IL-15 superagonist N-803 improves IFNγ production and killing of leukemia and ovarian cancer cells by CD34+ progenitor-derived NK cells

Allogeneic natural killer (NK) cell transfer is a potential immunotherapy to eliminate and control cancer. A promising source are CD34 + hematopoietic progenitor cells (HPCs), since large numbers of cytotoxic NK cells can be generated. Effective boosting of NK cell function can be achieved by interleukin (IL)-15. However, its in vivo half-life is short and potent trans-presentation by IL-15 receptor α (IL-15Rα) is absent. Therefore, ImmunityBio developed IL-15 superagonist N-803, which combines IL-15 with an activating mutation, an IL-15Rα sushi domain for trans-presentation, and IgG1-Fc for increased half-life. Here, we investigated whether and how N-803 improves HPC-NK cell functionality in leukemia and ovarian cancer (OC) models in vitro and in vivo in OC-bearing immunodeficient mice. We used flow cytometry-based assays, enzyme-linked immunosorbent assay, microscopy-based serial killing assays, and bioluminescence imaging, for in vitro and in vivo experiments. N-803 increased HPC-NK cell proliferation and interferon (IFN)γ production. On leukemia cells, co-culture with HPC-NK cells and N-803 increased ICAM-1 expression. Furthermore, N-803 improved HPC-NK cell-mediated (serial) leukemia killing. Treating OC spheroids with HPC-NK cells and N-803 increased IFNγ-induced CXCL10 secretion, and target killing after prolonged exposure. In immunodeficient mice bearing human OC, N-803 supported HPC-NK cell persistence in combination with total human immunoglobulins to prevent Fc-mediated HPC-NK cell depletion. Moreover, this combination treatment decreased tumor growth. In conclusion,  N-803 is a promising IL-15-based compound that boosts HPC-NK cell expansion and functionality in vitro and in vivo. Adding N-803 to HPC-NK cell therapy could improve cancer immunotherapy.

Rare vulvar malignancies; incidence, treatment and survival in the Netherlands

OBJECTIVE

To describe trends in incidence, treatment and survival of patients with basal cell carcinomas and melanomas of the vulva. Also to compare survival of vulvar and cutaneous melanoma patients.

METHODS

All women with a vulvar malignancy between 1989 and 2012 were selected from the Dutch Cancer Registry (n=6436). Standardized incidence rates, estimated annual percentage change (EAPC) and 5-year relative survival rates were calculated for basal cell carcinomas (BCCs) and melanomas. Patients with vulvar melanomas were matched to women with cutaneous melanomas on period of diagnosis, age, Breslow thickness, tumour ulceration, lymph node status and distant metastases. Differences in survival were evaluated using Kaplan-Meier curves and the log rank test.

RESULTS

489 women were diagnosed with a BCC and 350 with a melanoma of the vulva. The EAPC in incidence for melanomas was 0.2% and 1.1% for BCCs. Eighty-six percent of patients with BCC underwent surgical treatment in 1989-2006 and 95% in 2005-2012. Forty-five percent with BCC and 79% with melanoma were treated in a referral centre. Five-year relative survival for BCCs was 100% and for melanomas survival increased from 37% (95%CI 28-47%) in 1989-1999 to 45% (95%CI: 37-54%) in 2000-2012. Five years after diagnosis survival of women with vulvar melanoma was 15% lower compared to matched cutaneous melanoma patients (p=0.002).

CONCLUSION

No trends in age-adjusted incidence have been observed but more patients with BCC received surgical treatment over time. Having had vulvar BCC did not affect life expectancy. Well-known prognostic factors explained most of the differences in survival between cutaneous and vulvar melanoma patients, however a difference of 15% remained unexplained.

Improved outcomes due to changes in organization of care for patients with ovarian cancer in the Netherlands

OBJECTIVES

Objectives of this study were to evaluate the effect of changes in patterns of care, for example centralization and treatment sequence, on surgical outcome and survival in patients with epithelial ovarian cancer (EOC).

METHODS

Patients diagnosed with FIGO stage IIB-IV EOC (2004-2013) were selected from the Netherlands Cancer Registry. Primary outcomes were surgical outcome (extent of macroscopic residual tumor after surgery) and overall survival. Changes in treatment sequence (primary debulking surgery and adjuvant chemotherapy (PDS+ACT) or neo-adjuvant chemotherapy and interval debulking surgery (NACT+IDS)), hospital type and annual hospital volume were also evaluated.

RESULTS

Patient and tumor characteristics of 7987 patients were retrieved. Most patients were diagnosed with stage III-IV EOC. The average annual case-load per hospital increased from 8 to 28. More patients received an optimal cytoreduction (tumor residue≤1cm) in 2013 (87%) compared to 2004 (55%, p<0.001). Complete cytoreduction (no macroscopic residual tumor), registered since 2010, increased from 42% to 52% (2010 and 2013, respectively, p<0.001). Optimal/complete cytoreduction was achieved in 85% in high volume (≥20 cytoreductive surgeries annually), 80% in medium (10-19 surgeries) and 71% in small hospitals (<10 surgeries, p<0.001). Within a selection of patients with advanced stage disease that underwent surgery the proportion of patients undergoing NACT+IDS increased from 28% (2004) to 71% (2013). Between 2004 and 2013 a 3% annual reduction in risk of death was observed (HR 0.97, p<0.001).

CONCLUSION

Changes in pattern of care for patients with EOC in the Netherlands have led to improvement in surgical outcome and survival.

Epigenetic analysis leads to identification of HNF1B as a subtype-specific susceptibility gene for ovarian cancer

HNF1B is overexpressed in clear cell epithelial ovarian cancer, and we observed epigenetic silencing in serous epithelial ovarian cancer, leading us to hypothesize that variation in this gene differentially associates with epithelial ovarian cancer risk according to histological subtype. Here we comprehensively map variation in HNF1B with respect to epithelial ovarian cancer risk and analyse DNA methylation and expression profiles across histological subtypes. Different single-nucleotide polymorphisms associate with invasive serous (rs7405776 odds ratio (OR)=1.13, P=3.1 × 10(-10)) and clear cell (rs11651755 OR=0.77, P=1.6 × 10(-8)) epithelial ovarian cancer. Risk alleles for the serous subtype associate with higher HNF1B-promoter methylation in these tumours. Unmethylated, expressed HNF1B, primarily present in clear cell tumours, coincides with a CpG island methylator phenotype affecting numerous other promoters throughout the genome. Different variants in HNF1B associate with risk of serous and clear cell epithelial ovarian cancer; DNA methylation and expression patterns are also notably distinct between these subtypes. These findings underscore distinct mechanisms driving different epithelial ovarian cancer histological subtypes.

External validation of serum hCG cutoff levels for prediction of resistance to single-agent chemotherapy in patients with persistent trophoblastic disease

Van Trommel et al have previously shown that serum human chorionic gonadotropin (hCG) cutoff levels can provide early prediction of resistance to first-line methotrexate (MTX) in patients with persistent trophoblastic disease (PTD). In this study, we validate this approach of prediction of resistance to single-agent chemotherapy in an independent and larger cohort of PTD patients using a different hCG assay. Receiver operating characteristics (ROC) curves were constructed to determine hCG cutoff levels and sensitivity between patients cured on single-agent chemotherapy (control group) and patients requiring change to combination chemotherapy (study group). Receiver operating characteristics analysis identified an hCG cutoff value of 737 IU l⁻¹ that enabled us to predict the subsequent development of single-agent chemotherapy resistance in 52% of patients before their fourth MTX course at 97.5% specificity. This would have enabled an earlier switch to combination chemotherapy reducing the MTX exposure by an average of 2.5 courses. The present findings confirm that serum hCG cutoff levels predict resistance to single-agent therapy earlier than traditional methods. Change to combination chemotherapy should be considered for patients whose serum hCG levels exceed these hCG cutoff values. For patients not exceeding the hCG cutoff levels, static or rising hCG levels should still be included in the criteria for change of chemotherapy.

No efficacy of annual gynaecological screening in BRCA1/2 mutation carriers; an observational follow-up study

BRCA1/2 mutation carriers are offered gynaecological screening with the intention to reduce mortality by detecting ovarian cancer at an early stage. We examined compliance and efficacy of gynaecological screening in BRCA1/2 mutation carriers. In this multicentre, observational, follow-up study we examined medical record data of a consecutive series of 888 BRCA1/2 mutation carriers who started annual screening with transvaginal ultrasonography and serum CA125 between 1993 and 2005. The women were annually screened for 75% of their total period of follow-up. Compliance decreased with longer follow-up. Five of the 10 incident cancers were interval tumours, diagnosed in women with a normal screening result within 3–10 months before diagnosis. No difference in stage distribution between incident screen-detected and interval tumours was found. Eight of the 10 incident cancers were stage III/IV (80%). Cancers diagnosed in unscreened family members had a similar stage distribution (77% in stage III/IV). The observed number of cases detected during screening was not significantly higher than expected (Standardized Incidence Ratio (SIR): 1.5, 95% confidence interval: 0.7–2.8). For the subgroup that was fully compliant to annual screening, a similar SIR was found (1.6, 95% confidence interval: 0.5–3.6). Despite annual gynaecological screening, a high proportion of ovarian cancers in BRCA1/2 carriers are interval cancers and the large majority of all cancers are diagnosed in advanced stages. Therefore, it is unlikely that annual screening will reduce mortality from ovarian cancer in BRCA1/2 mutation carriers.

Normal appearing endometrial cells in cervical smears of asymptomatic postmenopausal women have predictive value for significant endometrial pathology

The objective of this study was to determine whether postmenopausal asymptomatic women with normal endometrial cells in their smear are at higher risk for endometrial pathology compared with women without these cells. Histologic follow-up outcome and otherwise cytologic follow-up of 29,144 asymptomatic postmenopausal women was determined. Presence of normal endometrial cells, age, use of hormones, and reported elevated maturation index were assessed. The effect of each variable on outcome as well as the combined effect were evaluated. Prevalence rate of (pre)malignant uterine disease was significantly higher when normal endometrial cells were found in the cervical smear (6.5%) as compared to smears without these cells (0.2%), resulting in a relative risk of 40.2 (95% CI 9.4-172.2). Neither age nor hormone use or elevated maturation index showed significant impact on the outcome. Asymptomatic postmenopausal women with normal endometrial cells in their smear are at significant higher risk for (pre)cancerous endometrial lesion than women without these cells. These cases should be reported to the physician with an explicit comment that normal endometrial cells in a smear of a postmenopausal woman is an abnormal finding, possibly associated with significant endometrial pathology. It raises the question whether further gynecological examination would be more appropriate.

Surveillance of women at high risk for hereditary ovarian cancer is inefficient

To determine the effectiveness of annual gynaecological screening (pelvic examination, transvaginal ultrasound, and CA-125), a prospective cohort study of women at high risk for hereditary ovarian cancer was conducted. Women were offered DNA analysis followed by either annual screening or prophylactic bilateral salpingo-oophorectomy (BSO). Study population consisted of 512 high-risk women (median follow-up 2.07 years, range 0–9.4 years): 265 women (52%) had a BRCA mutation. Persisting abnormalities indicated diagnostic surgery in 24 women resulting in one primary ovarian cancer FIGO stage IIIc was found. The effectiveness of screening was studied by calculating the probability of finding ovarian cancers in the BRCA-1 and BRCA-2 carrier group and comparing this to the identified number of ovarian cancers. The number of ovarian cancer patients found at surveillance was in accordance with the predicted number of ovarian cancers. A total number of 169 women underwent prophylactic BSO: one ovarian cancer stage IIb was found. In conclusion, the surveillance programme for hereditary ovarian cancer does identify patients with ovarian cancer but is very inefficient considering the high number of surveillance visits and the advanced stage of ovarian cancer in the identified patient. For prevention of advanced stage ovarian cancer, prophylactic BSO from age 35–40 years is a more efficient alternative.

Intraperitoneal radioimmunotherapy in an ovarian carcinoma mouse model: Effect of the radionuclide

Despite debulking surgery and multidrug chemotherapy, advanced stage ovarian cancer has a high mortality rate. Radioimmunotherapy (RIT) is a treatment modality using specific, radiolabeled antibodies that guide cytotoxic radionuclides to cancer cells. In the present study, the therapeutic efficacy of RIT with murine monoclonal antibody HMFG1 labeled with three different beta-radiation emitting radionuclides (90Yttrium, 186Rhenium, and 131Iodine) was assessed in athymic BALB/c mice with intraperitoneally growing NIH:OVCAR-3 ovarian carcinoma xenografts. Each of the three intraperitoneally administered radiolabeled antibody preparations (90Y-HMFG1, 186Re-HMFG1, and 131I-HMFG1) caused a significant delay in ascites formation and mortality as compared to the control groups treated with 90Y-labeled irrelevant antibody, nonradiolabeled HMFG1, or phosphate buffered saline. Intraperitoneally (ip) administered 90Y-HMFG1 was shown to have a significantly higher abdominal retention as compared to the intraperitoneally administered irrelevant antibody 90Y-G250. Furthermore, intraperitoneally administered 90Y-HMFG1 more effectively inhibited tumor growth than intravenously administered 90Y-HMFG1. It was concluded that in intraperitoneally located malignant disease with ascitic cell clusters and tumor deposits, intraperitoneal administration of RIT seemed preferable as compared to intravenous administration. The choice of the most optimal radionuclide in intraperitoneally located malignancies needs further research, but could well depend on tumor characteristics such as the size of the tumor lesions.

High prevalence of premalignant lesions in prophylactically removed breasts from women at hereditary risk for breast cancer

PURPOSE

Women with a hereditary predisposition for breast cancer have an extremely high risk of developing invasive breast carcinoma, and many women consider prophylactic mastectomy to avoid this risk. The use of prophylactic mastectomy is still debated. Identification of frequent premalignant lesions in mastectomy specimens would support the preventive concept of prophylactic mastectomy.

PATIENTS AND METHODS

We performed a prospective study of breast specimens from 67 women at extremely high genetic risk of breast cancer, with or without previous breast cancer, who were undergoing prophylactic mastectomy (66% were carriers of a BRCA1 or BRCA2 mutation). Breast specimens were studied by radiographic and macroscopic examination of 5-mm tissue slices, with subsequent histology of suspicious lesions and random samples from each quadrant of the breast and the nipple area.

RESULTS

In 57% of the women, one or more different types of high-risk histopathologic lesions were present: 37% atypical lobular hyperplasia, 39% atypical ductal hyperplasia, 25% lobular carcinoma-in-situ, and 15% ductal carcinoma-in-situ. A 4-mm invasive ductal carcinoma was found in one woman with ductal carcinoma-in-situ. None of these lesions was detected at palpation or mammography, which were performed before the mastectomy. The presence of high-risk lesions was independently related to age older than 40 years (odds ratio, 6.6; P =.01) and to bilateral oophorectomy before prophylactic mastectomy (odds ratio, 0.2; P = 0.02).

CONCLUSION

Many women at high risk of hereditary breast cancer develop high-risk histopathologic lesions, especially after the age of 40 years. Surveillance does not detect such high-risk histopathologic lesions.

Glutathione S-transferases P1-1 and A1-1 in ovarian cyst fluids

PURPOSE

The purpose of the present study was to determine the gluthathione S-transferases (GST) P1-1 and A1-1 levels in cyst fluid from malignant, borderline, and benign ovarian tumors. The clinical relevance of these enzymes in cyst fluid was investigated, including the possible relation with resistance to chemotherapy.

METHODS

A total of 90 ovarian cysts were punctured for cyst fluid collection. GSTP1-1 and GSTA1-1 concentrations were determined by ELISA in cyst fluid from 23 malignant, 9 borderline, and 51 benign primary ovarian tumors, and levels were correlated with histopathological data.

RESULTS

Significantly higher GSTP1-I concentrations were found in cyst fluid from malignant (median: 477 ng/ml), compared with benign (median: 52 ng/ml) ovarian cysts (p < 0.0001), as well as in fluid from borderline (median: 366 ng/ml) compared with benign cysts (p < 0.0001). No significant differences were found in cyst fluid GSTA1-1 concentrations between the histologic subgroups. In cyst fluid from malignant tumors higher GSTPI-1 and lower GSTAI-1 concentrations were found in patients with worse prognostic factors: FIGO II-III-IV, grade 2-3, residual tumor > 2 cm, presence of ascites, patients with recurrent disease, and survival, but differences were not significant. In the subgroup of patients that received cisplatin-based chemotherapy (n = 14) significantly higher GSTP1-1 (p = 0.01) concentrations were found in patients with recurrence compared with patients without recurrence. Considering only FIGO stage I patients, a differentiation could be made between patients with or without recurrence based on cyst fluid GSTP I - I concentrations.

CONCLUSIONS

Determination of glutathione S-transferases P 1-1 in cyst fluid samples from ovarian tumors can be of additiona] value in the differentiation between histologic subgroups. In case of possible low malignant potential cysts where sampling of the most representative tissue can be an issue, determination of GSTP- I concentrations in cyst fluid may optimise histopathologic classification. Cyst fluid GSTP1-1 seems to be a good marker for aggressiveness of the ovarian tumor, and it may predict response to chemotherapy.

Post-radiotherapy contrast enhancement changes in fast dynamic MRI of cervical carcinoma

This pilot study determines fast dynamic gadolinium enhanced MRI contrast enhancement parameters (onset of enhancement and time to peak enhancement) before and after radiotherapy in 10 cervical carcinoma patients. Before radiotherapy, onset of enhancement and time to peak enhancement were early, with a median of 4.5 and 5.2 seconds, respectively. High-grade tumors showed early enhancement, compared with low-grade. After radiotherapy, contrast enhancement patterns differed. In survivors, onset of enhancement after radiotherapy was later than before radiotherapy. In non-survivors, onset of enhancement after radiotherapy was still early. The median difference in onset of enhancement before and after radiotherapy in survivors and non-survivors was an increase of 3.2 and a decrease of 1.1 seconds, respectively. Early onset of enhancement after radiotherapy was a better predictor for survival than a high-signal intensity zone on post radiotherapy unenhanced T1/T2-weighted MRI. It is concluded that enhancement parameters from fast dynamic Gd-enhanced MR images can provide additional functional information with regard to tumor vascularization, and may have prognostic significance. It complements clinical examination and unenhanced MRI in determining the effectiveness of radiotherapy treatment in cervical carcinoma. Future studies will focus on the clinical utility and improvements of the estimation of contrast-enhanced parameters with this new technique.

Vascular endothelial growth factor in ovarian cyst fluid

BACKGROUND

The purpose of the current study was to determine vascular endothelial growth factor (VEGF) concentrations in cyst fluid from malignant, borderline, and benign ovarian tumors, and to correlate these data with preoperative serum VEGF concentrations and clinicopathologic characteristics.

METHODS

One hundred seven ovarian cysts were removed and punctured for cyst fluid collection. Histologic diagnosis revealed 25 malignant, 12 borderline, and 70 benign ovarian tumors. The VEGF concentrations of all the cyst fluid specimens as well as in 37 preoperatively collected serum samples were determined by making use of a sandwich type double determinant enzyme linked immunoadsorbent assay based on a combination of 4 polyclonal antibodies.

RESULTS

Statistically significantly higher VEGF concentrations were found in cyst fluid from malignant (median, 21.5 microg/L) compared with borderline (median, 3.2 microg/L; P = 0.01) or benign tumors (median, 1.3 microg/L; P < 0.0001). Preoperative serum VEGF concentrations were significantly higher in patients with malignant (median, 0.63 microg/L; range, 0.016-17.7 microg/L) compared with nonmalignant tumors (median, 0.28 microg/L; range, 0.016-0.89 microg/L; P = 0.008). A significant correlation of preoperative serum VEGF was found with VEGF cyst fluid concentrations (r = 0.38; P = 0.02). Significantly higher VEGF cyst fluid concentrations were found in serous malignant (median, 31.9 microg/L) compared with mucinous malignant tumors (median, 4.7 microg/L; P = 0.004). Not significant, though higher median VEGF cyst fluid concentrations were found in advanced International Federation of Gynecology and Obstetrics (FIGO) Stage II, III, and IV, histologic Grade 2 and 3, patients with residual tumor greater than 2 cm, with malignant cells in ascites or peritoneal washings, or with recurrent disease, as compared with FIGO Stage I, histologic grade 1, patients with less than or equal to 2-cm residual tumor, without malignant cells in ascites/peritoneal washings, or without recurrent disease, respectively.

CONCLUSIONS

It has become clear from the increased study sample that ovarian tumors of different histologic etiology vary in VEGF cyst fluid concentrations, with the highest VEGF cyst fluid concentrations in malignant tumors. The prognostic significance of VEGF cyst fluid concentrations in advanced FIGO stage seems to be of limited value but may be important in the selection of high risk FIGO Stage I and borderline types. Data from this study indicate a possible role for VEGF as a serum tumor marker.

High-resolution proton nuclear magnetic resonance spectroscopy of ovarian cyst fluid

Most ovarian tumors are cystic structures containing variable amounts of fluid. Several studies of ovarian cyst fluid focus on one specific metabolite using conventional assay systems. We examined the potential of (1)H-nuclear magnetic resonance spectroscopy in evaluation of the overall metabolic composition of cyst fluid from different ovarian tumors. Ovarian cyst fluid samples obtained from 40 patients with a primary ovarian tumor (12 malignant and 28 benign) were examined. After deproteinization and pD standardization, we performed (1)H-NMR spectroscopy on a 600 MHz instrument. With (1)H-NMR spectroscopy we found detectable concentrations of 36 metabolites with high intersample variation. A number of unassigned resonances as well as unexpected metabolites were found. We introduce an overall inventory of the low-molecular-weight metabolites in ovarian cyst fluid with corresponding resonances. Significant differences in concentration (p < 0.01) were found for several metabolites (including an unknown metabolite) between malignant and benign ovarian cysts. Furthermore, higher concentrations in malignant- and lower in benign fluids were found compared to normal serum values, indicating local cyst wall metabolic processes in case of malignant transformation. We conclude that (1)H-nuclear magnetic resonance spectroscopy can give an overview of low-molecular-weight proton-containing metabolities present in ovarian cyst fluid samples. The metabolic composition of cyst fluid differs significantly between benign and malignant ovarian tumors. Furthermore, differences between benign subgroups possibly related to histopathological behaviour can be detected. The presence of N-acetyl aspartic acid and 5-oxoproline exclusively in serous cystadenoma samples is remarkable. Future studies will concentrate on these findings and explore the possibilities of extrapolating information from the in vitro studies to in vivo practice, in which metabolic differences between malignant and benign subtypes can be of great importance in a pre-operative phase.

The role of MR imaging in invasive cervical carcinoma

In this article the role of MR imaging in the management of cervical cancer is reviewed and illustrated. The appearance of the normal uterine cervix and of cervical carcinoma is shown. Important factors for optimal MR imaging of cervical carcinoma are reviewed. The value of MR imaging in the staging of cervical carcinoma is illustrated by showing parametrial invasion and lymph node involvement. Finally, the value of MR imaging staging is compared with clinical staging, CT staging, and surgical findings. The role of new imaging techniques, such as fast dynamic enhanced MR imaging, is described.

Cytologic examination to detect clear cell adenocarcinoma of the vagina or cervix

OBJECTIVE

The aim of this study was to determine the sensitivity of cytopathologic examination for the detection of vaginal or cervical clear cell adenocarcinoma (CCA).

METHODS

Systematic collection in the Dutch automated nationwide pathology archive of all cytology and histology data of women with CCA, born in The Netherlands after 1947 was performed. All cytologic examinations within 2 years prior to histological diagnosis of CCA were included.

RESULTS

Ninety patients with CCA have been registered. Forty-nine of these patients had cytologic examinations prior to histology. Eighty-five percent of cervical CCAs were preceded by a positive cervical smear. One hundred percent of vaginal CCAs were preceded by a positive vaginal smear. Cervical smears are relatively insensitive to detect vaginal CCA. Vaginal smears were often omitted. Only 2 apparently false-negative smears were found. The mean numbers of smears in diethylstilbestrol (DES)-exposed and nonexposed women were minimally different: 1.0 and 0.8, respectively. This suggests an only modest impact of the awareness of DES as a risk factor. FIGO tumor stage I was preceded more frequently by cytology than the higher tumor stages.

CONCLUSION

The majority of CCA cases can be detected at an early stage by yearly clinical and cytological examinations, which must comprise cervical as well as vaginal sampling. Since CCA may also occur in postmenopausal women, for the purpose of secondary prevention of CCA regular cytologic examinations of DES-exposed women must be continued after menopause.

Leiomyomatosis peritonealis disseminata: does malignant transformation occur? A literature review

Leiomyomatosis peritonealis disseminata (LPD) is a rare smooth muscle tumor. In the literature more than 100 cases have been described. LPD is characterized by multiple small nodules on the peritoneal surface, mimicking a malignant process with metastases, but generally demonstrates benign histologic features. Exposure to estrogen seems to play an etiologic role. Many patients have uterine leiomyomas as well. The diagnosis of LPD is easily made on biopsy. Reduction of estrogen exposure is generally sufficient to cause regression of LPD. Surgical castration or gonadotrophin releasing hormone agonists seem good alternatives in the case of progression or recurrence of LPD. In six patients a malignant leiomyosarcoma has been described shortly after the diagnosis of LPD was made. Five of these patients did not have uterine leiomyomas or exposure to exogenous or increased endogenous estrogen. The relationship with pregnancy in the sixth patient may be coincidental. Whether malignant transformation of LPD occurs remains uncertain. Characteristics of these patients differ from those of LPD patients and may indicate a high malignant potential, necessitating a different approach.

An illustration of the clinical relevance of detecting human antimouse antibody interference by affinity chromatography

Elevated Cancer antigen 125 (CA 125) serum concentrations (up to 221 kU/1) were measured in a 39 year old woman with a positive family history of breast cancer. The serum determinations were performed with the automated Immulite OM-MA chemiluminescent enzyme immunoassay system (Diagnostic Products). Laparoscopic evaluation of the ovaries did not reveal any abnormalities. CA 125 measurements in the same patient using the automated IMx immunoassay system (Abbott) demonstrated normal serum levels. Using a previously reported chromatography procedure IgG type human antimouse antibody activity was found to be present in the serum samples explaining the falsely elevated levels. To prevent this interference the manufacturer modified the assay system by replacing the monoclonal M11 detection antibody with a rabbit polyclonal antibody. Using the modified OM-MA CA 125 assay results were comparable with the IMx values.

Uterine malignant leiomyoblastoma (epithelioid leiomyosarcoma) during pregnancy

A case of uterine malignant leiomyoblastoma (UML) which was initially mistaken for uterine leiomyoma on two different occasions is presented. About 20 cases of uterine leiomyoblastoma taking a malignant course have been described in the literature. This case of UML is the first diagnosed during pregnancy. In retrospect, tumor tissue removed from the uterus 4 years earlier already showed histological signs of UML. The large and metastatic tumor showed nuclear atypia, a moderate mitotic index, and tumor cell necrosis, indicating malignancy. Treatment consisted of hysterectomy, bilateral salpingo-oophorectomy, and debulking of most other tumor masses. In the literature, radio- and chemotherapy have not proved to be effective in these tumors. Hormonal therapy has only been used in 2 patients. In this patient, hormonal influence on tumor growth may be substantial. The tumor was progesterone- and estrogen-receptor positive and increased in size rapidly during pregnancy. Since little is known about these tumors further studies are necessary to evaluate hormonal influences both as a causative factor and as a therapeutic possibility.

Dosimetric analysis of chimeric monoclonal antibody cMOv18 IgG in ovarian carcinoma patients after intraperitoneal and intravenous administration

In this study the potential of intraperitoneal (i.p.) and intravenous (i.v.) administration of chimeric iodine-131-labelled MOv18 IgG for radioimmunotherapy was determined. The dosimetry associated with both routes of administration of cMOv18 IgG was studied in patients. Eight patients suspected of having ovarian carcinoma received 150 MBq 131I-cMOv18 IgG i.p. Blood and urine were collected and serial gamma camera images were acquired. Another group of four patients received 7.5 MBq 131I-cMOv18 IgG i.v. For all patients, tissue biopsies were obtained at surgery. Activity in the blood after i.p. administration was described by a bi-exponential curve with a mean uptake and elimination half-life of 6.9+/-3.2 h and 160+/-45 h, respectively. For i.v. infusion the mean half-life for the elimination phase was 103+/-12 h. Cumulative excretion in the urine was 17%+/-3% ID and 21%+/-7% ID in 96 h for i.p. and i.v. administration, respectively. Scintigraphic images after i.p. administration showed accumulation in ovarian cancer lesions, while all other tissues showed decreasing activity with time. Tumour uptake determined in the ovarian cancer tissue specimens ranged from 3.4% to 12.3% ID/kg for i.p. administration and from 3.6% to 5.4% ID/kg for i.v. administration. Dosimetric analysis of the data indicated that 1.7-4.3 mGy/MBq and 1.7-2.2 mGy/MBq can be guided to solid or ascites cells after i.p. and i.v. administration, respectively. Assuming that an absorbed dose to the bone marrow of 2 Gy will be dose limiting, a total activity of 4.1 GBq 131I-cMOv18 IgG can be administered safely via the i.p. route and 3.5 GBq via the i.v. route. At this maximal tolerated dose, a maximum absorbed dose to 1-g tumours in the peritoneal cavity of 18 and 8 Gy can be reached after i.p. and i.v. administration, respectively. For the i. p. route of administration, dose estimates for the tumour are even higher when the electron dose of the peritoneal activity is also taken into account: total doses to the tumour of 30 Gy and 22 Gy will be absorbed at the tumour surface and at 0.2 mm depth, respectively. In conclusion, therapeutic tumour doses can be achieved with 131I-cMOv18 IgG in patients with intraperitoneal ovarian cancer lesions with no normal organ toxicity. The i.p. route of administration seems to be preferable to i.v. administration.

Borderline ovarian malignancy: ultrasound and fast dynamic MR findings

Ovarian tumors of borderline malignancy are low-grade malignant neoplasms, and have a rather good prognosis. They account for approximately 10-20% of all ovarian tumors. Very few reports available in literature that analyses ultrasound and MR findings in establishing the diagnosis. The purpose of this study is to describe eight cases of ovarian tumors of borderline malignancy with dynamic gadolinium-enhanced MR imaging. Comparison is made with CA 125 serum levels and ultrasound findings. Early enhancing endocystic vegetations, local cystic masses in, and (irregular) thickened walls of large multicystic tumors were important findings in borderline malignant tumors. The accuracy to detect a malignant tumor of borderline malignancy with CA 125, ultrasound and MRI in these eight cases was 50, 63 and 75%, respectively. MRI is a valuable imaging modality to characterize adnexal tumors and might play a role in preoperative evaluation of borderline malignancies.

Serum CA 125 measurements to identify patients with endometrial cancer who require lymphadenectomy

BACKGROUND

Most studies evaluating the role of serum CA 125 measurements in endometrial cancer report a positive correlation with prognostic factors. The present study investigates the role of serum CA 125 measurements as a preoperative aid in the decision whether lymphadenectomy or sampling should be part of the surgical procedure.

PATIENTS AND METHODS

We retrospectively studied clinical data of 98 patients with endometrial cancer (FIGO stage I to III), who had serum samples available for analysis of IMx CA 125. Clinical information was included in the analysis in the order in which it became available to the clinician. Patients were grouped retrospectively on the basis of histopathologically determined factors. Those with grade 3 tumors, and/or myometrial invasion > or = 1/2, and/or cervical involvement, and/or parametrial or adnexal tissue involvement, and/or blood vessel invasion, were retrospectively assigned to require lymphadenectomy or sampling (N = 60). All other patients were classified as not requiring such a procedure (N = 38).

RESULTS

Serum IMx CA 125 concentrations correlated with all factors included in the surgical FIG0 classification. The sensitivity to identify patients who would have required a lymphadenectomy or sampling on the basis of precurretage serum CA 125 measurements ranged between 17% (10/60) with cut-off of 35 U/ml, and 53% (32/60) with a 15 U/ml cut-off. Corresponding specificity to exclude patients for lymphadenectomy or sampling ranged from 95% (36/28) to 76% (29/38), respectively. After curettage, information regarding histological grade became available. Using only this information, 17 out of 60 patients who would have required a lymphadenectomy or sampling could be identified because of their grade 3 tumor. The combination of serum CA 125 and histological grade could identify between 37% (22/60) and 65% (39/60) of the patients who required a lymphadenectomy or sampling cut-offs again ranging from 35 to 15 U/ml.

CONCLUSIONS

CA 125 serum levels may provide additional information in the preoperative assessment of endometrial cancer patients. More studies are needed to establish the appropriate cut-off level for serum CA 125 in this respect.

1H-magnetic resonance spectroscopy: a new technique to discriminate benign from malignant ovarian tumors

BACKGROUND

Currently used techniques such as ultrasound, computed tomography, and magnetic resonance imaging are not fully capable of differentiating benign from malignant ovarian tumors. Magnetic resonance spectroscopy (MRS) may help solve this clinical problem by analyzing the composition of fluid from ovarian cysts.

METHODS

The authors studied fluid samples from 28 different ovarian cysts. Nine patients were found to have a malignant ovarian tumor whereas 19 patients had benign cysts. Single pulse 1H-Nuclear Magnetic Resonance spectra were obtained in all fluid samples.

RESULTS

Compared with the group of benign epithelial cysts (n = 17) the 8 malignant epithelial ovarian cysts had significantly higher levels of lactate, isoleucine, valine, 3-hydroxybutyric acid, methionine, and alanine (P < 0.05). In two benign cysts (endometrioma and mature teratoma) surprisingly high levels were found for a large number of compounds. Values were as high as 100-fold the values in fluid from benign cysts.

CONCLUSIONS

1H-NMR spectroscopy demonstrates significant differences in metabolite concentration between benign and malignant ovarian cysts. This ultimately may lead to the noninvasive differential diagnosis of ovarian tumors by in vivo MRS.

Fast dynamic contrast enhanced MR imaging of cervical carcinoma

The first pass phase of contrast material is most important to study vascularization and perfusion of tissue and can be studied using dynamic magnetic resonance (MR) imaging. The purpose of this prospective study was to evaluate the usefulness of pre-contrast vs. post-contrast and fast dynamic MR imaging in the pre-operative staging of cervical carcinomas. To assess the normal onset of enhancement of the uterus and cervix 15 volunteers underwent dynamic MR imaging. Forty-two consecutive patients with invasive cervical cancer underwent pre-operative evaluation using MR imaging. The results of the MR examinations were correlated with clinical (FIGO) staging under anaesthesia (n = 42) and with histopathological findings after operation (n = 26). The staging results of pre-contrast T1-weighted and T2-weighted turbo spin-echo (TSE) MR images, pre-contrast MR images plus post-contrast enhanced (two dimensional fast low angle shot (FLASH 2-D) post contrast), pre-contrast MR images plus post-contrast enhanced plus fast dynamic enhanced (single slice turbo fast low angle shot (turbo FLASH)) MR images compared to histopathology (n = 26) were 77%, 81% and 85% respectively. The improvement was statistically not significant. The result of MR staging compared to clinical staging (n = 42) with pre-contrast MR images was correct in 79% of the cases. Pre-contrast MR images combined with post-contrast MR images did not significantly improve staging accuracy (83%). Pre-contrast plus post-contrast plus fast dynamic MR imaging improved staging to 91%. However, the improvement was only statistically significant for one reader (P = 0.01), whereas the improvement of the second reader was not significant (P = 0.07). The single slice turbo FLASH images showed enhancement of all squamous cell carcinomas (n = 32) with an average onset of 5s (range 4-8s) during the first 45s of bolus injection of gadolinium. The normal cervix showed enhancement with an average of 10s (range 6-14 s). FLASH 2-D post-contrast images showed less intense enhancement of the cervical tumours with respect to the parametria and other surrounding structures. Fast dynamic MR imaging and to a lesser degree post-contrast MR imaging showed a higher level of confidence than pre-contrast MR. Fast dynamic MRI compared with clinical staging (n = 42) was correct in 91% (38/42) and to histopathology in 85% (22/26). Comparison of clinical staging with histopathology was 85% (22/26). In conclusion, fast dynamic MR imaging is superior to post-contrast and pre-contrast MR imaging and is at least as good as clinical staging in the evaluation of cervical carcinoma.

[Circulatory arrest following sulprostone administration in postpartum hemorrhage]

In a woman aged 39 cardiac arrest occurred 3.5 hours after administration of 250 micrograms sulprostone directly into the uterine wall for a post-partum haemorrhage after manual removal of the placenta. A long period of resuscitation was necessary. After further evaluation the woman demonstrated specific contraindications to the administration of sulprostone. as formulated by the French authorities: age > 35 years, heavy cigarette smoking, and cardiovascular risk factors. In the Netherlands sulprostone is registered for intravenous administration only. We would strongly advise against administration directly into the uterine wall.

Quantitation of IgG and IgM human anti-mouse antibodies (HAMA) interference in CA 125 measurements using affinity chromatography

Currently no available immunoassay system offers complete protection against spuriously elevated or lowered results due to interference by Human Anti-Mouse Antibodies (HAMA). Although routine use of chromatography procedures is not an acceptable option because of the extra cost and workload involved, such a procedure would be highly desirable to ensure accurate immunoassay results. The present report describes a relatively simple affinity chromatography procedure using a HiTrap Protein G column to isolate immunoglobulin G (IgG) HAMA, followed by a HiTrap N-hydroxy-succinimide (NHS)-activated column coupled to goat-anti human immunoglobulin M (IgM) to bind IgM HAMA. To examine the usefulness of this purification procedure we determined CA 125 in forty serum samples prior to and following chromatography. Pre- and post-injection samples were obtained from 20 patients injected with 1 mg of 111In-labelled murine OC 125 F(ab')2 fragments in an immunoscintigraphy study. It is shown that this analytical procedure provides a technique to determine the extent and the nature of the existing HAMA interference in samples of patients after in vivo use of monoclonal antibodies for diagnostic or therapeutic purposes. The procedure can also contribute to the clarification of clinically discordant CA 125 results. Finally, the availability of such a procedure in the clinical laboratory provides an opportunity to test the robustness of newly developed immunoassay systems towards HAMA interference.

Comparison of four 'second generation' immunoassay systems to determine CA 125 in serum by using a graphical approach to method comparison analysis

Clinical management of ovarian cancer patients is facilitated by CA 125 determinations in serum. Presently, several assay systems based on different concepts and different methodologies are available to measure CA 125. Method comparison analysis of such assay systems is usually performed through (linear) regression analysis, which requires assumptions about the distribution of experimental data and its measurement error. The aim of the present study was to compare four newly developed second generation assay systems for quantitation of CA 125 by utilizing an alternative simple approach to method comparison analysis. This alternative comprises the construction of relative difference plots and mountain plots, previously described by Krouwer et al. (Eur J Clin Chem Clin Biochem 1995; 33:525-7). In addition, the diagnostic value of the assays was illustrated through receiver-operating-characteristic (ROC) curves. Sera obtained from 300 women were assayed for CA 125 using the Abbott IMx CA 125 assay (Abbott), the Centocor CA 125 II RIA assay (Centocor), the Berilux Ov testing kit for CA 125 (Behringwerke), and the CA 125 TR-FIA assay (Wallac Oy). Both the relative difference plots and the mountain plots revealed higher serum concentrations with the Centocor RIA II (Median +33%, P2.5 to P97.5: -25% to 161%) and Berilux (Median +28%, P2.5 to P97.5: -17% to 108%) compared to the Abbott IMx system. The TR-FIA assay system showed lower serum concentrations (Median - 17%, P2.5 to P97.5: -74% to 229%). The combination of relative difference plots and mountain plots demonstrated clearly the wide range of differences between CA 125 assays measuring the same analyte. The relative difference plots provided insight into the distribution of the differences over the range of measurement as well as the identification of outliers. A simple quantitative assessment of the median differences could be made from the overlaying mountain plots. The close correspondence observed between the ROC curves illustrated that assay systems for CA 125 differing in design (type of antibodies used) and format can produce similar results on group level. However, the results of the clinical evaluation underline the importance of the application of assay specific cut-off values.

Improvement of clinical staging in cervical cancer with serum squamous cell carcinoma antigen and CA 125 determinations

Staging of cervical cancer is routinely performed by means of examination under anesthesia in combination with radiographic and/or endoscopic techniques. This "clinical" staging leads to 10-25% misclassification, mostly due to positive lymph nodes or lymph or blood vessel invasion. Determination of pretreatment squamous cell carcinoma antigen (SCC) and CA 125 serum levels may solve part of this staging problem and may improve the selection of the most appropriate individual therapy. Using 2.5 ng/ml (SCC) and 35 U/ml (CA 125) as cutoff levels, we studied 99 patients retrospectively. Elevated levels were found in 27% (SCC) and 23% (CA 125). In clinical stage IB or IIA disease 45/81 patients had positive nodes or lymph or blood vessel invasion at operation. Of these patients 49% had elevated serum levels of SCC or CA 125. Strongest correlation was found with blood vessel invasion (57%). Only 19% of low-stage patients without evidence of vascular spread of disease had positive levels. The positive predictive value of SCC and CA 125 for detection of vascular spread of disease in low-stage cervical cancer was 76%. In most centers surgery is the primary treatment of choice in low-stage cervical cancer. Nevertheless, with respect to patient survival, results of primary surgery and primary radiotherapy are comparable. Radiotherapy given in an adjuvant setting leads to a high incidence of severe complications. In order to overcome part of these complications one should consider radiotherapy as the primary therapy of choice in patients with clinical stage IB or IIA cervical cancer with elevated pretreatment SCC or CA 125 levels.

Ovarian cancer incidence (1989-1991) and mortality (1954-1993) in The Netherlands

OBJECTIVE

To examine ovarian cancer incidence and mortality in the Netherlands, and to relate trends in mortality to changes in parity and use of oral contraceptives.

METHODS

Age-standardized and age-specific incidence and mortality rates are presented using incidence data from the Netherlands Cancer Registry, 1989-1991, and mortality data from the Netherlands Central Bureau of Statistics, 1954-1993.

RESULTS

In the period 1989-1991, age-standardized incidence of ovarian cancer was 14.9 per 10(5) woman-years. The majority (89%) of these tumors had an epithelial origin. Two-thirds of all newly diagnosed ovarian cancers already showed extension to the pelvis or beyond at diagnosis. From the period 1954-1958 to 1969-1973, age-standardized mortality rates increased from 10.6 to 13.1 per 10(5) woman-years. Thereafter, a decline was noted to 11.4 per 10(5) woman-years in the period 1989-1993. Age-specific mortality rates showed a pattern of rising mortality in the elderly, whereas mortality in the younger age categories was declining. The number of live births has declined gradually, and oral contraceptive use has increased.

CONCLUSION

Incidence of ovarian cancer is high in the Netherlands, but comparable to other countries in north-western Europe and North America. Mortality rates are rising in the elderly and declining in the young. Further research is needed concerning the effects of oral contraceptives, fertility drugs, and hormone replacement therapy on the incidence and mortality of ovarian cancer.

Pharmacokinetics, biodistribution and biological effects of intravenously administered bispecific monoclonal antibody OC/TR F(ab')2 in ovarian carcinoma patients

The bispecific monoclonal antibody (biMAb) OC/TR combines the anti-ovarian-cancer reactivity of the MOv18 monoclonal antibody (MAb) with the reactivity of an anti-CD3 MAb. Pre-clinical studies have indicated that this biMAb is able to redirect the cytolytic activity of T cells towards tumour cells, resulting in efficient tumour-cell lysis. To assess the clinical potential of systemic biMAb-based cancer therapy we initiated a study in ovarian-cancer patients. Five patients suspected of ovarian cancer received 123I-OC/TR F(ab')2 i.v. Unexpectedly, the first patient developed side effects (grade III-IV toxicity) starting 30 min after infusion (p.i.) of 1 mg of OC/TR F(ab')2. After approval of the Ethical Committee, the study was continued at lower dose levels (0.1 mg; 0.2 mg). However, at the 0.2-mg dose level similar side effects were observed. FACS analysis indicated that all peripheral T cells were coated with biMAb immediately following the infusion. The cytokines tumour necrosis factor-alpha, interferon-gamma and interleukin-2 showed maximum serum concentrations 2 h p.i. Tumour uptake ranged from 0.8 to 1.9% ID/kg, resulting in tumour/background ratios of 3 to 8. Our results suggest that at higher antibody dose levels OC/TR F(ab')2 causes T-cell activation with acute release of cytokines. Only low doses of biMAb can be administered safely. Despite the interaction with T cells, OC/TR F(ab')2 preferentially localizes in tumours following i.v. administration, thus offering therapeutic perspectives.

Humoral anti-OV-TL 3 response after the intravenous administration of radiolabelled Fab' or F(ab')2 fragments in ovarian cancer patients

The human anti-mouse antibody (HAMA) response was determined in the serum of patients suspected of having ovarian cancer who underwent radioimmunoscintigraphy with either 99Tcm-OV-TL 3 Fab' (n = 20) or 111In-DTPA-OV-TL 3 F(ab')2 (n = 73). Blood samples were collected prior to and at several time points post-intravenous injection. The detection of HAMA was performed with an in-house OV-TL 3 F(ab')2-based sandwich-type immunoradiometric assay (IRMA). The homologous IRMA demonstrated that 8 of 20 (40%) patients had developed HAMA responses after injection of Fab' fragments and that 14 of 73 (19%) patients had developed HAMA responses after F(ab')2 administration. The subclass of the measured HAMA was analysed in a limited number of samples, showing IgG or IgM as well as mixed responses. The kinetics of the HAMA responses varied greatly. Our study showed the relevance of the sampling time and frequency: HAMA responses can be easily underestimated with a low sampling frequency. The homologous IRMA described in this study was able to quantify the OV-TL 3-specific HAMA responses. With additional assays, the subclass of the HAMA could be further analysed. Remarkably, the fraction of HAMA responders after injection of OV-TL 3 Fab' fragments was in the same range as the proportion of HAMA responders after F(ab')2 administration.

Tumour targeting of the anti-ovarian carcinoma x anti-CD3/TCR bispesific monoclonal antibody OC/TR and its parental MOv18 antibody in experimental ovarian cancer

The anti-tumour x anti-T-cell bispecific monoclonal antibody (biMAb) OC/TR is a biologically produced biMAb combining the anti-ovarian carcinoma activity of the MOv18 MAb with anti-CD3/T-cell receptor (TCR) complex activity. In this study, the in vitro binding characteristics of the OC/TR biMAb and its tumour targeting potential in nude mice with Hela tumours was studied. Scatchard analysis revealed that the affinity constant of the biMAb was 7 times lower than the affinity of the parental MOv18 antibody. Uptake of the OC/TR antibody in the Hela xenografts in nude mice was significantly higher than the tumour uptake of an irrelevant control antibody, indicating that the radioiodinated OC/TR biMAb specifically localized in the tumour xenografts. However, tumour uptake was significantly lower than the tumour uptake of the parental MOv18 antibody. This reduced tumour uptake most likely is a result of its reduced affinity. We conclude that, despite the loss of bivalent tumour cell binding, the biMAb OC/TR can still specifically localize in tumours. This indicates that the first prerequisite of an effective therapeutic approach using systemically applied biMAb can be met. Whether the interaction with human T-cells will affect the tumour targeting potential of the biMAb in patients remains to be investigated.

Analytical and clinical performance of improved Abbott IMx CA 125 assay: comparison with Abbott CA 125 RIA

We compared the improved Abbott IMx cancer antigen (CA) 125 assay (cat. no. 7A89) with the Abbott CA 125 RIA. Serum specimens were from healthy perimenopausal women (n = 124) and from patients with benign gynecologic and nongynecologic diseases (n = 124), ovarian carcinoma (n = 104), or other malignancies (n = 193). The IMx assay detected as little as 0.193 kAU/L CA 125 (AU = arbitrary Abbott unit), demonstrated up to 29% overestimation upon serum dilution, low within-assay (2.7-5.6%) and between-assay (4.8-8.2%) CVs, and no high-dose hook effect < or = 46,000 kAU/L nor influence from human anti-mouse antibodies in serum of women injected with OC 125 F(ab')2. Values by IMx were 20% lower than by RIA for healthy perimenopausal women (n = 100; IMx = 0.80 RIA - 2.5 kAU/L), and at least 50% higher for those with benign or malignant ovarian disorders at concentrations < 100 kAU/L. Receiver-operating characteristic (ROC) curve analysis of ovarian neoplasma vs perimenopausal controls indicated a gain of specificity and sensitivity with the improved IMx assay over the RIA, but ROC performance was the same with either assay if patients with benign ovarian disorders were used as controls.

Analytical and clinical performance of improved Abbott IMx CA 125 assay: comparison with Abbott CA 125 RIA

We compared the improved Abbott IMx cancer antigen (CA) 125 assay (cat. no. 7A89) with the Abbott CA 125 RIA. Serum specimens were from healthy perimenopausal women (n = 124) and from patients with benign gynecologic and nongynecologic diseases (n = 124), ovarian carcinoma (n = 104), or other malignancies (n = 193). The IMx assay detected as little as 0.193 kAU/L CA 125 (AU = arbitrary Abbott unit), demonstrated up to 29% overestimation upon serum dilution, low within-assay (2.7-5.6%) and between-assay (4.8-8.2%) CVs, and no high-dose hook effect &lt; or = 46,000 kAU/L nor influence from human anti-mouse antibodies in serum of women injected with OC 125 F(ab')2. Values by IMx were 20% lower than by RIA for healthy perimenopausal women (n = 100; IMx = 0.80 RIA - 2.5 kAU/L), and at least 50% higher for those with benign or malignant ovarian disorders at concentrations &lt; 100 kAU/L. Receiver-operating characteristic (ROC) curve analysis of ovarian neoplasma vs perimenopausal controls indicated a gain of specificity and sensitivity with the improved IMx assay over the RIA, but ROC performance was the same with either assay if patients with benign ovarian disorders were used as controls.

Effect of the route of administration on the biodistribution of radioiodinated OV-TL 3 F(ab')2 in experimental ovarian cancer

The effect of the route administration on the distribution of radioiodinated OV-TL 3 F(ab')2 was studied in Balb/c female mice with intraperitoneal or subcutaneous ovarian carcinoma xenografts. In the intraperitoneal tumour model in which both ascites and solid tumour deposits were present, intraperitoneal administration resulted in a lower estimated radiation dose to blood as compared with intravenous administration. In this model normalization to equal estimated radiation doses to blood for both routes of administration indicated that a twice as high estimated radiation dose can be guided to solid intraperitoneal tumour deposits following intraperitoneal administration. Evacuation of ascitic tumour cells prior to monoclonal antibody injection further increased the estimated radiation dose to solid intraperitoneal tumour deposits following intraperitoneal delivery. Following simultaneous intravenous and intraperitoneal injection of the monoclonal antibody, tissue uptake showed no relevant differences in the subcutaneous tumour model. Overall, the intraperitoneal route of administration was found to be the best choice for therapeutic delivery of iodine-131 labelled monoclonal antibodies.

Decreased kidney uptake of technetium-99m-labelled Fab' fragments in ovarian carcinoma bearing nude mice using a cleavable chelator

A new 99mTc labelling method using a cleavable chelator, RP-1, was developed. In this study Balb/c mice with ovarian carcinoma xenografts received various Fab' fragments labelled with 99mTc either directly or via RP-1. Kidney uptake was significantly lower for the RP-1 linked conjugates. Tumour uptake showed no significant differences between RP-1 conjugates and directly labelled preparations. In conclusion, with the use of the cleavable linker RP-1, kidney uptake can be reduced significantly resulting in a lower radiation dose to the kidneys.

CA 125 serum levels in the early post-operative period do not reflect tumour reduction obtained by cytoreductive surgery

In order to assess whether CA 125 serum levels reflect the outcome of cytoreductive surgery, CA 125 antigen levels were determined prior to and after debulking surgery in 50 ovarian cancer patients and compared to CA 125 serum levels before and after surgery in a control group of 140 patients undergoing laparotomy for various malignant or benign diseases. A significant CA 125 decrease in the first post-operative week was seen in 56% of ovarian cancer patients whereas 26% remained stable and 18% showed a significant increase after surgery. Although removal of tumour had been complete in all 14 stage I-II ovarian carcinomas, only 2 of these patients showed a subsequent significant CA 125 decrease after cytoreductive surgery, while 4 patients showed a significant increase. Such increases of CA 125 following surgery were also seen in uterine carcinomas (30%), in gastrointestinal carcinomas (75%) and in patients after laparotomy for benign gynaecological diseases (23%). CA 125 pre-treatment levels were significantly lower in patients with post-operative increases than in patients with stable or decreasing CA 125 patterns. Patients with stable CA 125 levels also had lower CA 125 pretreatment levels compared to patients with a post-operative CA 125 decrease. Post-operative increases were observed for at least 2 weeks after debulking in the case of ovarian cancer. Pre-operative levels of these patients were either within the normal range or moderately elevated. Serial measurements during surgery in partial debulking showed a rapid CA 125 decline within 24 h followed by increasing CA 125 values thereafter. Our data indicate that CA 125 serum levels in the direct post-operative period do not always reflect the outcome of cytoreductive surgery. There appears to be an effect on CA 125 levels caused by the abdominal surgical procedure itself. Consequently, CA 125 levels after abdominal surgery should be interpreted with caution.

Tumour detection and localization using 99Tcm-labelled OV-TL 3 Fab' in patients suspected of ovarian cancer

Fab' fragments of the monoclonal antibody OV-TL 3, that recognizes an ovarian carcinoma-associated antigen (OA3), were labelled with 99Tcm using D-glucarate as a ligand. Twenty patients suspected of having primary or recurrent ovarian cancer received intravenously 1 mg of the Fab' labelled with 740 MBq 99Tcm. Both planar and single photon emission computed tomographic (SPECT) scintigraphy were performed up to 30 h after intravenous infusion. In 19 out of 20 patients surgical and histopathological evaluation was performed between 2 and 6 days postinfusion. Imaging results were compared with X-ray computed tomography (CT), ultrasonography (US) and CA 125 serum level. Blood clearance was fast with median t1/2 beta of 9.5 h. Thirty-seven per cent of the injected dose (% ID) was excreted in the urine within the first 24 h, whereas 7% ID was excreted in the 24 h faeces. In one patient with an OA3 negative ovarian carcinoma, radioimmunoscintigraphy (RIS) did not visualize the tumour. In two other patients a benign ovarian cyst was found, also showing no elevated uptake. In 13 out of 17 patients ovarian cancer lesions were detected with RIS, whereas CT and US detected lesions in, respectively, 15 and 12 patients. Of 36 surgically defined tumour deposits larger than 1 cm in diameter, 53% were detected and localized with RIS, whereas CT and US detected 61 and 40%, respectively. Radioimmunoscintigraphy with 99Tcm-OV-TL 3 Fab' is less distressing for the patients but the overall imaging performance is not improved when compared with 111In-OV-TL 3 F(ab')2.

Specific and nonspecific immunoassays to detect HAMA after administration of indium-111-labeled OV-TL 3 F(ab')2 monoclonal antibody to patients with ovarian cancer

The development of human anti-mouse antibodies (HAMA) may cause problems in radioimmunotargeting studies, but may also improve survival of patients. To identify the presence of HAMA in blood samples from patients intravenously injected with 1 mg of 111In-labeled OV-TL3-F(ab')2, we developed three specific OV-TL 3-based HAMA assays and tested these along with two commercially available nonspecific HAMA assays (Sorin and Immunomedics). The specific assays were positive for HAMA with 10 postinjection serum samples from 7 patients. Eight of the 10 samples were also HAMA positive with one or both nonspecific HAMA assays. Conflicting results were observed with half the number of samples. The two nonspecific assays also reacted positively with another 11 serum samples from 5 patients including their preinjection samples. Despite some contradictory results, the nonspecific HAMA assays identify both pre-existent and Mab-induced HAMA, whereas the specific OV-TL3-based HAMA assays identify specific immune-responses occurring after the OV-TL 3 injection.

Dosimetric evaluation of immunoscintigraphy using indium-111-labeled monoclonal antibody fragments in patients with ovarian cancer

This study reports the biodistribution and dosimetry for a monoclonal antibody against ovarian carcinoma. Eight patients received 140 MBq 111In-OV-TL 3 F(ab')2; thereafter gamma camera imaging was performed daily up to 96 hr. By using the conjugated view counting method, activity in the organs was quantitated by phantom calibration and by whole-body measurements using a whole-body counter with the conjugated view counting method. Red bone marrow uptake was derived from regions of interest over the lumbar vertebrae and iliac crest. In both methods, organ uptake varied only slightly with time, having a mean value of approximately 18%, 4%, 6% and 17% of the injected dose in the liver, spleen, kidneys and red bone marrow, respectively. The mean radiation dose to these organs was 0.9, 1.5, 1.2 and 0.5 mGy/MBq. The effective dose equivalent was 0.4 mSv/MBq. In this study, two different methods of uptake calculations, result in similar values of organ uptake.

Biodistribution of iodine-125 and indium-111 labeled OV-TL 3 intact antibodies and F(ab')2 fragments in tumor-bearing athymic mice

The monoclonal antibody OV-TL 3, directed against an ovarian carcinoma-associated antigenic determinant, was tested as a vehicle for radioimmunolocalization of ovarian carcinomas in athymic mice bearing NIH:OVCAR-3 xenografts. The biodistribution of intact. OV-TL 3 was compared with the distribution of OC 125. Tumor uptake with OV-TL 3 was significantly higher than with OC 125, and almost 7 times higher than with a non-specific control antibody (OV-TL 19). Administration of a mixture of intact OV-TL 3 and OC 125 did not improve tumor uptake in comparison with OV-TL 3 alone. Subsequently, intact OV-TL 3 and its F(ab')2 fragments were labeled with either 111In or 125I. The highest tumor uptake was obtained with 111In-labeled intact OV-TL 3 (14.7% ID/g, 48 hr p.i.). For both antibody forms uptake of 111In in liver, spleen and kidneys was very high. Furthermore, 111In cleared more slowly from most tissues than 125I. As a result, tumor/tissue ratios with 111In-labeled OV-TL 3 were lower than with 125I-labeled OV-TL 3. The highest tumor/tissue ratios (6.9 to 53) were obtained with 125I-labeled OV-TL 3 F(ab')2 fragments, 48 hr post injection. 111In-labeled OV-TL 3 F(ab')2 has already been shown to be a clinically useful label for the detection of ovarian cancer. The results of our comparative animal study suggest that these clinical results may even be improved by using 123I-labeled OV-TL 3 F(ab')2.

Kinetics and biodistribution in relation to tumour detection with 111In-labelled OV-TL 3 F(ab')2 in patients with ovarian cancer

The biological behaviour of 111In-labelled OV-TL 3 F(ab')2 was studied in 22 patients with suspected ovarian cancer. After i.v. injection with 140 MBq 111In-OV-TL 3 F(ab')2 (1 mg) blood samples were taken up to 96 h and urine and faeces were collected throughout the whole study. At surgery, 5 to 7 days post-injection, primary and metastatic tumour tissues, as well as fragments of several normal tissues, were removed and 111In uptake was measured. Blood activity disappeared with half-life values of 6.1 +/- 1.1 and 17.9 +/- 6.5 h. Within 96 h excretion in urine and faeces was 16.1 +/- 2.0% i.d. (mean +/- S.D.) and 3.1 +/- 1.9% i.d., respectively. Mean tissue uptake, expressed as % i.d. kg-1 was 3.9 +/- 1.0 for primary tumour, 11.5 +/- 5.0 for liver and 0.4 +/- 0.1 for several normal background tissues. Higher tumour uptake correlated with a higher detection rate at immunoscintigraphy. However, no strict correlation was found between the amount of tumour uptake and the expression of the monoclonal antibody defined OA3 antigen. Quantitation of organ activity, using region of interest analysis, resulted in mean peak organ activities for the liver of 16% i.d., spleen 9% i.d. and kidney 4% i.d. Distribution data indicate that besides specific antibody-antigen interaction several other mechanisms play a role in uptake in tumour and other tissues.

Carcinoma-associated mucin serum markers CA M26 and CA M29: efficacy in detecting and monitoring patients with cancer of the breast, colon, ovary, endometrium and cervix

Two recently developed monoclonal antibody (MAb)-based anti-mucin assays, CA M26 and CA M29, were studied in 250 cancer patients and compared to 3 well-established marker tests, viz., CA 125, CA 15.3 and SCC, in order to assess their clinical usefulness as serum tumor markers. Pre-treatment sera were obtained from patients with predominantly low-stage epithelial malignancies comprising 200 adenocarcinomas (of the ovary, endometrium, breast and large intestine) and 50 squamous-cell carcinomas (of the uterine cervix). Pretreatment sera of 50 patients with benign ovarian tumors were included to evaluate levels in benign disease, CA M26 and CA M29 cut-off levels were established in 89 healthy controls. In patients with adenocarcinomas, overall positivity for CA M29 was 24%, ranging from 10% in breast cancer to 60% in ovarian cancer. Overall positivity was highest for CA 125 (30%) and lowest for CA M26 (18%) with CA M29 (24%) being similar to CA 15.3 (25%). In adenocarcinomas the combined CA M26-CA M29 assays equalled results obtained with the CA 125-CA 15.3 combination (33% vs. 36%). Elevation of 2 or more markers was highly indicative of advanced disease (p less than 0.025). A majority of positive patients showed either CA M26 or CA M29 elevations, indicating that both antibodies detect distinct epitopes. After adjustment for tumor site and stage, the profile of CA M26 as a single marker differed significantly from the profiles of CA 125 and of CA M29. CA M26 was frequently (32%) elevated in patients with squamous-cell carcinoma of the cervix and CA M26 levels were often independently elevated. CA M26 seems to be valuable as an additional marker in breast cancer and perhaps as a new marker in cervical cancer. CA M29 may be useful in ovarian cancer in addition to CA 125.