Suppression of diacylglycerol levels by antibodies reactive with the c-erbB-2 (HER-2/neu) gene product p185c-erbB-2 in breast and ovarian cancer cell lines.

Seven of 10 murine monoclonal antibodies reactive with the extracellular domain of p185c-erbB-2 inhibited the anchorage independent growth of the SKBr3 breast cancer cell line that overexpressed p185c-erbB-2. Significant inhibition (56-72%) of diacylglycerol (DAG) levels (P < 0.0001) was observed with the 10 antibodies that inhibited SKBr3 growth (RC1, NB3, RC6, PB3, 741F8, DB5, ID5), whereas the 3 antibodies (TA1, 520C9, 454C11) that failed to inhibit SKBr3 growth also failed to affect DAG levels. Thus, DAG levels correlated with antibody-mediated growth regulation for each of the 10 monoclonal reagents. Antibody-induced inhibition of anchorage-independent growth of SKBr3 could be reversed by incubation with phorbol myristate acetate. The ID5 antibody inhibited growth of the SKBr3, SKOv3, and OVCA 432 tumor cell lines, but not of OVCA 420, OVCA 429, and OVCA 433. DAG levels were significantly decreased after ID5 treatment of the SKBr3 and SKOv3 cell lines, but not the OVCA 420, OVCA 429, and OVCA 433 lines. In the 432 line, there was a decrease which did not reach significance. Consequently, changes in DAG levels correlated with growth regulation in 5 of 6 breast and ovarian carcinoma cell lines tested with a trend toward correlation in the sixth. Decreases in DAG may be one mediator of the growth regulatory signals produced by anti-p185c-erbB-2 antibodies.

The role of surgery in the management of ovarian cancer: primary and interval cytoreductive surgery.

Ovarian cancer remains the number one cause of mortality in gynecologic malignancies and the fifth most common cause of death among all malignancies in women. Unfortunately, recent data confirm that only approximately 90% of "apparent" early ovarian cancer are inadequately staged, and only approximately 80% of patients with advanced-stage disease are adequately staged. Interval debulking surgery, a newer treatment modality, appears to have a promising role for patients who cannot be adequately debulked at their initial surgery. Second-look laparotomy continues to be the most accurate way to document responses to chemotherapy in protocol settings, but additional clinical trials with newer second-line chemotherapy will be necessary before definitive statements can be made with regard to survival advantages in patients who undergo second-look laparotomy.

Gynecologic cancers.

In conclusion, significant advances have been made in ovarian cancer. Specifically, these relate to the success of paclitaxel and platinum-based regimens. The appropriate scheduling, dosing, and the selection of carboplatin vs cisplatin remains controversial. The role of interval debulking surgery is still investigational and we remain cautiously optimistic as to its long-term benefit. The progress in the delivery of chemotherapy to patients with cervical carcinoma, endometrial carcinoma, vaginal carcinoma, and vulvar carcinoma has been slowed by the paucity of prospective-randomized trials. Although numerous single institution non-randomized trials show promising regimens, they lack significant power and appropriate study design to prove meaningful. Our goals in the future should be to try to enter most of these patients into national collaborative studies where significant conclusions can be made because of appropriate study design and adequate patient numbers.

Microscopic benign and invasive malignant neoplasms and a cancer-prone phenotype in prophylactic oophorectomies.

BACKGROUND: The occurrence of approximately 5% of common epithelial malignant tumors of the ovary can be traced to inheritance of risk. One prophylactic strategy to decrease the probability of development of disease in individuals within families where this mendelian-dominant pattern of occurrence is apparent is to remove the ovaries of individuals at risk for ovarian cancer. The procedure, when done for this purpose, is recommended soon after completion of childbearing. PURPOSE: Our goal was to compare the histologic features of the ovaries of women at increased risk for ovarian cancer to those at no known increased risk for the disease. METHODS: Ovaries removed for prophylaxis from 20 women considered to be at increased risk for developing ovarian cancer were examined histologically. During the course of this work, it seemed apparent that these ovaries contained numerous atypical features compared with the expected appearance of normal ovaries. Hence, we expanded the study to include a control group whose ovaries were removed for reasons unrelated to cancer. The study, therefore, was not blinded. The increased risk in the cancer-prone individuals was determined by family history, specifically the presence of at least one first-degree relative and one second-degree relative with ovarian and/or breast cancer and positive linkage or mutational analysis of BRCA1 in some. The difference in mean ages of patients in the control and high-risk groups was not statistically significant. The difference among both groups with respect to the number of atypical features as well as the intensity of those features was ascertained by computing probabilities using Fisher's exact test (two-sided) for rows x columns contingency tables. RESULTS: Two unanticipated microscopic or near-microscopic malignant neoplasms and other benign and borderline tumors were discovered in the ovaries of the high-risk individuals. Of substantial interest was the finding that among the ovaries of high-risk women, 85% presented two or more and 75% presented three or more of the following histologic features: surface epithelial pseudostratification; surface papillomatosis; deep cortical invaginations of the surface epithelium, frequently with multiple papillary projections within small cystic spaces (microscopic papillary cystadenomas); epithelial inclusion cysts, frequently with epithelial hyperplasia and papillary formations; cortical stromal hyperplasia and hyperthecosis; increased follicular activity; corpus luteum hyperplasia; or hilar cell hyperplasia. Two or more or three or more such changes were observed in a lesser percentage (30% or 10%, respectively) of ovaries obtained from the control individuals, with a statistically significant difference (P = .001 or P = .00007, respectively), particularly considering that a detailed determination of a family history of cancer in the control group was not possible. CONCLUSIONS: The frequency of these changes in the high-risk ovaries compared with control ovaries suggests a characteristic histologic preneoplastic phenotype defined by an increased frequency and intensity of the above-described histologic features in the high-risk ovaries. Limited access to numerous small (stage I) ovarian cancers or cancer-prone ovaries by any one pathologist may explain the failure to identify the phenotype in the past. IMPLICATIONS: We suggest that the ovaries removed from ovarian cancer-prone individuals as a preventative measure should be thoroughly examined histologically to identify or rule out microscopic or near-microscopic invasive neoplasms.

Early ovarian cancer: a review of its genetic and biologic factors, detection, and treatment.

Early-stage ovarian carcinoma requires comprehensive surgical staging; reexploration for patients who had suboptimal initial surgery would indicate an apparent early ovarian carcinoma. After proper surgery, patients can be subdivided into a high- or low-risk group, and treatment options then can be discussed with the patient. Patients in the low-risk category can be followed up expectantly without any form of adjuvant therapy. Patients in the high-risk category, however, should be encouraged to participate in randomized clinical trials, because it is unclear at the current time which combination of chemotherapy and how many treatments should be used. A platinum-based paclitaxel regimen probably should be used, although the relative merits of carboplatin and cisplatin and the appropriate schedule for taxol (1 hour vs. 3 hours vs. 24 hours vs. 96 hours) are yet unknown. It is hoped that clinicians will continue to encourage patients to participate in randomized clinical trials so that optimal therapy for early ovarian cancer can be established.

Current status of staging laparotomy in colorectal and ovarian cancer.

Colon and rectal carcinomas. Accurate staging of colon and rectal carcinomas (CRCs) is vital to insure appropriate surgical and adjuvant therapy, and appropriate enrollment in and interpretation of adjuvant or neoadjuvant trials. Historically, CRC staging has relied on pathologic examination of surgical speciments. These newer techniques of endoscopic and intraoperative ultrasound, laparoscopy, and radioimmunoguided surgery may permit increased accuracy of staging by the surgeon. Cautious interpretation of investigations of these modalities is warranted, as studies include small numbers of patients and some of the work is preliminary. Despite this, we remain optimistic that as surgeons become more familiar with these techniques and as these modalities become more widely available, more accurate staging will facilitate optimal patient management in terms of complete resection of occult disease and appropriate adjuvant therapy. Ovarian carcinoma. The survival of patients with ovarian cancer has not appreciably changed in the past several decades. There are several reasons for this, some of which are related to the surgical procedures used to diagnose and treat these cancers. First, despite a great deal of literature that suggests an elevated CA-125 level in a postmenopausal woman with a pelvic mass is virtually diagnostic of ovarian carcinoma, an unexceptably large number of patients are still explored in community hospitals by a surgeon or obstetrician-gynecologist who is not prepared or adequately trained to perform the aggressive cytoreductive surgery that the patients require. Similarly, a large percentage of patients with "apparent" early ovarian cancer are not fully surgically staged at their initial surgery and often require reoperation to accurately define the extent of their disease, which will then determine the need for adjuvant therapy. Despite ongoing health care reforms, these patients should be referred to centers where the appropriate surgical procedure can be performed by an experienced gynecologic oncologist. Second-look laparotomy (SLL) has become more and more controversial, mainly because of a lack of effective second-line therapy, and should not be performed unless the patient fully understands its limitations and is willing preoperatively to participate in a subsequent trial based on the operative findings. Laparoscopy, both in the initial staging surgery and at reassessment laparotomy (SLL), is being re-evaluated but should be considered experimental until definitive trials determine its role.

Characterization of chromosome 9 in human ovarian neoplasia identifies frequent genetic imbalance on 9q and rare alterations involving 9p, including CDKN2.

We have examined 41 forms of ovarian cancer for genetic alterations on chromosome 9 using a combination of five RFLP DNA probes and 15 simple tandem repeat polymorphisms. Genetic imbalance (i.e., loss of heterozygosity, microsatellite instability, amplification) for 1 or more informative markers on chromosome 9 was observed in 66% (27 of 41) of our tumor panel. Genetic imbalance was observed on 9q in 59% (24 of 41) of tumors informative for at least one locus. In contrast, only 13% (5 of 40) of informative tumors demonstrated a genetic alteration involving 9p. Furthermore, allelic loss on 9q was more common in late stage tumors (63%, 17 of 27) and poorly differentiated tumors (75%, 15 of 20) as compared to benign and early stage tumors (30%, 3 of 10). Evaluation of 15 tumors showing limited regions of genetic imbalance has identified 2 candidate tumor suppressor regions on 9q and 1 on 9p. Interestingly, the regions defined to 9p21-p24, 9q31, and 9q32-q34 all overlap with several known disease loci. In this aspect, the potential role of the CDKN2 gene at 9p21-p22 in ovarian carcinogenesis was assessed in an extended panel of ovarian tumors, 11 human ovarian carcinoma cell lines, and 1 cervical tumor cell line. With the use of comparative multiplex PCR, homozygous deletions were detected in 16 of 115 (14%) fresh tumors and 3 of 12 cancer cell lines. For those tumors demonstrating allelic loss for markers on 9p no somatic mutations were observed in the retained allele of CDKN2, as determined by single-strand conformation polymorphism analysis, but a mutation was observed in an additional cell line. Furthermore, CDKN2 mRNA levels were similar in the 9 cancer cell lines that retain CDKN2, as compared to normal human ovarian surface epithelial cell lines. Overall, our results suggest the potential involvement of a gene or genes on chromosome 9q and de-emphasize a significant role for the CDKN2 gene on 9p in the initiation and progression of ovarian cancer.

Recurrence patterns and complications in endometrial adenocarcinoma with cervical involvement.

BACKGROUND: Cervical involvement in endometrial carcinoma is a diverse entity, and the optimal management of these patients is not well understood. METHODS: Recurrence patterns and complications in 202 patients with histologically confirmed endometrial carcinoma with cervical involvement were retrospectively studied. RESULTS: The 5-year actuarial survival rate for all patients was 65%. Recurrences were documented in 80 (40%) of the patients, and the overall long-term survival rate in this group was 4%. Patients treated with radical hysterectomy (n = 33) had a 6% isolated pelvic recurrence rate and the lowest serious complication rate among the five treatment groups despite having the highest frequency of risk factors for recurrence among any of the groups studied. Patients treated with extrafascial hysterectomy alone (n = 37) had a 14% pelvic recurrence rate and very few complications. When radiotherapy preceded extrafascial hysterectomy (n = 37), the frequency of pelvic recurrences was 30%, and 19% experienced serious gastrointestinal or genitourinary tract complications. When radiotherapy followed extrafascial hysterectomy (n = 68), the pelvic recurrence rate was 24%, and 13% experienced serious complications. Overall, 24% of patients (49 of 202) had isolated pelvic recurrences, whereas 10% (21 of 202) had isolated distant recurrences and 5% (10 of 202) were simultaneously diagnosed with both pelvic and distant recurrences. CONCLUSIONS: This large data base suggests that older conventional forms of therapy, particularly those using preoperative radiotherapy, subject the patient to significant morbidity over a 5- to 10-year period and, in terms of local control, are not necessarily superior to therapeutic modalities using primary surgical evaluation, such as radical hysterectomy. Consideration of primary surgery should be given in the appropriate situation, and radical hysterectomy should be considered when gross cervical involvement is encountered and intraoperative exploration does not show obvious extrauterine disease.

The management of early ovarian cancer.

Approximately one third of patients with epithelial ovarian cancer present with localized or early-stage disease. Prognostic features identify certain subsets of patients with good risk characteristics who do not require adjuvant treatment after comprehensive surgical staging and cytoreduction. Only a minority of patients undergo such a complete procedure, which often results in understaging of these patients. In the United States, patients with poor prognostic features, such as stage IC to II disease, poorly differentiated histologic grade, clear cell histology, dense adhesions, and large volume ascites, have received adjuvant chemotherapy. Single-agent or combination chemotherapy, whole abdominal irradiation, and intraperitoneal phosphorus 32 have been evaluated, although no modality has been shown to improve overall survival. Randomized trials investigating the optimal therapy or whether any therapy is truly effective are in progress. Until the completion of these trials, the most common postoperative adjuvant therapy in these patients in this country remains combination chemotherapy.

Prognostic factors and long-term survival in endometrial adenocarcinoma with cervical involvement.

The clinical, surgical, and histopathologic data from 202 patients with endometrial adenocarcinoma with cervical involvement are presented. One hundred fifty-one (75%) had histopathologically confirmed cervical involvement at the time of their definitive surgery, while in 51 (25%) no cervical involvement was conclusively identified. The 5-year actuarial survival for patients with true surgical stage II endometrial carcinoma (N = 24) was 76%. Extrauterine disease was documented in 32% (27/84) of patients in which the primary treatment modality was surgical. The 5-year actuarial survival was 65% for all patients with clinical surgical stage II disease. There appeared to be a survival advantage for patients treated by radical surgery as compared with more conventional treatments, especially in patients with numerous high-risk factors. The subgroup of patients (N = 53) having tumor grossly involving the cervix had a 5-year survival of 48%. In this subgroup of patients, radical hysterectomy offered improved 5-year survival over more traditional forms of treatment, particularly compared with simple hysterectomy or combined treatment with radiation and surgery. Multivariate analysis positively correlated myometrial invasion, grade, uterine serosal involvement, lower uterine segment involvement, adnexal metastasis, pelvic metastasis, aortic node metastasis, and peritoneal cytology, with disease-free survival. Clinical and surgical findings correlated poorly; therefore, primary surgical evaluation is recommended when possible.

The biology of ovarian cancer.

Recent studies have begun to elucidate the molecular events involved in the development of ovarian cancer. First, it has been shown that epithelial ovarian cells both produce and have receptors for many peptide growth factors. It is possible that these growth factors may participate in autocrine and paracrine growth-regulatory pathways in these cells. Increased activity of stimulatory factors, eg, transforming growth factor-alpha, or decreased activity of inhibitor factors, eg, transforming growth factor-beta, may facilitate malignant transformation. In addition, it has been shown that ovarian cancer cells often have acquired the ability to degrade extracellular matrix and invade the underlying tissues. Finally, alterations in several oncogenes and tumor-suppressor genes, including HER2/neu, c-myc, and p53, have been found in ovarian cancers. Although exciting insights into the molecular pathology of ovarian cancer have been gained, we remain far from a comprehensive understanding of the biology of this highly lethal disease.

Antibody-induced growth inhibition is mediated through immunochemically and functionally distinct epitopes on the extracellular domain of the c-erbB-2 (HER-2/neu) gene product p185.

Over-expression of the c-erbB-2 (HER-2/neu) gene product p185 occurs in 30% of breast and ovarian cancers. The p185 protein might serve as a target for serotherapy in that antibodies against different epitopes on the extracellular domain of p185 can inhibit growth of tumor cells in the absence of cellular or humoral effector mechanisms. To define epitopes of functional relevance, 11 monoclonal antibodies (MAbs) were evaluated for their ability to bind to the extracellular domain of p185. Results of competition studies with 125I-labeled and non-labeled antibodies indicated that 10 of 11 epitopes were grouped in a linear array. Antibodies against 7 epitopes inhibited anchorage-independent growth and antibodies against 2 of these epitopes also inhibited anchorage-dependent growth of SKBr3 breast-cancer cells that over-expressed p185. Treatment with antibodies exerted cytotoxic rather than cytostatic effects. When antibodies were used in combination, additive or supra-additive inhibition of anchorage-independent and anchorage-dependent growth was observed between pairs of antibodies. Growth inhibition did not relate to the affinity of the antibody or its isotype. Two antibodies that inhibited both anchorage-dependent and anchorage-independent growth also blocked binding of the HER-2/neu ligand, whereas 5 antibodies that inhibited only anchorage-independent growth had no effect on ligand binding. Inhibition of cell growth did not correlate with internalization of p185 or down-regulation of p185 on the cell surface. Fab fragments of active antibodies could also inhibit anchorage-independent growth of SKBr3. Thus, murine MAbs and their fragments recognized both immunochemically distinct and functionally distinct epitopes on the p185 molecule. Whereas inhibition of anchorage-dependent growth correlated with the ability of antibodies to block ligand binding, inhibition of anchorage-independent growth did not correlate with effects on ligand binding, internalization, cell-surface expression or cross-linking of p185.

The effect of antibodies and immunotoxins reactive with HER-2/neu on growth of ovarian and breast cancer cell lines.

OBJECTIVE: Because HER-2/neu is overexpressed in one third of breast and ovarian cancers, we examined the effect of unconjugated monoclonal antibodies (ID-5, PB-3, TA-1) and an immunotoxin (TA-1-ricin) reactive with this protooncogene on the growth of breast and ovarian cancer cell lines. STUDY DESIGN: The tritiated thymidine incorporation assay was used to examine the effect of unconjugated antibodies on proliferation. A limiting dilution clonogenic assay was used to assess the effect of immunotoxin on cellular cytotoxicity. RESULTS: Scatchard analysis revealed that OVCA 420, OVCA 429, OVCA 432, and OVCA 433 cells had approximately 10(4) HER-2/neu receptors per cell, whereas the SKOv3 and SKBr3 cell lines expressed 10(5) and 10(6) receptors per cell, respectively. Monoclonal antibody ID-5 caused significant inhibition of tritiated thymidine incorporation in SKBr3, SKOv3, and OVCA 420 cells (p < 0.002). The TA-1-rich immunotoxin significantly inhibited the clonogenic growth of only SKBr3 and SKOv3 cells. CONCLUSION: HER-2/neu may be a useful target for immunotherapy with unconjugated antibodies and immunotoxins in ovarian and breast cancers that overexpress this protooncogene.

Growth regulation and transformation of ovarian epithelium.

The discovery of peptide growth factors and cancer-causing genes (oncogenes and tumor-suppressor genes) has provided us with the exciting opportunity to begin to understand the molecular pathology of human ovarian cancer. Activation of several genes, including HER-2/neu, myc, ras, and p53 have been described in some ovarian cancers. In addition, some protooncogenes such as the epidermal growth factor receptor (erbB) and the M-CSF receptor (fms) are expressed along with the respective ligands (peptide growth factors) in some ovarian cancers. Although the studies reviewed in this paper represent a promising beginning, we remain far from a comprehensive understanding of growth regulation and transformation of human ovarian epithelium.

The effect of interferon gamma on epidermal growth factor receptor expression in normal and malignant ovarian epithelial cells.

OBJECTIVE: We examined the effect of interferon gamma on proliferation and epidermal growth factor receptor expression in ovarian cancer cell lines and normal ovarian epithelial cells. STUDY DESIGN: The tritiated thymidine incorporation assay was used to assess the effect of interferon gamma on proliferation. Scatchard analysis of anti-epidermal growth factor receptor antibody binding, and Western blotting of immunoprecipitates was used to assess the effect of interferon gamma on epidermal growth factor receptor expression. RESULTS: Although interferon gamma elicited 30% to 40% decreases in proliferation, epidermal growth factor receptor expression was strikingly increased in all four ovarian cancer cell lines. Scatchard analysis indicated that this increase occurred primarily at the cell surface, but total cellular receptor levels also were increased. In contrast, interferon gamma treatment of normal ovarian epithelial cells affected neither proliferation nor epidermal growth factor receptor levels. CONCLUSION: Because the up-regulation of epidermal growth factor receptors by interferon gamma appears to be confined to malignant cells, interferon gamma may facilitate immunotherapy and imaging of ovarian cancers by means of immunoconjugates directed against the epidermal growth factor receptor.

Regulation of growth of normal ovarian epithelial cells and ovarian cancer cell lines by transforming growth factor-beta.

OBJECTIVE: The purpose of this study was to study the role of transforming growth factor-beta in regulation of proliferation of normal and malignant ovarian epithelial cells. STUDY DESIGN: We examined production of and responsiveness to transforming growth factor-beta in primary monolayer cultures of epithelial cells from five normal human ovaries and in five ovarian cancer cell lines. RESULTS: In normal ovarian epithelial cells, proliferation always was inhibited by transforming growth factor-beta (greater than 40%) (p less than 0.01). Among the cancer cell lines, proliferation of one was markedly inhibited (greater than 95%) (p less than 0.01), two were only modestly inhibited (15% to 20%) (p less than 0.05), and two were unaffected. In addition, we found that all of the normal ovarian epithelial cells and four of five ovarian cancer cell lines produce transforming growth factor-beta ribonucleic acid and protein. CONCLUSIONS: These data suggest that transforming growth factor-beta may act as an autocrine growth inhibitory factor for normal ovarian epithelium in vivo. Because most of the ovarian cancer cell lines are relatively resistant to the growth inhibitory effect of transforming growth factor-beta and because one cell line does not produce transforming growth factor-beta, it is possible that loss of the transforming growth factor-beta pathway may play a role in the development of some ovarian cancers.