The routinization of intraperitoneal (intracavitary) chemotherapy and immunotherapy

In Vivo Anticancer Efficacy and Toxicity Studies of a Novel Polymer Conjugate N-Acetyl Glucosamine (NAG)-PEG-Doxorubicin for Targeted Cancer Therapy

A novel polymer-drug conjugate, polyethylene glycol-N-(acetyl)-glucosamine-doxorubicin (PEG-NAG-DOX) was evaluated in this study for its in vivo potential for treatment of tumours demonstrating improved efficacy and reduced toxicity. The proposed polymer-drug conjugate comprised of polyethylene glycol-maleimide (mPEG-MAL, 30000 Da) as a carrier, doxorubicin (DOX) as an anticancer drug and N-acetyl glucosamine (NAG) as a targeting moiety as well as penetration enhancer. Doxorubicin has a potent and promising anticancer activity; however, severe cardiotoxicity limits its application in cancer treatment. By modifying DOX in PEG-NAG-DOX prodrug conjugate, we aimed to eliminate this limitation. In vivo anticancer efficacy of the conjugate was evaluated using BDF mice-induced skin melanoma model by i.v. administration of DOX conjugates. Anticancer efficacy studies were done by comparing tumour volume, body weight, organ index and percent survival rate of the animals. Tumour suppression achieved by PEG-NAG-DOX at the cumulative dose of 7.5 mg/kg was two-fold better than that achieved by DOX solution. Also, the survival rate for PEG-NAG-DOX conjugate was >70% as compared to <50% survival rate for DOX solution. In addition, toxicity studies and histopathological studies revealed that while maintaining its cytotoxicity towards tumour cells, PEG-NAG-DOX conjugate showed no toxicities to major organs. Therefore, PEG-NAG-DOX conjugate can be suggested as a desirable candidate for targeted cancer therapy.

Review: Advances in Intraperitoneal (Intracavitary) Administration of Synthetic Polymers for Immunotherapy and Chemotherapy

Intraperitoneal (IP) catheters linked to subcutaneous portals have made routine intracavitary chemotherapy or immunotherapy safe and convenient. The IP route is anatomically appropriate for adjuvant or palliative treatment of intracavitary disease. IP chemotherapy has been successfully applied to ovarian, mesothelial, and gastrointestinal tumors.

Data shows that IP divinyl ether/maleic anhydride copolymer. MVE-2 (MW 15,000), has distinct localizing and toxicologic differences from that given intravenously (IV). When MVE-2 is given IV renal injury is observed; this is not seen on IP administration. The highest IP concentrations are found in mediastinal and mesenteric nodes, thymus and testis while the highest IV MVE-2 accumulation is found in the liver, spleen, adrenal, and kidney.

The IP route for treatment of tumors allows for high local tumoricidal drug concentrations or for regionalized immunostimulation with activating polymers or leukokines. The IP space can provide an antitumor, and antiviral immunizing site and/or a source of activated antitumor peritoneal exudate cells. The use of IP chemotherapy readily permits systemic neutralization of drug toxicity and can provide high portal venous concentrations of drug for the treatment of early liver metastasis.

This review speaks to the convenience and safety of the IP intracavitary route which provides a new option for the clinical utilization of polymers where regionalized abdominal effects and improved therapeutic index are warranted. The biologic application of IP polymers requires polymer distribution and kinetic studies which will provide unique tissue concentrations for application to immunization, cancer treatment and other diseases.

Fluorouracil Plus Leucovorin Induces Submandibular Salivary Gland Enlargement in Rats

The administration of 5-fluorouracil (FU) and leucovorin (LV) to rats induced a previously unreported sialoadenitis-like toxicity. Four different treatment regimens were used: daily-times-5 iv or ip injections of LV (200 mg/kg) followed 30 minutes later by FU (27.5 mg/kg or 35 mg/kg). These treatments resulted in 3 severity levels of systemic toxicity indicated by changes in body weight. In addition to the well known FU+LV-induced diarrhea, myelosuppression, and stomatitis, facial edema, and enlargement of the submandibular salivary gland were consistently seen. Facial edema occurred almost exclusively in rats that subsequently underwent excessive weight loss and were euthanized. The submandibular, but not parotid or sublingual, salivary gland was enlarged and the severity of this effect changed in a bell-shaped relationship with respect to increasing FU+LV induced loss of body weight. Histologic examination of affected glands established the occurrence of bacterial infection, sialoadenitis and destruction of gland tissue. This paper provides the first known documentation of FU+LV treatment-induced selective pathology of the submandibular salivary gland. The selectivity of this toxicity, apparently not normally seen in humans, to the submandibular salivary gland of the rat is of interest and its mechanism warrants further investigation.

Polymer conjugates as anticancer nanomedicines

The transfer of polymer-protein conjugates into routine clinical use, and the clinical development of polymer-anticancer-drug conjugates, both as single agents and as components of combination therapy, is establishing polymer therapeutics as one of the first classes of anticancer nanomedicines. There is growing optimism that ever more sophisticated polymer-based vectors will be a significant addition to the armoury currently used for cancer therapy.

The dawning era of polymer therapeutics

As we enter the twenty-first century, research at the interface of polymer chemistry and the biomedical sciences has given rise to the first nano-sized (5-100 nm) polymer-based pharmaceuticals, the 'polymer therapeutics'. Polymer therapeutics include rationally designed macromolecular drugs, polymer-drug and polymer-protein conjugates, polymeric micelles containing covalently bound drug, and polyplexes for DNA delivery. The successful clinical application of polymer-protein conjugates, and promising clinical results arising from trials with polymer-anticancer-drug conjugates, bode well for the future design and development of the ever more sophisticated bio-nanotechnologies that are needed to realize the full potential of the post-genomic age.

Mechanism of tumor-targeted delivery of macromolecular drugs, including the EPR effect in solid tumor and clinical overview of the prototype polymeric drug SMANCS

This review article describes three aspects of polymeric drugs. The general mechanism of the EPR (enhanced permeability and retention) effect and factors involved in the effect are discussed, in view of the advantages of macromolecular therapeutics for cancer treatment, which are based on the highly selective EPR-related delivery of drug to tumor. Also described are advantages of more general water-soluble polymeric drugs as primary anticancer agents, using SMANCS as an example. Last, SMANCS/Lipiodol is discussed with reference to the type of formulation for arterial injection with most pronounced tumor selective delivery, as well as its advantages, precautions, and side effects from the clinical standpoint.

Ovarian adenocarcinoma in premenarchal girls

Ovarian neoplasms are unusual in the paediatric age group; the majority of them are of germ cell origin. Malignant epithelial tumours of the ovary occur infrequently in adolescent girls. Ovarian carcinoma in particular is extremely rare before puberty. The authors describe 3 cases of adenocarcinoma of the ovary in premenarchal girls and highlight the unique characteristics of this tumour in this age group.

Intramedullary cisplatin chemotherapy: experience in four dogs with osteosarcoma

Single-agent intramedullary cisplatin chemotherapy provided effective localised control in two of four dogs with advanced stage osteosarcoma unable to withstand an amputation or limb-sparing surgery. Complete remission of the local neoplasm was observed in one of the four dogs, partial remission of the local neoplasm in one dog and progressive disease in the other two. Limb function was preserved in one dog for seven months and that dog was found to be tumour-free when euthanased due to unrelated causes. These preliminary results warrant further investigation into the use of intramedullary cisplatin chemotherapy in the localised management of canine appendicular osteosarcoma. It is possible that this mode of treatment may be combined with other treatments to maximise the survival (i.e., systemic control) in other dogs affected with appendicular osteosarcoma.

Complications of heated intraperitioneal chemotherapy and strategies for prevention

Heated intraperitoneal chemotherapy is a potentially useful strategy for therapy of peritoneal carcinomatosis in adult patients, and we have found it to be associated with an acceptable complication rate. Careful perioperative management is critical, and we have presented our current experience guidelines for management and overview of complications.

Development of lung metastases after curative intraperitoneal chemotherapy in a rat colon cancer model

A model of colon peritoneal carcinomatosis was developed by injecting 5 x 10(7) viable tumor cells intraperitoneally into Fisher 344 rats. All 40 control rats developed bulky abdominal tumor with ascites and died of peritoneal carcinomatosis and bowel obstruction (median survival 5 weeks). One day after tumor implantation, treatment group rats received a single intraperitoneal injection of single agent or combination chemotherapy. The most active intraperitoneal single agents were 5-fluorouracil, cisplatin, and etoposide. The most active combination was 5-fluorouracil and cisplatin. Combination chemotherapy produced a significant increase in median, 10-week, and 20-week survival (vs control and single agent). Six of 11 (55%) rats treated with intraperitoneal combination chemotherapy dying between 10-20 weeks died of lung metastasis with cure of intraperitoneal tumor. The increased ability of intraperitoneal combination chemotherapy to cure intraperitoneal disease was offset by the development of lung metastasis.

Intraperitoneal tumor growth and chemotherapy in a rat model

Animal models are important to evaluate new treatment modalities. In the present paper a new animal model is described, in which the effects of intraperitoneal (i.p.) administration of cytostatic drugs on cancers restricted to the peritoneal cavity can be studied. The tumor cell line used is a chemically induced carcinoma (CC531), sensitive in vitro to cisplatin (cDDP), carboplatin (CBDCA), 5-fluorouracil (5-FU), doxorubicin and mitoxantrone. Three to 5 weeks after i.p. inoculation of 2 x 10(6) CC531 cells, 80% of Wag/Rij rats develop small tumor nodules on peritoneal surfaces. Both tumor size and localization at this time are comparable to the human situation, especially to cases of minimal residual disease ovarian carcinoma. The model has been used to determine the usefulness of i.p. treatment in comparison to i.v. Changing the route of administration of cDDP from i.v. to i.p. increases tumor platinum concentrations and prolongs survival. The model offers the possibility to study drug pharmacokinetics and tumor drug penetration related to i.p. drug administration.