Ovarian surface epithelial-stromal tumors

Clear Cell Adenocarcinoma Arising from Adenofibroma in a Patient with Endometriosis of the Ovary

Ovarian clear cell adenocarcinomas (CCACs) are frequently associated with endometriosis and, less often with clear cell adenofibromas (CCAFs). We encountered a case of ovarian CCAC arising from benign and borderline adenofibromas of the clear cell and endometrioid types with endometriosis in a 53-year-old woman. Regions of the adenofibromas showed transformation to CCAC and regions of the endometriosis showed atypical endometriotic cysts. This case demonstrates that CCAC can arise from CCAF or endometriosis.

Management, prognosis and reproductive outcomes of borderline ovarian tumor relapse during pregnancy: from diagnosis to potential treatment options

BACKGROUND

fertility sparing surgery is the first option for treatment of childbearing age women affected by borderline ovarian tumor (BOT). This review put in evidence the benefits and the risks of conservative surgery procedure. Moreover, the literature review is aimed to analyze the possibility of fertility sparing surgery in BOTs and to define a standard treatment in the management of this pathology during pregnancy.

METHODS

systematic analysis of the relevant literature for fertility sparing during pregnancy for BOT, accessed through MEDLINE (1982-2015), bibliographies, and interactions with investigators. The data were assimilated into a rigorous and objective contemporary description, enriched by prospective, controlled, and evidence-based studies.

RESULTS

there are not many studies about BOT during pregnancy. It can reasonably assumed that after the diagnosis of a suspected BOT during the third trimester of pregnancy, an attitude of close surveillance could be adopted. To the best of our knowledge, we report the only case in literature focused about the treatment and management of borderline ovarian tumor relapse detected during pregnancy.

CONCLUSION

basing on our experience and on literature reported, the conservative management of BOT during gestation up to delivery could be considered feasible. The conservative debulking surgery should be performed at the time of cesarean section in a third referral center for gynecologic oncology.

Pregnancy after laparoscopic bilateral partial ovarian decortication for stage IC borderline ovarian tumour

BACKGROUND

Fertility preservation techniques are a growing area of research as more women in the reproductive age group develop gynaecologic cancers. We report here a novel technique of fertility preservation used in the treatment of a patient with borderline ovarian tumour.

CASE

A 29-year-old woman with stage I borderline ovarian tumour was referred to our tertiary level hospital. She had a history of infertility and requested fertility preservation be considered in treatment decisions. We performed bilateral laparoscopic partial decortication of the ovaries, and the patient successfully conceived spontaneously following the procedure.

CONCLUSION

Fertility-preserving surgery should be an option for young women with borderline ovarian tumours who wish to retain fertility. Removing abnormal ovarian tissue may restore fertility. The laparoscopic approach is safe and feasible for these patients.

Prognosis in patients with serous and mucinous stage I borderline ovarian tumors

INTRODUCTION

The purpose to this study was to compare the clinicopathologic characteristics and prognosis of patients with serous stage I borderline ovarian tumors (BOTs) to patients with mucinous stage I BOTs.

METHODS

This was a retrospective cohort series of patients with stage I BOTs diagnosed and treated between 1995 and 2009 at a single institution. The records were analyzed for patients' clinicopathologic information. The recurrence rates were compared using the Kaplan-Meier method.

RESULTS

During the study period, 198 patients (73.6%) with mucinous BOTs and 71 patients (26.4%) with serous BOTs were identified. Patients with serous tumors tended to be asymptomatic (53.5%) and frequently had elevated CA-125 levels and positive results from peritoneal cytology. Conversely, mucinous tumors were more related to the presence of symptoms (70.7%), elevated CA-19-9 levels, and pseudomyxoma and were larger tumors with a mean size of 15.6 cm. After a median follow-up of 56.5 months, 15 patients had developed 16 recurrences. Among these, 14 borderline recurrences developed in 6 patients with mucinous tumors and in 7 patients with serous tumors, and 2 invasive recurrences developed in only patients with mucinous tumors. No difference in recurrence rate between mucinous and serous tumors was observed. In addition, no disease-related death occurred.

CONCLUSIONS

Our study found that, although distinct differences in clinical and pathologic characteristics between stage I mucinous and serous BOTs are seen, result from tumor histology was not associated with disease prognosis.

Induction of senescence by progesterone receptor-B activation in response to cAMP in ovarian cancer cells

OBJECTIVE

Progesterone receptor (PR) expression is a favorable prognostic marker in ovarian cancer. We previously demonstrated that the induction of PR-B by treatment with cAMP was associated with G0/G1 arrest of the cell cycle and growth inhibition in NIH 3T3 cells. In this study, we examined the effect of cAMP treatment on cell growth in Ras-transformed NIH3T3 cells and ovarian cancer cells.

METHODS

1) The levels of PR-B and cell cycle associated proteins (p21, p27 and Rb) following treatment with cAMP in the Ras-transformed NIH3T3 cells (K12V) and ovarian cancer cell lines (SKOV cells) were investigated by Western blots. 2) The effects of PR overexpression following treatment with cAMP or after infection of an adenovirus expressing PR-B on cell growth and tumorigenicity in a soft agar culture were examined.

RESULTS

1) Treatment with cAMP increased PR-B and p27 levels in K12V cells and inhibited cell growth by inducing premature senescence. Induction of senescence was specific to the transformed cells. 2) In SKOV cells, treatment with cAMP induced PR-B, p27 and p21 expression, reduced the level of phosphorylated Rb, caused accumulation of cells in the G0/G1 fraction of the cell cycle, and induced senescence. 3) Both anchorage-dependent and -independent SKOV cell growths were inhibited by cAMP treatment. 4) Induction of both the expression and transcriptional activity of PR-B is critical for the induction of senescence and suppression of tumorigenicity.

CONCLUSION

Treatment of cAMP, through activation of PR-B, induced senescence and suppressed tumorigenicity in ovarian cancer cells.

Surgical management of borderline ovarian tumors: The role of fertility-sparing surgery

OBJECTIVE

To evaluate the recurrence, survival, and pregnancy outcomes of patients with borderline ovarian tumors (BOT) treated with fertility-sparing surgery.

METHODS

The medical records of patients with BOT who underwent surgery between 1989 and 2008 were retrospectively reviewed. Outcomes were compared between groups that underwent radical or fertility-sparing surgery. Fertility-sparing surgery was defined as the preservation of the uterus and ovarian tissue in one or both adnexa.

RESULTS

During the study period, 360 patients with BOT were identified; of these, 344 had stage I, one had stage II, and 15 had stage III disease. A total of 176 patients underwent radical surgery (23 laparoscopically and 153 laparotomically), and 184 underwent fertility-sparing surgery (48 laparoscopically and 136 laparotomically). After surgery, 45 patients received adjuvant chemotherapy. After a median follow-up time of 70 months (range, 3-216 months), 18 patients had recurrent disease and 5 died of disease. The recurrence rate was similar in the radical and fertility-sparing surgery groups (4.9% vs. 5.1%, p=0.923). In the fertility-sparing surgery group, however, the most common site of recurrence was the remaining ovarian tissue which was successfully salvaged with a second round of fertility-sparing surgery. Multivariate analysis showed no difference in disease-free survival between groups that underwent radical or fertility-sparing surgery (p=0.651). To date, there have been 34 full-term deliveries by women in the fertility-sparing surgery group.

CONCLUSIONS

Fertility-sparing surgery for patients with BOT is safe and can permit future pregnancy, suggesting that such surgery should be considered for young patients who wish to preserve fertility.

mtDNA sequence variants in subtypes of epithelial ovarian cancer stages in relation to ethnic and age difference

Epithelial ovarian cancer is the fifth leading cause of cancer mortality among women in the United States. For this disease, differences in age-adjusted incidence and survival rates between African American and Caucasian women are substantial. The objective of this study was to examine mtDNA sequence variants in 118 frozen tissues of three subtypes of epithelial ovarian cancer (serous, n = 48 endometrioid, n = 47 and mucinous, n = 23) and matched paracancerous normal tissues (n = 18) in relation to racial/ethnic and age differences. Restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR)-based sequencing were used to evaluate two regions of mtDNA spanning 5317 to 7608 and 8282 to 10110 bp and including ND subunits 2, 3, MT-COI, II, and III, ATPase 8, a part of ATPase 6, and tRNA genes in frozen ovarian tissues obtained from the southern regional Cooperative Human Tissue Network (CHTN) and University of Alabama-Birmingham (UAB) Ovarian Spore Center. Thirty-nine mtDNA variants were detected of which 28 were previously unreported. One somatic variant of C9500T was observed. A variant, C7028T in the MT-CO1 gene, had an ascending frequency from borderline (8%) to stages III/IV (75%) among the three ovarian cancer subtypes and stages. It was found in 86% (42/49) of African-American and 43% (37/87) of the Caucasian women. A variant, T8548G in the ATPase 6 gene was detected at a frequency of 72% (18/25) in ovarian serous subtype tissues in stages III/IV. Of the African American patients under age 40, 95% (20/21) harbored the T8548G variant; this was in contrast to only 22% (8/35) of Caucasian patients in same age group. Variants C7256T and G7520A had a frequency of 54% (6/11) in endometrioid stage III; no corresponding variants were observed in mucinous subtype stage III. Furthermore, variants C7256T and G7520A were absent in serous ovarian cancer subtype. Interestingly, the C7520T variant in tRNA gene was present in 74% (36/49) of African American and 26% (23/87) of Caucasian patients. Taken together, our results suggest that, with respect to ethnic and age difference, these mtDNA variants may be involved in epithelial ovarian carcinogenesis.

Laparoscopy in the treatment of ovarian tumours of low malignant potential

Laparoscopy is increasingly used by gynaecologists for the investigation of adnexal masses. Uncertainty exists whether ovarian tumours of low malignant potential can effectively be treated by laparoscopy, whether staging bears a benefit for all patients, whether port-site metastases are a problem and how long patients need to be followed up after surgery. This review summarises the evidence to address these important questions.

Primary peritoneal serous borderline tumors

CONTEXT

Primary peritoneal serous borderline tumor is a rare epithelial proliferation that can present as an incidental finding at laparotomy and raises concern for a primary ovarian tumor with peritoneal implants.

OBJECTIVE

To present a brief history of this condition and describe its distinctive histology and clinical presentation, as well as to review the chief differential diagnostic considerations, to include mesothelial proliferations, endosalpingiosis, endometriosis, high-grade primary peritoneal papillary serous carcinoma, and implants from primary ovarian serous neoplasms.

DATA SOURCES

Relevant articles indexed in PubMed (National Library of Medicine) between 1966 and 2005, references thereof, and reference surgical pathology texts.

CONCLUSIONS

Primary peritoneal serous borderline tumor should be considered in the differential diagnosis of an epithelial proliferation with prominent psammoma bodies on the peritoneal surface of specimens submitted for nongynecologic complaints.

Mitochondrial DNA sequence variants in epithelial ovarian tumor subtypes and stages

BACKGROUND

A majority of primary ovarian neoplasms arise from cell surface epithelium of the ovaries. Although old age and a positive family history are associated risk factors, the etiology of the epithelial ovarian tumors is not completely understood. Additionally, knowledge of factors involved in the histogenesis of the various subtypes of this tumor as well as those factors that promote progression to advanced stages of ovarian malignancy are largely unknown. Current evidence suggests that mitochondrial alterations involved in cellular signaling pathways may be associated with tumorigenesis.

METHODS

In this study, we determined the presence of polymorphisms and other sequence variants of mitochondrial DNA (mtDNA) in 102 epithelial ovarian tumors including 10 matched normal tissues that paired with some of the tumors. High-resolution restriction endonucleases and PCR-based sequencing were used to assess the mtDNA variants spanning 3.3 kb fragment that comprised the D-Loop and 12S rRNA-tRNAphe, tRNAval, tRNAser, tRNAasp, tRNAlys, ATPase 6, ATPase 8, cytochrome oxidase I and II genes.

RESULTS

Three hundred and fifty-two (352) mtDNA sequence variants were identified, of which 238 of 352 (68%) have not been previously reported. There were relatively high frequencies of three mutations in the 12S rRNA gene at np 772, 773, and 780 in stage IIIC endometrioid tumors, two of which are novel (773delT and 780delC), and occurred with a frequency of 100% (7/7). Furthermore, two mutations were observed in serous tumors only at np 1657 in stage IV (10/10), and at np 8221delA in benign cystadenomas (3/3) and borderline tumors (4/4). A high frequency, 81% (13/16) of TC insertion at np 310 was found only in early stages of serous subtype (benign cystadenomas, 3/3; borderline tumors, 4/4; stage I tumors, 2/5 and matched normal tissues 4/4).

CONCLUSION

Our findings indicate that certain mtDNA mutations can reliably distinguish the different histologic subtypes of epithelial ovarian tumors. In addition, these data raise the possibility that certain mtDNA mutations may be useful biomarkers for predicting tumor aggressiveness and may play a potential role in tumorigenesis.

Results of the national survey of borderline ovarian tumors in Spain

MATERIAL AND METHODS

Retrospective multi-center analysis of women diagnosed with borderline ovarian tumor and treated between January 1990 and December 1997. A national survey was conducted, in which 457 patients from 27 centers corresponding to ten of Spain's autonomous communities were analyzed.

RESULTS

Four hundred fifty-seven women with borderline ovarian tumor were analyzed. The mean age of patients was 45.5+/-16.9 years. Of these, 390 patients (85.3%) were at stage I, 8 (1.8%) were at stage II and 36 (7.9%) at stage III. A bilateral tumor was observed in 63 women (13.8%). The mean tumor size was 14.2 cm and in 88 cases (19.3%) the tumor was on the surface of the ovary. Microinvasion was observed in 25 (5.5%) cases, and 29 women (6.3%) showed a micropapillary pattern. Study of the factors related to the appearance of peritoneal implants revealed positive tumor markers (OR 15.02: 1.9-32.9) and a tumor on the ovarian surface (OR 8.0: 1.8-127) to be independent risk factors. With respect to recurrence, the presence of peritoneal implants at the time of initial surgery (OR 3.4: 1.1-10.4) and signs of microinvasion in the anatomicopathological study (OR 5.5: 1.5-17.8) were found to be independent risk factors. The overall survival rate in our series was 97% with a mean follow-up of 88.3 months. The survival rate by stage was 97% for stage I, 100% for stage II and 97% for stage III.

CONCLUSIONS

Although borderline ovarian tumors have an excellent prognosis, they are not exempt from a risk of recurrence. Characterization of patients with borderline ovarian tumor is essential in order to prevent their evolution. Likewise, the taking on board of risk factors will enable more selective treatments to be offered in each case.

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.

Demographic and genetic characteristics of patients with borderline ovarian tumors as compared to early stage invasive ovarian cancer

OBJECTIVE

Evaluation whether Jewish founder mutations in BRCA predispose to borderline tumors as they do to early invasive ovarian cancers.

METHODS

All Jewish women with borderline or invasive ovarian tumors, diagnosed over a 5-year period (1994-1999), were identified in the frame of a nationwide epidemiological study on ovarian cancer in Israel. Out of a total of 1489 patients, 1269 were interviewed; of them 256 (20.2%) patients were identified with stage I and II invasive epithelial ovarian tumors, and 233 (18.3%) patients were identified with borderline tumors. All patients underwent interviews, and blood or tissue samples from 117 borderline tumors and 161 early stage invasive tumors were analyzed for the presence of the 185delAG and 5382insC BRCA1, and the 6174delT BRCA2 Jewish founder mutations.

RESULTS

Patients with borderline tumors were younger at diagnosis, and more frequently of the serous type (P < 0.001) as compared to patients with early stage ovarian cancer. Prevalence of Jewish founder mutations in BRCA1 and BRCA2 was only 4.3% of patients with borderline tumors as compared to 24.2% of patients with early stage ovarian cancer (P = 0.001).

CONCLUSIONS

This nationwide study comparing patients with early stage borderline and invasive epithelial tumors of the ovary confirms our previous pilot study that showed a lower incidence of BRCA mutations in patients with borderline tumors. Our results suggest that the genetic predisposition and the molecular mechanisms underlying tumor initiation differ between invasive and borderline tumors of the ovary.

Estrogen-induced loss of progesterone receptor expression in normal and malignant ovarian surface epithelial cells

While estrogens are suspected risk factors for epithelial ovarian cancer (OCa), progesterone (P4) has been shown to exert protective effects. The biological actions of P4 in target cells are mediated by progesterone receptors (PRs) that exist principally as A- and B-isoforms. We observed overexpression of PR-A and PR-B protein in two lines of OCa cells when compared to two lines of nontumorigenic, normal human ovarian surface epithelial (HOSE) cells. Treatment of HOSE or OCa cells with estrone or 17beta-estradiol at 10(-8) M for a period of 72 h induced significant loss of PR-A and PR-B mRNA and protein expression, with the regulation primarily controlled at the transcriptional level. In contrast, breast cancer cells (line MCF-7) exposed to estrogens upregulated PR-A and PR-B expression. Of significance, both the inhibitory and stimulatory actions of estrogens were blocked by the specific ER-antagonist ICI 182,780 (ICI, 10(-5) M), confirming estrogen specificity. Co-treatment of estrogen-exposed HOSE, OCa, and MCF-7 cell lines with inhibitors of type 1- and type 2-17beta hydroxysteroid dehydrogenase did not affect the previously observed changes in PR expression, suggesting that the action of each estrogen is direct and not mediated via conversion to its metabolic counterpart. Green fluorescence protein (GFP)-PR-A and GFP-PR-B were localized in the cytoplasmic compartment of untreated HOSE cells and translocated to the nucleus after P4 treatment, while both chimera PRs resided in the nuclei of OCa cells in a ligand-independent manner. In OCa cell cultures, P4 (10(-6) M), but not RU486 (10(-5) M), induced apoptosis that was blocked by co-treatment with the antiprogestin but enhanced by co-treatment with ICI. In sharp contrast, P4 induced proliferation, while ICI and RU486 caused cell death in MCF-7 cells. In conclusion, this study is first to demonstrate estrogens as negative regulators of PR expression in HOSE/OCa cells and to provide a mechanistic basis upon which to explain the antagonism of estrogens on the anti-OCa action of progestins. It also raises the possibility of using progestin and ICI as a combinational therapy for OCa treatment.

Expression of progesterone receptor is a favorable prognostic marker in ovarian cancer

OBJECTIVE

Receptors for estrogen (ER), progesterone (PR), or androgen (AR) are predictive and prognostic markers of malignancy of multiple endocrine organs, including endometrial and breast cancer. However, the role of ERs, PRs, or ARs in the carcinogenesis of ovarian cancer, another sex hormone-dependent malignancy, is still controversial despite numerous studies that have attempted to determine their role. The disagreement in the findings may result from the fact that the numbers of tumor samples in studies have been small and that different immunohistochemical methods have been used that can introduce variation in the scoring of the histology. We therefore examined the pattern of expression of ERs, PRs, and ARs in a large number of samples of primary ovarian carcinoma by using a tissue microarray technique.

METHODS

We constructed a tissue microarray with 322 samples of primary ovarian carcinoma obtained at surgery performed at The University of Texas M. D. Anderson Cancer Center between 1990 and 2000. Immunohistochemistry studies were performed by using the immunoperoxidase technique against primary antibodies (ER, PR, and AR).

RESULTS

ERs, PRs, and ARs were differently expressed in different histotypes of ovarian cancer: ERs were expressed in 77.3% of all cases but more highly expressed in serous and endometrioid types; PRs were expressed in 26.2% of all cases but most highly expressed in the endometrioid type < 64.2%; and ARs were expressed in 43.7% of all cases but were most highly expressed in serous (47.5%) carcinomas. Of particular importance, the expression of PRs, but not ERs or ARs, was associated with better survival (P < 0.0001) in univariate and multivariate analyses.

CONCLUSIONS

The PR is an independent marker, with its overexpression associated with a favorable prognosis in women with ovarian cancer.

Dietary Determinants of Epithelial Ovarian Cancer: A Review of the Epidemiologic Literature

Ovarian cancer is commonly a fatal disease and, despite advances in screening and treatment, the lack of understanding of the underlying etiology has limited prevention strategies. This article reviews the epidemiologic literature on the relationship between consumption of major food groups and the risk of epithelial ovarian cancer (EOC). We identified 7 cohort studies and 27 case-control studies of consumption of major food groups (fruits and vegetables, meats, eggs, fish, dairy products, grains, fats and oils) and EOC risk. Vegetable but not fruit consumption was found to possibly exhibit beneficial effects on the risk of EOC, whereas high meat consumption may be associated with an increased risk. A protective effect on risk of EOC for whole-grain food consumption as well as for consumption of low-fat milk is suggested by the results of the studies. However, evidence for associations of foods such as fish, grains, milk products, and fats and oils with EOC risk is limited and inconsistent, and further examination of these dietary determinants of EOC are warranted. In conclusion, a typical Western diet, which is high in meats and low in vegetables, may be positively associated with ovarian cancer incidence. However, the association between specific dietary factors and EOC risk remains unclear and merits further examination. In particular, future studies need to address the effect of milk products according to fat content and possible biological mechanisms to explain observed effects.

Estrogen, progesterone and epithelial ovarian cancer

Ovarian carcinoma (OCa) continues to be the leading cause of death due to gynecologic malignancies and the vast majority of OCa is derived from the ovarian surface epithelium (OSE) and its cystic derivatives. Epidemiological evidence strongly suggests that steroid hormones, primarily estrogens and progesterone, are implicated in ovarian carcinogenesis. However, it has proved difficult to fully understand their mechanisms of action on the tumorigenic process. New convincing data have indicated that estrogens favor neoplastic transformation of the OSE while progesterone offers protection against OCa development. Specifically, estrogens, particularly those present in ovulatory follicles, are both genotoxic and mitogenic to OSE cells. In contrast, pregnancy-equivalent levels progesterone are highly effective as apoptosis inducers for OSE and OCa cells. In this regard, high-dose progestin may exert an exfoliation effect and rid an aged OSE of pre-malignant cells. A limited number of clinical studies has demonstrated efficacies of antiestrogens, aromatase inhibitors, and progestins alone or in combination with chemotherapeutic drugs in the treatment of OCa. As a result of increased life expectancy in most countries, the number of women taking hormone replacement therapies (HRT) continues to grow. Thus, knowledge of the mechanism of action of steroid hormones on the OSE and OCa is of paramount significance to HRT risk assessment and to the development of novel therapies for the prevention and treatment of OCa.

Noninvasive and invasive micropapillary (low-grade) serous carcinoma of the ovary: a clinicopathologic analysis of 135 cases

Reports describing the behavior of micropapillary serous carcinomas (MPSCs) of the ovary have focused on those that are noninvasive. There are only very limited data on the behavior of those that are invasive. To further characterize the behavior of MPSCs, invasive versus noninvasive primary tumors were distinguished based on the presence or absence of destructive infiltrative growth. To qualify for inclusion, invasive MPSCs, like the noninvasive tumors, were required to display a micropapillary architecture and low-grade nuclei. A total of 135 cases of MPSC were identified: 96 noninvasive and 39 invasive. On follow-up, survival for 10 patients with stage I noninvasive and invasive MPSCs was 100%, and survival for women with stage II and III noninvasive and invasive MPSCs with noninvasive implants was 80%. In contrast, the 5-year and 10-year survival for patients with stage II and III noninvasive MPSCs with invasive implants was 85% and 55%, respectively. The 5-year and 10-year survival for women with invasive MPSCs and invasive implants was 55% and 45%, respectively. The median time from diagnosis to death for women with noninvasive and invasive MPSCs with invasive implants was 60 months (range 33-240 months). The indolent behavior of these low-grade carcinomas distinguishes them from conventional serous carcinomas, which are high-grade aggressive neoplasms. Five of six patients with small (<5 mm) MPSCs in whom follow-up was available presented with high stage disease. Of these five women, three are alive and well and two are alive with disease (one with invasive and one with noninvasive implants). Nearly three fourths of noninvasive MPSCs were associated with atypical proliferative serous tumors, adenofibromas, or both, and 62% of invasive MPSCs were associated with noninvasive MPSCs, atypical proliferative serous tumors, and adenofibromas, alone or in combination. In addition to the frequent mixtures of these tumor components, transitions between them were common. These data in conjunction with recent molecular genetic studies strongly suggest that MPSCs (low-grade carcinomas) arise from atypical proliferative serous tumors unlike conventional serous carcinomas (high-grade carcinomas), which appear to develop de novo. The findings provide further support for the hypothesis that there are distinct pathways of carcinogenesis for low-grade and high-grade serous carcinoma of the ovary.

Evaluation of restaging in clinical stage 1A low malignant potential ovarian tumours

OBJECTIVE

This study was undertaken to evaluate whether restaging clinical stage 1A low malignant potential (LMP) tumours previously incompletely staged in a non-gynaecology oncology centre yields useful information for management and prognosis.

METHODS

A retrospective chart review was undertaken of all patients with LMP tumours treated at the Queensland Centre for Gynaecological Cancer (QCGC) from 1982-2000.

RESULTS

Fifty-six (69%) of the 81 patients referred with a provisional stage 1A diagnosis underwent a second operation for staging purposes. Four (7%) out of the 56 patients who underwent restaging had their tumours upstaged. A single patient out of the 25 patients who did not undergo restaging had disease recurrence and died as a result. The mean follow-up for all patients in the study was 60 months.

CONCLUSION

It is hard to justify routine surgical restaging for patients with a LMP ovarian tumour apparently confined to a single ovary At the very least, hundreds of patients with clinical stage 1A tumours will need to be restaged before a single patient will have data that will change management. Consequently the morbidity of routine restaging is difficult to justify for such a small clinical gain.

Fertility and tumor recurrence rate after conservative laparoscopic management of young women with early-stage borderline ovarian tumors

OBJECTIVE

To evaluate the efficacy of laparoscopic conservative surgery in young women with borderline ovarian tumors who want to preserve their childbearing potential, and to assess whether pregnancy influences the recurrence rate during the follow-up evaluation period.

DESIGN

Retrospective study.

SETTING

Center for Reconstructive Pelvic Endosurgery, Reproductive Medicine Unit, S. Orsola Hospital, University of Bologna, Italy.

PATIENT(S)

Nineteen women (mean age 27.4 +/- 4.7) with borderline ovarian tumors who underwent laparoscopy between January 1995 and January 1998. All of the women wanted to preserve their fertility.

INTERVENTION(S)

A standardized conservative laparoscopic approach and a strict follow-up schedule.

MAIN OUTCOME MEASURE(S)

A complete preoperative examination.

RESULT(S)

Follow-up evaluations (mean 42 +/- 19 months) were made available to all patients. Among 19 patients, 10 attempted pregnancy and 6 conceived spontaneously. All six pregnancies went to term and the disease did not affect the gestation or the follow-up period after the pregnancy (24.5 +/- 15.7 months).

CONCLUSION(S)

Conservative laparoscopic management of borderline ovarian tumors is a potentially safe alternative in young women who want to retain their childbearing potential. Fertility and pregnancy outcome remain excellent in these women. Our preliminary data seem to indicate that the recurrence rate after pregnancy is not influenced by this approach.

Behavior of Borderline Tumors With Particular Interest to Persistence, Recurrence, and Progression to Invasive Carcinoma: A Prospective Study

PURPOSE: Borderline tumors account for 10% to 20% of epithelial ovarian tumors, and their prognosis is outstanding; nevertheless, a mortality of up to 20% has been reported, particularly in earlier reports. There is a lack of information about the actual mortality and the rate of progression into invasive carcinoma in large and prospectively accrued populations.

PATIENTS AND METHODS: All women with borderline ovarian tumors undergoing primary surgery in our department or referred within 3 months from surgery performed elsewhere from 1982 to 1997 were prospectively accrued and observed.

RESULTS: We studied 339 women (83.4% stage I, 7.9% stage II, and 8.5% stage III). The median age at diagnosis was 39 years. A total of 150 women underwent radical surgery, and 189 underwent fertility-sparing surgery. After surgery, 13 women had macroscopic residual disease. With a median follow-up of 70 months, 317 women are alive with no clinical disease (eight with documented subclinical persistence of implants), three are alive with clinical disease, two died of disease, 10 died of other reasons, and seven women have been lost to follow-up. The recurrence of disease was higher after fertility-sparing surgery (35 of 189 cases) than after radical surgery (seven of 150 cases); nevertheless, all but one woman with recurrence of borderline tumor or progression to carcinoma after conservative surgery were salvaged. We observed seven progressions (2.0%) into invasive carcinoma, five in serous tumors (2.4%), and two in mucinous tumors (1.6%). The disease-free survival is 99.6% in stage I patients, 95.8% in stage II, and 89% in stage III.

CONCLUSION: The survival of patients with borderline tumors is higher than previously described in some retrospective studies. Conservative surgery is safe and may be proposed to several patients with early and disseminated disease after thorough discussion of all therapeutic options. Progression to carcinoma is approximately 2% and may be observed in both mucinous and serous tumors.

Refined diagnostic criteria for implants associated with ovarian atypical proliferative serous tumors (borderline) and micropapillary serous carcinomas

Characterization of invasive peritoneal implants from patients with noninvasive serous ovarian tumors has important prognostic and treatment implications, but the criteria for distinguishing invasive and noninvasive implants vary among investigators and can be difficult to apply. The authors studied 148 implants from 60 patients, 33 with primary atypical proliferative serous tumor, and 27 with primary noninvasive micropapillary serous carcinoma, with a mean follow-up of 62 months (median follow-up, 52 months). Previously reported and newly proposed histologic features for implant classification were evaluated and correlated with clinical outcome. Three criteria were applied for the diagnosis of "invasive" implants: invasion of underlying normal tissue, micropapillary architecture, and solid epithelial nests surrounded by clefts. Implants displaying any one of these three features were classified as "invasive," whereas those lacking all three features were classified as "noninvasive." Sixty-six implants were invasive and 82 were noninvasive. Of the 31 patients with invasive implants, six were dead of disease (DOD), 13 were alive with progressive disease (AWPD), and 12 were alive with no evidence of disease (NED). Of the 29 patients with noninvasive implants, two were DOD, one was dead of uncertain causes, one was AWPD, and 25 were alive with NED. Eighty-nine percent of invasive implants had a micropapillary architecture and 83% had solid epithelial nests surrounded by clefts. A minority of invasive implants (14% of those with underlying normal tissue) demonstrated invasion of normal underlying tissue. Nuclear atypia, mitoses, calcification, necrosis, and identification of individual cells "infiltrating" the stroma did not correlate with implant type. The proposed criteria permitted recognition of implants that correlated strongly with adverse outcome. Sixty-one percent of patients with implants displaying any one of the three features used to diagnose invasive implants were AWPD or DOD compared with 10% of patients whose implants lacked these features (p = 0.00001). Because implants associated with an adverse outcome can be identified before they invade underlying normal tissue, the term invasive implant to describe them is inaccurate and misleading. These implants resemble patterns of growth in micropapillary serous carcinoma of the ovary and the recurrent tumor that is obvious carcinoma. Accordingly, we propose that these extraovarian lesions be designated "well-differentiated serous carcinoma."

CA 125 measurement and ultrasonography in borderline tumors of the ovary

OBJECTIVES

Our goal was to perform an analysis of ultrasonographic characteristics and CA 125 levels in ovarian tumors of borderline malignancy.

STUDY DESIGN

We performed a retrospective analysis of CA 125 levels and ultrasonographic parameters in 91 patients with borderline tumors.

RESULTS

Serous tumors of borderline malignancy were associated with elevated CA 125 levels in 75% of patients before surgery (mean, 156 IU/mL) compared with 30% of mucinous tumors (mean, 28 IU/mL; P =.004). CA 125 was elevated in 35% of stage IA serous tumors (mean, 67 IU/mL) compared with 89% of tumors with spread beyond the ovary (mean, 259 IU/mL; P =.001). Mucinous tumors tended to be bigger (13.1 +/- 7 cm) on ultrasonography than serous tumors (9.3 +/- 6.2 cm, P =.016). Mucinous tumors were multilocular in half the patients and contained papillations in 40% of the patients. Serous tumors were multilocular in 30% of the patients but presented with solid or papillary patterns in 78% of the patients (P =.001). A resistance index of <0.4 was found in 36% of mucinous tumors and half the cases of serous tumors. In 13% of patients, ultrasonographic characteristics were compatible with a simple cyst only, including 1 patient with microinvasion and 1 patient with stage IIIB disease. Sensitivity of gray-scale ultrasonography was 87%, that of CA 125 measurement was 62%, and that of flow was 55%. At least 1 diagnostic test result was abnormal in 93% of patients, 2 were abnormal in 69% of patients, and all 3 were abnormal in 21% of patients.

CONCLUSIONS

A high proportion of borderline tumors of the ovary, particularly of the serous type, were associated with elevated CA 125 levels and abnormal ultrasonographic characteristics, although some tumors presented as simple cysts.

Surgery for borderline tumor of the ovary

The five-year survival for women with Stage I borderline tumors is about 95% to 97%, but because of late recurrence the 10-year survival is only 70% to 95%. The five-year survival for Stage II-III patients is 65% to 87%. A more correct staging procedure, classification of true serous implants, and agreement on how the presence of gelatinous ascites in mucinous tumors contributes to cancer stage might change the distribution of stage and survival data by stage for women with borderline tumors in the future. Independent prognostic factors for patients with borderline tumors without residual tumor after primary surgery are: DNA ploidy, morphometry, International Federation of Gynecology and Obstetrics (FIGO) stage, histologic type, and age. Different types of surgery and chemotherapy were not independent prognostic factors. Questions which should be addressed include the following: 1) Have patients with borderline tumors been over treated in general, and how should these patients be treated? 2) In which group of patients is fertility-sparing surgery advisable? 3) Do patients with borderline tumors benefit from adjuvant treatment? And 4) How is the high-risk patient defined?

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."

Disabled-2 inactivation is an early step in ovarian tumorigenicity

Disabled-2 (Dab2) functions in mitogenic signal transduction pathway, and is frequently activated by homozygous gene deletion in tumors, suggesting that Dab2 is a candidate tumor suppressor. Here, we surveyed the expression of Dab2, and report that Dab2 is expressed in a variety of tissues, and the level of expression is particularly high in ovary and breast. Dab2 expression was also detected in immortalized breast and ovarian epithelial cells. However, in more than a dozen established tumor cell lines derived from breast and ovarian epithelial tumors examined by Western blotting, Dab2 expression was undetectable in 90% of these cell lines. Histological staining of human ovarian tissues with specific anti-Dab2 antibodies indicated that Dab2 is highly expressed in the surface epithelial layer. In an immunohistological study of 26 ovarian carcinomas, 22 (85%) of the tumors were found to lose the expression of Dab2 in the tumor cells, which are epithelial origin. Loss of Dab2 expression is not correlated with tumor grade, suggesting that Dab2 is lost in an early stage of tumorigenicity. Indeed, loss of Dab2 correlates closely with morphological transformation of the surface epithelial cells. Additionally, loss of Dab2 protein occurs in hyperproliferative, but histological benign ovarian epithelium, suggesting that loss of Dab2 occurs in pre-malignant lesions. Thus, this study indicates that the loss of Dab2 expression is correlated with tumorigenicity of the cells disregarding the grade of the tumors, and loss of Dab2 expression is an early event in ovarian malignancies.

Rates of Jewish ancestral mutations in BRCA1 and BRCA2 in borderline ovarian tumors

BACKGROUND

Germline mutations in the BRCA1 and BRCA2 genes are known to be associated with an increased risk of breast and epithelial ovarian cancers. Two specific mutations, 185delAG-BRCA1 and 6174delT-BRCA2, have been detected in a substantial proportion (20%-60%) of unselected Ashkenazi Jewish patients--i.e., Jewish patients of Eastern/Northern European descent--with invasive ovarian cancer and in a measurable proportion (2%) of the general Ashkenazi Jewish population. However, uncertainty exists concerning the heritable basis of borderline ovarian tumors and whether these tumors represent an early form of ultimately invasive disease. To gain insight into these issues, we determined the rates of 185delAG-BRCA1 and 6174delT-BRCA2 mutations in patients with borderline ovarian tumors.

METHODS

Analysis of 185delAG-BRCA1 and 6174delT-BRCA2 germline mutations was performed by use of a heteroduplex formation assay in samples from 46 consecutive patients with borderline ovarian tumors and 59 consecutive patients with invasive epithelial ovarian cancers. Forty-eight samples were also analyzed by restriction enzyme analysis for the presence of the 5382insC-BRCA1 mutation, a mutation detected in 2.2% of Ashkenazi Jewish patients with breast, but not ovarian, cancer.

RESULTS

One (2.2%) of the 46 patient with borderline tumors was identified as a carrier of the 185delAG-BRCA1 mutation, and no patients were found to carry the 6174delT-BRCA2 mutation. Nineteen (32%) of the 59 patients with invasive ovarian cancer were found to carry one of these two mutations; 17 carried 185delAG-BRCA1 and two carried 6174delT-BRCA2 (chi2 test with continuity correction, P = .00028). None of the patients analyzed for 5382insC-BRCA1 were found to carry the mutation. In one high-risk family that included 185delAG-BRCA1 carriers, a single patient with stage IIIc borderline ovarian tumor did not carry the mutation.

CONCLUSIONS

Invasive epithelial and borderline ovarian tumors appear to differ in their genetic predisposition and in the molecular mechanisms underlying their genesis.

Histopathology and molecular biology of ovarian epithelial tumors

Carcinogenesis in the ovary presents special features related to that organ. First, the preinvasive or even invasive lesions are difficult to detect, which explains why most cases are diagnosed at an advanced stage. Second, the group of tumors of low malignant potential (borderline tumors) are still a controversial category of ovarian lesions. Finally, familial ovarian tumors represent an interesting hereditary model of carcinogenesis at the molecular level. Flow cytometry and immunohistochemistry for proliferative markers or oncogenes provide important prognostic information in patients with ovarian tumors. Molecular data, such as loss of heterozygosity at specific genetic loci, also have been correlated with prognosis. Clonality studies in patients with multiple ovarian/pelvian lesions analyzing chromosome X inactivation patterns and genetic deletions or mutations have contributed to the understanding of the origin of these lesions. New technologies to study gene expression patterns, such as cDNA library construction and DNA microarray technologies, are being applied to study histologic phases of tumor progression, such as normal, preinvasive, and tumor tissues. It is hoped that these studies will contribute important information not only for a better understanding of the process of carcinogenesis, but also for assessing the biology and behavior of individual tumors, determining patient prognosis, and eventually influencing therapy.

Molecular genetic events in the development and progression of ovarian cancer in humans

Ovarian tumor development is characterized by specific clinical and pathological features that provide an interesting model of carcinogenesis: first, the pre-invasive and even invasive lesions are difficult to detect; second, a group of cases with a known familial predilection constitute an important heredltary model of carcinogenesis; and third, the category of morphologically borderline ovarian tumors (tumors of low malignant potential) poses several unanswered questions such as: what histologic criteria should be used for their diagnosis; what is their natural history; and what is their molecular relationship to invasive tumors? Recently, molecular studies have contributed to a better understanding of the biology of these tumors, their behavior in vivo, and their response to therapy. This article summarizes the most recent molecular advances.

Telomerase activity in benign and malignant epithelial ovarian tumors

BACKGROUND

Ovarian epithelial tumors include benign lesions lacking invasive and metastatic abilities (cystadenomas) in addition to malignant lesions (carcinomas). An intermediate category, called tumors of low malignant potential (LMP), is also recognized. The merit of this classification is being challenged because the clinical behavior of LMP tumors appears closer to that of cystadenomas than to that of carcinomas.

PURPOSE

To verify our hypothesis that the expression of the enzyme telomerase distinguishes these two categories of ovarian epithelial tumors, we examined and compared such expression in ovarian cystadenomas and carcinomas. By examining the expression of telomerase in LMP tumors, we then sought to determine if these tumors were more closely related to cystadenomas or to carcinomas with regard to telomerase expression.

METHODS

We examined a total of 64 consecutive ovarian tumors subdivided into 20 carcinomas, 17 LMP tumors, and 27 cystadenomas. We subsequently discarded three of the 27 cystadenomas because of the presence of admixed normal ovarian stroma in those specimens. Tumor subtyping was done without knowledge of the telomerase results, and telomerase assays were likewise interpreted without knowledge of tumor types. Telomerase activity was determined by use of the TRAP (i.e., telomeric repeat amplification protocol) assay. Differences between the proportions of tumors expressing this enzyme in each subgroup were evaluated by use of Fisher's exact test (two-sided).

RESULTS

Telomerase activity was detected in all 20 carcinomas and in all 17 LMP tumors examined. In contrast, it was not detected in 19 of the 24 cystadenomas. These differences between rates of telomerase expression in either carcinomas or LMP tumors and those in cystadenomas were statistically significant (P<.0001). All five of the telomerase-positive cystadenomas belonged to a variant called papillary cystadenomas, whereas none of the telomerase-negative cystadenomas belonged to this variant (P<.0001).

CONCLUSIONS AND IMPLICATIONS

The presence of telomerase expression in ovarian LMP tumors supports the merit of continuing to separate these tumors from cystadenomas, in spite of their apparent benign clinical course. The finding of telomerase expression in papillary cystadenomas suggests that such tumors may be mechanistically related to LMP tumors and should perhaps be reclassified as variants of LMP tumors. Lack of telomerase expression in ovarian cystadenomas raises questions about the alleged immortality of these tumors because expression of this enzyme is thought to be essential for continuous growth in adult tumors.

A pregnant woman with clear cell adenocarcinoma of the ovary arising from endometriosis and with benign and borderline adenofibroma of the clear cell and endometrioid types

We encountered a case of ovarian cancer in a 33-year-old, 8-week pregnant woman. Histological examination revealed both a transitive form of ovarian endometriosis with marked decidual changes due to pregnancy and clear cell carcinoma. Benign and borderline clear cell adenofibroma and benign and borderline endometrioid adenofibroma were also found. Parts of these adenofibromas showed transformation to clear cell carcinoma. This case suggests that clear cell carcinoma can arise from clear cell adenofibromas and/or ovarian endometriosis, even in young patients.

p53 mutation, allele loss on chromosome 17p, and DNA content in ovarian carcinoma

The aim of this investigation was to explore the relationships between p53 mutation, DNA aneuploidy, 17p deletions, and clinical stage in ovarian cancer. Nuclear suspensions were obtained by tissue disaggregation, stained with propidium iodide, and analysed on a Coulter EPICS Elite flow cytometer. DNA cell cycle analysis was performed using Multicycle software (Phoenix Flow Systems). DNA extracted from paraffin-embedded archival carcinomas/non-tumour tissue was used as template for PCR amplification of the microsatellite dinucleotide repeat polymorphism D17S513, a locus telomeric to p53 on 17p13.1. Allele loss at D17S513 was detected in 64.5 per cent of carcinomas (20 of 31 informative cases). DNA aneuploidy was detected in 20 of 54 (37 per cent) carcinomas. Eight of ten cases previously shown to harbour p53 mutations showed aneuploid DNA content. Although ten other DNA aneuploid cases had shown no p53 mutations, the results show a statistically significant association between p53 mutation and DNA aneuploidy (P < 0.01). Furthermore, the mean DNA index of the DNA aneuploid cases was significantly higher in p53 mutant cases compared with those showing no p53 mutation (P = 0.02). There was also a significant association between p53 mutations and stage, between ploidy and stage, and between allelic deletions at D17S513 or p53 and stage, but not between these allelic deletions and ploidy. p53 mutations appear to be associated with DNA aneuploidy in ovarian cancer independently of 17p deletions. p53 mutations, DNA aneuploidy, and 17p deletions are associated with late stage.

The borderland between benign and malignant surface epithelial ovarian tumors. Current controversy over the nature and nomenclature of "borderline" ovarian tumors

In the early 1970s, the International Federation of Gynecology and Obstetrics (FIGO) and the World Health Organization (WHO) adopted the terms "borderline malignancy" and "carcinoma of low malignant potential" in their classifications of surface epithelial tumors of the ovary in order to denote a subset of patients with a significantly more favorable prognosis than those with the "usual" surface epithelial carcinomas. Subsequently, a considerable clinicopathologic body of literature has arisen concerning borderline tumors, particularly the serous and mucinous types. Some of them, particularly advanced stage borderline tumors, have been purported to cause significant illness and death. However, some investigators have impugned their malignant nature, especially in Stage I disease, and blame the suggested poor prognosis in advanced cases on a paucity of accurate morbidity and mortality data and ambiguity in current histopathologic terminology; to address the latter, they have proposed to remove any connotation of malignancy by replacing the aforementioned terms with designations such as "atypical proliferating (serous or mucinous) tumor." Another soon-to-be proposed classification will use the terminology "borderline tumors" as a generic group without destructive invasion but with subdivisions into tumors with "epithelial atypia" and those with "intraepithelial carcinoma." The clinical and therapeutic implications of accurate diagnosis of ovarian borderline tumors mandate additional investigation to elucidate their true prognosis; indeed, further dialogue is necessary to arrive at a nosologic system to reflect that biologic behavior. However, until a consensus has been reached, the pathologic diagnosis should reflect, at some point, the currently sanctioned FIGO/WHO classification of surface epithelial ovarian tumors to obviate any misunderstanding that could lead to patient mismanagement.

The biology of ovarian cancer development

BACKGROUND

In theory, all the cell types that comprise the human ovary have the potential for malignant transformation. The vast majority of malignant ovarian tumors in the human, however, arise from the ovarian surface epithelium. These cells have important functions during reproductive life; they contribute to follicular rupture and by cell division repair the wound that accompanies ovulation. There has been much speculation that the rapid cycles of cell division associated with wound repair contribute significantly to the development of ovarian cancer. Such speculation is based on the observation that ovarian cancer occurs most frequently at the end of a woman's reproductive life and is associated with nulliparity. It is of potential significance that, unlike most epithelia, these cells are not replaced through replenishment stem cells with the development of one end-stage cell and one cell with continued growth potential. Rather, the division of an ovarian surface epithelial cell yields two daughter cells with equal potential for subsequent growth. Thus, all potential mutations as they accumulate are passed on to near-exponentially expanding subsequent generations of cells that can acquire additional mutations that could confer the malignant phenotype.

METHODS

We have developed a model to test the hypothesis that repeated cell division by ovarian surface epithelial cells contributes to development of malignancy. In this model, rat ovarian surface epithelial cells are isolated and subjected in vitro to repetitious cell division to mimic in a simple way growth of the surface epithelium in vivo.

RESULTS

These cells develop a malignant phenotype based on loss of contact inhibition, the ability for substrate independent growth, tumorigenicity in athymic mice, and cytogenetic changes.

CONCLUSIONS

Our data support the involvement of tumor suppressor genes in the development of ovarian cancer.

Ovarian cancer, Part I: Biology

The ovary is among the more complex organs of the body and its functions are achieved by numerous cell types. All of these cell types have some tendency to undergo malignant transformation, but the vast majority of ovarian cancers are believed to be the result of malignant transformation of the ovarian surface epithelium. The concept that most ovarian cancer arises from this modified peritoneal mesothelium is credited to Sir Spencer Wells in 1872. Ovarian cancer is the most frequently fatal gynecologic malignancy, and approximately 20,000 cases per year are diagnosed in the United States. Progress in understanding the biology of this disease, including factors involved in its etiology, progression, and tendency to change from a relatively chemotherapy-sensitive tumor to one with marked drug resistance, has been slow. In this review, the complex features of the normal ovarian surface epithelial cells are considered in relation to the etiology and progression of the disease. The hypothesis that incessant or repetitious ovulation contributes to the initiation of the disease is explored in detail based on experimental data, epidemiologic information, and the potential for antioncogene inactivation in this interesting cell type. Lastly, based on the experimental data available, potential mechanisms of resistance to platinum, the cornerstone of aggressive ovarian cancer therapy, are discussed, as are approaches to overcoming drug resistance. It is hoped that the reader will be left with the feeling that the pace of our understanding of the biology of ovarian cancer is increasing at such a rate that answers to the questions of etiology and why chemotherapy often fails will be known in the foreseeable future.