Vincent R. Zurawski

A Radioimmunoassay Using a Monoclonal Antibody to Monitor the Course of Epithelial Ovarian Cancer

The murine monoclonal antibody OC 125 reacts with an antigen (CA 125) common to most nonmucinous epithelial ovarian carcinomas. An assay has been developed to detect CA 125 in serum. By this assay, only 1 per cent of 888 apparently healthy persons and 6 per cent of 143 patients with nonmalignant disease had serum CA 125 levels above 35 U per milliliter. In contrast, 83 of 101 patients (82 per cent) with surgically demonstrated ovarian carcinoma had elevated levels of antigen. In 38 patients with epithelial ovarian carcinoma monitored on 2 to 18 occasions during 2 to 60 months, antigen levels ranged from less than 1 to more than 8000 U per milliliter. Rising or falling levels of CA 125 correlated with progression or regression of disease in 42 of 45 instances (93 per cent). Determination of CA 125 levels may aid in monitoring the response to treatment in patients with epithelial ovarian cancer.

Comparison of circulating CA15-3 and carcinoembryonic antigen levels in patients with breast cancer.

An immunoradiometric assay (IRMA) has been used to determine circulating levels of the breast cancer-associated antigen, CA15-3. Of 1,050 normal control subjects, serum from 99 (9.4%) had CA15-3 antigen levels greater than 22 U/mL, while that from 58 (5.5%) and 14 (1.3%) had levels greater than 25 U/mL and 30 U/mL, respectively. In contrast, 115 of 158 patients (73%) with metastatic breast cancer had CA15-3 levels greater than 22 U/mL. Thirteen of 26 patients (50%) with only local metastases, 27 of 34 (79%) of those with only bone metastases, and 20 of 24 (83%) with hepatic metastases had CA15-3 levels greater than 22 U/mL. Furthermore, nine of 31 patients (29%) with primary breast cancer had CA15-3 levels greater than 22 U/mL. CA15-3 and carcinoembryonic antigen (CEA) levels were compared for the same patient population. Significantly more patients with metastatic breast cancer had elevated CA15-3 levels than had elevated CEA levels (P less than .001). Furthermore, the CA15-3 IRMA was more sensitive than the CEA assay in patients with only bone metastases, as well as those with only local metastases. Significantly more patients with primary carcinoma of the breast also had elevated CA15-3 than had elevated CEA levels (P less than .02). CA15-3 levels were greater than 22 U/mL in patients with nonmalignant conditions, including five of 25 patients (20%) with benign breast diseases, and 23 of 52 patients (44%) with benign liver diseases. Furthermore, CA15-3 levels were also greater than 22 U/mL in 24 of 54 patients (44%) with gastrointestinal (GI) malignancies, 12 of 17 patients (71%) with bronchogenic carcinoma, and 29 of 44 patients (66%) with epithelial ovarian carcinoma. Serial CA15-3 levels correlated with clinical disease course. Nineteen of 21 patients (91%) with tumor progression had at least a 25% increase in CA15-3 levels. Conversely, seven of nine patients (78%) with tumor regression had at least a 50% decrease in CA15-3 levels. Among 27 patients with stable disease, 16 (59%) had levels that did not vary by more than +/- 25% of the original CA15-3 levels. These results indicate that the CA15-3 antigen is a sensitive marker for the evaluation and monitoring of patients with breast cancer.

Preoperative evaluation of serum CA 125 levels in premenopausal and postmenopausal patients with pelvic masses. Discrimination of benign from malignant disease

CA 125 levels were measured in 158 patients with palpable pelvic masses who were about to undergo diagnostic laparotomy. When the 68 patients found to have cancer were compared with the 90 patients with benign disease, those with malignancies were significantly older, were more frequently postmenopausal, and had significantly higher values of serum CA 125. Patients with benign pelvic masses had CA 125 levels greater than 65 U/ml in 8% of cases, whereas those with malignancies had CA 125 levels greater than 65 U/ml in 75% of cases. If only those patients who had frankly malignant, primary, nonmucinous epithelial ovarian carcinomas were considered, CA 125 levels greater than 65 U/ml predicted malignancy with a sensitivity of 91% for all patients. Greater sensitivity and specificity were observed in the postmenopausal subgroup than in the premenopausal subgroup. In the postmenopausal group with a 63% prevalence of ovarian cancer the predictive positive value was 98% and the predictive value negative was 72%. In a premenopausal population with a 15% prevalence of ovarian cancer the predictive value for a positive test was 49%, while the predictive value for a negative test was 93%.

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.

Carcinoembryonic antigen (CEA) and carbohydrate determinant 19-9 (CA 19-9) localization in 121 primary and metastatic ovarian tumors: an immunohistochemical study with the use of monoclonal antibodies.

: An immunoperoxidase study, using the Avidin-Biotin-Peroxidase complex method and the monoclonal antibodies, anti-carcinoembryonic antigen (CEA) and anti-carbohydrate determinant 19-9 (CA 19-9), was carried out on 108 common epithelial tumors of the ovary and 13 epithelial tumors metastatic to the ovary. Primary mucinous tumors were positive in 62% of the cases (benign, 15%; borderline, 80%; and carcinomatous, 100%) with anti-CEA. None of the serous tumors were positive with anti-CEA, but 27% (benign, 23%; borderline, 40%; and carcinomatous, 20%) were positive with anti-CA 19-9. With anti-CEA, 30% of the endometrioid carcinomas, 50% of the malignant mesodermal mixed tumors, 14% of the clear cell carcinomas, 36% of the Brenner tumors, and 83% of the metastatic carcinomas from the large intestine were positive. With anti-CA 19-9, 76% of the mucinous, 40% of the endometrioid, 25% of the malignant mesodermal mixed tumors, 57% of the clear cell carcinomas, 45% of the Brenner tumors, and all the metastatic carcinomas from the large intestine were positive. All the undifferentiated carcinomas were unreactive with both antibodies. Although neither CEA nor CA 19-9 is a specific marker for any type of ovarian tumor or for malignancy per se, the presence of the former antigen can be useful in differentiating serous from mucinous tumors. Moreover, demonstration of either antigen in a variety of tumors may indicate its potential value as a serum marker in monitoring the course of the patient.

The CA 125 assay as a predictor of clinical recurrence in epithelial ovarian cancer

Abstract Serum CA 125 levels were obtained from 55 women with epithelial ovarian cancer before a second-look surgical procedure and serially thereafter. All patients were clinically and radiographically free of tumor at the time of the second-look operation and were followed to clinical recurrence. Median follow-up was 12 months. CA 125 levels obtained at the second-look operation had a sensitivity and specificity for predicting clinical recurrence of 94% and 88%, respectively. Patients with an elevated CA 125 level (≥35 U/ml) had a 60% chance of clinical recurrence within 4 months, while patients with levels

Comparison of IgE and IgG antibody-dependent cytotoxicity in vitro and in a SCID mouse xenograft model of ovarian carcinoma.

Allergic reactions are mediated by IgE antibodies bound to high‐affinity receptors on mast cells in peripheral tissues and are characterized by their immediacy and hypersensitivity. These properties could also be advantageous in immunotherapy against cancer growth in peripheral tissues. We have constructed chimeric IgE and IgG1 antibodies with murine V regions and human C regions corresponding to the MOv18 monoclonal antibody against the human ovarian tumor‐associated antigen, folate binding protein. The antibodies exhibited the expected binding affinities for antigen and Fc receptors, and effector activities with human basophils and platelets in vitro. The protective activities of MOv18‐IgE and MOv18‐IgG1 were compared in a SCID mouse xenograft model of ovarian carcinoma. The beneficial effects of MOv18‐IgE were greater and of longer duration than those of MOv18‐IgG1. Our results suggest that the allergic reaction could be harnessed for the suppression of ovarian tumors.

An initial analysis of preoperative serum CA 125 levels in patients with early stage ovarian carcinoma

Preoperative serum CA 125 levels were determined for 36 patients with Stage I and II ovarian carcinoma. Levels ranged from 9 to 1962 U/ml with a mean of 216 U/ml. In Stage I patients, CA 125 levels averaged 133 U/ml and in Stage II patients 382 U/ml. Nine of 24 Stage I (38%) and 9 of 12 Stage II patients (75%) had CA 125 levels in excess of 65 U/ml in a population somewhat overrepresented in mucinous tumors. Patients with non-mucinous neoplasms had CA 125 elevations more often--in 75% of the cases--than those with mucinous tumors. A larger study will be required to more precisely estimate the fraction of early stage patients with elevated preoperative serum CA 125 levels; however, this investigation demonstrates an assay sensitivity minimally adequate to initiate a pilot evaluation of serum CA 125 levels in a population at risk for ovarian carcinoma.

Prospective evaluation of serum CA 125 levels in a normal population, phase I: The specificities of single and serial determinations in testing for ovarian cancer

To determine the potential efficacy of the CA 125 assay as one component of a strategy for early detection of ovarian malignancy, serum CA 125 levels were determined in 1082 women 40 years of age or older in Stockholm. Initial serum CA 125 levels exceeded 35 U/ml in 36 women (3.3%) and 65 U/ml in 11 women (1.0%), placing the exact 95% upper confidence limits on false positive rates for a single screen at 4.3 and 1.7%, respectively. Follow-up CA 125 levels were obtained for those women with initially elevated levels and a group of age-matched controls. Mean CA 125 levels declined significantly for women with initially elevated levels (P = 0.0014). Interindividual variation and variation within individual subjects over the entire follow-up period were 52 and 35%, respectively. Of the 36 subjects with initially elevated serum CA 125 levels, only 2 showed a doubling of these levels; in only 1 of these 2 was this increase sustained. Intensive clinical follow-up with pelvic examination and ultrasonography, with investigators blinded to CA 125 results, led to the diagnosis of Stage III ovarian cancer in the latter individual. Diagnosis was made 21 months after the initially elevated serum CA 125 measurement and 15 months after the first measured doubling of that level. Because no other malignancies were identified at entry or during the follow-up period (median 560 days) in the women with elevated CA 125 levels, the specificity of the assay over that time period would have been 99.9% using the doubling of an initially elevated value as the criterion for determining positivity and 100% using as the criterion a sustained increase in level for those with initially elevated levels that doubled. These results support the continued investigation of longitudinally collected CA 125 levels to identify individuals at high risk for ovarian malignancy.

Elevation of serum CA 125 prior to diagnosis of an epithelial ovarian carcinoma

In a single fortuitous case it has been possible to measure serum levels of CA 125 during 3 years preceding the diagnosis of an epithelial ovarian carcinoma. CA 125 levels were elevated 10-12 months prior to clinical detection of the malignancy. CA 125 deserves further evaluation as a marker for early detection of ovarian cancer.