p53 and HER-2/neu overexpression in ovarian borderline tumors

EGF-induced EMT and invasiveness in serous borderline ovarian tumor cells: a possible step in the transition to low-grade serous carcinoma cells?

In high-grade ovarian cancer cultures, it has been shown that epidermal growth factor (EGF) induces cell invasion by activating an epithelial-mesenchymal transition (EMT). However, the effect of EGF on serous borderline ovarian tumors (SBOT) and low-grade serous carcinomas (LGC) cell invasion remains unknown. Here, we show that EGF receptor (EGFR) was expressed, that EGF treatment increased cell migration and invasion in two cultured SBOT cell lines, SBOT3.1 and SV40 large T antigen-infected SBOT cells (SBOT4-LT), and in two cultured LGC cell lines, MPSC1 and SV40 LT/ST-immortalized LGC cells (ILGC). However, EGF induced down-regulation of E-cadherin and concurrent up-regulation of N-cadherin in SBOT cells but not in LGC cells. In SBOT cells, the expression of the transcriptional repressors of E-cadherin, Snail, Slug and ZEB1 were increased by EGF treatment. Treatment with EGF led to the activation of the downstream ERK1/2 and PI3K/Akt. The MEK1 inhibitor PD98059 diminished the EGF-induced cadherin switch and the up-regulation of Snail, Slug and ZEB1 and the EGF-mediated increase in SBOT cell migration and invasion. The PI3K inhibitor LY294002 had similar effects, but it could not block the EGF-induced up-regulation of N-cadherin and ZEB1. This study demonstrates that EGF induces SBOT cell migration and invasion by activating EMT, which involves the activation of the ERK1/2 and PI3K/Akt pathways and, subsequently, Snail, Slug and ZEB1 expression. Moreover, our results suggest that there are EMT-independent mechanisms that mediate the EGF-induced LGC cell migration and invasion.

Clinical implications of the ErbB/epidermal growth factor (EGF) receptor family and its ligands in ovarian cancer

The ERBB or EGF receptor (EGFR) proto-oncogene family, which consists of four structurally-related transmembrane receptors (i.e., EGFR, ErbB2, ErbB3, and ErbB4), plays an etiological role in the molecular pathogenesis of cancer and is a key therapeutic target in many types of cancer, including ovarian cancer. These ErbB/EGF receptor tyrosine kinases play important physiologic roles in cell proliferation, survival, adhesion, motility, invasion, and angiogenesis. It is, therefore, not surprising that gene amplification, genetic mutation, and altered transcription/translation result in aberrant ErbB/EGF receptor expression and/or signal transduction, contributing to the development of malignant transformation. Clinically, the diagnostic, prognostic, and theragnostic significance of any single ErbB receptor and/or ErbB ligand is controversial, but generally, ErbB receptor overexpression has been correlated with poor prognosis and decreased therapeutic responsiveness in ovarian cancer patients. Thus, anticancer agents targeting ErbB/EGF receptors hold great promise for personalized cancer treatment. Yet, challenges remain in designing prospective clinical trials to assess the clinical utility of ErbB receptors and their ligands to diagnose cancer; to predict progression-free and overall survival, therapeutic responsiveness, and disease recurrence; and to monitor treatment responsiveness. Here, we review the tissue expression and serum biomarker studies that have evaluated the diagnostic, prognostic, and theragnostic utility of ErbB/EGF receptors, their circulating soluble isoforms (sEGFR/sErbBs), and their cognate ligands in ovarian cancer patients.

Prognostic, predictive and therapeutic implications of HER2 in invasive epithelial ovarian cancer

The HER2 oncogene encodes a transmembrane protein partially homologous to epidermal growth factor receptor. This oncogene has been studied mainly in breast cancer where it has prognostic, predictive and therapeutic target value. The expression of HER2 in epithelial ovarian cancer has been less studied. HER2 expression can be determined through IHC, FISH, CISH and ELISA among other tests, with reported positivity frequencies of overexpression varying from 1.8% to 76%. In some studies HER2 overexpression has been associated with advanced stages, poorly differentiated tumors, resistance to chemotherapy and shortened survival. Although trastuzumab is able to produce a low response rate as a single agent in pretreated ovarian cancer patients with overexpression of HER2, its usefulness is limited due to the low frequency of strong expression. To date there is not enough bases for assessment and HER2-based therapies in epithelial ovarian cancer.

Serous and mucinous borderline (low malignant potential) tumors of the ovary

The prognosis for stage I serous borderline ovarian tumors (SBOTs) is thought to be excellent, despite rare, late recurrences. The behavior of advanced-stage SBOTs primarily depends on the invasiveness vs noninvasiveness of associated extraovarian implants. Pelvic and abdominal lymph node involvement and foci of microinvasion do not seem to adversely affect prognosis. Serous tumors with a micropapillary and/or cribriform growth pattern seem to be more frequently bilateral and exophytic and manifest at an advanced stage with a higher incidence of invasive implants than typical SBOTs. Molecular data suggest that such tumors may represent an intermediate stage in the typical SBOT-invasive low-grade serous carcinoma progression. Limited experience with endocervical (müllerian)-type mucinous borderline tumors shows a possible relation to SBOTs in clinicopathologic features and biologic behavior Intestinal-type mucinous borderline ovarian tumors (I-MBOTs) and well-differentiated mucinous carcinomas manifest at stage I in most cases; the prognosis is excellent. Mucinous tumors associated with pseudomyxoma peritonei are almost always secondary to similar tumors of the appendix or other gastrointestinal sites and should not be diagnosed as high-stage I-MBOTs. Rare primary ovarian mucinous tumors associated with pseudomyxoma peritonei are those arising in mature cystic teratomas. Advanced-stage ovarian mucinous carcinomas typically show frank, infiltrative-type invasion; the prognosis is poor.

Expression of p53, c-erbB-2, Ki-67, and CD34 in granulosa cell tumor of the ovary

The purpose of this study is to investigate the expression of p53, c-erbB-2, Ki-67, and angiogenic activity and their correlation with the clinicopathologic characteristics in a series of granulosa cell tumors of the ovary (GCTO). Eighteen GCTO cases assisted at the Department of Obstetrics and Gynecology, School of Medical Science, UNICAMP, after diagnostic confirmation by three pathologists, were submitted to immunohistochemistry for assessment of p53, c-erbB-2, Ki-67, and CD34 expressions. The mean tumor size was 13 cm (range: 4-30 cm). Six (33%) cases presented with extraovarian disease. Thirteen (72%) cases presented some solid diffuse or sarcomatoid pattern and six (33%) moderate or strong atypia. Fourteen cases presented </=2 mitoses/10 HPF. Thirteen cases were focally positive for Ki-67. The mean Ki-67 proliferative index was 1.0%. One case presented positive expression for mutant p53 but all cases were negative for c-erbB-2 expression. The mean microvascular density was 28.9/mm2 (range: 0-50). No significant correlations could be established between the biologic markers and clinicopathologic variables. GCTO showed a markedly low rate of immunohistochemical staining for p53 or c-erbB-2 overexpression/amplification, as well as low proliferative and angiogenic activities. Further studies are urgently needed to elaborate the factors responsible for the highly unpredictable clinical course of GCTO.

TP53 and ovarian cancer

Ovarian cancer represents the fourth most frequent type of cancer among females and is the leading cause of death from gynecological cancer in the western world. This review describes gene alterations in ovarian cancer. Specific emphasis is placed on genetic alterations and the prevalence of TP53 (p53) gene alterations in the distinct biological ovarian tumors (benign, borderline, and malignant) and histological subtypes (serous, mucinous, endometrioid, clear cell), as well as in BRCA1-associated hereditary ovarian cancer. Although multi-modality treatment regimens, including cytoreductive surgery and cisplatin-containing combination chemotherapy, have usefully prolonged survival, the overall cure rate of the disease has not changed dramatically. Ovarian cancer is difficult to eradicate completely by surgery and many patients have only a partial response to postoperative chemotherapy and/or many will develop chemotherapy resistance. All these important factors contribute to the poor prognosis of ovarian cancer patients. In this review, the putative prognostic or predictive value of TP53 in ovarian cancer is addressed.

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.

Analysis of p53 and c-erbB-2 expression in ovarian endometrioid carcinomas arising in endometriosis

We assessed the immunohistochemical expression of p53 and c-erbB-2 oncoproteins in 13 ovarian endometrioid adenocarcinomas arising from endometriosis (group 1) and compared the findings with 15 otherwise similar cases without associated endometriosis (group 2). Tumors in group 1 showed a higher expression of both p53 and c-erbB-2 (p = 0.015 and p = 0.048, respectively). The expression of the two proteins was also significantly associated in group 1 (p = 0.013) but not in group 2 (p = 0.63) tumors. The different pattern of expression of p53 and c-erbB-2 in the two groups suggests that different molecular pathways may be involved in their pathogenesis.

Clinical management potential tumours of low malignancy

Approximately 3000 American women are diagnosed with borderline ovarian tumours annually. Common signs and symptoms include abdominal/pelvic pain and a palpable adnexal mass. Pelvic sonography may be helpful, although not specific, in the diagnosis. Serum CA 125 is abnormal in only about 50% of patients. Primary surgery is the principal treatment; it consists of resection of the primary tumour(s) (frequently in the form of fertility-sparing surgery), frozen-section analysis and consideration of comprehensive surgical staging. The role of surgical staging remains unclear; further research is necessary. For patients with stage I disease, surgery alone is the standard. For patients with stage II-IV disease (with non-invasive or invasive peritoneal implants), the role of post-operative therapy remains unclear. Approximately 20-30% of the latter will relapse, frequently after several years. Most so-called recurrences are low-grade carcinomas. Potential predictive or prognostic factors include age, FIGO stage, residual disease and the micropapillary pattern. After fertility-sparing surgery, most patients retain normal reproductive function.

Physiologic and pathologic drug resistance in ovarian carcinoma--a hypothesis based on a clonal progression model

Conventional models for successful chemotherapy suggest that early-stage ovarian cancer should be more responsive to cytotoxic drugs than advanced disease, that multiple drugs will prove more efficacious than single agents and that more intensive chemotherapy will prove superior to conventional doses. The purpose of numerous clinical studies has been to test these predictions and the results often fall short of the expectations. In trials to date, adjuvant chemotherapy for high-risk, early-stage ovarian cancer has provided only a modest, equivocal increase in disease-free survival. Combination chemotherapy produces higher response rates but this has not consistently resulted in prolonged survival. Dose intensification with high-dose chemotherapy increases rate of response further, but most responses are of short duration. The objective of this review is to integrate clinical and molecular biological observations into a novel model of drug resistance. We hypothesize that drug sensitivity is an acquired characteristic of neoplastic cells, and that there are two broad cellular forms of resistance to cytotoxic drugs. 'Physiological drug resistance' is a cellular state when drug sensitivity of cancer cells is similar to that of the corresponding normal tissue. This form of drug resistance can precede the acquisition of drug sensitivity and may be predominant in the early stages of neoplastic progression. A distinct, 'pathological drug resistance' can reappear later during tumor progression or during chemotherapy as a result of increased detoxification, upregulation of repair pathways or defective apoptosis. Tumors are formed of heterogeneous cell populations and in terms of drug sensitivity three distinct cell types may be present: drug-sensitive, physiologically drug-resistant and pathologically drug-resistant. Clinical response to chemotherapy is determined by the relative contribution of these different cell populations to the total cellular mass. Depending on the predominant type of surviving population, distinct patterns of clinical failure may develop that require different treatment strategies for optimal management. For chemosensitive cells that survived insufficient chemotherapy, consolidation with further, perhaps, high-dose chemotherapy is a rational option. For pathologically drug-resistant cells, pharmacological manipulation of drug resistance, and signaling pathways in combination with chemotherapy could be exploited. For physiologically drug-resistant cells, non-chemotherapy-based, 'chemopreventive' strategies to arrest tumor progression may prove beneficial.

Ovarian serous borderline tumors: a critical review of the literature with emphasis on prognostic indicators

BACKGROUND

The behavior of ovarian serous borderline tumors (SBTs) and significance of various prognostic factors are unclear and difficult to evaluate because of inconsistencies and confusion in the literature. Recent studies have suggested that the morphological features of the primary tumor (presence or absence of micropapillary features) and the peritoneal "implants" (presence or absence of invasive features) can reliably subclassify SBTs into benign and malignant types. The aim of the current review was to test two hypotheses. First, that the alleged malignant behavior of SBTs is poorly documented, and second, that the morphological features of the primary ovarian tumors and the associated peritoneal implants are sufficient to separate SBTs into benign and malignant types, thereby obviating the need for the category.

METHODS

245 studies reporting approximately 18,000 patients with borderline ovarian tumors were reviewed. After excluding series that lacked clinical follow-up or were not analyzable for other reasons, there remained 97 reports that included 4,129 patients. In addition to recurrences and survival, we evaluated the type of peritoneal implants, microinvasion, lymph node involvement, late recurrences, and progression to carcinoma, as these features have served as the underpinning of the concept of "borderline malignancy" or "low malignant potential."

RESULTS

Among 4,129 patients with SBTs reviewed, the recurrence rate after a mean follow-up of 6.7 years was 0.27% per year for stage I tumors, the disease-free survival was 98.2%, and the overall disease-specific survival rate was 99.5%. For patients with advanced-stage tumors, the recurrence rate was 2.4% per year. However, the majority (69%) of reported recurrences were not pathologically documented, and only 26 cases (8.4% of all recurrences) were documented to have recurred from an adequately sampled ovarian tumor. The most reliable prognostic indicator for advanced stage tumors was the type of peritoneal implant. After 7.4 years of follow-up, the survival of patients with noninvasive peritoneal inplants was 95.3%, as compared with 66% for invasive implants (P < .0001). Microinvasion in the primary ovarian tumor was associated with a 100% survival rate at 6.7 years, and lymph node involvement was associated with a 98% survival rate at 6.5 years. The few reported cases of stage IV disease, progression to invasive carcinoma, and very late (>20 years) recurrences were poorly documented. The survival for all stages among approximately 373 patients in 6 prospective randomized trials followed for a mean of 6.7 years was 100%.

CONCLUSION

Surgical pathological stage and subclassification of extraovarian disease into invasive and noninvasive implants are the most important prognostic indicators for SBTs. Survival for stage I tumors is virtually 100%. Survival for advanced stage tumors with noninvasive implants is 95.3%, whereas survival for tumors with invasive implants is 66%. Invasive implants behave as carcinomas and are most likely metastatic. The precise nature of so-called noninvasive implants is not clear, but they behave in a benign fashion. The presence of a micropapillary architecture in the primary ovarian tumor is a strong predictor of invasive implants. These data support the recommendation that ovarian tumors with a micropapillary architecture be designated "micropapillary serous carcinomas," and those lacking these features, "atypical proliferative serous tumors."

The management of borderline epithelial tumors of the ovary

The histopathological diagnosis and treatment of borderline epithelial tumors of the ovary (BTO) still pose problems to both pathologists and gynecologists. BTO is a disease of younger, fertile females and generally has an excellent prognosis. A minority of patients, however, succumb to this disease. A review of the literature is given addressing aspects of epidemiology, histology, treatment and prognosis, resulting in a proposal for the management of serous and mucinous borderline tumors of the ovary.

Epidemiologic differences between women with borderline ovarian tumors and women with epithelial ovarian cancer

OBJECTIVE

The aim of this study was to study the relationship between borderline ovarian tumors (BLOT) and epithelial ovarian cancer (EOC) by comparing the epidemiologic features of women with BLOT with those of women with EOC of similar histology.

MATERIAL AND METHODS

The epidemiologic features of 32 women with serous and mucinous BLOT were compared with those of 273 women with primary serous or mucinous EOC. We included all women with the documented respective histologic diagnoses admitted to Roswell Park Cancer Institute between 1982 and 1996 who returned a self-administered epidemiologic questionnaire which contained 44 items pertaining to reproductive, contraceptive, medical, social, dietary, occupational, and family histories of cancer. Individual variables between both groups were compared using the Student t test, chi2 analysis, the Mantel-Haenszel test, and the Wilcoxon nonparametric test. Two-tailed P < 0.05 was considered significant.

RESULTS

The response rate to the questionnaire was 63% in the BLOT group and 60% in the EOC group. There was no significant difference between the two groups in geographic location, race, education, income, smoking, marital status, age at first pregnancy, age at first birth, history of hysterectomy, history of infertility, history of tubal surgery, use of hormone replacement therapy, or history of diaphragm or intrauterine contraceptive device use. There were no significant differences in family history of malignancy between women with BLOT and those with EOC. Women with BLOT were significantly younger than those with EOC (mean age 47 +/- 14.0 versus 56 +/- 13.7, P < 0.01). There was an apparent difference in oral contraceptive pill use between both groups. However, when we adjusted for age by stratification this difference was not significant (P = 0.089).

CONCLUSIONS

The epidemiologic features of women with BLOT are similar to those of women with EOC with the exception of an earlier age of onset. These findings might be consistent with one etiology for both conditions.

Hormonal etiology of epithelial ovarian cancer, with a hypothesis concerning the role of androgens and progesterone

In the United States, ovarian cancer is the fourth most frequent cause of cancer death among women, following lung, breast, and colorectal cancers. Each year, approximately 26,000 women are diagnosed with ovarian cancer and 14,000 die of it. Germline mutations in BRCA1, BRCA2, or other genes have been implicated in a small fraction of cases. However, it has been suggested that, for the great majority of patients, the risk of epithelial ovarian cancer could be related to "incessant ovulation" (i.e., to the chronically repeated formation of stromal epithelial clefts and inclusion cysts following ovulation) or to some type of hormonal stimulation of ovarian epithelial cells, either on the surface of the ovary or within ovarian inclusion cysts, possibly mediated through excessive gonadotropin secretion. From the evidence to date, the relative importance of these two hypotheses--incessant ovulation and gonadotropin stimulation--cannot be distinguished. While either or both may play a role in the development of ovarian cancer, it appears that an additional major factor must also be involved. The purpose of this review is to evaluate evidence for and against the incessant ovulation and gonadotropin hypotheses, as well as to consider the possibility that risk of ovarian cancer may be increased by factors associated with excess androgenic stimulation of ovarian epithelial cells and may be decreased by factors related to greater progesterone stimulation. Many features of the evidence bearing on the pathophysiology of ovarian cancer appear to support a connection with androgens and progesterone.