Serum CA125 Concentrations Research Articles

Screening for ovarian cancer is not effective

A strategy for early detection of ovarian cancer in Japan has shown that screening for ovarian cancer by use of ultrasonography and serum concentrations of CA-125 does not improve detection of early-stage ovarian cancer. (Int J Gynecol Cancer, published online July 21, 2007; DOI:10.1111/j.1525-1438.2007.01035x).

Effect of renal function and hemodialysis on the serum tumor markers in patients with chronic kidney disease

In patients with chronic renal failure, whether they have had hemodialysis or not, the specificity of some of the serum tumor markers for the diagnosis of the corresponding tumors is decreased while others remain as valuable as they are in patients with normal kidney function. The detection of tumor markers is extensively used for the diagnosis of corresponding tumors. It has been recently shown that some tumor markers are higher in patients with chronic kidney disease (CKD) than in the normal population. The effects of renal function and hemodialysis were examined on serum levels of some of the tumor markers including CEA, CA199, CA125, AFP, CA153, CA724, CYFRA21-1, NSE, SCC-Ag, PSA, and fPSA. The 232 non-dialysis patients with CKD and 37 chronic uremic patients treated with maintenance hemodialysis were enrolled in this study. The 232 non-dialysis patients were divided into three groups according to their Ccr. In group 1, Ccr was [Symbol: see text] 25 mL/min. In group 2, Ccr was between 25 and 50 mL/min. In group 3, Ccr was [Symbol: see text] 50 mL/min. The male patients were also divided into three groups to compare the serum levels of PSA and fPSA among the three groups. Nine tumor markers in 37 uremic patients were tested. For comparison, 37 non-dialysis patients with similar Ccr of the same age and gender served as controls. There existed significant differences in serum levels of CEA, CA199, CYFRA21-1, NSE, and SCC-Ag among different Ccr groups and the markers bore a negative correlation with Ccr. There were no significant differences among the three groups in the serum concentrations of CA125, AFP, CA153, CA724, PSA and fPSA. The serum levels of CA125 and NSE were significantly higher (P < 0.01) in hemodialysis patients than in the nondialysis control patients. In patients with chronic renal failure, who were or were not on hemodialysis, the specificity of serum CEA, CA199, CYFRA21-1, NSE, CA125 and SCC-Ag for the diagnosis of the corresponding tumors was decreased while serum AFP, CA153, CA724, PSA and fPSA were as valuable as they were in patients with normal kidney function. Hemodialysis further increased the serum level of CA125 and NSE.

Metastatic colorectal adenocarcinoma involving the ovary with elevated serum CA125: A potential diagnostic pitfall

Elevated serum levels of CA125 are observed not only in association with primary ovarian epithelial neoplasms but also in a variety of other clinical settings, including ovarian involvement by metastatic disease. There is considerable overlap in gross and histologic features between primary ovarian tumors and metastatic colorectal adenocarcinoma, which can make diagnosis particularly challenging in the setting of an increased CA125 level. The aims of this study were to determine how frequently serum CA125 is elevated in women with ovarian involvement by metastatic colorectal adenocarcinoma and to compare the features of cases with and without associated elevations of serum CA125. Eighty-nine cases of histologically confirmed ovarian involvement by metastatic colorectal adenocarcinoma were identified by retrospective review. Clinicopathologic data were analyzed, including preoperative serum CA125 level (available in 42 cases). Features of cases with an associated increase in serum CA125 were compared with those of cases with no such elevation. Twenty-nine patients had an elevated serum CA125 level (>35 U/mL) preoperatively (range 39.0-556.3, median 143.0, mean 199.1). Thirteen patients had a serum CA125 level within the reference range, while forty-seven patients had no preoperative testing for serum CA125. Clinical, gross, and histologic features of cases with an associated increase in serum CA125 were generally similar to those of cases with a non-elevated serum CA125 concentration. In three cases, the tumor was initially diagnosed as an ovarian primary. At least 32.6% of women with ovarian involvement by metastatic colorectal adenocarcinoma have an elevated serum CA125 level prior to oophorectomy. Such cases do not differ significantly from cases lacking such an association with respect to a variety of clinicopathologic features. The possibility of metastasis from a colorectal carcinoma merits consideration in the formation of the differential diagnosis for a woman with an adnexal mass and elevated serum CA125, even in the absence of an established history of gastrointestinal malignancy.

Severe Ascites with Hypothyroidism and Elevated CA125 Concentration: A Case Report

Ascites caused by hypothyroidism is rare and the pathogenesis is unclear. Several reports have presented cases of progressive ascites with hypothyroidism and elevated tumor markers. We report a 31-year-old female case with massive ascites and elevated serum CA 125 concentrations. The patient had no typical feature of hypothyroidism except an accumulation of ascitic fluid which showed elevated total protein concentration and a high serum-ascites albumin gradient (SAAG). There was no finding of malignancy. Following thyroid hormone replacement, the ascites was completely resolved accompanied by reduced concentrations of serum CA125. In general, primary hypothyroidism with ascites presents with coexisting massive pericardial or pleural effusion. The massive ascites and increased serum CA125 concentrations may have led us to make the incorrect diagnosis of ovarian malignancy. The evaluation of thyroid function is useful to determine the pathology of high-protein ascites or elevated tumor markers, and ascites may be treatable by thyroid replacement therapy.

Evaluation of tumor markers CA-125 and CEA in acute myocardial infarction

Serum carbohydrate antigen (CA-125) and carcinoembryonic antigen (CEA) have always been of clinical importance in the diagnosis and follow-up of various tumors. This study was devised to investigate the relationship between these tumor markers and acute myocardial infarction (MI). Seventy consecutive cases (59 male patients with a diagnosis of acute ST segment elevation MI and 11 male patients with a diagnosis of non-ST segment elevation MI; mean age, 57+/-8.2 y) were admitted to the University Medical Center and were included in this study as "the patient group." All patients in the patient group underwent transthoracic echocardiographic examination on the third day of hospitalization. On the basis of echocardiographic findings, these 70 patients were grouped according to left ventricular ejection fraction (EF) values; EF <55% (group 1) (n=40) and EF >or=55% (group 2) (n=30). Other parameters, including systolic pulmonary artery pressure (sPAP) and mean pulmonary artery pressure (mPAP), were also measured on transthoracic echocardiography. Serial blood samples (for follow-up of myocardial enzymes (eg, creatine kinase MB [CKMB], troponin I [TnI], troponin T, and other routine parameters) were drawn from each patient. Serum concentrations of CEA and CA-125 measured at the 72nd hour of hospitalization and peak serum concentrations of CKMB and TnI in the patient group were collected for comparison between subgroups (groups 1 and 2) and with "the control group," which included 30 subjects (mean age, 54+/-7.6 y) with no history or evidence of overt cardiac disease and with normal echocardiographic findings. The presence of any condition characterized by potential elevations in CA-125, CEA, and myocardial enzymes (CKMB, TnI) was considered an exclusion criterion. Patients included in patient groups 1 and 2 differed significantly in terms of mean EF, mean sPAP, mean mPAP, and mean CA-125 values (P<.001 for CA-125; P<.05 for the other values). EF was found to be negatively correlated with sPAP (r=-0.692, P=.000) and mPAP (r=-0.393, P=.001). EF was also negatively correlated with CA-125 (r=-0.557, P=.000). A positive correlation was noted between CA-125 and sPAP (r=0.396, P=.001) and between CA-125 and mPAP (r=0.754, P=.000). A statistically significant difference was identified between the patient and control groups with regard to values for EF, PAP, CA-125, and myocardial enzymes (CKMB and TnI) (P<.05 for mPAP; P<.001 for the other values). The serum concentration of CA-125, but not of CEA, may be elevated in those with acute MI compared with normal subjects. Regardless of the presence of pulmonary hypertension, elevations in CA-125 during myocardial infarction were significantly correlated with the severity of left ventricular systolic dysfunction on transthoracic echocardiography.

Citation classics in Fertility and Sterility, 1975–2004

Citation classics in Fertility and Sterility, 1975–2004

Evaluation of factors that may be responsible for cyclic change of CA125 levels during menstrual cycle

To evaluate the factors responsible for fluctuation of CA125 levels during menstrual cycle The study was performed with patients who had undergone hysterectomy for benign gynecological disease (group I, n = 30) and patients who had undergone laparoscopy for tubal ligation (group II, n = 30) or for investigation of pelvic cause of infertility (group III, n = 24) and showed normal laparoscopic findings. In groups II and III, blood samplings for serum CA125 determination were performed in menstrual and no-menstrual period. In group I, sampling times were determined by using estrogen and progesterone levels. Mean serum CA125 concentrations were compared using one-way analysis of variance (ANOVA) for multiple group comparisons and paired t test for within-group comparisons. Intra-individual serum CA125 concentrations of group I was not significantly different (P > 0.05). In group II, mean menstrual CA125 concentration was on average 18.2% higher than that of non-menstrual concentration (P < 0.001). Group III showed a similar pattern to that of group II, with a difference of 22% (P < 0.001). Mean CA125 concentration of group I in both menstrual and non-menstrual period was lower than those of groups II and III (P < 0.001). However, there was no significant difference between groups II and III when compared with the corresponding menstrual and non-menstrual CA125 concentrations (P > 0.05). Endometrium is responsible for the cyclic changes in serum CA125 concentration during menstrual cycle.

Laparoscopic management of fallopian tube carcinoma with paraneoplastic cerebellar degeneration

An asymptomatic tumor of the fallopian tube with elevation of serum CA125 concentration was found in a 75-year-old woman during a search for primary malignancy that was causing paraneoplastic cerebellar degeneration with a positive anti-Yo antibody. Since there were no apparent metastatic lesions detected by image diagnostic procedures, a diagnosis of early fallopian tube carcinoma was made preoperatively. After confirmation of the presence of a left tubal tumor without apparent invasion to the adjacent organs and peritoneal metastasis, laparoscopic salpingo-oophorectomy was subsequently performed. The histopathological diagnosis was of moderately differentiated serous adenocarcinoma of the fallopian tube with marked plasma cell infiltration. After surgery, the CA125 value immediately decreased, and there was no evidence of tumor recurrence noted thereafter. The patient died 51 months after surgery due to progression of neurological symptoms.

Significance of early changes in the serum CA-125 antigen level on overall survival in advanced ovarian cancer

Objective. The relationship between survival and early changes in the serum level of the CA-125 antigen in patients with advanced ovarian cancer remains poorly defined. Methods. To explore this issue, the serum CA-125 values from 101 patients with advanced ovarian cancer who participated in a Southwest Oncology Group trial (SWOG 8412), which compared the systemic delivery of cisplatin/cyclophosphamide vs. carboplatin/cyclophosphamide (both delivered every 28 days for 6 cycles) in suboptimal residual stage III and IV ovarian cancer, were evaluated. All patients in this analysis had CA-125 values available for at least 8 weeks following initiation of chemotherapy. Cox proportional hazards regression was used in multivariate analysis to determine the prognostic significance of the CA-125 concentration. Results. While pretreatment CA-125 values did not correlate with survival, the concentration of this tumor marker 8 weeks after initiation of therapy was a powerful independent prognostic factor. The median survivals for patients ( n = 51) with a CA-125 < 35 U/ml, vs. patients ( n = 50) with a CA-125 > 35 U/ml, at this time point, were 26 months and 15 months, respectively ( P = 0.0001). Further, women with serum CA-125 values <50% of their pretreatment concentration at 8 weeks experienced a median survival of 21 months, compared to only 10 months for individuals with tumor marker levels >50% of their baseline value ( P = 0.0003). Conclusion. Reduction in the serum CA-125 concentration over the initial two cycles of platinum-based chemotherapy is a powerful independent predictor of survival for patients with suboptimal stage III or IV ovarian cancer. Patients without significant declines in CA-125 after two cycles of platinum-based chemotherapy have a particularly poor prognosis.

AC-039 The relationship between serum CA-125 concentrations and the likelihood of pregnancy after IVF–embryo transfer

AC-039 The relationship between serum CA-125 concentrations and the likelihood of pregnancy after IVF–embryo transfer

Use of CA125 fluctuation during the menstrual cycle as a tool in the clinical diagnosis of endometriosis; a preliminary report

Objective: To elucidate whether endometriosis can be diagnosed clinically by assessing the differences between serum CA125 levels during menstruation and during the rest of the menstrual cycle. Methods: The study was performed in 28 patients who underwent laparoscopy to check for pelvic causes of infertility. Patients with endometriosis were selected as the study group, and patients with normal laparoscopic findings functioned as the control group. Blood specimens were taken for CA125 determination during menstruation and during the rest of the menstrual cycle. Mean serum CA125 concentrations were compared by the two-sample t-test for between-group comparisons and the paired t-test for within-group comparisons. The receiver operating characteristic curve was applied to assess the usefulness of CA125 level changes during the menstrual cycle in the clinical diagnosis of endometriosis. Results: The mean CA125 concentrations of healthy women during menstruation and during the rest of the menstrual cycle were 12.2 and 10 U ml −1, respectively. In this group, the mean CA125 concentration was an average of 22% higher during menstruation than during the rest of the menstrual cycle ( P<0.001). The patients with endometriosis showed a similar pattern to that of normal women, but the levels differed by 198.3% in these patients ( P<0.001). Mean CA125 concentrations of these patients during menstruation and in the rest of the cycle were 35.8 and 12 U ml −1, respectively. The mean CA125 concentration during menstruation was significantly higher in patients with endometriosis than in normal women ( P<0.001), but CA125 concentrations at other points in the menstrual cycle were found to be similar in both groups ( P>0.05). ROC curve analyses set a cutoff of 83% (percentage increment of CA125 level during menstruation compared with that on days without menstrual bleeding), which gives a sensitivity of 93% and specificity of 92%, with a corresponding likelihood ratio of 11.3. Conclusions: It may be possible to diagnose endometriosis clinically by assessment of the differences in CA125 level during menstruation as against the remainder of the menstrual cycle.

Carbohydrate 19-9 Antigen Is Not a Marker of Liver Disease in Patients with Cystic Fibrosis

Serum concentration of carbohydrate 19-9 antigen (CA 19-9), a sensitive marker of pancreatic cancer and cholangiocarcinoma, increases in a variety of liver diseases due to higher production and release by bile duct cells. Biliary epithelial cells are primarily affected in liver disease associated with cystic fibrosis (CF), which develops in up to 30% of CF patients. Our aim was to evaluate the usefulness of serum CA 19-9 concentration as a test of liver involvement in CF. Serum concentration of CA 19-9, liver enzymes, bile acids, and total amylase was determined in 107 CF patients (49 with and 58 without liver disease) and 56 healthy subjects. Serum CA 19-9 concentration was significantly higher in CF patients (67 U/ml, 95% CI 53.5-80.5 U/ml) than in controls (11.8 U/ml, 95% CI 2.5-44 U/ml; p < 0.001) and in CF patients with liver disease (92.3 U/ml, 95% CI 75-109.5 U/ml) compared to CF patients without liver disease (46.6 U/ml, 95% CI 27.8-65.4 U/ml; p < 0.001). In CF patients, stepwise logistic regression analysis identified alanine aminotransferase, gamma-glutamyltranspeptidase, amylase, and CA 19-9 as the most useful predictors of liver disease (p < 0.0001). Receiver-operating characteristic (ROC) curve analysis revealed gamma-glutamyltranspeptidase and CA 19-9 as the best tests for identification of liver disease in CF patients; at a CA 19-9 cut-off arbitrarily fixed at 73 U/ml, positive and negative predictive value was 70% and 78%, respectively (sensitivity 57%, specificity 81%). To increase sensitivity to 94%, the cut-off had to be fixed at 31 U/ml, which corresponds to a specificity of only 36.2% (predictive value 33%). Our study indicates that measurement of the serum CA 19-9 concentration alone cannot be proposed as a reliable test of early hepatic involvement in CF.

Results of surgical treatment for intrahepatic cholangiocarcinoma and clinicopathological factors influencing survival.

The results of surgical treatment for intrahepatic cholangiocarcinoma (ICC) and specific factors influencing survival are still unclear. Between 1984 and 2001, 62 patients with ICC underwent laparotomy, with a 77 per cent (48 patients) resectability rate. The tumours in these 48 patients were reviewed retrospectively to examine the relationship between gross appearance (mass forming, periductal infiltrating, intraductal growth, and mass forming plus periductal infiltrating) and patient survival, as well as the manner of recurrence. In patients with mass-forming and mass-forming plus periductal infiltrating types, univariate and multivariate analyses of potential prognostic factors were performed. The 1-, 3- and 5-year survival rates were 62, 38 and 23 per cent respectively. All patients with the intraductal growth type remained alive after intervals ranging from 8 to 72 months. Univariate analysis showed multiple hepatic lesions, liver capsule invasion, presence of cancer cells in the resection margin, and high serum carbohydrate antigen (CA) 19-9 level to be significant negative prognostic factors. Lymph node involvement, however, was not identified as a significant prognostic factor. With multivariate analysis, multiple hepatic lesions and high serum CA19-9 concentration were found to be significantly related to prognosis. The most frequent recurrence site was the remnant liver. These results suggest that the intraductal growth type of tumour should be treated as a distinct entity compared with other types of ICC. Multiple tumours and high serum CA19-9 level were signs of dismal prognosis, whereas not all patients with lymph node involvement had a poor prognosis.

Predicting Response of Ovarian Cancer to Paclitaxel Treatment Based on Trend Analysis of Serum CA125

Recent randomized studies have reported significantly improved quality of life and survival in cancer patients who underwent tumor marker-directed treatment compared with patients treated according to Union Internationale Contre le Cancer (UICC) criteria [see Ref. (1) and references therein]. According to these studies, systematic analysis of tumor markers may document whether therapy is effective and should be continued in spite of its ultimate adverse toxic effects or whether it should be terminated because of ineffectiveness. The advantages of biochemical assessment are objectivity and reproducibility as well as the fact that tumor marker assays are subjected to longitudinal external and internal quality control. We aimed to determine whether changes in serum concentrations of the tumor marker CA125 evaluated by a newly developed algorithm predict response to chemotherapy in paclitaxel-treated ovarian cancer patients. Ovarian cancer patients with advanced disease (stage III at the time of diagnosis; n = 101; median age, 56 years; age range, 33–69 years) were enrolled in a prospective study monitoring changes in serum CA125 and the effect of therapy. Patients were treated with paclitaxel (Taxol; Bristol-Myers-Squibb) as part of a first-line combination chemotherapy. They received a median of six courses (range, three to nine) of chemotherapy. During a total of 689 chemotherapy cycles, serum CA125 concentrations were evaluated (AxSYM; Abbott Laboratories) and externally controlled through the CAPTMX tumor marker survey. Serum samples were obtained before starting therapy (specimen c ) and before each chemotherapy cycle (specimens c 1– c n). The univariate Cox regression model and the stepwise Cox regression model were used for selecting the optimal variables that most accurately predicted disease-free interval. The statistical package SAS, release 8.22 (SAS, Inc.), was used. The time-to-progression (TTP) in different patient groups was compared using Wilcoxon and log-rank tests. CA125 concentrations between groups of responders and nonresponders to …

Value of serum CA-125 concentrations as predictors of pregnancy in assisted reproduction cycles.

The means by which endometrial receptivity influences conception rates in assisted reproductive technology (ART) is poorly understood. As the glycoprotein CA-125 is a product of human endometrium and is measurable in the peripheral circulation, it was investigated whether it might serve as an indicator of endometrial receptivity and predictor of pregnancy. In this prospective study, serum CA-125 concentrations of 75 ART cycles were measured 1 day before and on the day of human chorionic gonadotrophin (HCG) administration, and on the day of oocyte retrieval. These women did not have endometriosis and were induced by long-protocol gonadotrophin-releasing hormone analogue. Pregnancy was achieved in 35 (46.7%) cycles, but not in 40 cycles (53.3%). Serum CA-125 concentrations 1 day before and on the day of HCG administration and on the day of oocyte retrieval were significantly higher in cycles with pregnancy than in those without pregnancy (P < 0.05). It was noted that CA-125 concentrations on the day of oocyte retrieval were the best predictors of pregnancy, with concentrations >10 IU/ml having an accuracy of 86.6% for pregnancy. In conclusion, in intracytoplasmic sperm injection cycles, women with high serum CA-125 concentrations (>10 IU/ml) on the day of oocyte retrieval had very high pregnancy rates.

Maternal Serum CA125 and CA15-3 Antigen Levels in Normal and Pathological Pregnancy

Objective: To evaluate the value of maternal serum CA125 and CA15-3 concentrations for discriminating pathological from normal pregnancies. Methods: Serum samples from 120 women, in whom pregnancy outcome was pathological, i.e. spontaneous abortion, fetal death, intrauterine growth retardation, chromosomal and structural abnormalities, and (pre)eclampsia, were assessed for CA125 and CA15-3 and compared with levels found in 350 women with a normal pregnancy outcome matched for age and duration of pregnancy. Results: Maternal CA125 serum values were significantly higher in the first and the third trimester of pregnancy (median 23.0 and 21.0 U/ml; p < 0.00001 and p < 0.001, respectively), compared to those in the second trimester (median 14.0 U/ml), but not significantly different from those obtained in pathological pregnancies. Maternal serum CA15-3 values were significantly higher during the third trimester (median 26.0 U/ml) compared to the first and second trimester of pregnancy (median 14.0 and 15.0 U/ml; p < 0.0001); CA15-3 serum levels in normal and pathological pregnancies showed no significant difference. Conclusion: Maternal serum levels of CA125 are higher during the first and third trimester of pregnancy. CA15-3 maternal serum levels are higher during the third trimester compared to the first and second trimester. Maternal CA125 and CA15-3 serum levels showed no relation with a pathological outcome of pregnancy.

Measurement of serum CA-125 concentrations does not improve the value of Chlamydia trachomatis antibody in predicting tubal pathology at laparoscopy.

Chlamydia antibody testing (CAT) has been used to predict tubal pathology associated with Chlamydia infection, the leading cause of pelvic inflammatory disease (PID). Tubal pathology not related to C. trachomatis is unlikely to be identified by CAT alone. A correlation between serum CA-125 concentrations and the severity of adnexal inflammation during acute PID was demonstrated. The objectives of this study were to determine the prevalence of C. trachomatis infection in an Asian infertile population and to assess the role of a combination of serum CA-125 and CAT in the prediction of tubal pathology as shown by laparoscopy. A total of 110 consecutive women attending an infertility clinic for work-up were recruited. Blood was taken for CAT and CA-125 on the day of hospital admission and an endocervical swab was taken for culture of C. trachomatis prior to laparoscopy. Two (1.8%) women had C. trachomatis found in the endocervix and 28 (25.5%) women had CAT of > or = 1:32. Serum CA-125 concentrations were > 35 IU/ml in 11 (10%) women. The discriminative capacity of CAT in the diagnosis of tubal pathology including both proximal and distal obstruction was not improved by measuring serum CA-125, regardless of the threshold values of serum CA-125 concentration.

Elevated Serum CA-125 Concentrations Due to Expression by a Diffuse Large B-Cell Lymphoma

The CA-125 antigen is expressed on a glyco­ protein produced by the cells derived from the coelomic epithelium and can be detected in the pleura, pericardium, peritoneum and the Mill­ lerian duct derivatives.' Serum CA-125 concen­ tration is elevated in the vast majority of patients with ovarian cancer and has proved to be a very useful tumour marker in these patients. How­ ever, serum CA-125 concentrations may also be elevated in a large number of other malignant diseases such as colorectal, breast, lung and pancreatic cancer. In addition, elevated serum CA-125 concentrations may be found in other conditions, including pleural effusions and ascites irrespective of the cause. In recent years elevated serum CA-125 has also been demonstrated in patients with non-Hodgkin's Iymphoma.v? In the cases reported, no immuno­ reactivity for CA-125 on the lymphoma cells could be demonstrated and it was proposed that the elevated CA-125 concentration was a reactive phenomenon.t-' However, it was shown recently that lymphoma cells might secrete CA-125 under specific conditions.! We report a case which provides further evidence that high serum CA-125 concentrations in patients with malignant lymphoma may be derived from the tumour cells.

Benign conditions associated with raised serum CA-125 concentration

A retrospective audit carried out in the Department of Clinical Biochemistry, covering a period of 42 months, showed 19 benign conditions, that gave rise to elevated serum CA-125 concentrations. These included six patients with non-malignant gynaecological disease, six patients with abdominal disorders, and seven patients with lung disease. These observations confirm that false-positive elevations can occur and that care must be taken before attributing an elevated serum CA-125 as an indicator of ovarian malignancy.

CA-125 levels are related to the likelihood of pregnancy after in vitro fertilization and embryo transfer.

To assess the relationship between serum cancer antigen (CA)-125 concentrations and the likelihood of pregnancy after in vitro fertilization/embryo transfer (IVF ET). A prospective longitudinal follow-up study was conducted in 44 IVF patients receiving luteinizing hormone-releasing hormone (LHRH) suppression, followed by human menopausal gonadotrophin (hMG). There were no indications of endometriosis. Progesterone or human chorionic gonadotrophin (hCG) were given as luteal support. Serum samples were taken just before oocyte pick-up (OPU), 14 days after ET and, after the establishment of a clinical pregnancy, on day ET + 21. Samples were stored at -80 degrees C until analysis. CA-125 was measured using a commercially available enzyme immunoassay (IMx CA-125; Abbott, North Chicago, IL, USA). The signed rank (paired samples) and Wilcoxon tests were used for statistical analysis. There were no differences in CA-125 concentrations at the time of OPU between pregnant (n = 18) and non-pregnant (n = 26) IVF patients. After OPU. the CA-125 concentrations rose both in pregnant (P<0.0001) and in non-pregnant (P <0.001) patients. This rise was greater after successful implantation, and 14 days after ET, higher CA-125 concentrations were found in the pregnant patients (P< 0.01). Differences in serum CA-125 concentrations between pregnant and non-pregnant IVF patients appear to be related to the likelihood of successful implantation.