oncocytic neoplasms of the thyroid, expression of p53, Ki-67, and bcl-2 has been studied in oncocytic carcinomas (n = 17) and compared with results obtained in oncocytic adenomas (n = 20). P53 protein accumulation was found immunohistochemically in 75% of the oncocytic adenomas (15 of 20) and 88% of the oncocytic carcinomas (15 of 17). Eight of 17 of the carcinomas (47%), but only 3 of the 20 adenomas (15%), showed nuclear p53 accumulation in more than 10% of the cells, mostly in a focal pattern. Ki-67 expression also differed significantly between adenomas and carcinomas. The median of Ki-67-positive cells was 12/10 high-power fields (HPF) for adenomas and 76/10 HPF for carcinomas (P < .001). Furthermore, metastatic carcinomas had a significantly higher Ki-67 positivity than nonmetastasized carcinomas (164/10 HPF v 42/10 HPF, P < .05). Bcl-2 immunohistochemistry showed a constantly positive reaction in normal thyroid tissue. In contrast, bcl-2 protein was not detected in most of the adenomas (70%) and carcinomas (76%). In conclusion, p53 protein and Ki-67 is more prevalent in oncocytic carcinomas than in oncocytic adenomas of the thyroid, indicating that these factors may be involved in the progression of oncocytic neoplasms in the thyroid. In contrast, loss of bcl-2 appears to be an early event in the formation of oncocytic neoplasms of the thyroid. Its importance for malignant transformation is, however, unclear.

An immunohistochemical analysis of heat shock protein 70, p53, and estrogen receptor status in carcinoma of the uterine cervix

OBJECTIVES

It has been shown that heat shock proteins (HSPs) protect cells from death caused by various noxious stimuli. Overexpression of HSP70 seems to be related to hormonal regulation of cell proliferation and/or down-regulation of sex steroid receptors. Wild-type p53 has been reported to repress HSP70 gene expression. It has been shown that mutant p53-HSP70 complex is highly expressed in cancer. However, the relationship between HSPs and steroid receptors or tumor suppressor gene products has not been well understood in uterine cervical carcinoma. This study was undertaken to examine the expression of HSP70, estrogen receptor (ER), and p53 in carcinoma of the uterine cervix. In addition, we analyzed HPV infection status and compared it to such immunohistochemical parameters. We also analyzed the relationship between these biological products and their clinicopathologic characteristics.

METHODS

Paraffin-embedded tissue sections were obtained from 84 patients with carcinoma of the uterine cervix. Expression of HSP70, p53, and ER was evaluated by immunohistochemical staining using anti-HSP70 monoclonal antibody (SPA810), anti-p53 (BP53.12), and ER1D5 antibody, respectively. PCR HPV detection was done by dot hybridization method.

RESULTS

Positive staining of HSP70 was detected in 73% of the cases. HSP70 positivity was significantly higher in stage I cervical cancer than in stages II-IV (P = 0.02). This was associated with neither tumor size, lymph node status, parametrial involvement status, nor tumor markers (TA-4). Furthermore, there was no significant correlation between HSP70 positivity and the expression of p53 or ER or HPV infection status.

CONCLUSION

These data suggested that HSP70 positivity was frequent in uterine cervical cancer, especially in the early stages. However, this was not significantly correlated with clinicopathologic characteristics nor with the expression of p53 or ER nor with HPV infection in carcinoma of the uterine cervix.

Immunohistochemical markers of cell cycle control applied to ovarian and primary peritoneal surface epithelial neoplasms: p21(WAF1/CIP1) predicts survival and good response to platinin-based chemotherapy

Immunohistochemistry for p53, p21(WAF1/CIP1), and Ki-67 provides insight into the molecular events controlling the cell cycle. We tested the hypothesis that these cell cycle markers will aid in the clinical evaluation of ovarian and primary peritoneal surface epithelial neoplasms (SENs). Paraffin sections from a retrospective surgical series of 117 SENs were immunostained with anti-p53 (clone DO7, Novacastra Laboratories, UK), anti-p21(WAF1/CIP1) (clone EA10, Oncogene Science, Cambridge, MA), and anti-Ki-67 (clone MIB-1, Immunotech, Westbrook, ME). The Ki-67 proliferation index (Ki-67PI) and immunoreactivity were evaluated. One hundred seventeen SENs reacted as follows: p53 50%+ and p21(WAF1/CIP1) 65%+. Ki-67PI ranged from 4% to 88% (mean/median = 44/46%). p53 reactivity associated with transitional cell histology, decreased p21(WAF1/CIP1) staining, increased Ki-67PI, architectural/nuclear grade, and stage (P < .05, 1 x 10(-7), .01, .05/.0001, .001,). p21(WAF1/CIP1) staining was associated with endometrioid/clear cell histology, decreased Ki-67PI, architectural/nuclear grade, and stage (P < 05/.05, .05, .01/1 x 10(-8), 1 x 10(-5)). Ki-67PI associated with increased architectural/nuclear grade but not mucinous histology (P < 1 x 10(-5)/1 x 10(-6), .01). Sixty-seven patients had disease at last follow-up; 53 were dead of disease at 0 to 67 months (mean/median, 21/18), and 14 were alive with disease at 12 to 224 months (mean/median, 56/40). Fifty patients were disease free at 5 to 214 months (mean/median, 59/41). Predictors of survival include decreased Ki-67PI, stage, architectural/nuclear grade (P < 1 x 10(-6), 1 x 10(-10), 1 x 10(-10)/.005) and p21(WAF1/CIP1) IMS (multivariate P < 1 x 10(-6)). p21(WAF1/CIP1), a potent inhibitor of cyclin-dependent kinases necessary for cell cycle progression, functions as a key checkpoint in cell cycle control. Immunoreactivity for p21(WAF1/CIP1) provides prognostic information independent of other histological and clinical predictors, p53 IMS, and Ki-67PI in this series of 117 PTs with SENs. Our preliminary data suggest an interrelationship between p21(WAF1/CIP1) expression and an effective clinical response to platinin-based chemotherapy, both associated with apoptosis. Further investigation seems warranted.

p53, c-erbB2, and PCNA status in benign, proliferative and malignant ovarian surface epithelial neoplasms: a study of 75 cases

Low malignant potential tumors of the ovary are believed to behave in a manner intermediate to their benign and malignant counterparts. However, recent evidence suggests these lesions are in fact benign and better classified as proliferative. Based on our previous work and evaluating p53, c-erbB2, and PCNA status in a full spectrum of ovarian surface epithelial tumors, with emphasis on low malignant potential tumors, we tested this hypothesis. Immunohistochemical stains with monoclonal antibodies were used on 75 archival ovarian neoplasms. The results demonstrated anti-p53 reactivity in 30 carcinomas (40%), 2 of which were proliferative, and no reactivity in the benign tumors. Overexpression of c-erbB2 was seen in 31 malignant neoplasms (64.5%), 4 of which were proliferative (22.1%), and none in benign tumors. The PCNA proliferative index showed means of 42.8%, 22.8%, and 14.9% with benign, low malignant potential, and malignant tumors, respectively. Predicting immunoreactivity in carcinomas for anti-PCNA (Student t test), anti-p53, and anti-c-erbB2 (Pearson chi2 test) versus a lack of immunoreactivity in proliferative tumors indicate P values of .001, <.001, and <.001, respectively. These data show significant differences in the expression of these markers in ovarian tumors and suggest a possible role for these oncogenes as supplemental tools in diagnostic pathology. Further, our findings also support the designation of proliferative as opposed to the current nomenclature of low malignant potential tumors.

Abnormal expression or mutation of TP53 and HPV in vulvar cancer

HPV (human papillomavirus) plays an important role in cervical cancer and may also play a role in vulvar cancer. TP53 mutation is common in a variety of cancers but its role in vulvar cancer is not well established. The aim of this study was to assess the prevalence of HPV infection and TP53 mutation as well as their correlation in vulvar cancer. Also, HPV detection and abnormal p53 expression were assessed in relation to age, co-existing vulvar intraepithelial neoplasia and vulvar dystrophy. Forty-eight samples of vulvar cancer were studied. DNA was extracted from formalin-fixed paraffin embedded tissue for polymerase chain reaction/Southern blot study with HPV 16 and 18 and L1 primers. Paraffin sections were immunostained (IHS) for p53 protein using three antibodies, p1801, CM1 and DO7. The p53 mutation was also screened using polymerase chain reaction (PCR) single-stranded conformation polymorphism (SSCP) and confirmed by sequencing. Overall, HPV was detected in 48% (23/48), of which 96% (22/23) were HPV 16 or 18. By IHS, p53 overexpression was detected in 46% of cases whilst TP53 mutations were identified in 21%. In HPV positive and negative tumours, p53 abnormal expression was detected in 39% and 52%, respectively, and TP53 mutation was found in 22% and 20%, respectively. Mutations were mainly found at codons 273 and 204. Age was not found to be associated with HPV detection. However, the presence of HPV (71%) or absence of abnormal p53 expression (65%) were higher in tumours with VIN3, but were not correlated with dystrophy.

Clear cell carcinoma has an expression pattern of cell cycle regulatory molecules that is unique among ovarian adenocarcinomas

BACKGROUND

The purpose of this study was to identify biologic differences between ovarian clear cell carcinoma and other ovarian adenocarcinomas by comparing the expression of cell cycle regulatory molecules and by analyzing the survival of the patients.

METHODS

In 51 cases of epithelial ovarian carcinoma, the expression of the cell proliferation marker Ki-67 and that of the cell cycle regulatory molecules p53, p16, p21, p27, cyclin E, and cyclin A was studied using immunohistochemical techniques. The correlations among clinical stage, histologic subtype, labeling index for Ki-67, and expression of these cell cycle regulators were examined statistically. Multivariate survival analysis was performed using these factors in the Cox proportional hazards model.

RESULTS

Clear cell carcinoma revealed such trends as low expression of both p53 and cyclin A and significantly increased expression of both p21 and cyclin E (compared with the other histologic subtypes). In all ovarian carcinomas, a very strong positive correlation (correlation coefficient 0.79; P < 0.0001) between p53 positive staining and cyclin A positive staining and a weak positive correlation (correlation coefficient 0.47; P < 0.01) between p21 positive staining and cyclin E positive staining were recognized at the level of expression of cell cycle regulatory molecules. Clinical stage was the only independent predictive factor for the survival of the patients.

CONCLUSIONS

Among ovarian adenocarcinomas, clear cell carcinoma exhibits a unique pattern of expression of cell cycle regulatory molecules, though in this study the survival of the patients did not correlate with histologic subtype, only with clinical stage.

Expression of the cell cycle inhibitor p27KIP1 is a new prognostic marker associated with survival in epithelial ovarian tumors

This case-control study was designed to identify factors associated with long-term survival. We examined two groups of patients with epithelial ovarian cancer, one group of long-term survivors (> 5 years) and one group of short-term survivors (< 2 years), for levels of expression of p53 and p27KIP1 proteins (as both proteins have been shown to be independent prognostic markers in tumors other than ovary) and the relationship with patient survival. Our findings show that p27KIP1 expression, in contrast to p53 expression, is positively associated with long-term survival in univariate analysis (P = 0.001), in analyses stratified by residual disease (P = 0.02) or performance status (P = 0.02), the two strongest prognostic factors for ovarian cancer, as well as multivariate analysis (P = 0.002) adjusting simultaneously for age, tumor stage, residual disease, performance status, and grade of differentiation. Therefore, immunostaining for levels of p27KIP1 expression may have potential as a new prognostic factor in the management of ovarian cancer.

Assessment of the prognostic relevance of serum anti-p53 antibodies in epithelial ovarian cancer

The objective of this study was to assess the prognostic relevance of preoperative serum anti-p53 antibodies in epithelial ovarian cancer. These autoantibodies were detected with a new generation enzyme-linked immunosorbent assay in blood samples preoperatively drawn from 86 patients with this malignancy. Serum anti-p53 antibodies were found in 3 (10.0%) of the 30 patients with stage I-II and 15 (26.8%) of the 56 patients with stage III-IV epithelial ovarian cancer (P = 0.09). We assessed in detail 44 patients with stage III-IV disease who underwent six cycles of first-line platinum-based chemotherapy. A pathological complete response at second-look was achieved by none of the 15 patients with serum anti-p53 antibodies compared to 24.1% of the 29 patients without autoantibodies (P = 0.09). However, the preoperative serum anti-p53 antibody status had no prognostic relevance for progression-free survival and survival. In conclusion, the assessment of preoperative serum anti-p53 antibodies seems to have a limited clinical value in the management of patients with advanced epithelial ovarian cancer.

The p53 tumour suppressor gene

BACKGROUND

Abnormalities of the p53 tumour suppressor gene are thought to be central to the development of a high proportion of human tumours. This article reviews current understanding of its function and potential clinical significance.

METHODS

Material was identified from previous review articles, references cited in original papers, a Medline search of the literature over the 12 months to January 1998, and by scanning the latest issues of relevant journals.

RESULTS AND CONCLUSION

p53 is considered to be a stress response gene, its product (the p53 protein) acting to induce cell cycle arrest or apoptosis in response to DNA damage, thereby maintaining genetic stability in the organism. These functions are executed by a complex and incompletely understood series of steps known as the 'p53 pathway', part of which involves induction of the expression of a number of other genes. As p53 is the most commonly mutated gene in human cancer, it has attracted a great deal of interest as a prognostic factor, diagnostic tool and therapeutic target. However, despite many promising studies, its potential in practical cancer management has still to be realized.

Immunohistochemical analysis of p53 protein in uterine sarcomas

This study was undertaken to evaluate the frequency and prognostic significance of p53 protein accumulation in uterine sarcomas. Immunostaining for p53 protein was performed on formalin-fixed, paraffin-embedded sections from 158 patients with verified uterine sarcomas using monoclonal p53 antibody (DO-1). Antigen retrieval was performed with microwave oven technique. Nuclear p53 protein accumulation was demonstrated in 45% of the cases, more often in carcinosarcomas (73%) than in leiomyosarcomas (38%) and endometrial stromal sarcomas (27%). A significant correlation was found between p53 protein accumulation and malignancy grade (P = 0.003), mitotic count (P = 0.007), and DNA ploidy (P = 0.007), but not to FIGO stage (P = 0.6). The 5-year survival was not influenced by level of p53 protein accumulation. In Cox multivariate analysis, free resection margins at primary surgery (P < 0.0001), tumor diameter (P = 0.002), malignancy grade (P = 0.0004), and age at diagnosis (P = 0.0001) were found to be of independent prognostic significance while p53 protein accumulation had no significance (P = 0.022). Our results indicate that p53 alterations may play an important role in the carcinogenesis of uterine sarcomas, but in our study p53 protein accumulation had no impact on prognosis.

Evaluation of FHIT gene alterations in ovarian cancer

The FHIT gene, recently cloned and mapped on chromosome 3p14.2, has frequently been found to be abnormal in several established cancer cell lines and primary tumours. As alterations of chromosome 3p are common events in ovarian cancers with breakpoint sites at 3p14.2, we decided to investigate the role of FHIT in human ovarian tumorigenesis. Fifty-four primary ovarian carcinomas were studied by reverse transcription of FHIT mRNA followed by polymerase chain reaction (PCR) amplification and sequencing of products. The same tumours and matched normal tissues were also investigated for loss of heterozygosity using three microsatellite markers located inside the gene. We found an abnormal transcript of the FHIT gene in two cases (4%) and allelic losses in eight cases (15%). Twelve (22%) of the 54 tumours investigated belonged to young patients with a family history of breast/ovarian cancer. In none of these cases was the FHITgene found to be altered. Our results indicate that FHITplays a role in a small proportion of ovarian carcinomas.

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.

P53 gene product and EGF-receptor are highly expressed in placental site trophoblastic tumor

Immunohistochemical analysis of curettage material from a placental site trophoblastic tumor (PSTT) revealed a high expression of p53 gene products, of epidermal growth factor receptor (EGF-R) and of Ki-67 (MIB-1) proliferation associated antigen. bcl-2 was not expressed. These results show that in PSTT inactivation/dysregulation of p53 and upregulation of EGF-R and MiB-1 occurs, indicating that these factors are probably involved in tumor genesis and propagation of PSTT. The prognostic significance of the molecular genetic data, however, remains to be established.

p53 is a persistent and predictive marker in advanced ovarian carcinomas: multivariate analysis including comparison with Ki67 immunoreactivity

p53 mutation and p53 protein overexpression are common findings in ovarian carcinomas. In order to evaluate the prognostic significance of the p53 status and its role in metastasis, we examined 104 ovarian carcinomas, among them 83 cases with follow-up data, and 40 pairs of primary tumors and metastases, by p53 immunohistochemistry and temperature-gradient gel electrophoresis. Comparison of primary tumors and their metastases revealed identical results in 88%-90% of the cases, indicating that, in most cases, mutant p53 occurs prior to metastatic spread and remains clonally conserved. With respect to all tumors, moderate/high p53 expression was significantly more prevalent in serous-papillary types, carcinomas with high grade, and high Ki67 scores, but was not associated with age, stage, or hormone receptor status. Kaplan-Meier analysis of 83 cases, followed-up for 9-96 months, demonstrated that moderate/high p53 overexpression in the group of 66 stage T3/M1 tumors was associated significantly (P = 0.0028 and P = 0.0105) with shorter overall and recurrence-free survival. Multivariate analysis revealed that advanced clinical stage and p53 positivity were the only independent predictive variables. No significance was seen in regard to second-look results and outcome of 50 patients receiving platinum-based chemotherapy. These observations show that p52 immunohistochemistry is an independent prognostic indicator at the given cut-off level, but does not reliably predict chemotherapy response.

Increased expression of fatty acid synthase (OA-519) in ovarian neoplasms predicts shorter survival

Certain cancers exhibit derangement of de novo fatty acid biosynthesis, manifested as overexpression and hyperactivity of the lipogenic enzyme fatty acid synthase (FAS). Correlation of elevated FAS with high tumor grade and advanced stage in primary breast, prostate, and colorectal cancers has drawn attention to the enzyme as a possible marker of poor prognosis. To find a similar utility of FAS in ovarian neoplasms, we compared FAS expression in 68 ovarian tumors with their histological features and clinical outcome. Immunohistochemical localization of FAS was observed in 48 (71%) cases in which staining was either focal (defined as positive staining in 1% to 20% of cells) or multifocal/diffuse (positive staining in >20% of cells). Most (83%) of the 48 cases were represented by endometrioid, serous, or mucinous carcinomas and malignant mixed mullerian tumors (MMMTs). In contrast, ovarian adenomas and tumors of low malignant potential (LMPs) contained little or no FAS. Association between FAS expression and histological diagnosis was statistically significant. The extent of FAS immunostaining was also predictive of prognosis. Among all patients with ovarian malignancies (including LMPs), median survival was 64.8 months, when their tumors exhibited no or focal immunostaining for FAS, as opposed to 31.2 months, when staining was multifocal/diffuse (P = .005). Similar median survival values were obtained when cases were limited to endometrioid, serous, and mucinous carcinomas. Short-term survival at 1 and 2 years was significantly higher in patients whose tumors showed no or focal expression of FAS compared with multifocal/diffuse expression. Thus, elevated FAS may serve as an independent marker for predicting poor clinical outcome in patients with ovarian cancer.

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-2 immunoreactivity and tumour proliferative fraction in ovarian carcinomas are still debated.

PATIENTS AND METHODS

One hundred twelve ovarian carcinomas were immunostained for p53 protein, for bcl-2 and for the cell cycle-associated Ki-67 antigen. The immunostaining results were correlated with conventional clinico-pathological variables, response to induction chemotherapy, and patient survival.

RESULTS

p53 accumulation and bcl-2 immunoreactivity in more than 10% of neoplastic cells were detected in 61 (54.5%) and 42 (37.5%) cases, respectively. A positive correlation between p53 accumulation and high (more than 30% neoplastic cells) MIB1 labelling index (r = 0.235; P = 0.015) was ascertained, whereas no significant association was found between bcl-2 immunoreactivity and p53 accumulation or MIB1 labeling index. Both p53 accumulation and MIB1 immunoreactivity correlated significantly with a reduced overall survival, but the association was lost in multivariate analysis. However, patients with tumours simultaneously showing p53 accumulation and MIB1 labelling index higher than 30% had significantly reduced overall survivals, in both univariate and multivariate analyses.

CONCLUSION

The simultaneous evaluation of p53 accumulation and MIB1 labelling index has independent prognostic implications in common epithelial malignancies of the ovary, irrespective of the disease stage.

Immunohistochemical detection of p53 and c-erbB-2 in oesophageal carcinoma; no correlation with prognosis

TNM staging of oesophageal cancer provides significant prognostic information but its clinical impact is limited as many patients present with advanced disease (i.e. T3N1). Additional prognostic markers may help separate those with 'good' and 'bad' prognosis tumours and so help with decisions such as selection for adjuvant therapy. p53 and c-erbB-2 overexpression may correlate with poor prognosis in oesophageal cancer, but this is uncertain. This study aimed to investigate the value of these biomarkers as prognostic indicators in resected oesophageal cancer. Two hundred and five oesophageal tumours (127 adenocarcinoma, 78 squamous) resected by a single surgeon between June 1979 and January 1991 were investigated for p53 and c-erbB-2 overexpression using DO-7 and CB-11 immunohistochemistry. Patient survival was analysed by Kaplan-Meir life tables. Median survival was 61 weeks (range: 5-747) and survival diminished significantly with increasing UICC stage (P < 0.0001). Sixty-eight per cent of squamous tumours and 66% of adenocarcinomas overexpressed p53 but there was no statistically significant correlation with prognosis. Twenty-six per cent of squamous tumours and 23% of adenocarcinomas overexpressed c-erbB-2, but again this did not correlate with survival. p53 and c-erbB-2 are commonly overexpressed in oesophageal cancer but do not appear to be related to prognosis in this large series of resected oesophageal cancers and other candidate biomarkers must be sought.