Tumor markers in gynecologic cancer.

The development of biochemical tumor markers has increased the use of antibody-dependent tumor marker assays in gynecologic oncology. Several monoclonal antibodies directed against novel epitopes on tumor-associated antigens have allowed the development of sensitive assays for serum markers. Assays for human chorionic gonadotrophin and TA-4 have been improved. CA 125 has provided a useful first-generation markers. Ovarian cystoadenocarcinoma-associated antigen and lipid-associated sialic acid have been developed for ovarian cancer, transforming growth factor for squamous cancer, and placenta protein 4 for endometrial and cervical cancer. The most widely applied procedures to identify these markers are immunofluorescent microscopy and immunocytochemical staining. Multiple markers and modalities may be required to increase the sensitivity of tumor detection. CA 15-3 and GCDFP-15 markers have been useful in detecting breast cancer. The application of radionuclide imaging will provide a new field for the diagnosis of gynecologic malignancies.     

Detection of human ovarian tumor-associated antigens by antibodies isolated from ovarian carcinoma ascitic fluid

Ascitic fluid from patients with ovarian epithelial cancer contains large amounts of soluble immune complexes and is a potential source of antibodies and antigens associated with the tumor. The antibodies against tumor-associated antigens were purified from the ascitic fluids of patients with ovarian serous cystadenocarcinoma. These antibodies showed specificity toward ovarian epithelial cancer when tested against ovarian tumor cell lines and paraffin-embedded tissue sections of ovarian cancer. The antigens in sera of patients were separated from IgG and IgG complexes by affinity chromatography and the free antigens were isolated. With the antibodies purified from ascitic fluid, the levels of tumor-associated antigens in sera of 10 patients with serous cystadenocarcinoma and 12 control patients were detected by an enzyme-linked immunosorbent assay. The antigens in patients with ovarian epithelial cancer were 2 to 10 times higher than those in control patients. These studies demonstrate that the antibodies isolated from ascitic fluid detect the tumor-associated antigens on tumor cells as well as the shed antigens present in serum.     

Vakzinierung – neue Hoffnung für eine zielgerichtete Therapie

Immunological therapeutic strategies are based on the expression of tumor-specific antigens. In breast cancer, the extracellular domain of the Her2-neu receptor is a well-characterized antigen. In ovarian cancer, CA-125 is described as a tumor-specific antigen. Both these antigens have been used in phase I/II trials with different vaccination strategies. In Her2-positive breast cancers, the single-peptide vaccine E75 was investigated as an adjuvant treatment and was found to reduce significantly the risk of recurrence in a small cohort of patients. In patients with advanced ovarian cancer, vaccination therapy has also been tested using the anti-idiotypic antibody abagovomab. In this setting, the host produces anti-anti-idiotypic antibodies, which in turn target the initial antigen CA-125. The vaccine improved the median survival of these patient significantly. No severe toxicities have been reported for the two vaccines; however, there are no long-term safety profiles available, especially on the induction of autoimmune reactions. In general, vaccination in breast and ovarian cancer patients is promising as a future treatment option.     

Immune responses to murine monoclonal antibody-B43.13 correlate with prolonged survival of women with recurrent ovarian cancer

OBJECTIVE: We evaluated the therapeutic efficiency of the murine monoclonal antibody-B43.13 in the treatment of patients with recurrent ovarian cancer. STUDY DESIGN: This was a retrospective study of immune responses and survival in 44 patients who were treated with technetium 99m-labeled monoclonal antibody-B43.13, a murine monoclonal antibody that is directed against the tumor-associated antigen CA125. Most patients were pretreated heavily. Biologic activity was quantified by the assay of immune responses to the human anti-murine antibodies against the monoclonal antibody-B43.13 variable region (Ab(2)) and antibodies that target the CA 125 antigen itself (anti-CA 125 antibody). RESULTS: More than one half of patients (56.8%) survived for >12 months after the first dose of monoclonal antibody B43.13; 34.1% of the patients survived >24 months. To date, 6 of the 44 patients are alive, with survival times of 4 to 7.5 years after the start of the antibody treatment. More than 60% of the evaluable patients met predefined criteria for robust, treatment-emergent human anti-murine antibodies and Ab(2) responses, and these responses were associated with improved survival rates. Median survival time increased approximately 3-fold for human anti-murine antibody responders (22.6 months) versus nonresponders (7.2 months; P <.0016, log-rank test) and 2-fold for Ab(2) responders (18.3 months) versus nonresponders (9.3 months). No serious drug-associated adverse events were reported. CONCLUSION: The associations between multiple types of immune response and improved clinical outcomes suggest that monoclonal antibody-B43.13 should be further evaluated for potential use as an immunotherapy for CA125-expressing malignancies.     

Radioimaging of human ovarian carcinoma xenograft in nude mice

Human ovarian carcinomas in nude mice were radioimaged using a well-characterized antibody against a tumor-associated antigen (CA 125) and three transplantable human ovarian carcinoma tumor lines: NIH:OVCAR 3, NIH:OVCAR 5, and NIH:OVCAR 9. Radioiodinated monoclonal antibody OC125 was used in these studies. In order to establish the optimal conditions for imaging, tumor/blood ratios were determined. Gamma scintigraphy of nude mice bearing subcutaneous transplants of human ovarian carcinomas 3-4 days after 131I-OC125 administration demonstrated selective localization of the radiolabeled monoclonal antibody by these tumors without need for any background subtraction techniques.     

Appraisal of anti-idiotypic antibodies in the treatment of solid tumors in humans.

Anti-idiotypic antibodies may be valuable in the induction of antitumor immunity in two ways--they can serve as a ready source of antigen when the appropriate TAA is difficult or impossible to purify. More importantly, regulatory anti-idiotypic antibodies can activate specific T-helper cells, bringing all the components of cellular immunity to bear on neoplastic process. Although the results in studies in animals have demonstrated resistance to tumor challenge after immunization with anti-idiotypic antibodies, studies of humans with advanced malignancies have failed to produce substantial clinical results. Nevertheless, immunization with anti-idiotypic antibodies has influenced some tumors. These studies represent important, initial steps toward understanding the immune network and modulating it in favor of the host, against human tumors. As a continued understanding of the immune network evolves and strategies for activating and suppressing specific immune responses are developed, it should be possible to design vaccines for specific uses. Although current anti-idiotypic vaccines do not seem promising for the treatment of established solid tumors in humans, we can look with anticipation to studies of polyvalent vaccines for the prevention of carcinoma in high risk groups.     

单克隆抗体治疗卵巢癌的研究进展

单克隆抗体治疗卵巢癌的实验与临床研究均已取得较大进展。贝伐单抗（nevacizumab,BEV）通过抑制新生血管形成,达到抑制肿瘤的目的;曲妥珠单抗（trastuzumab）、帕妥珠单抗（pertuzumab）选择性作用于人类表皮生长因子受体2,抑制肿瘤细胞的生长;西妥昔单抗（cetuximab）通过结合细胞表皮生长因子受体1,抑制细胞增殖、诱导凋亡;oregovomab通过与CA125形成免疫复合物,引起针对CA125的独特型免疫应答。单克隆抗体治疗卵巢癌可弥补传统治疗的不足。综述单克隆抗体治疗卵巢癌的研究进展。     

单克隆抗体治疗卵巢癌的研究进展

单克隆抗体治疗卵巢癌的实验与临床研究均已取得较大进展。贝伐单抗（nevacizumab,BEV）通过抑制新生血管形成,达到抑制肿瘤的目的;曲妥珠单抗（trastuzumab）、帕妥珠单抗（pertuzumab）选择性作用于人类表皮生长因子受体2,抑制肿瘤细胞的生长;西妥昔单抗（cetuximab）通过结合细胞表皮生长因子受体1,抑制细胞增殖、诱导凋亡;oregovomab通过与CA125形成免疫复合物,引起针对CA125的独特型免疫应答。单克隆抗体治疗卵巢癌可弥补传统治疗的不足。综述单克隆抗体治疗卵巢癌的研究进展。     

CA125 expression at clinical diagnosis by ovarian carcinoma not detected through antecedent serum CA125 screening

At the time of clinical presentation with ovarian carcinoma, 85% of women have an elevated serum level of the CA125 antigen, but the duration of the preclinical phase of expression of CA125 is unknown. From the database of The Royal London Hospital ovarian cancer screening project, 19 women were identified who had a serum CA125 level <30 IU ml⁻¹, measured between 2 and 24 months prior to their clinical diagnosis of ovarian cancer. Histological sections of tumor removed from these women were reviewed. In 17 cases tumor tissue was immunocytochemically stained for CA125 expression. Tumor blocks of 40 women presenting clinically with ovarian cancer with known preoperative CA125 levels were also stained for CA125 expression. The serum CA125 level at the time of diagnosis was available in six of the 19 screening study cases, four of which had levels> 30 IU ml⁻¹. In five of the 13 cases with unknown serum CA125 levels, ovarian tumor tissue expressed CA125. Among the 40 controls, 24 tumors expressed CA125 and all 24 had a serum level greater than 47 IU ml⁻¹. An annual screening test using serum levels of CA125 at a cut-off of 30 IU ml⁻¹, cannot detect all cases of ovarian cancer that express the antigen at the time of clinical diagnosis. The development of a panel of complementary tumor markers will be necessary to provide a test with a higher sensitivity for the detection of preclinical ovarian cancer.     

CA125- and tumor-specific T-cell responses correlate with prolonged survival in oregovomab-treated recurrent ovarian cancer patients

OBJECTIVE: To evaluate immune responses and clinical outcomes for combined oregovomab and chemotherapy treatment of patients with recurrent ovarian cancer. METHODS: Patients with advanced recurrent ovarian cancer were administered oregovomab over 12 weeks before chemotherapy, then optionally concurrent with chemotherapy x 2. Antibody responses, including human anti-mouse antibody (HAMA), anti-idiotypic antibody (Ab2) and anti-CA125, were assessed by ELISA; T-cell responses to CA125, autologous tumor and oregovomab by interferon (IFN)-gamma enzyme-linked immunoSPOT (ELISPOT) were also evaluated. Clinical outcomes were recorded. RESULTS: Twenty patients were enrolled; median follow-up was 15.8 months. Oregovomab was well tolerated and did not produce drug-related serious adverse reactions. In 15/19 (79%) patients, robust treatment-emergent humoral responses were observed to the constant (HAMA) and variable region (Ab2) of oregovomab, and 2/19 (11%) patients developed anti-CA125 antibodies. Significant increases in T-cell responses were measured in 7/18 (39%) patients in response to CA125, in 5/8 (63%) patients in response to autologous tumor and in 9/18 (50%) patients in response to oregovomab. Immune responses appeared by week 12 (four doses) and were generally maintained or augmented in patients continuing combined treatment with oregovomab and chemotherapy. Median survival was 70.4 weeks (4.6-141.6 weeks), and the median progression-free interval was 11 weeks (2.6-114.6 weeks). Patients who mounted a T-cell response to CA125 and/or autologous tumor showed significantly improved survival (median not reached vs. 51.9 weeks, P = 0.002) compared to patients who did not. CONCLUSIONS: Oregovomab was well tolerated and induced multiple antigen-specific immune responses, maintained during concomitant chemotherapy. A significant survival benefit was observed in patients mounting a T-cell response to CA125 and/or autologous tumor.     

Monitoring human ovarian carcinoma with a combination of CA 125, CA 19-9, and carcinoembryonic antigen

CA 125 and CA 19-9 are antigenic determinants associated with human epithelial ovarian carcinomas. Murine monoclonal antibodies have been raised against these determinants, and immunoradiometric assays have been developed to monitor antigen levels in the serum of cancer patients. This study was undertaken to determine whether concomitant measurement of CA 125, CA 19-9, and carcinoembryonic antigen would provide a more precise correlation with tumor progression or regression than could be obtained with any single assay. Among 105 patients with surgically demonstrable epithelial ovarian carcinoma, serum CA 125 levels were elevated (greater than 35 U/ml) in 83%, CA 19-9, levels (greater than 37 U/ml) in 17%, and carcinoembryonic antigen levels (greater than or equal to 2.5 ng/ml) in 37%. Within individual samples, no correlation was found among values for the three markers, but patients with elevated CA 19-9 levels also had increased levels of CA 125. At least one of the three markers was elevated in 90% of the subjects. When 41 patients were monitored serially over 2 to 60 months, alterations in CA 125 levels correlated with disease progression or regression in 94% of instances, whereas alterations in CA 19-9 levels correlated in 33% and alterations in carcinoembryonic antigen levels in 25% of instances. Concomitant measurement of CA 125, CA 19-9, and carcinoembryonic antigen did not prove superior to measurement of CA 125 alone in the monitoring of patients with epithelial ovarian carcinoma.     

Clinical value of sialyl SSEA-1 antigen in patients with ovarian cancer

The efficacy of sialyl SSEA-1 antigen (SLX), a tumor-associated carbohydrate antigen, as a test for gynecological cancer was investigated. The test was found to be positive in 64.5% of all patients with ovarian cancers; this rate is lower than that obtained with CA 125. On the other hand, relatively few false-positive results were observed. Tests were false-positive in 25.0% of patients with endometrial cysts; 25.0% of women in the first trimester of pregnancy and 0.0% of menstruating woman had false-positive results. These percentages were lower than those for CA 125. It is concluded that SLX is a tumor marker with inferior sensitivity and high specificity, compared with CA 125. Since positive tests with SLX in patients with ovarian cancer mostly overlapped the positive tests for CA 125, the usefulness of a combination assay was considered to be low. The SLX test was positive in 18.6 and 25.0% of patients with cervical cancer and endometrial cancer, respectively, and it was concluded that SLX is useless as a serum tumor marker for uterine cancer.     

Effect of differentiation agents on expression of CA 125, alkaline phosphatase, and cytokeratins in human ovarian adenocarcinoma cells (OVCA 433).

A number of chemical agents have been found to influence the proliferation, morphology, enzymatic activity, and antigen expression of neoplastic cells toward a more differentiated phenotype. We studied the effects of differentiating agents retinoic acid, sodium butyrate, and dibutyryl cyclic AMP on the expression of the tumor-associated antigen CA 125 and several biochemical markers of differentiation in cultured OVCA 433 ovarian cancer cells. Treatment of OVCA 433 cells with these agents for 96 hr reduced cellular proliferation and altered cellular morphology. Quantitation of cell surface CA 125 using flow cytometry revealed that CA 125 expression was reduced by 35-50%. The amount of CA 125 antigen shed into the culture media was reduced to a similar degree. In addition, differentiation inducers markedly enhanced cellular alkaline phosphatase activity and induced the expression of a 65-67-kDa cytokeratin. These findings provide support for the induction of a more differentiated phenotype by these agents.     

Tumor-associated antigen Ca 125 before and during the treatment of ovarian carcinoma

Serum concentrations of Ca 125, a tumor-associated antigen of epithelial ovarian cancer, were measured in 29 ovarian cancer patients before cytoreductive surgery and in 112 patients during and after treatment. Ca 125 levels were increased (greater than 30 IU/mL) in 89.8% of patients with clinically demonstrable ovarian tumors and were negative in 92.1% of clinically disease-free patients. Low levels of Ca 125 were associated with early clinical stages or a minimal tumor burden, and predicted a successful response to treatment and a low recurrence rate. High values indicated advanced disease and a poor response to cytotoxic chemotherapy. In 77% of patients the operation was explorative, with a preoperative Ca 125 level higher than 1000 IU/mL, whereas all the patients with values less than 100 IU/mL could be operated radically. Serum levels of Ca 125 were increased in similar frequency in epithelial, sex cord, and germ cell ovarian malignancies. The assay of Ca 125 seems to be a reliable noninvasive method for monitoring the presence and clinical behavior of ovarian cancer. Preoperative values have prognostic significance in predicting operability and response to chemotherapy.     

Clinical evaluation of specificity of serum CA125 as a tumor marker of ovarian carcinoma

To evaluate whether elevated serum CA125 levels have specificity to ovarian malignancies, CA125 levels were measured in sera of 48 malignancies, 56 benign diseases and 40 healthy women. Furthermore serum CA125 levels were serially followed up in all the patients with positive serum CA125 levels (35 U/ml less than or equal to) to evaluate the correlation between serum CA125 levels and the response to treatment. Results obtained were as follows. A significantly higher positive rate (91%) of serum CA125 levels was observed in patients with ovarian malignancies than that (30%) in patients with other malignancies. Positive serum CA125 levels were also observed in patients with endometriosis, benign ovarian tumor, hydrosalpinx, uterine myoma and peritoneal tuberculosis. Serum CA125 levels in patients with malignancies depend on the volume of the solid part of the tumor irrespective of the tumor type. In patients with positive serum CA125 levels, rising or falling of the serum levels of this antigen correlated well with progression or regression of all kinds of diseases. These results suggested that a high positive rate of this antigen in patients with ovarian malignancies was not merely derived from the tumor specificity of this marker but partly from the fact that tumor sizes of ovarian malignancies were generally larger than those of other malignancies.     

False changes in CA 125 levels in ovarian cancer patients after infusion of OC125 fragments for diagnostic and therapeutic purpose

The influence of human anti-OC125 antibodies formed after multiple infusions of OC125 F(ab′)₂ fragments on the apparent levels of CA 125 measured with four different tests were examined in two ovarian cancer patients. With the homologous Assay 1, involving only OC125 antibodies, false increases of CA 125 values were observed after infusion of OC125 fragments, which completely covered real CA 125. In contrast, with Assay 2, 3 and 4, which involve no OC125 antibodies as capture antibodies, only slight false increases occurred in the presence of very high anti-OC125 antibody concentrations. Interference was eliminated by addition of non-specific murine IgG in Assay 2 and 4, but not in Assay 1 and 3 indicating that the false increases in Assay 1 and 3 were caused by anti-idiotypic anti-OC125 antibodies. In the presence of elevated real CA 125, with Assay 2 and to a considerably lesser degree with Assay 4, an inhibitory effect of anti-OC125 antibodies became evident leading to false decreases of CA 125 values. In Assay 4 reduction of assay response was eliminated by addition of non-specific murine IgG. The results confirm that all available CA 125 tests are influenced by interference with human anti-OC125 antibodies. Thus, CA 125 levels in patients who have been treated with OC125 fragments should be interpreted with care.     

The study of antibodies and antigens dissociated from the immune complexes extracted from ovarian carcinoma ascitic fluid

In previous studies in our laboratory, heteroantisera were produced in rabbits by immunization with extracts of ascitic fluids from ovarian epithelial carcinomas. Reverse passive hemagglutination (RPHA) assay of these sera was used for the immunodiagnosis of ovarian cancer. Antibodies attached to lysed sheep red blood cells were able to detect tumor antigens in 63% of ovarian carcinoma sera. In the present study we have shown that the antigens detected in these assays are in fact contained in circulating immune complexes and are recoverable by disassociation with 8 M urea and separation of antibody and antigen by ion exchange chromatography. The antibodies thus obtained from immune complexes (IC) were assayed by indirect immunofluorescence against a variety of paraffin-embedded tissue sections. Poorly differentiated ovarian epithelial carcinomas and papillary serous adenocarcinomas, as well as the tumors grown by implantation of the latter in nude mice, were all positively stained, while the Krukenberg tumor metastatic to the ovary, the benign ovarian cyst, the normal ovary, and the normal fallopian tube were all negative. Complete blocking of immunofluorescence staining by prior absorption of antibody with the dissociated antigen was achieved. The present study demonstrates that the antibodies and antigens dissociated from the immune complexes isolated from the ascitic fluids provide useful reagents for immunodiagnosis.     

Construction of an immunoradiometric assay for ovarian cancer associated antigen CA125 recognizing different antigenic determinant.

We generated five murine monoclonal antibodies reactive with ovarian cancer-associated antigen CA125. These monoclonal antibodies seemed to bind to separate epitopes from OC125 antibody, known to recognize CA125. A series of immunoradiometric assays for measuring serum CA125 values rapidly and sensitively were devised using these monoclonal antibodies. The antigenic determinant of a new immunoradiometric assay was different from that of a currently used CA125 kit employing OC125 both as a catcher and a tracer. However, serum antigen levels were closely correlated to each other and were elevated not only in patients with ovarian cancer, but also in patients with endometriosis and in some normal females during menstruation. These results suggest that CA125 has at least two antigenic determinants close to each other and this new rapid assay is useful, although not specific for ovarian cancer, in patients with gynecological disorders.     

组织多肽抗原在卵巢癌诊断及监测中的应用

目的评价组织多肽抗原（ＴＰＡ）在卵巢癌诊断和监测中的临床价值。方法应用放射免疫方法测定了２４例正常妇女、２７例妇科良性疾患及６０例卵巢癌患者的血清ＴＰＡ及ＣＡ１２５值并进行比较分析。结果ＴＰＡ在卵巢上皮性癌患者中的异常检出率为８２％,ＣＡ１２５为７０％,二者总的异常检出率为９２％。在绝大多数正常妇女和卵巢良性肿瘤患者中,ＣＡ１２５和ＴＰＡ在正常范围。作为卵巢癌相关标志物,ＴＰＡ与ＣＡ１２５具有相似敏感性。１９例动态观察结果显示,ＴＰＡ和ＣＡ１２５二者与病情转归是一致的。结论ＴＰＡ和ＣＡ１２５联合应用对卵巢癌的鉴别诊断及提高总的异常检出率具有价值。     

4种肿瘤标志物对上皮性卵巢癌定性诊断价值的初步研究

目的：探讨多胺（ＰＡ）、ＣＡ１２５、ＣＡ１５．３和ＣＡ１９．９在定性诊断上皮性卵巢癌中的价值。方法：应用ＨＰ％Ｍ高效液相色谱仪和ＨＰ１０４０Ａ荧光检测器或酶联免疫吸附法测定上皮性卵巢癌４０例和卵巢良性肿瘤１８例血清中ＰＡ、ＣＡ１２５、ＣＡ１５．３和ＣＡ１９．９水平。结果：４种标志物中，ＰＡ诊断卵巢癌的敏感性、阳性预测率、阴性预测率和预测准确率最高，其次是ＣＡ１２５。结论：ＰＡ对人类恶性肿瘤缺乏特异性，但可作为鉴别卵巢良、恶性病变的有价值标志物。联合测定ＰＡ和ＣＡ１２５时，其敏感率为９４．９％。因此，联合测定ＰＡ和ＣＡ１２５可作为筛查卵巢良、恶性肿瘤的方法。