Optimal drug delivery for intraperitoneal paclitaxel (PTX) in murine model.

BACKGROUND: Repeated intraperitoneal (IP) administration of paclitaxel (PTX) with concurrent systemic chemotherapy is clinically effective for the treatment of peritoneal metastases (PM) from gastric cancer. However, it is unclear how biochemical modifications may affect the pharmacokinetics and bioavailability of IP administered PTX. METHODS: In a xenograft PM model using human gastric cancer cells, MKN45, fluorescein-conjugated PTX (OG-PTX) was given IP and the intra-tumor distribution of PTX examined with fluorescein microscopy. RESULTS: After IP injection, PTX was seen to directly infiltrate up to several hundred micrometers from the surface of the PM. Co-injection with 5 % non-animal stabilized hyaluronic acid increased PTX infiltration and suppressed the development of PM more efficiently than PTX alone. PTX solubilized with amphiphilic polymer composed of 2-methacryloyloxyethyl phosphorylcholine (MPC) and n-butyl methacrylate (BMA) efficiently formed a micellar formation 50-100 nm in diameter. IP injection of the nanomicellar PTX (PTX-30W) also showed significantly enhanced tumor infiltration and further inhibition of the growth of PM compared with PTX solubilized with Cremophor-ethanol (PTX-Cre). Finally, IP administration of NK105, another nanomicellar PTX, inhibited the growth of subcutaneous tumors as well as PM, compared with conventional PTX-Cre in the same murine model. CONCLUSIONS: PTX administered IP directly infiltrates PM and are thus a useful strategy for the treatment of PM. Drug modification with nanotechnology may further enhance penetration of PM resulting in improved clinical efficacy.

[A case of carcinomatous cardiac tamponade caused by breast cancer treated with instillation of paclitaxel and minocycline].

The patient was a 56-year-old woman who had undergone the Patey operation for left breast cancer when she was 45 years old. She had complained of dyspnea and shortness of breath at the time of exercise. Bilateral accumulation of pleural effusion and pericardial fluid was observed on chest radiographs and computed tomography(CT)scans. Under the diagnosis of cardiac tamponade, the patient was treated with pericardial drainage and local chemotherapy(intra-pericardial dosage of paclitaxel 45 mg and minocycline 100 mg)with the aim of preventing the accumulation of pericardial effusion. Subsequently, the pericardial effusion continued to disappear. The patient was treated with systemic chemotherapy. At the age of 58 years, she died of breast cancer. After treatment with pericardial drainage and local chemotherapy, she did not experience pericardial reaccumulation or cardiac tamponade. Thus, the method of local chemotherapy(intra-pericardial dosage of paclitaxel 45 mg and minocycline 100 mg)was considered effective.

Intraperitoneal administration of cisplatin via an in situ cross-linkable hyaluronic acid-based hydrogel for peritoneal dissemination of gastric cancer.

PURPOSE: To develop a drug-delivery system for the prolonged retention of intraperitoneally (i.p.) administered cisplatin (CDDP) to deliver intraperitoneal chemotherapy against peritoneal carcinomatosis effectively. METHODS: CDDP was encapsulated inside an in situ cross-linkable hyaluronic acid (HA)-based hydrogel. The gelation and degradation kinetics of the hydrogel and the release kinetics of CDDP were investigated in vitro, and the antitumor effect was investigated in a mouse model of peritoneal dissemination of human gastric cancer. RESULTS: The gelation time varied according to the concentration of two polymers: HA-adipic dihydrazide and HA-aldehyde. CDDP was released from the hydrogel for more than 4 days. A cell proliferation assay showed that the polymers themselves were not cytotoxic toward MKN45P, a human gastric cancer cell line. By mixing the two polymers in the peritoneum, in situ gelation was achieved. The weight of peritoneal nodules decreased in the hydrogel-conjugated CDDP group, whereas no significant antitumor effect was observed in the free CDDP group. CONCLUSIONS: In situ cross-linkable HA hydrogels represent a promising biomaterial to prolong the retention and sustain the release of intraperitoneally administered CDDP in the peritoneal cavity and to enhance its antitumor effects against peritoneal dissemination.

Flow cytometric quantification of intraperitoneal free tumor cells in patients with peritoneal metastasis.

BACKGROUND: Peritoneal metastasis (PM) is the most life-threatening type of metastasis in abdominal malignancy. To improve the diagnostic accuracy of cytologic detection (CY) of free tumor cells (FTC) in the peritoneal cavity, we tried to quantify the FTC to leukocyte ratio using flow cytometry in patients with peritoneal metastasis. METHODS: Cells were recovered from ascites or peritoneal lavages from 106 patients who underwent abdominal surgery and additional 89 samples which were obtained from peritoneal catheter or access port in patients with PM (+) gastric cancer. The cells were immunostained with monoclonal antibodies to CD45 and to CD326 (EpCAM). Using flow cytometry, CD326 (+) and CD45 (+) cells were classified as either tumor cells (T) or leukocytes (L) and the T/L ratio (TLR) was calculated. RESULTS: In 106 samples obtained by laparotomy, Median (M) of the TLR of PM (+) patients was 1.39% (0-807.87%) which was significantly higher than PM (-) patients (M=0%, 0-2.14%, P < 0.001). In PM (+) patients, 86 CY (+) samples showed higher TLR than 61 CY (-) samples (M=2.81%, 0.02-1868.44% vs. M=0%, 0-3.45%, p<0.0001). In all of the 24 patients who were monitored for TLR before and after intraperitoneal (IP) chemotherapy, the TLR was reduced which was more dramatic than the results of the change in cytology. CONCLUSIONS: TLR measured with FACS is an excellent reflection of the tumor spread in the peritoneal cavity and could be a reliable diagnostic biomarker to determine the severity of PM as well as effectiveness of IP chemotherapy.

Flow cytometric quantification of intraperitoneal free tumor cells (FTC) in patients with peritoneal metastasis.

Background: Peritoneal metastasis (PM) is the most life-threatening type of metastasis in abdominal malignancy. To improve the diagnostic accuracy of cytologic detection (CY) of free tumor cells (FTC) in the peritoneal cavity, we tried to quantify the FTC to leukocyte ratio using flow cytometry in patients with peritoneal metastasis. Methods: Cells were recovered from ascites or peritoneal lavages from 106 patients who underwent abdominal surgery and additional 89 samples which were obtained from peritoneal catheter or access port in patients with PM (+) gastric cancer. The cells were immunostained with monoclonal antibodies to CD45 and to CD326 (EpCAM). Using flow cytometry, CD326 (+) and CD45 (+) cells were classified as either tumor cells (T) or leukocytes (L) and the T/L ratio (TLR) was calculated. Results: In 106 samples obtained by laparotomy, Median (M) of the TLR of PM (+) patients was 1.39% (0-807.87%) which was significantly higher than PM (-) patients (M=0%, 0-2.14%, p<0.001). In PM (+) patients, 86 CY (+) samples showed higher TLR than 61 CY (-) samples (M=2.81%, 0.02-1868.44% vs. M=0%, 0-3.45%, p<0.0001). In all of the 24 patients who were monitored for TLR before and after intraperitoneal chemotherapy, the TLR was reduced which was more dramatic than the results of the change in cytology. Conclusion: TLR measured with FACS is an excellent reflection of the tumor spread in the peritoneal cavity and could be a reliable diagnostic biomarker to determine the severity of PM as well as effectiveness of IP chemotherapy. © 2013 Clinical Cytometry Society.

Spatial distribution of intraperitoneally administrated paclitaxel nanoparticles solubilized with poly (2-methacryloxyethyl phosphorylcholine-co n-butyl methacrylate) in peritoneal metastatic nodules.

Intraperitoneal (i.p.) administration of paclitaxel nanoparticles (PTX-30W) prepared by solubulization with the amphiphilic copolymer of 2-methacryloxyethyl phosphorylcholine and n-butyl methacrylate can efficiently suppress the growth of peritoneal metastasis. In this study, we characterized the drug distribution of i.p. injected PTX-30W in peritoneal tumor and liver in a mouse model using MKN45, human gastric cancer cells. Oregon green-conjugated PTX-30W showed perivascular accumulation in MKN45 tumor in the peritoneum at 24 h after intravenous (i.v.) injection; however, the amount of PTX in tumor was markedly less than that in liver. In contrast, a larger amount of PTX accumulated in the peripheral area of disseminated nodules at 1 h after i.p. injection and the area gradually enlarged. The depth of PTX infiltration reached 1 mm from the tumor surface at 48 h after i.p. injection, and the fluorescence intensity was markedly greater than that in liver. Interestingly, i.p. injected PTX preferentially accumulated in relatively hypovascular areas, and many tumor cells in the vicinity of PTX accumulation showed apoptosis. This unique accumulation pattern and lesser washout in hypovascular areas are thought to be attributable to the superior penetrating activity of PTX-30W, and thus, PTX-30W is considered to be highly suitable for i.p. chemotherapy for peritoneal dissemination.

Weekly intravenous and intraperitoneal paclitaxel combined with S-1 for malignant ascites due to advanced gastric cancer.

Malignant ascites caused by gastric cancer are chemotherapy resistant and carry a poor prognosis. The efficacy of a regimen including intraperitoneal paclitaxel (PTX) was evaluated in 33 gastric cancer patients with ascetic fluid in the peritoneal cavity diagnosed with computed tomography (CT) scanning. Synchronous administration of intravenous (50 mg/m(2)) and intraperitoneal (20 mg/m(2)) PTX was performed via a subcutaneously placed intraperitoneal catheter on days 1 and 8, and S-1 was administered twice daily at 80 mg/m(2)/day for 14 consecutive days from day 1 to day 14, followed by 7 days of rest. The ascitic fluid volume was calculated with NIH Image J software using continuous CT images. After 2-4 treatment cycles, 23 (70%) patients showed reductions in their ascitic volumes of >50%. Ascites disappeared completely in 8 patients and were markedly reduced (to <3% of the original volume) in 4 of the 9 patients (44%) who initially had massive (>2,500 ml) ascites. Median overall survival was significantly better in patients with ascitic reduction. Weekly intravenous and intraperitoneal PTX combined with S-1 was highly effective in gastric cancer with malignant ascites. The change in ascitic fluid volumes determined by CT image measurements is a useful predictor of outcome in these patients.

Adiponectin receptors are downregulated in human gastric cancer.

BACKGROUND: Adiponectin has been shown to have suppressive effects on tumor development, but the expression of adiponectin receptors in tumor tissue has not been fully elucidated. The purpose of this study was to quantitatively evaluate the expression of two adiponectin receptors, AdipoR1 and AdipoR2, in gastric cancer tissue. METHODS: The mRNA levels of AdipoR1 and AdipoR2 were evaluated by quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemical staining in 67 gastric cancer tissues and their normal counterparts. In addition, the effects of cytokines on AdipoR1 and AdipoR2 expression in cultured gastric cancer cells were examined. RESULTS: As compared to findings in the normal counterparts, AdipoR1 mRNA expression, standardized by ß-actin mRNA, tended to be lower (cancer 0.488 ± 0.039, normal 0.955 ± 0.281, p = 0.0726) and AdipoR2 expression was significantly lower (0.818 ± 0.081, 1.500 ± 0.222, p = 0.0035) in gastric cancer tissue. Immunohistochemical examination showed the same tendency for AdipoR1 and AdipoR2 expression in epithelial cells. Moreover, AdipoR2 was strongly expressed in interstitial cells. However, the expression levels of these receptors did not show a strong correlation with various pathological factors. An in vitro experiment using two gastric cancer cell lines, MKN-74 and NUGC-3, showed that the expression levels of AdipoR1 and AdipoR2 were significantly decreased by transforming growth factor (TGF)-ß in a dose-dependent manner. CONCLUSIONS: Two major adiponectin receptors were decreased in gastric cancer as compared to findings in normal gastric epithelium. TGF-ß may be involved in this receptor downregulation. This downregulation may be an ideal strategy for cancer cells to escape the antiproliferative effects of adiponectin in the initial phase of tumor development.

Intraperitoneal administration of paclitaxel solubilized with poly(2-methacryloxyethyl phosphorylcholine-co n-butyl methacrylate) for peritoneal dissemination of gastric cancer.

Intraperitoneal (i.p.) administration of paclitaxel (PTX) is a hopeful therapeutic strategy for peritoneal malignancy. Intravenously (i.v.) injected nanoparticle anticancer drugs are known to be retained in the blood stream for a long time and favorably extravasated from vessels into the interstitium of tumor tissue. In this study, we evaluated the effect of i.p. injection of PTX (PTX-30W), which was prepared by solubulization with water-soluble amphiphilic polymer composed of PMB-30W, a co-polymer of 2-methacryloxyethyl phosphorylcholine and n-butyl methacrylate, for peritoneal dissemination of gastric cancer. In a peritoneal metastasis model with transfer of MKN45P in nude mice, the effect of i.p. administration of PTX-30W was compared with conventional PTX dissolved in Cremophor EL (PTX-Cre). The drug accumulation in peritoneal nodules was evaluated with intratumor PTX concentration and fluorescence microscopic observation. PTX-30W reduced the number of metastatic nodules and tumor volume significantly more than did conventional PTX dissolved in Cremophor EL (PTX-Cre), and prolonged the survival time (P < 0.05). PTX concentration in disseminated tumors measured by HPLC was higher in the PTX-30W than in the PTX-Cre group up to 24 h after i.p. injection. Oregon green-conjugated PTX-30W, i.p. administered, preferentially accumulated in relatively hypovascular areas in the peripheral part of disseminated nodules, which was significantly greater than the accumulation of PTX-Cre. I.p. administration of PTX-30W may be a promising strategy for peritoneal dissemination, due to its superior characteristics to accumulate in peritoneal lesions.

Phase I pharmacokinetic study of weekly intravenous and intraperitoneal paclitaxel combined with S-1 for advanced gastric cancer.

OBJECTIVES: A dose-escalation study of weekly intraperitoneal paclitaxel (PTX) combined with S-1 and intravenous PTX was performed to determine the maximum-tolerated dose (MTD) and recommended dose (RD) in gastric cancer patients. PATIENTS AND METHODS: Nine gastric cancer patients with peritoneal dissemination and/or cancer cells on peritoneal cytology were enrolled. PTX was administered intravenously on days 1 and 8 at a fixed dose of 50 mg/m(2), and intraperitoneally with an initial dose of 20 mg/m(2), stepped up to 30 or 40 mg/m(2). S-1 was administered at a fixed dose of 80 mg/m(2)/day for 14 consecutive days, followed by 7 days of rest. A pharmacokinetic study of PTX was also performed. RESULTS: The MTD was determined to be 30 mg/m(2), as 2 of 3 patients developed dose-limiting toxicities, grade 3 febrile neutropenia and diarrhea. Therefore, the RD was determined to be 20 mg/m(2). The intraperitoneal and serum PTX concentration remained effective for over 72 and 48 h, respectively. CONCLUSIONS: Combined chemotherapy of S-1 plus weekly intravenous and intraperitoneal PTX was shown to be a safe regimen that should be further explored in clinical trials.

Intraoperative blood loss is a critical risk factor for peritoneal recurrence after curative resection of advanced gastric cancer.

BACKGROUND: Perioperative blood transfusion has been shown to be associated with poor outcome in various types of malignancy. However, the relationship between the amount of blood loss and specific types of cancer recurrence has not been documented. METHODS: We retrospectively examined the amount of intraoperative blood loss and the recurrence pattern in 146 patients who underwent curative gastrectomy for advanced gastric cancer and assessed the possible correlation between intraoperative blood loss and peritoneal, locoregional, and hematogenous recurrences. RESULTS: The amount of intraoperative blood loss in patients who developed peritoneal recurrence was significantly greater than that in patients without peritoneal recurrence, irrespective of blood transfusion. In contrast, the blood loss was not associated with nodal or hematogenous recurrence. Multivariate analysis demonstrated that large blood loss as well as operative curability B and adjuvant chemotherapy were independent risk factors for peritoneal recurrence and a worse outcome in advanced gastric cancer. CONCLUSIONS: Intraoperative blood loss in curative gastrectomy for advanced gastric cancer may have a specific association with the development of peritoneal recurrence. Surgeons must remember that clean and dry surgery may lessen not only 30-day mortality and morbidity but long-term peritoneal recurrence in gastric cancer.

Intra-peritoneal administration of paclitaxel with non-animal stabilized hyaluronic acid as a vehicle--a new strategy against peritoneal dissemination of gastric cancer.

BACKGROUND AND AIM: Intra-peritoneal administration (i.p.) of Taxanes has recently been reported to be effective for the treatment of peritoneal dissemination, presumably because extremely high concentration of the drug is achievable onto the disseminated nodules as compared to intra-venous administration. Here, we aimed to investigate the ability of non-animal stabilized hyaluronic acid (NASHA) to retain the anti-cancer drugs in the peritoneal cavity, and, consequently, improve the efficacy of i.p. administration of paclitaxel. METHODS: Mice were inoculated i.p. with MKN45P gastric cancer cells. The mice received i.p. administrations of paclitaxel, without or with NASHA, once a week for 3 consecutive weeks, and the intra-peritoneal nodules were counted after 4 weeks. The ability of NASHA to retain the i.p. administered liquid and paclitaxel in abdominal cavity was also investigated. Finally, the concentration of paclitaxel in metastatic nodule was measured with HPLC. RESULTS: In the group receiving paclitaxel with NASHA, the number of disseminated nodules were significantly smaller than in those receiving paclitaxel without NASHA. The fluid volumes and concentration of paclitaxel recovered from the abdominal cavity as well as the concentrations of paclitaxel in metastatic nodule were significantly increased by the addition of NASHA. CONCLUSION: Our results indicate that NASHA improves the exposure time of i.p. administrated paclitaxel to disseminated nodules by retaining the drug in the abdominal cavity. Since the material is used in cosmetic surgery with few adverse effects, NASHA can be clinically used as the vehicle for the i.p. administration of anti-cancer agents for advanced gastric cancer with peritoneal dissemination.