Benign Serous Tumors Research Articles

Benign Epithelial Ovarian Tumours—cancer Precursors or Markers for Ovarian Cancer Risk?

The natural history of the development of epithelial ovarian cancer remains obscure and no effective screening test exists. In several human malignancies progression from benign to invasive tumour occurs, but this sequence has not been established for epithelial ovarian cancer. We have reviewed epidemiological, histopathological and molecular studies of benign epithelial ovarian tumours to assess the evidence for and against such a progression in ovarian cancer. These data suggest that a diagnosis of a benign ovarian cyst or tumour is associated with an increased risk of ovarian cancer later in life. Current evidence also suggests that benign serous tumours can progress to low-grade serous cancer and that benign mucinous tumours can progress to mucinous cancer. The more common high-grade serous ovarian cancers are likely to arise de novo.

Altered patterns of transcription of the septin gene, SEPT9, in ovarian tumorigenesis

Ovarian carcinoma represents the most lethal gynaecological malignancy. A variety of morphological subtypes are recognised (e.g. serous, mucinous, endometrioid), which may be benign, borderline or malignant. While their relationship is controversial, knowledge of the molecular mechanisms of ovarian tumorigenesis may help resolve this issue and perhaps identify early markers of disease. Perturbed patterns of expression of the SEPT9 gene on chromosome 17q25.3 have been implicated in a variety of tumour types including both breast and ovarian neoplasia. In preliminary studies, we showed that SEPT9 mRNA was upregulated in a bank of ovarian tumours, which included benign, borderline and malignant tumours, and reported increased levels of one splice variant, SEPT9_v4*. We now describe a comprehensive analysis of SEPT9 expression specifically in serous and mucinous ovarian tumours (benign, borderline and malignant), using cDNA microarray, semi- and quantitative RTPCR of microdissected archival tumour material. Our data show consistent and specific overexpression of both SEPT9_v1 and SEPT9_v4* transcripts in the epithelial component of ovarian tumours. These transcripts show highest levels of expression in serous and mucinous borderline tumours. SEPT9_v1 is also upregulated in both serous and mucinous carcinomas. Interestingly, highest levels of expression are observed in serous borderline and low-grade tumours rather than high-grade in keeping with a model of progression of benign, borderline and low-grade serous tumours.

Tumor protein D52 (TPD52) is overexpressed and a gene amplification target in ovarian cancer

Recurrent chromosome 8q gain in ovarian carcinoma is likely to reflect the existence of multiple target loci, as the separate gain of chromosome bands 8q21 and 8q24 has been reported in independent studies. Since tumor protein D52 (TPD52) has been identified as a chromosome 8q21 amplification target in breast and prostate carcinoma, we compared TPD52 expression in normal ovarian epithelium (n = 9), benign serous adenomas (n = 11), serous borderline tumors (n = 6) and invasive carcinomas of the major histologic subtypes (n = 57) using immunohistochemistry. These analyses revealed that all normal ovarian epithelium samples and benign serous tumors were predominantly TPD52-negative, whereas TPD52 was overexpressed in most (44/57; 77%) ovarian carcinomas regardless of histologic subtype. TPD52 subcellular localization was predominantly cytoplasmic, although nuclear localization was also frequently observed in mucinous and clear cell carcinomas. In an independent cohort of stage III serous carcinomas (n = 18), we also directly compared in situ TPD52 expression using immunohistochemistry and TPD52 copy number using interphase FISH analyses. This revealed that TPD52 dosage and TPD52 expression were significantly positively correlated. TPD52 therefore represents a novel molecular marker in ovarian cancer, which is broadly expressed across the different histologic subtypes and whose upregulation frequently reflects increased TPD52 copy number.

Ovarian Serous Tumors of Low Malignant Potential (Borderline Tumors)

The natural history, classification, and nomenclature of ovarian serous tumors of low malignant potential (S-LMP) (serous tumors of borderline malignancy, atypical proliferating tumors) are controversial. To determine long-term outcome for patients with S-LMP and further evaluate whether S-LMP can be stratified into clinically benign and malignant groups, the clinicopathologic features of 276 patients with S-LMP and > or =5 year follow-up were studied. The histology of the ovarian primary, extraovarian implants, and recurrent tumor(s) were characterized using World Health Organization criteria and correlated with FIGO stage and clinical follow-up. After censoring nontumor deaths, overall survival and disease-free survival for the 276 patients was 95% (98% FIGO stage I; 91% FIGO II-IV) and 78% (87% FIGO stage I; 65% FIGO stage II-IV), respectively. Unresectable disease (P < 0.001) and invasive implants (P < 0.001) were associated with decreased survival. When compared with typical S-LMP, S-LMP with micropapillary features were more strongly associated with invasive implants (P < 0.008) and decreased overall survival (P = 0.004), but patient outcome with micropapillary S-LMP was not independent of implant type. Stromal microinvasion in the primary tumor was also correlated with adverse outcome, independent of stage of disease, micropapillary architecture, and implant type (P = 0.03). There was no association between outcome and lymph node status. Transformation to low-grade serous carcinoma occurred in 6.8% of patients at intervals of 7 to 288 months (58% > or = 60 months) and was strongly associated with increased tempo of disease and decreased survival (P < 0.001). S-LMP forms a heterogeneous group, morphologically and clinically distinct from benign serous tumors and serous carcinoma. The majority of S-LMP are clinically benign, but recurrences are not uncommon, and persistent disease as well as deaths occur. Progression to low-grade serous carcinoma is highly predictive of more aggressive disease. Other features associated with recurrent and/or progressive disease include FIGO stage, invasive implants, microinvasion in the primary tumor, and micropapillary architecture. These predictors tend to co-occur, and no single clinical or pathologic feature or combination of features identify all adverse outcomes. The small, but significant risk of progression over time to low-grade serous carcinoma emphasizes the need for prolonged follow-up in patients with S-LMP.

Expression of Growth Hormone Secretagogue Receptor Type 1a, the Functional Ghrelin Receptor, in Human Ovarian Surface Epithelium, Mullerian Duct Derivatives, and Ovarian Tumors

Ghrelin, the endogenous ligand of the GH secretagogue receptor (GHS-R), is a newly identified, ubiquitously expressed molecule that has been involved in a wide array of endocrine and nonendocrine functions, including cell proliferation. In this context, our group recently reported the expression of ghrelin and its functional receptor, the GHS-R type 1a, in the human ovary and testis as well as several testicular tumors. Ovarian malignancies, however, remain unexplored. Notably, a vast majority of ovarian tumors derive from the surface epithelium, which originates from the celomic epithelium. Considering the proven expression of ghrelin in the human ovary, and its reported effects in the proliferative activity of different cancer cell lines, we aimed at evaluating whether the ovarian surface epithelium as well as related reproductive structures and tumors are potential targets of ghrelin. To this end, expression of GHS-R1a was analyzed by immunohistochemistry in a panel of normal, metaplastic, and neoplastic tissues. Uniform GHS-R1a immunostaining was detected throughout the ovarian surface epithelium. Likewise, ciliated cells within the fallopian tube epithelium showed strong GHS-R1a expression. In contrast, other celomic derivatives, such as endometrium and endocervix, were negative for GHS-R1a immunoreactivity. In keeping with data from normal tissues, inclusion cysts from the surface epithelium expressed GHS-R1a. Similarly, benign serous tumors resembling fallopian tube epithelium were also positive, whereas serous cystadenocarcinomas showed GHS-R1a expression only in highly differentiated specimens. In contrast, other neoplasms, such as mucinous cystadenomas and cystadenocarcinomas, endometrioid tumors, clear cell carcinomas, and Brenner tumors, did not express GHS-R1a. In conclusion, our results demonstrate that the ovarian surface epithelium and related tumors are potential targets for systemic or locally produced ghrelin because they express the functional type 1a GHS-R. Considering the relevant role of the ovarian surface epithelium in key physiological events (such as ovulation) and neoplastic transformation of the ovary, the potential actions of ghrelin in those phenomena merit further investigation.

Relationship among COX-2 protein expression, PGs levels and biologic behavior in ovarian carcinoma tissues

Objective: To study the relationship among cyclooxygenase-2 (COX-2) protein expression, prostaglandins levels and biologic behavior in ovarian carcinoma tissues. Methods: The expression of COX-2 protein, levels of prostaglandin (PG)E2, 6-keto-PGF1α and thromboxane (TX)B2 in 54 biopsy specimens from patients with ovarian serous tumors which included three groups: 33 samples of ovarian serous carcinoma; 10 samples of borderline ovarian serous tumors and 11 samples of benign ovarian serous tumors and 10 samples of normal ovarian tissues were detected by Western blot analysis and radioimmunoassay to investigate their clinical significance. Results: The expression of COX-2 protein (82%, 27/33) and its relative content (20.08±3.53) in ovarian serous carcinoma tissues were statistically higher than those in benign ovarian serous tumor tissues and normal ovary tissues i.e., 0 and (15.04±0.12), 0 and (15.33±0.60) (P 0.05). The levels of PGE2, 6-keto-PGF1α and TXB2 showed no significant differences in ovarian carcinoma tissues with different clinical stages (I to II and III to IV), different histological grades, with or without ascites and lymph metastasis. COX-2 expression was correlated with the levels of PGE2, 6-KETO-PGF1α and TXB2 (P<0.01). Conclusion: Our data suggest that COX-2 overexpression leads to increased PGE2, 6-KETA-PGFPGF1α and TXB2 biosynthesis, which may be mechanisms underlying the contribution of COX-2 to the development of ovarian serous carcinoma. BGF2, 6-keto-PGF1α and TXB2 may be helpful parameters of diagnosis and differentiate diagnosis in ovarian serous carcinoma.

Benign ovarian serous tumors: a re-evaluation and proposed reclassification of serous “cystadenomas” and “cystadenofibromas”

Objective. Serous cystadenomas and cystadenofibromas of the ovaries are currently regarded as neoplasms and are considered the most common ovarian neoplasms. The purpose of this study is to determine what proportion of benign serous tumors contain an epithelial proliferation (the hallmark of a neoplastic process in nearly all other sites) that can be considered neoplastic as opposed to reactive in nature. Methods. An unselected series of 113 ovarian serous tumors (76 serous cystadenomas and 37 serous cystadenofibromas) were histologically evaluated. A 1-mm in diameter area of epithelial proliferation was considered potentially neoplastic. Results. Eight tumors (7%) displayed at least 1 mm of epithelial proliferation (1% of serous cystadenomas and 19% of serous cystadenofibromas). Conclusion. The vast majority of benign serous tumors may not be bona fide epithelial neoplasms, but rather, may represent cystically dilated glandular inclusions (cystadenomas) and fibromas with epithelial inclusions (cystadenofibromas). A recently published study evaluating clonality in serous cystadenomas found that the vast majority are polyclonal and thus supports this hypothesis. These findings have important implications for the pathogenesis of ovarian cancer, for the distribution of ovarian neoplasms, and for the interpretation of molecular biological studies of ovarian tumors.

Immunohistochemical patterns for α- and β-catenin, E- and N-cadherin expression in ovarian epithelial tumors

Objectives. This study aims were to analyze and compare the E- and N-cadherin, β- and α-catenin expression in benign and malignant epithelial neoplasms of the ovary, correlating with tumor staging, histological grade, and presence of metastases during evolution. Methods. Immunohistochemical reactions were performed on paraffin-embedded tissues and evaluated according to the number of positive, stained cellular structures and reaction intensity for each molecule. Information about histological type and grade, tumoral stage, and disease evolution was obtained from the patients' clinical records. Results. Most of the carcinomas showed more intense β-catenin reaction ( P = 0.02). More than 50% of the endometrioid carcinomas showed increased β-catenin expression, with a large number of positive cells and more intense staining, being the same also observed for most of the serous benign tumors ( P < 0.01). E-cadherin membrane expression was frequently observed in carcinomas without metastasis, whereas cases with metastases in evolution were negative or showing E-cadherin expression only in the cytoplasm ( P = 0.04). N-cadherin expression differed according to histological type and grade and α-catenin was also related to histological type, but these findings were not conclusive. Conclusions. Increased β-catenin expression was more frequent in ovarian carcinomas, especially, but not only, in the endometrioid ones. The maintenance of E-cadherin expression in cellular membrane may be an independent marker of good prognosis in ovarian cancer. New studies about N-cadherin and α-catenin and their importance during ovarian carcinogenesis will be required.

Immunohistochemical localization of survivin in serous tumors of the ovary.

The aim of this study was to determine the immunohistochemical distribution of survivin in benign, borderline, and malignant serous tumors of the ovary. Survivin was localized by an indirect immunoperoxidase method in 42 cases of serous tumors of the ovary (15 cystadenomas, 15 borderline tumors, and 12 cystadenocarcinomas). Nuclear staining and cytoplasmic staining were separately scored. Cytoplasmic staining was detected in 27% of adenomas/borderline tumors and in 58% of carcinomas. Nuclear staining was detected in 87% of adenomas/borderline tumors but in only 42% of carcinomas. Although the differences in the intensity of cytoplasmic staining between adenomas and borderline tumors versus carcinomas were not significant, the differences in the intensity of nuclear staining between low-grade versus malignant tumors were significant. These findings suggest that survivin is widely expressed in benign, borderline, and malignant serous tumors but that nuclear localization of survivin is more common in benign or borderline tumors than in malignant serous tumors of the ovary. The molecular mechanisms that determine the subcellular distribution of this protein may reflect the role of survivin in the regulation of apoptosis during the processes of malignant transformation.

Plasminogen fragmentation and increased production of extracellular matrix-degrading proteinases are associated with serous epithelial ovarian cancer progression

Objective. Elevated levels of proteases are linked to the malignant phenotype in a wide variety of solid tumors. Therefore, the expression of plasminogen, matrix metalloproteinases (MMP-2 and MMP-9), and of the serine protease urokinase-type plasminogen activator (uPA) in serous epithelial carcinoma of the ovary were investigated. Methods. Plasminogen antigen was analyzed in tissue extracts and in the urine of patients with normal ( n = 12), benign ( n = 6), borderline ( n = 9), and invasive serous tumors ( n = 22) by Western immunoblotting using rabbit polyclonal plasminogen and murine monoclonal angiostatin antibodies. In the same tissue extracts, semiquantitative estimates of MMP-2, MMP-9, total MMP activity, and uPA activity were determined using semiquantitative gelatin zymography in the presence or absence of human plasminogen. Results. Bands corresponding to Glu-plasminogen (approximately 92 kDa) and Lys-plasminogen (approximately 86 kDa) were detected in all ovarian tissues and in corresponding urine samples. Densitometric analysis of combined Glu- or Lys-plasminogen levels showed significantly decreased levels in malignant compared to normal tissue. In Grade 3 cancers, there was no evidence of Glu-plasminogen or angiostatin. MMP activity was significantly elevated in both borderline and in Grade 3 ovarian cancer tissues. Increased tissue uPA activity on zymograms was detected only in Grade 3 ovarian cancer tissue. Conclusion. These data suggest that proteolytic activity of the plasminogen activation cascade increases in serous epithelial ovarian carcinoma.

Expression of Fas and FasL in human serous ovarian epithelial tumors

The expression of Fas and FasL was studied in 86 patients with benign, borderline, and malignant serous ovarian lesions. Four normal ovaries, and monolayer epithelial cultures from a human fetal ovary, a borderline, and a serous adenocarcinoma were used for comparison. Expression of Fas and FasL was studied immunohistochemically and flowcytometrically. Fas was expressed in all 90 lesions; FasL in 57 lesions, including 2 normal ovaries. Fas expression was significantly increased in borderline tumors compared with benign (P = 0.005, t = −2.94) or malignant serous tumors (P = 0.0001, t = 4.15). FasL expression was significantly increased in malignant tumors compared with benign (P = 0.039, t = −2.10) and borderline tumors (P = 0.0016, t = −3.33). Flow cytometry showed a range of Fas expression in short-term cultures isolated from normal, borderline, and malignant ovarian serous tissue; in the few samples studied, FasL was not expressed. Expression in three serous ovarian cell lines was similar. Fas and FasL expression differed throughout the spectrum of ovarian lesions. FasL expression was increased in malignant tumors, and Fas expression was increased in borderline tumors. Changes in Fas/FasL expression in ovarian surface epithelium might play a functional role in the biology of ovarian tumors. HUM PATHOL 34:74-79. Copyright 2003, Elsevier Science (USA). All rights reserved.

Expression of MUC1 and MUC2 mucin gene products in human ovarian carcinomas.

Aberrations in expression of mucin glycoproteins have been observed during malignant transformation of human ovarian epithelium. To date, several secretory mucin genes designated the MUC gene family have been identified, of which MUC1 encodes a mammary-type and MUC2 an intestinal-type epithelial mucin. However, information on the expression and potential value of MUC1 and MUC2 mucins in ovarian cancer is limited. This study investigated immunohistochemical expressions of MUC1 and MUC2 mucins in 23 benign and 45 malignant human ovarian tumors to assess their clinicopathological relevance. All benign serous tumors and also associated normal-appearing epithelia expressed MUC1 mucin on the cell surfaces. Benign mucinous tumors occasionally expressed MUC1 and MUC2 mucins. Most serous carcinomas (19/21; 90%) expressed MUC1 but not MUC2 mucin. Of the 16 mucinous carcinomas, 10 (62%) and five (31%) expressed MUC1 and MUC2 mucins, respectively. Four of the five clear cell and the three endometroid type carcinomas expressed MUC-1 but not MUC-2 mucin. A significant association was found between a high expression of MUC1 and histological grade (P = 0.005) and also disease stage (P = 0.001). These results suggest that a high expression of MUC1 may contribute to a poor prognosis in ovarian carcinoma.

Alpha(v)beta(6) integrin-A marker for the malignant potential of epithelial ovarian cancer.

The mechanism(s) responsible for the progression of non-metastatic or borderline ovarian cancer to invasive Grade I/III ovarian cancer is still unknown. An epithelium-restricted integrin, alpha(v)beta(6), is present in malignant epithelia but not in normal epithelia. We studied the relative expression and distribution of alpha(v)beta(6) integrin in early and late-stage invasive (Grade I and Grade III) and non-invasive (benign and borderline) ovarian tumors of serous, mucinous, endometrioid, and clear-cell carcinoma subtypes, to assess its potential as a marker for epithelial ovarian cancer progression. Sixty-six specimens, including eight normal, 13 benign, 14 borderline, 13 Grade I, and 18 Grade III tumors were evaluated by immunohistochemistry (IHC) using a monoclonal antibody (MAb) against alpha(v)beta(6) integrin. Normal ovarian surface epithelium was negative for alpha(v)beta(6) integrin expression. All 45 carcinomas studied were positive, and the staining intensity significantly correlated with the grade of the tumor. The Grade III carcinomas of all types showed strong staining intensity. Only mucinous benign tissues were positive, and no reactivity was observed in benign serous neoplasms. On the basis of these observations, we hypothesize that the expression of alpha(v)beta(6) integrin is associated with epithelial ovarian cancer and that a gradual increase in the expression of the molecule may be a correlative index of the progression of this disease.

CYP1A1 gene polymorphism and risk of epithelial ovarian neoplasm.

Gene-environment interactions have been the focus of a number of recent studies of the occurrence of human cancers, and an association between the risk and the CYP1A1*3 polymorphism has been noticed for several cancers. Previous studies suggest that estrogens are involved in the etiology of ovarian cancer. The cytochrome P450 1A1 (CYP1A1) gene polymorphism may play role in the development of epithelial ovarian neoplasm by detoxification of polycyclic hydrocarbons and other compounds and the concentration of estrogens and their metabolites. Therefore, we assessed the association of CYP1A1 gene polymorphism in patients with epithelial ovarian neoplasm in the Turkish populations through a case-control study. Using an allele-specific polymerase chain reaction (PCR)-based method, CYP1A1*3 polymorphism, in exon 7 of the gene, was analyzed in 117 epithelial ovarian neoplasm patients and 202 control subjects. The CYP1A1 Ile/Val genotype significantly increased the risk for patients with epithelial ovarian neoplasm (OR 5.7, 95% CI 3.34-9.76). Furthermore, there were statistical differences in the distribution of CYP1A1 Val/Val genotype among all patients (OR 5.85, 95% CI 2.40-14.25). In other words, the presence of the Val allele significantly increased the risk of epithelial ovarian neoplasm. Among benign tumors, the frequency of Ile/Val and Val/Val genotypes was found to be statistically significant with an ORs of 6.01 and 4.38 (95% CI 2.61-13.84 and 1.04-18.38, respectively). In the benign serous ovarian tumors, patients with Ile/Val and Val/Val revealed a 7.2- and 10.5-fold higher risk of having ovarian carcinoma (95% CI 2.22-23.40 and 2.16-51.19), respectively. In the benign mucinous ovarian carcinoma patients, the frequency of Ile/Val was found to be statistically significant with an OR of 5.15 (95% CI 1.75-15.16). However, no patient with Val/Val genotype was observed in this group and no statistical distribution was performed. Among borderline tumors, CYP1A1 Ile/Val genotype significantly increased the risk for patients (OR 5.15, 95% CI 1.75-15.16). However, only one patient was observed with the Val/Val allele and the frequency of this genotype was not found to be statistically different with an OR of 2.50 (95% CI 0.27-22.64). Among ovarian cancer patients, there were statistically differences in the distribution of CYP1A1 Ile/Val and Val/Val genotypes (OR 5.73, 95% CI 3.04-10.76; and OR 7.42, 95% CI 2.80-19.66), suggesting that patients carrying these genotypes were at increased risk for ovarian carcinoma. In serous carcinoma, patients with CYP1A1 Ile/Val and Val/Val revealed a 6.5- and 10-fold higher risk of having ovarian cancer (OR 7.09, 95% CI 3.30-15.22; and OR 8.77, 95% CI 2.83-27.14). In mucinous carcinoma, patients with CYP1A1 Ile/Val and Val/Val also revealed a 5.4 and 10.5 times higher risk of having ovarian cancer. There were no statistical significance in the distribution of Val allele among endometroid-type cancer patients. Our data, although based on a small number of subjects, suggest that variant alleles of CYP1A1 gene in ovarian epithelial cells, directly or through other components, may contribute to initiation of ovarian carcinogenesis.

Aspiration Cytology of 147 Adnexal Cysts with Histologic Correlation

To assess the usefulness of cytology in the diagnosis of 147 histologically established adnexal cysts. Retrospective, macro-microscopic study based on fluid aspirated from 132 ovarian and 15 extraovarian cysts and projected as a cytohistologic correlation. Typical macroscopic features were identified in 76% of endometriotic cysts, in 53% of mucinous neoplasms and in 67% of dermoid cysts. Cytology helped to identify 67% of nonneoplastic and 56% of neoplastic cysts. The lowest diagnostic sensitivities were observed in functional cysts and benign serous neoplasms (50%), while the highest were shown by endometriotic cysts (76%) and malignant epithelial neoplasms (71%). Inadequate samples were obtained from all types of cysts, even malignant ones (two mucinous cystadenocarcinomas). Diagnostic cytology was useless in extraovarian cysts (33% sensitivity). An adult granulosa cell tumor was erroneously diagnosed as a follicular cyst by cytologic examination. Examination of the cyst fluids obtained by aspiration demonstrated low sensitivity, with 43% of inadequate samples obtained from all types of cysts. Malignant cystic neoplasms may be overlooked in inadequate samples. Our study also revealed that specificity in this type of analysis is high in inadequate samples, provided that the technique is carried out correctly.

Changes in gene expression during progression of ovarian carcinoma

The molecular events leading to the development and progression of serous ovarian carcinoma are not completely understood. We performed a large scale survey for the identification of differentially expressed genes in serous ovarian carcinoma by using cDNA array analysis. Differences in gene expression between serous adenocarcinoma and benign serous adenoma, and between advanced and/or moderately or poorly differentiated and local, highly differentiated serous adenocarcinoma were assessed. The most striking difference between adenocarcinoma and benign adenoma was upregulation of RHOGDI2 in the carcinomas irrespective of the clinical tumor stage. Other changes in carcinoma were upregulation of MET and Ne-dlg, and downregulation of HGFAC, desmin, and PDGFA. The most prominent differences between advanced and local adenocarcinoma were upregulation of COL3A1, CFGR, and MET in advanced carcinoma, and downregulation of HGFAC, FZD3, and BFL1 in the same tumors. In conclusion, significant differences were found in the gene expression between benign and malignant serous ovarian tumors, and between local, highly differentiated and advanced and/or moderately or poorly differentiated serous adenocarcinomas. The differentially expressed genes may be related to the carcinogenesis and progression of the malignant growth.

Cross-linked telopeptides of type I and III collagens in malignant ovarian tumours in vivo.

Malignant tumours often induce a fibroproliferative response in the adjacent stroma, characterized by increased expression of type I and type III procollagens. In normal tissues, fibrillar collagens normally undergo extensive intermolecular cross-linking that provides tensile strength to the tissue. Here we set out to characterize collagen cross-linking in human ovarian carcinoma tissue in vivo. Biochemical and immunochemical methods were used for cross-linked telopeptides of type I and III collagens in samples of benign and malignant serous tumours. The locations and staining patterns of these proteins were visualized immunohistochemically. The contents of both total collagen and the cross-linked type I and type III collagens in the malignant samples were only about 20% of those in the benign tumours. The cross-linked telopeptide antigens derived from the collagens were smaller and more heterogeneous in size in the malignant than in the benign tumours, indicating a defective cross-linking process scarcely leading to the formation of mature cross-links in the collagen fibres in malignancy. Immunostaining revealed disorganized type I and type III collagen bundles in carcinomas. These findings suggest that the collagen cross-linking process is aberrant in malignant tumours, possibly resulting in increased susceptibility of tumour collagens for the proteolysis often associated with tumour invasion. © 1999 Cancer Research Campaign

Immunohistochemical analysis of bcl-2, bax, mcl-1, and bcl-X expression in ovarian surface epithelial tumors.

Cell survival may be enhanced in tumors by the inhibition of apoptosis, which allows tumor promotors to exert their effects. The bcl-2 related genes have been shown to contribute to either the inhibition or induction of apoptosis in a variety of neoplasms; therefore, it was hypothesized that the expression of these genes might contribute to malignant transformation in ovarian surface epithelial tumors. The expression of bcl-2 family proteins was investigated in 28 ovarian surface epithelial tumors, including serous and mucinous benign, borderline, and malignant tumors by immunohistochemical staining with antibodies to bcl-2, bax, bcl-X, and mcl-1 proteins. Staining intensity was scored on a 1+ to 3+ scale and the benign, borderline, and malignant tumors were compared. Significantly less immunoreactive bcl-2 and bcl-X proteins were present in malignant serous tumors compared to their benign counterparts. No difference was seen in immunostaining for bax or mcl-1 when benign, borderline, or malignant serous tumors were compared. In the mucinous tumors, no differences were seen in immunostaining for any of the bcl-2 family proteins between tumor types. The loss of expression of the antiapoptotic proto-oncogenes bcl-2 or bcl-X in serous carcinomas compared to benign serous tumors, together with previous demonstrations that the presence of bcl-2 in ovarian surface epithelial cancers is a favorable prognostic indicator, suggests that bcl-2 and bcl-X have biological functions in the ovary other than inducing apoptosis, acting instead as tumor suppressor proteins.

72-kilodalton type IV collagenase, type IV collagen, and Ki 67 antigen in serous tumors or the ovary: a clinicopathologic, immunohistochemical, and Serological study.

The immunohistochemical expression of 72-kDa type IV collagenase [matrix-metalloproteinase (MMP)-21], basement membrane component type IV collagen and proliferation-related antigen Ki 67 were investigated in 43 benign, borderline, and malignant serous tumors of the ovary. The results were compared with the histotypes of ovarian serous tumors and with their clinical behavior. Serum evaluation of MMP-2 was performed in 14 patients with cystadenocarcinoma and the data compared with that of a control group. The basement membrane (BM) was continuous in benign cystadenomas and in some borderline tumors, whereas it was discontinuous or absent in other borderline tumors, in borderline tumors with microinvasion, and cystadenocarcinomas. The percentage of MMP-2- and Ki 67-expressing cells increased from cystadenomas to borderline tumors, being the highest in malignant tumors; a frequent basal disposition of the MMP-2 cytoplasmic granules also was observed in cystadenocarcinomas. Statistical analysis demonstrated that MMP-2 expression was inversely related to BM integrity. Serum MMP-2 values did not differ from that of the control group. Cox regression analysis showed that tumor stage and grade were significant prognostic factors, whereas MMP-2 and Ki 67 immunohistochemical expression added no further significant information to the prognosis. The investigators conclude that the correlation between increasing MMP-2 expression and BM alteration gives support to the hypothesis of a direct role of the metalloproteinase in the process of destructive stromal invasion. MMP-2, type IV collagen, and Ki 67 immunodetection varied according to the histologic classification of ovarian serous tumors. However, neither these factors nor the serum evaluation of MMP-2 appear useful as prognostic predictors in this series.

Immunocytochemical versus biochemical receptor determination in normal and tumorous tissues of the female reproductive tract and the breast

The development of highly specific and sensitive monoclonal antibodies directed against human estrogen (ER) and progesterone receptors (PR) provides a new approach in precise histochemical receptor location independent of hormone binding. Over the years receptor determination was the domain of the radioligand-binding assay, in which receptors are measured by tritiated ligand and unbound ligand is removed by the dextran-coated charcoal (DCC) procedure. Presented here are the results and experiences obtained by the classic DCC and the immunocytochemical method in the different normal and tumorous tissues of the female reproductive tract and the breast. The results of both methods were compared, and overall concordance of the results was found to vary considerably among the different types of tissue analyzed. Best agreement (86%) was found for PR determination in breast cancer, and the lowest rate of concordance for ER determination in fibrocystic disease of the breast. Special attention was directed toward the heterogeneity of receptor distribution in the specimens examined. In all tissues investigated, ER and PR were located in the nuclei of cells in both paraffin and frozen sections. Staining intensity varied among different cell types and from cell to cell for a single cell type, as well as in tumorous and normal tissues. In breast cancer, randomly scattered single cell receptor positivity was distinguished from focal/clonal positivity. Paraffin-embedded lymph node metastases showed significantly weaker staining as compared with their respective primary tumors. In the normal ovary, the corpus luteum and the stromal layer of the outer cortex were revealed as highly receptive elements for progestins, whereas ER was barely demonstrable in the normal ovary. Benign serous and mucinous ovarian tumors showed opposite ER and PR distribution among the stromal and epithelial components. Of special interest were the highly significant changes in ER and PR content in the stromal and glandular cells of the different layers of the normal endometrium throughout the menstrual cycle.