Intraperitoneal therapy of malignant ascites associated with carcinoma of ovary and breast using radioiodinated monoclonal antibody 2G3

The Roles of Transmembrane Mucins Located on Chromosome 7q22.1 in Colorectal Cancer

Colorectal cancer (CRC) is one of the most common types of cancers. It is associated with a poor prognosis and high mortality. The role of mucins (MUCs) in colon tumorigenesis is unclear, but it might be significant in the progression of malignancy. Some mucins, such as MUC1 and MUC13, act as oncogenes, whereas others, such as MUC2 and MUC6, are tumor suppressors. However, there are still mucins with unidentified roles in CRC. In this review, we discuss the reported roles of mucins in CRC. Moreover, we review the capability of the mucin family to serve as a sensitive and specific histopathological marker for the early diagnosis of CRC. Lastly, the role of mucin genes clustered on chromosome 7q22 in CRC and other cancers is also discussed.

Cancer-associated mucins: role in immune modulation and metastasis

Mucins (MUC) protect epithelial barriers from environmental insult to maintain homeostasis. However, their aberrant overexpression and glycosylation in various malignancies facilitate oncogenic events from inception to metastasis. Mucin-associated sialyl-Tn (sTn) antigens bind to various receptors present on the dendritic cells (DCs), macrophages, and natural killer (NK) cells, resulting in overall immunosuppression by either receptor masking or inhibition of cytolytic activity. MUC1-mediated interaction of tumor cells with innate immune cells hampers cross-presentation of processed antigens on MHC class I molecules. MUC1 and MUC16 bind siglecs and mask Toll-like receptors (TLRs), respectively, on DCs promoting an immature DC phenotype that in turn reduces T cell effector functions. Mucins, such as MUC1, MUC2, MUC4, and MUC16, interact with or form aggregates with neutrophils, macrophages, and platelets, conferring protection to cancer cells during hematological dissemination and facilitate their spread and colonization to the metastatic sites. On the contrary, poor glycosylation of MUC1 and MUC4 at the tandem repeat region (TR) generates cancer-specific immunodominant epitopes. The presence of MUC16 neo-antigen-specific T cell clones and anti-MUC1 antibodies in cancer patients suggests that mucins can serve as potential targets for developing cancer therapeutics. The present review summarizes the molecular events involved in mucin-mediated immunomodulation, and metastasis, as well as the utility of mucins as targets for cancer immunotherapy and radioimmunotherapy.

Bone marrow stromal antigen 2 expressed in cancer cells promotes mammary tumor growth and metastasis

Introduction

Several innate immunity genes are overexpressed in human cancers and their roles remain controversial. Bone marrow stromal antigen 2 (BST-2) is one such gene whose role in cancer is not clear. BST-2 is a unique innate immunity gene with both antiviral and pro-tumor functions and therefore can serve as a paradigm for understanding the roles of other innate immunity genes in cancers.

Methods

Meta-analysis of tumors from breast cancer patients obtained from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) datasets were evaluated for levels of BST-2 expression and for tumor aggressiveness. In vivo, we examined the effect of knockdown of BST-2 in two different murine carcinoma cells on tumor growth, metastasis, and survival. In vitro, we assessed the effect of carcinoma cell BST-2 knockdown and/or overexpression on adhesion, anchorage-independent growth, migration, and invasion.

Results

BST-2 in breast tumors and mammary cancer cells is a strong predictor of tumor size, tumor aggressiveness, and host survival. In humans, BST-2 mRNA is elevated in metastatic and invasive breast tumors. In mice, orthotopic implantation of mammary tumor cells lacking BST-2 increased tumor latency, decreased primary tumor growth, reduced metastases to distal organs, and prolonged host survival. Furthermore, we found that the cellular basis for the role of BST-2 in promoting tumorigenesis include BST-2-directed enhancement in cancer cell adhesion, anchorage-independency, migration, and invasion.

Conclusions

BST-2 contributes to the emergence of neoplasia and malignant progression of breast cancer. Thus, BST-2 may (1) serve as a biomarker for aggressive breast cancers, and (2) be a novel target for breast cancer therapeutics.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-014-0493-8) contains supplementary material, which is available to authorized users.

The FACIT-AI, a new tool for assessing symptoms associated with malignant ascites

OBJECTIVE

The objectives of this study are to assess the clinical relevance and validity of the Functional Assessment of Chronic Illness Therapy-Ascites Index (FACIT-AI) in women with ovarian cancer and malignant ascites, and to modify the instrument guided by qualitative feedback from patients with recurrent malignant ascites.

METHODS

Fourteen adult female patients with recurrent symptomatic malignant ascites were enrolled from three centers. All completed an open-ended symptom list to identify their primary concerns regarding their condition. They then completed a draft 10-item FACIT-AI questionnaire created from expert input. Eleven patients provided comments regarding the FACIT-AI questionnaire using a written feedback format. Three patients participated in a "think-aloud" cognitive debriefing interview to ensure patient comprehension of questionnaire items.

RESULTS

Of the first 11 patients surveyed, 7 believed that the draft FACIT-AI contained all important symptoms associated with malignant ascites. Responses from the remaining 4 patients revealed three symptoms that 2 or more patients nominated for inclusion: urinary frequency, constipation and emotional distress. These items were added to the original FACIT-AI to produce a 13-item index of symptoms associated with malignant ascites.

CONCLUSIONS

The 13-item FACIT-AI has content validity among women with malignant ascites associated with ovarian cancer. It is available for use in clinical research or practice, with the expectation that more will be learned about its performance and interpretation over time.

Malignant ascites: pathophysiology and treatment

Malignant ascites (MA) accompanies a variety of abdominal and extra-abdominal tumors. It is a primary cause of morbidity and raises several treatment challenges. MA has several symptoms, producing a significant reduction in the patient's quality of life: loss of proteins and electrolyte disorders cause diffuse oedema, while the accumulation of abdominal fluid facilitates sepsis. Treatment options include a multitude of different procedures with limited efficacy and some degree of risk. A Pubmed, Medline, Embase, and Cochrane Library review of medical, interventional and surgical treatments of MA has been performed. Medical therapy, primarily paracentesis and diuretics, are first-line treatments in managing MA. Paracentesis is widely adopted but it is associated with significant patient discomfort and several risks. Diuretic therapy is effective at the very beginning of the disease but efficacy declines with tumor progression. Intraperitoneal chemotherapy, targeted therapy, immunotherapy and radioisotopes are promising medical options but their clinical application is not yet completely elucidated, and further investigations and trials are necessary. Peritoneal-venous shunts are rarely used due to high rates of early mortality and complications. Laparoscopy and hyperthermic intraperitoneal chemotherapy (HIPEC) have been proposed as palliative therapy. Literature on the use of laparoscopic HIPEC in MA includes only reports with small numbers of patients, all showing successful control of ascites. To date, none of the different options has been subjected to evidence-based clinical trials and there are no accepted guidelines for the management of MA.

Transmembrane mucins as novel therapeutic targets

Membrane-tethered mucin glycoproteins are abundantly expressed at the apical surfaces of simple epithelia, where they play important roles in lubricating and protecting tissues from pathogens and enzymatic attack. Notable examples of these mucins are MUC1, MUC4 and MUC16 (also known as cancer antigen 125). In adenocarcinomas, apical mucin restriction is lost and overall expression is often highly increased. High-level mucin expression protects tumors from killing by the host immune system, as well as by chemotherapeutic agents, and affords protection from apoptosis. Mucin expression can increase as the result of gene duplication and/or in response to hormones, cytokines and growth factors prevalent in the tumor milieu. Rises in the normally low levels of mucin fragments in serum have been used as markers of disease, such as tumor burden, for many years. Currently, several approaches are being examined that target mucins for immunization or nanomedicine using mucin-specific antibodies.

Intraperitoneal radioimmunotherapy: Auger electron emitters for solid tumors

Evaluation of: Boudousq V, Ricaud S, Garambois V et al.: Brief intraperitoneal radioimmunotherapy of small peritoneal carcinomatosis using high activities of noninternalizing 125I-labeled monoclonal antibodies. J. Nucl. Med. 51, 1748–1755 (2010). Mesothelioma, pseudomyxoma peritonei, ovarian and colon cancers, and several other malignancies produce peritoneal carcinomatosis in their advanced stages. This condition is typically managed with curative intention by means of a radical cytoreductive surgery and intraperitoneal hyperthermic chemotherapy. The method has been shown to improve the survival of some patients with peritoneal dissemination. However, the intracavitary instillation of chemotherapy results in a nonuniform drug distribution and allows penetration of the drug only into the outermost layer of the cancer nodule. Authors of the current study demonstrate that 125I-radiolabeled monoclonal antibody, 35A7, which recognizes anti-carcinoembryonic antigen, can be used effectively and safely with low toxicity in the therapy of small volume peritoneal carcinomatosis after cytoreductive surgery.

Mucins in the pathogenesis of breast cancer: implications in diagnosis, prognosis and therapy

Mucins are high molecular weight, multifunctional glycoproteins comprised of two structural classes-the large transmembrane mucins and the gel-forming or secreted mucins. The primary function of mucins is to protect and lubricate the luminal surfaces of epithelium-lined ducts in the human body. Recent studies have identified a differential expression of both membrane bound (MUC1, MUC4 and MUC16) and secreted mucins (MUC2, MUC5AC, MUC5B and MUC6) in breast cancer tissues when compared with the non-neoplastic breast tissues. Functional studies have also uncovered many unique roles of mucins during the progression of breast cancer, which include modulation in proliferative, invasive and metastatic potential of tumor cells. Mucins function through many unique domains that can form complex association with various signaling molecules including growth factor receptors and intercellular adhesion molecules. While there is growing information about mucins in various malignancies including breast cancer, no focused review is there on the expression and functional roles of mucins in breast cancer. In this present review, we have discussed the differential expression and functional roles of mucins in breast cancer. The potential of mucins as diagnostic and prognostic markers and as therapeutic targets in breast cancer have also been discussed.

Management of ascites due to gastrointestinal malignancy

Ascites is the pathological accumulation of fluid within the abdominal cavity. The most common cancers associated with ascites are adenocarcinomas of the ovary, breast, colon, stomach and pancreas. Symptoms include abdominal distension, nausea, vomiting, early satiety, dyspnea, lower extremity edema, weight gain and reduced mobility. There are many potential causes of ascites in cancer patients, including peritoneal carcinomatosis, malignant obstruction of draining lymphatics, portal vein thrombosis, elevated portal venous pressure from cirrhosis, congestive heart failure, constrictive pericarditis, nephrotic syndrome and peritoneal infections. Depending on the clinical presentation and expected survival, a diagnostic evaluation is usually indicated as it will impact both prognosis and the treatment approach. Key tests include serum albumin and protein and a simultaneous diagnostic paracentesis, checking ascitic fluid, WBCs, albumin, protein and cytology. Median survival after diagnosis of malignant ascites is in the range of 1 to 4 months; survival is apt to be longer for ovarian and breast cancers if systemic anti-cancer treatments are available.

Treatment of malignant ascites

OPINION STATEMENT

The management of malignant ascites is a significant challenge in gastrointestinal medical oncology. Current treatment strategies include diuretic therapy, paracentesis, peritoneal drains, and venous shunts. However, there are no established evidence-based guidelines, and there is a lack of randomized controlled trials identifying optimal therapy. Newer therapies are emerging and will need further study. By summarizing published studies, this review is intended to add some clarity to currently available strategies for the management of malignant ascites associated with hepatobiliary cancers. Notably, however, much of the available data for the management of malignant ascites comes from the gynecologic oncology experience, specifically from studies in ovarian cancer. Therefore, successful approaches used in this malignancy may be lead candidates for development in hepatobiliary cancer-associated ascites and are reviewed in this paper.

Targeted radionuclide therapy for solid tumors: an overview

Although radioimmunotherapy (RIT) has been effective in non-Hodgkin's lymphoma (NHL) as a single agent, solid tumors have shown less clinically significant therapeutic response to RIT alone. The clinical impact of RIT or other forms of targeted radionuclide therapy for solid tumors depends on the development of a high therapeutic index (TI) for the tumor vs. normal tissue effect, and the implementation of RIT as part of synergistic combined modality therapy (CMRIT). Preclinical and clinical studies have provided a wealth of information, and new prototypes or paradigms have shed light on future possibilities in many instances. Evidence suggests that combination and sequencing of RIT in CMRIT appropriately can provide effective treatment for many solid tumors. Vascular targets provide RIT enhancement opportunities and nanoparticles may prove to be effective carriers for RIT combined with intracellular drug delivery or alternating magnetic frequency (AMF) induced thermal tumor necrosis. The sequence and timing of combined modality treatments will be of critical importance to achieve synergy for therapy while minimizing toxicity. Fortunately, the radionuclide used for RIT also provides a signal useful for nondestructive quantitation of the influence of sequence and timing of CMRIT on events in animals and patients. This can be readily accomplished clinically using quantitative high-resolution imaging (e.g., positron emission tomography [PET]).

Immunotherapy of malignant ascites with trifunctional antibodies

A new class of intact bispecific antibodies shows unmet effector qualities by activation of not only T cells but also simultaneous activation of Fcgamma receptor type I/III+ cells (macrophages, NK-cells and DC). These trifunctional antibodies (trAb) lead to efficient specific killing of targeted tumor cells without any pre- or co-stimulation. This concept was investigated in vivo in patients with malignant ascites in a clinical situation that allowed monitoring of tumor cell elimination and correlation with clinical effects. In a prospective study, 8 patients with malignant ascites due to peritoneal carcinomatosis were treated with intraperitoneal application of trAb, which bound either the EpCAM- or Her2/neu-antigen on tumor cells. Treatment consisted of 4-6 applications within 9-23 days with a total amount of 145-940 microg. Seven of eight patients required no further paracentesis during follow-up or until death with a mean paracentesis-free interval of 38 weeks (median = 21.5, range = 4-136). Tumor cell monitoring showed a complete elimination of tumor cells in ascites already at total doses as low as 40-140 microg. Clinical response with disappearance of ascites accumulation was seen in all patients, which was correlated with elimination of tumor cells (p = 0.0014). Severe adverse events were not observed. Clinically relevant side effects were fever, moderate abdominal pain and skin reactions. Intraperitoneal immunotherapy with trAb showed convincing efficacy in patients with malignant ascites. This treatment offers new therapeutic options for patients with peritoneal carcinomatosis.

Radioimmunodetection and therapy of breast cancer

Breast cancer is the second most-common cause of cancer death in women in the United States. Although more than 60% of patients can now be cured by initial treatment, the rest, although perhaps receiving palliation with currently available therapy, will die of their disease. Early detection of micrometastasis and improved treatment strategies are needed. Monoclonal antibody (mAb)-based imaging and tumor targeted therapy holds the potential to impact these problems. The most significant results of systemically administered antibody-based radiopharmaceuticals for detection and targeted therapy (radioimmunotherapy [RIT]) of breast cancer give strong evidence that this potential can be realized. Interest in immunoimaging recently has focused on small mAb modules used with 18F, 64Cu, or 124I to detect minimal disease in breast cancer by positron emission tomography or single-photon emission computed tomography. Reported therapy trials in advanced breast cancer have yielded objective responses and minimal toxicity. These studies have spanned several radionuclides as well as several mAb, fragments and approaches, including dose intensification with bone marrow support; combined therapy with other modalities (ie, CM-RIT); biodegradable peptide linkers; and pretargeting. RIT evaluated in clinical breast cancer trials has delivered as much as 4000 cGy to metastatic breast cancer per therapy dose with marrow stem cell support. Preclinical studies have demonstrated further promising strategies for breast cancer. RIT studies must address the key issue: enhancing the therapeutic index (tumor effect verses most sensitive normal tissue (bone marrow) effect). Approaches now include newly engineered mAb, scFv modular constructs, blood clearance on demand, enhanced pretargeting, applications of both alpha and beta emitting radionuclides, and combination therapy using molecular triggers for therapeutic synergy. These strategies for detection and treatment of metastatic breast cancer should lead to notable clinical impact on management and cure of breast cancer.

The current and future management of malignant ascites

Malignant ascites occurs in association with a variety of neoplasms. It is a frequent cause of morbidity and presents significant problems for which there are no clear management guidelines. In this article we discuss various modalities which are available including diuretic therapy, paracentesis, peritoneovenous shunts and intraperitoneal chemotherapy. There are no randomized trials of diuretic drugs to assess their efficacy in malignant ascites. Phase II data suggest that they are effective in approximately one-third of patients with malignancy, and their efficacy may be determined by plasma renin/aldosterone concentrations. Paracentesis provides relief in up to 90% of patients; because of varying reports of hypovolaemia, some advocate simultaneous intravenous fluid infusion. Permanent percutaneous drains may prevent the need for repeated paracentesis, although there is potential for infection. A peritoneovenous shunt also prevents the need for repeated paracenteses, whilst maintaining normal serum albumin concentrations. Blockage occurs in 25% of shunts, which are contraindicated in the presence of heavily bloodstained ascites because of the risk of occlusion. The preclinical and clinical experience with anti-angiogenic agents such as the matrix metalloproteinase inhibitors and the VEGF antagonists suggests that these agents may have a role in the treatment of malignant ascites.

Clinical trial design and scoring of radionuclide therapy endpoints: normal organ toxicity and tumor response

Like other cancer therapy agents under development, radionuclide therapies are usually evaluated in a progressive series of clinical trials after basic science, human cell culture and animal model studies. Toxicities during these trials are graded using common scoring systems that are in widespread use such as the Common Toxicity Criteria from the National Cancer Institute. Information on normal tissue toxicity from radionuclides is more limited than that from external beam radiation and is more variable. Variability is likely due to many biologic factors as well as less precise dose quantitation than those used in external beam radiation practice. As expected based on known radiobiologic effects, tolerance to radionuclide therapy appears to exceed that from high dose rate external beam radiation in most organs. Although the correlation between reported dose estimates and toxicity has progressively and substantially improved over the past two decades, further progress is needed to establish optimal toxicity predictive relationships. Continued refinement of dosimetry techniques and standardization is expected to increase the accuracy and comparability of radiation dose reports between institutions as well as improve dose/response correlation.

Efficacy of Re-188-labelled sulphur colloid on prolongation of survival time in melanoma-bearing animals

In this study, the effectiveness of a 188Re labeled sulfur colloid with two particle size ranges was used to evaluate the effectiveness of this agent on melanoma tumors in mice in terms of animal lifespan.

METHODS

Two separate group of animals were used for investigating biodistribution and survival time. A total of 188 B16F10-melanoma-bearing BDF(1) mice were injected intraperitoneally with 3.7 MBq (0.1mCi)/2mL of radiolabeled sulfur colloid ten days after intraperitoneal inoculation of 5x10(5) B16F10 melanoma cells/2ml. For group 1, 30 mice were sacrificed at 1, 4, 24, 48 and 72 hours for biodistribution studies. In group 2, 158 mice were divided into 9 groups (n=16 approximately 18/groups)each receiving respectively tumor alone, tumor with normal saline, cold colloid or hot colloid with 16, 23, 31, 46, 62, or 124 MBq activity. Each of these colloid groups was further divided into two groups, one receiving smaller particle sizes (<3 microm:80.4 +/-7.2%, colloid 1) and the other receiving larger particle sizes (<3 microm:12.3+/-1.0%, colloid 2). The animals were checked daily until death and their survival recorded.

RESULTS

Colloid 2 showed higher accumulation in almost all tissues, the highest accumulation organ was tumor ( approximately 40%), then spleen ( approximately 20%), stomach ( approximately 15%), diaphragm ( approximately 3%), and liver ( approximately 2%). There was a significant increase in survival time with increasing amount of the larger-particle-size colloid. Administered levels of 16-31 MBq/mouse were most efficacious and with higher amounts the survival times decreased significantly below that of the controls. There was a significant difference in the dose-response curves for the two preparations. Protection factors (1/Relative-risk) of nearly 5 were achieved using the larger colloid size, and nearly 30 using the smaller colloid size. An amount of 16-31 MBq of the colloid 2 was the optimal activity in these studies. On the one hand, the survival data agreed well with the biodistribution data, where higher accumulation was found in tumor with colloid 2.

CONCLUSION

Rhenium-188 offers on-site availability, medium half-life, higher beta-particle energy of 2.12 MeV for therapy and emission of 155keV gamma photon suitable for imaging. The present study demonstrated that 188Re-sulfur colloid is an effective agent in controlling tumor cells in the abdominal cavity in animals.

The curative and palliative potential of the monoclonal antibody MOv18 labelled with 211At in nude mice with intraperitoneally growing ovarian cancer xenografts--a long-term study

The purpose of the present study was to investigate the therapeutic efficacy of 211At-labelled specific monoclonal antibody MOv18 in nude mice with intraperitoneal growth of the human ovarian cancer cell line OVCAR3. In the first part of the study the antibody was injected intraperitoneally when the cancer growth was microscopic. The injected activity was 485-555 kBq. The median survival for treated mice was 213 days compared to 138 days for untreated mice (p < 0.014, log-rank test). No obvious toxicity was seen. Thirty-three percent of the mice were apparently free of cancer after 7 months and were probably cured. In the second part of the study mice with macroscopic cancer and signs of ascites were injected intraperitoneally with the same 211At-labelled antibody (377-389 kBq). This treatment possibly delayed the production of ascites. Hopefully radioimmunotherapy with regionally administered 211At-labelled antibody will be of value in women with ovarian cancer as well.

Clinical radioimmunotherapy

Radioimmunotherapy (RIT) is a promising new therapy for the treatment of a variety of malignancies. General principles of RIT are discussed, including important considerations in the selection of monoclonal antibodies (MAb) and radionuclides for RIT. Results of clinical trials using RIT for the treatment of lymphoma, leukemia, and solid tumors are summarized. The results from many of these trials are promising, especially for the treatment of lymphohematopoietic malignancies, in which a variety of MAb, radionuclides, and study designs have resulted in high response rates with a number of durable responses. Encouraging results have also been obtained using RIT to treat some solid tumors, primarily in patients with relatively low tumor burdens. RIT is generally well tolerated, with the primary toxicity being transient reversible myelosuppression in most nonmyeloablative studies. Nonhematologic toxicity, especially at nonmyeloablative doses, has been minimal in most studies. Approaches for increasing the therapeutic index of RIT are reviewed, which may further potentiate the efficacy and decrease the toxicity of RIT.

Characterization and distribution of an oncofetal antigen (M2A antigen) expressed on testicular germ cell tumours

M2A antigen is an oncofetal antigen associated with germ cell neoplasia, present in testis on fetal gonocytes and re-expressed on carcinoma in situ (CIS) and germ cell tumours. We developed a panel of monoclonal antibodies (mAb), M2A (IgG2a), D1-26 (IgG2b) and D2-40 (IgG1), to this antigen in order to characterize its structure and study its distribution among germ cell tumours. M2A antigen was purified by sequential lectin and antibody affinity chromatography and characterized as a monomeric M, 40 000 surface sialoglycoprotein, extensively glycosylated with O-linked carbohydrate structures, but devoid of N-linked sugars. Terminal sialic acid residues were required for reactivity with mAb M2A and D1-26, but not D2-40. Sections of 69 testicular germ cell tumours, fixed in formalin and embedded in paraffin, were stained with mAb D2-40 to examine the distribution of M2A antigen. Uniform membrane staining was observed in seminomas, and focal staining in 69% of embryonal carcinomas, 29% of teratomas and 25% of yolk sac tumours. CIS in the vicinity of all germ cell tumours also displayed uniform membrane staining. The characterization of M2A antigen, and the development of mAb which react with it in conventionally preserved archival specimens, provide important initiatives to study the origin and progression of germ cell neoplasia.

Breast cancer imaging with radiolabeled antibodies

Over the past 2 decades, numerous anticancer antibodies against different molecular targets and labeled with different gamma-emitting radionuclides have been studied in human tumor xenografts and in clinical trials. In breast cancer, these molecular targets have included principally tumor-associated antigens, such as carcinoembryonic antigen (CEA) and the polymorphic epithelial mucin antigen, MUC1, and more recently the growth factor receptors, EGF-R and HER-2/neu. No antibody-based agent has yet been approved for clinical use in the diagnosis of mammary carcinoma, because few trials have addressed the issue of clinical use of these imaging agents in the management of breast cancer patients. Recently, the CEA antibody Fab' fragment approved for colorectal cancer detection, Arcitumomab (CEA-Scan, [Immunomedics, Morris Plains, NJ]), has been found to image both palpable and nonpalpable breast lesions that were suspicious on screening mammograms. Results to date indicate that Arcitumomab can complement mammography by providing a high specificity and positive predictive value, thus indicating when a patient with an abnormal mammogram may proceed directly to definitive surgery without an intermediate diagnostic biopsy. Breast cancer immunoscintigraphy holds promise for advancing toward immunoPET, which should combine the specificity of antibodies with the high sensitivity and resolution of PET. It is also the foundation of breast cancer radioimmunotherapy with humanized antibodies against CEA and MUC1, as well as other immunotherapy strategies.

A survey of practice in management of malignant ascites

The purpose of this study was to determine physicians' attitudes toward and preferences for palliative management of malignant ascites. A random sample of eighty physicians practicing in Canada was selected from the memberships of the Canadian Association of Medical Oncologists, the Canadian Association of Gastroenterology, the Canadian Society of Palliative Care Physicians, and the Society of Gynecologic Oncologists of Canada. Physicians were questioned on their use of different modalities in management of malignant ascites, and preferences based on attitudes toward efficacy of various treatments. Eighty surveys were mailed, with a second mailing, followed by telephone contact. The response rate was 76% (59/78), with two potential respondents deemed ineligible. Among the 44 physicians who treat malignant ascites, paracentesis is employed by 43 (98%), and felt to be effective by 39 (89%). Diuretics are used by 61% (27/44), although fewer feel diuretics are effective management (20/44, 45%). Peritoneovenous shunts, dietary measures, and other modalities are used less frequently than either paracentesis or diuretics. The most commonly used means of managing malignant ascites is paracentesis, which is also felt to be the most effective by the group surveyed. After paracentesis, diuretics and peritoneovenous shunting are used most frequently, but there is no apparent consensus as to their effectiveness. Managing malignant ascites remains problematic, and we propose further study of management strategies to clarify the role of various treatments.

Local but no systemic immunomodulation by intraperitoneal treatment of advanced ovarian cancer with autologous T lymphocytes re-targeted by a bi-specific monoclonal antibody

We have reported a 27% overall anti-tumor response using i.p. immunotherapy of advanced ovarian carcinoma with autologous, ex vivo expanded, T lymphocytes re-targeted with bi-specific monoclonal antibody OC/TR, combined with soluble OC/TR and low-dose recombinant interleukin-2 (IL-2). This treatment had no effect on extraperitoneal disease. Therefore we studied in 13 patients whether this immunotherapeutic protocol resulted only in local or also in systemic immunomodulation. The phenotype of the ex vivo expanded lymphocytes was mainly CD3+, 4-, 8+, 16-, 56-. Their OC/TR-re-targeted cytolytic activity against Igrov-1 ovarian-carcinoma cells was approximately as high in responders as in non-responders. Following most therapeutic cycles, the immunophenotype of lymphocytes recovered from the peritoneal fluid was similar to that of the infused T cells (i.e., mainly CD3+, 4-, 8+) and they were coated with OC/TR. However, cytolytic activity of the recovered lymphocytes against Igrov- 1 cells was low in direct assays, and only slightly increased after additional in vitro re-targeting with OC/TR. Systemically, the i.p. immunotherapy resulted in a transient lymphopenia lasting for about 7 days, low (i.e., 5 to 13 ng/ml) serum concentrations of free, functional OC/TR, and very weak coating of circulating T lymphocytes with OC/TR. These peripheral-blood T lymphocytes did not exert OC/TR-re-targeted cytolytic activity. Thus, locoregional OC/TR-re-targeted cellular immunotherapy resulted in substantial local immunomodulation and anti-tumor effects but virtually no systemic immunomodulation.

Frontiers of Ovarian Cancer Therapy

Since the majority of patients with ovarian cancer present with advanced stages of disease, more effective systemic approaches are needed to add to the benefits of surgical staging and debulking. New combinations of taxoids with cisplatin have prolonged survival, and other chemotherapeutic agents are being evaluated. Immunotherapy, including intraperitoneal approaches with monoclonal antibodies, cellular therapies and vaccines, hormone therapy with well-known drugs such as tamoxifen, and gene therapy give promise for the future.

Palliative medicine and the medical oncologist. Defining the purview of care

The fusion of palliative medicine and medical oncology, in practice and in education, can provide a better standard of patient care, reduce the risk of oncologist burnout, and increase the likelihood of patient family and physician satisfaction. There need be no gulf between these disciplines, and only together do they represent truly comprehensive cancer care. The realization of this fusion will require the participation of individual clinicians, program directors, and the policy makers for cancer centers, professional organizations, and the health care regulatory authorities. It is a logical next step in the evolution of medical oncology.

Malignant ascites

Investigation and treatment of malignant ascites are often in the hands of the general surgeon and can be difficult. This article considers the aetiology and pathophysiology of malignant ascites and explores the best form of management. Established treatment modalities and new therapeutic options are reviewed and a new management regimen based on a knowledge of the tumour of origin is proposed, which aims to balance potential benefit against morbidity.

Radioimmunotherapy of solid cancers: A review

Depending on radionuclide characteristics, radioimmunotherapy (RIT) relies on radioactivity to destroy cells distant from immunotargeted cells. Therefore, even heterogeneous tumors (for antigen recognition) can be treated, because not all cells have to be targeted. Substantial complete response rates have been reported in patients with non-Hodgkin's lymphoma. Much more modest results have been reported for patients with bulky solid tumors, e.g. adenocarcinomas. The radiation doses delivered by targeting antibodies are generally too low to achieve major therapeutic responses. Dose escalation is limited by myelotoxicity, and higher doses need to be delivered to neoplasms less radiosensitive than lymphomas. Various trials for both systemic and regional RIT have been reported on. Intraperitoneal administration has been applied for colorectal and ovarian carcinomas. Our own results indicate that, e.g., intraperitoneal pseudomyxoma can be treated with RIT. Myelotoxicity can be reduced by anti-antibody-enhancement, 2- and 3-step strategies, bispecific monoclonal antibodies (MAbs), and extracorporeal immunoadsorption. The radionuclide has to be selected properly for each purpose; it can be a beta-emitter, e.g. I-131, Y-90, Re-188, Re-186, Lu-177 or Sm-153, an alpha-emitter At-211 or Bi-212 or an Auger-emitter, e.g. I-125, I-123. One major problem with RIT, besides slow penetration rate into tumor tissue and low tumor-to-normal tissue ratio, is the HAMA response, which can be partly avoided by the use of humanized MAbs and immunosuppression. However, RIT will be, because of all the recent developments, an important form of cancer management.

Monoclonal antibodies used in the detection and treatment of epithelial ovarian cancer

Conventional therapy for epithelial ovarian cancer, including aggressive cytoreductive surgery followed by combination chemotherapy regimens, has failed to reduce the number of deaths caused by this disease, which remains the most lethal of gynecologic malignancies. Monoclonal antibodies, which offer the promise of high selectivity for detection and therapy, may be targeted to tumor-associated antigens, growth factors, receptors, or oncogenes. They may be used alone as immunotherapeutic agents or conjugated to chemotherapeutic drugs, toxins, or radionuclides. Radioimmunoconjugates may also be used for preoperative or intraoperative tumor localization. The authors focused on the clinical utility, technical limitations, and potential of monoclonal antibodies in the detection and treatment of epithelial ovarian cancer with emphasis on radioimmunodetection and radioimmunotherapy.

A novel anti-seminoma monoclonal antibody (M2A) labelled with technetium-99m: potential application for radioimmunoscintigraphy

OBJECTIVE

To study the potential usefulness of monoclonal antibody (mAb) M2A specific for seminoma to image tumour nodules in a preclinical nude mouse model.

MATERIALS AND METHODS

MAb M2A was labelled with technetium-99m (99mTc) following reduction and was administered intraperitoneally to nude mice bearing subcutaneous HEY cell xenografts against which the antibody was originally raised. Biodistribution and gamma scintigraphy studies were performed 24 h after administration of 99mTc-M2A.

RESULTS

Biodistribution studies showed specific targeting of 99mTc-M2A to HEY tumours in comparison with control mAb 99mTc-6E8 and 99mTc-2G3 which do not bind to HEY cells. Subcutaneous HEY cell tumours (0.5-1.0 g) were successfully imaged using gamma-scintigraphy following administration of 99mTc-M2A.

CONCLUSION

The results of this study indicate the potential usefulness of 99mTc-M2A as a clinical reagent for imaging seminoma metastases.