Effect of intraperitoneal administration of docetaxel on peritoneal dissemination of gastric cancer

Intraperitoneal Paclitaxel Is a Safe and Effective Therapeutic Strategy for Treating Mucinous Appendiceal Adenocarcinoma

Appendiceal adenocarcinomas (AA) are a rare and heterogeneous mix of tumors for which few preclinical models exist. The rarity of AA has made performing prospective clinical trials difficult, which has partly contributed to AA remaining an orphan disease with no chemotherapeutic agents approved by the FDA for its treatment. AA has a unique biology in which it frequently forms diffuse peritoneal metastases but almost never spreads via a hematogenous route and rarely spreads to lymphatics. Given the localization of AA to the peritoneal space, intraperitoneal delivery of chemotherapy could be an effective treatment strategy. Here, we tested the efficacy of paclitaxel given by intraperitoneal administration using three orthotopic patient-derived xenograft (PDX) models of AA established in immunodeficient NSG mice. Weekly intraperitoneal paclitaxel treatment dramatically reduced AA tumor growth in all three PDX models. Comparing the safety and efficacy of intravenous with intraperitoneal administration, intraperitoneal delivery of paclitaxel was more effective, with reduced systemic side effects in mice. Given the established safety record of intraperitoneal paclitaxel in gastric and ovarian cancers, and lack of effective chemotherapeutics for AA, these data showing the activity of intraperitoneal paclitaxel in orthotopic PDX models of mucinous AA support the evaluation of intraperitoneal paclitaxel in a prospective clinical trial.

SIGNIFICANCE

The activity and safety of intraperitoneal paclitaxel in orthotopic PDX models of mucinous appendiceal adenocarcinoma supports the evaluation of intraperitoneal paclitaxel in a prospective clinical trial of this rare tumor type.

Utility of Molecular Analysis of Peritoneal Fluid in Staging Laparoscopy of Advanced Esophagogastric Junction and Gastric Cancer Prior to Neoadjuvant Treatment

PURPOSE

Molecular analysis of peritoneal fluid in staging laparoscopy of gastric cancer is performed to improve the detection of free intraperitoneal tumor cells. Nevertheless, its significance is controversial, especially in patients with negative cytology but positive molecular analysis. The aim of this study was to analyze the sensitivity of molecular analysis and its prognostic value.

METHODS

A retrospective analysis from April 2011 to October 2019 was performed. Cytology (Cyt) and molecular analysis were analyzed by real-time reverse transcriptase polymerase chain reaction (RT-PCR) of the carcinoembryonic antigen (CEA) and cytokeratin 20 (CK20) tumor makers.

RESULTS

During the study period, 138 staging laparoscopies were performed. Macroscopic carcinomatosis was found in 12.3%. Of the remaining 87.7%, 9.9% were Cyt + and 11.6% were Cyt- RT-PCR + . Of the latter, 9 responded to chemotherapy and underwent radical surgery. The sensitivity of cytology and molecular analysis was 0.70 and 0.76, respectively (p = 0.67). The 2-year overall survival (OS) of Cyt- RT-PCR + vs. Cyt + was similar (p = 0.1). The 2-year OS of Cyt-RT-PCR + subgroup who underwent radical surgery vs. Cyt-RT-PCR- patients was similar (p = 0.69), but disease-free survival was shorter in the first group (p = 0.005).

CONCLUSION

Our results show that the sensitivity of molecular analysis is similar to that of cytology. The prognostic value of positive molecular analysis was similar to positive cytology in terms of 2-year overall survival, except in the subgroup of operated patients in whom the overall survival was similar to that of those with a negative molecular analysis, albeit with a shorter disease-free survival.

Antitumor activity of intraperitoneal paclitaxel in orthotopic patient-derived xenograft models of mucinous appendiceal adenocarcinoma

Appendiceal adenocarcinomas (AAs) are a rare and heterogeneous mix of tumors for which few preclinical models exist. The rarity of AA has made performing prospective clinical trials difficult, and in part because of this AA remains an orphan disease with no chemotherapeutic agents approved by the FDA for its treatment. AA has a unique biology in which it frequently forms diffuse peritoneal metastases, but almost never spreads via a hematogenous route and rarely spreads to lymphatics. Given its localization to the peritoneal space we hypothesized that intraperitoneal (IP) delivery of chemotherapy could be an effective treatment strategy. Here we tested the efficacy paclitaxel given by IP administration using three orthotopic PDX models of AA established in NSG mice. Weekly treatment of 25.0 mg/kg of IP paclitaxel dramatically reduced AA tumor growth in TM00351 (81.9% reduction vs. control), PMP-2 (98.3% reduction vs. control), and PMCA-3 (71.4% reduction vs. control) PDX models. Comparing the safety and efficacy of intravenous (IV) to IP administration in PMCA-3, neither 6.25 nor 12.5 mg/kg of IV paclitaxel significantly reduced tumor growth. These results suggest that IP administration of paclitaxel is favorable to IV administration. Given the established safety record of IP paclitaxel in gastric and ovarian cancers, and lack of effective chemotherapeutics for AA, these data showing the activity of IP paclitaxel in orthotopic PDX models of mucinous AA support the evaluation of IP paclitaxel in a prospective clinical trial.

Delivery of aPD-L1 antibody to i.p. tumors via direct penetration by i.p. route: Beyond EPR effect

Chemotherapy for peritoneal dissemination is poorly effective owing to limited drug transfer from the blood to the intraperitoneal (i.p.) compartment after intravenous (i.v.) administration. i.p. chemotherapy has been investigated to improve drug delivery to tumors; however, the efficacy continues to be debated. As anticancer drugs have low molecular weight and are rapidly excreted through the peritoneal blood vessels, maintaining the i.p. concentration as high as expected is a challenge. In this study, we examined whether i.p. administration is an efficient route of administration of high-molecular-weight immune checkpoint inhibitors (ICIs) for the treatment of peritoneal dissemination using a model of peritoneal disseminated carcinoma. After i.p. administration, the amount of anti-PD-L1 antibody transferred into i.p. tumors increased by approximately eight folds compared to that after i.v. administration. Intratumoral distribution analysis revealed that anti-PD-L1 antibodies were delivered directly from the i.p. space to the surface of tumor tissue, and that they deeply penetrated the tumor tissues after i.p. administration; in contrast, after i.v. administration, anti-PD-L1 antibodies were only distributed around blood vessels in tumor tissues via the enhanced permeability and retention (EPR) effect. Owing to the enhanced delivery, the therapeutic efficacy of anti-PD-L1 antibody in the peritoneal dissemination models was also improved after i.p. administration compared to that after i.v. administration. This is the first study to clearly demonstrate an EPR-independent delivery of ICIs to i.p. tumors by which ICIs were delivered in a massive amount to the tumor tissue via direct penetration after i.p. administration.

Development of a nanocapsule-loaded hydrogel for drug delivery for intraperitoneal administration

Intraperitoneal (IP) drug delivery of chemotherapeutic agents, administered through hyperthermal intraperitoneal chemotherapy (HIPEC) and pressurized intraperitoneal aerosolized chemotherapy (PIPAC), is effective for the treatment of peritoneal malignancies. However, these therapeutic interventions are cumbersome in terms of surgical practice and are often associated with the formation of peritoneal adhesions, due to the catheters inserted into the peritoneal cavity during these procedures. Hence, there is a need for the development of drug delivery systems that can be administered into the peritoneal cavity. In this study, we have developed a nanocapsule (NCs)-loaded hydrogel for drug delivery in the peritoneal cavity. The hydrogel has been developed using poly(ethylene glycol) (PEG) and thiol-maleimide chemistry. NCs-loaded hydrogels were characterized by rheology and their resistance to dilution and drug release were determined in vitro. Using IVIS® to measure individual organ and recovered gel fluorescence intensity, an in vivo imaging study was performed and demonstrated that NCs incorporated in the PEG gel were retained in the IP cavity for 24 h after IP administration. NCs-loaded PEG gels could find potential applications as biodegradable, drug delivery systems that could be implanted in the IP cavity, for example at a the tumour resection site to prevent recurrence of microscopic tumours.

Phase I Trial of Hyperthermic Intraperitoneal Chemoperfusion (HIPEC) with Cisplatin, Mitomycin, and Paclitaxel in Patients with Gastric Adenocarcinoma and Associated Carcinomatosis or Positive Cytology

BACKGROUND

The purpose of this phase I trial is to evaluate the safety and toxicity of laparoscopic hyperthermic intraperitoneal perfusion with chemotherapy (HIPEC), combining mitomycin, cisplatin, and paclitaxel for patients with gastric cancer metastatic to the peritoneum.

PATIENTS AND METHODS

A Bayesian optimal interval design was used to prospectively identify the safety and tolerability of escalating doses of paclitaxel in combination with flat doses of mitomycin (30 mg) and cisplatin (200 mg) during laparoscopic HIPEC. The primary objective is to define the maximum tolerated dose. Secondary endpoints include surgical complications and overall survival (OS).

RESULTS

A total of 27 patients were treated between 11/2017 and 11/2018. No dose-limiting toxicities were observed. Treatment-related grade 1-2 toxicities were leukopenia (11%), oral dysesthesia (4%), arthralgia (4%), and diarrhea (4%). Treatment-related grade 3-4 toxicities included leukopenia (4%) and neutropenia (4%). The maximum dose for paclitaxel was 60 mg/m². Rates of Clavien-Dindo surgical complications were grade I 96% (all electrolyte deficiencies requiring replacement), II 4%, III 0%, IV 0%, and V 4%. The median follow-up time was 15 months. One- and 2-year OS rates from date of metastatic disease were 73.9% and 58.1%, respectively.

CONCLUSIONS

Laparoscopic HIPEC with mitomycin, cisplatin, and paclitaxel may be safely used at intraperitoneal doses of 30 mg, 200 mg, and 60 mg/m², respectively. Although electrolyte abnormalities were common, systemic toxicity was low. Survival rates were promising, supporting further research into intraperitoneal therapy for stage IV gastric cancer.

Therapeutic Targeting of MDR1 Expression by RORγ Antagonists Resensitizes Cross-Resistant CRPC to Taxane via Coordinated Induction of Cell Death Programs

Overexpression of ATP-binding cassette subfamily B member 1 (ABCB1)-encoded multidrug resistance protein 1 (MDR1) constitutes a major mechanism of cancer drug resistance including docetaxel (DTX) and cabazitaxel (CTX) resistance in castration-resistant prostate cancer (CRPC). However, no therapeutics that targets MDR1 is available at clinic for taxane sensitization. We report here that retinoic acid receptor-related orphan receptor γ (RORγ), a nuclear receptor family member, unexpectedly mediates MDR1/ABCB1 overexpression. RORγ plays an important role in controlling the functions of subsets of immune cells and has been an attractive target for autoimmune diseases. We found that its small-molecule antagonists are efficacious in resensitizing DTX and CTX cross-resistant CRPC cells and tumors to taxanes in both androgen receptor-positive and -negative models. Our mechanistic analyses revealed that combined treatment with RORγ antagonists and taxane elicited a robust synergy in killing the resistant cells, which involves a coordinated alteration of p53, Myc, and E2F-controlled programs critical for both intrinsic and extrinsic apoptosis, survival, and cell growth. Our results suggest that targeting RORγ with small-molecule inhibitors is a novel strategy for chemotherapy resensitization in tumors with MDR1 overexpression.

Concomitant intraperitoneal and systemic chemotherapy for extensive peritoneal metastases of colorectal origin: protocol of the multicentre, open-label, phase I, dose-escalation INTERACT trial

INTRODUCTION

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) has become standard of care for patients with peritoneal metastases of colorectal origin with a low/moderate abdominal disease load. In case of a peritoneal cancer index (PCI) score >20, CRS-HIPEC is not considered to be beneficial. Patients with a PCI >20 are currently offered palliative systemic chemotherapy. Previous studies have shown that systemic chemotherapy is less effective against peritoneal metastases than it is against haematogenous spread of colorectal cancer. It is suggested that patients with peritoneal metastases may benefit from the addition of intraperitoneal chemotherapy to systemic chemotherapy. Aim of this study is to establish the maximum tolerated dose of intraperitoneal irinotecan, added to standard of care systemic therapy for colorectal cancer. Secondary endpoints are to determine the safety and feasibility of this treatment and to establish the pharmacokinetic profile of intraperitoneally administered irinotecan.

METHODS AND ANALYSIS

This phase I, '3+3' dose-escalation, study is performed in two Dutch tertiary referral centres. The study population consists of adult patients with extensive peritoneal metastases of colorectal origin who have a good performance status and no extra-abdominal metastases. According to standard work-up for CRS-HIPEC, patients will undergo a diagnostic laparoscopy to score the PCI. In case of a PCI >20, a peritoneal access port will be placed in the abdomen of the patient. Through this port we will administer intraperitoneal irinotecan, in combination with standard systemic treatment consisting of 5-fluorouracil/leucovorin with oxaliplatin and the targeted agent bevacizumab. Therapy consists of a maximum of 12 cycles 2-weekly.

ETHICS AND DISSEMINATION

This study protocol is approved by a research medical ethics committee (Rotterdam, Netherlands) and the Dutch Competent Authority (CCMO, The Hague, Netherlands). The results of this trial will be submitted for publication in a peer-reviewed scientific journal.

TRAIL REGISTRATION NUMBER

NL6988 and NL2018-000479-33; Pre-results.

Downstaging of lymph node metastasis after neoadjuvant intraperitoneal and systemic chemotherapy in gastric carcinoma with peritoneal metastasis

PURPOSE

The aim of the present study was to evaluate the clinical features and prognosis of lymph node metastasis (LNM) in gastric cancer patients with peritoneal metastasis (PM) after neoadjuvant intraperitoneal and systemic chemotherapy.

METHODS

A total of 69 gastric cancer patients with PM and LNM who received neoadjuvant intraperitoneal and systemic chemotherapy (NIPS) of intraperitoneal docetaxel (DXT) and cisplatin (CDDP); intravenous chemotherapy of DXT and CDDP and oral S-1in Kishiwada Tokushukai Hospital between January 2008 and February 2017. After surgical resection, the response of LNMs was studied to confirm the effect of NIPS on LNMs.

RESULTS

After NIPS, 197 lymph nodes (LNs) (42.5%) were graded as G3, the progression in LNMs were significantly better than in the primary tumors. Until the last follow-up, 1-year overall survival rate was 82.6%, and the median survival period was 22.0 ± 3.7 months. In the group of patients who had achieved a more than 50% G3 grade of the response of LNMs, the median survival period is 38 months; in the less than 50% G3 grade group, it is 14 months, that is a significantly different result. Multivariate analyses showed that the factors PCI, Post-therapeutic N status and response of the LNMs were found to be as independent prognostic factors.

CONCLUSION

Downstaging of LNMs were achieved in patients of gastric cancer with PM who received NIPS. Downstaging of LNMs after NIPS is related with the prognosis of gastric cancer and should be valued in subsequent surgery for gastric cancer with peritoneal and lymph nodes metastasis.

Intraperitoneal chemotherapy for gastric cancer with peritoneal metastasis

Peritoneal metastasis is the most frequent pattern of gastric cancer recurrence or metastasis and is a definitive determinant of prognosis. However, an effective means of treating peritoneal disease has not yet been established. Systemic chemotherapy has only a limited effect on peritoneal metastasis, although some progress has been shown in terms of median survival time, especially among patients with a minimal or moderate disease burden. Clinical research related to intraperitoneal administration of anticancer drugs is currently underway. An advantage of intraperitoneal chemotherapy is the ability to achieve high concentrations of anticancer drugs in the peritoneal cavity and the direct exposure of peritoneal deposits and free cancer cells to those drugs. In addition, pharmacokinetic studies with taxanes have shown that these high intraperitoneal drug concentrations are sustained for a considerable length of time, allowing prolonged exposure. As taxanes are the most appropriate drugs for intraperitoneal administration, the development of repeated intraperitoneal chemotherapy using taxanes for gastric cancer peritoneal metastasis-either alone or in combination with systemic chemotherapy-has taken place over the past decade, mostly in Japan. Several phase II trials and a phase III trial have recently demonstrated the efficacy of this therapy, including median survival times of 14.4-24.6 months and one-year overall survival rates of 67-91%. These results may lead to the approval of intraperitoneal taxanes, especially paclitaxel, for official insurance coverage in the near future.

Enhanced antitumor effects by docetaxel/LL37-loaded thermosensitive hydrogel nanoparticles in peritoneal carcinomatosis of colorectal cancer

Intraperitoneal chemotherapy was explored in clinical trials as a promising strategy to improve the therapeutic effects of chemotherapy. In this work, we developed a biodegradable and injectable drug-delivery system by coencapsulation of docetaxel (Doc) and LL37 peptide polymeric nanoparticles (Doc+LL37 NPs) in a thermosensitive hydrogel system for colorectal peritoneal carcinoma therapy. Firstly, polylactic acid (PLA)-Pluronic L35-PLA (PLA-L35-PLA) was explored to prepare the biodegradable Doc+LL37 NPs using a water-in-oil-in-water double-emulsion solvent-evaporation method. Then, biodegradable and injectable thermosensitive PLA-L64-PLA hydrogel with lower sol–gel transition temperature at around body temperature was also prepared. Transmission electron microscopy revealed that the Doc+LL37 NPs formed with the PLA-L35-PLA copolymer were spherical. Fourier-transform infrared spectra certified that Doc and LL37 were encapsulated successfully. X-ray diffraction diagrams indicated that Doc was encapsulated amorphously. Intraperitoneal administration of Doc+LL37 NPs–hydrogel significantly suppressed the growth of HCT116 peritoneal carcinomatosis in vivo and prolonged the survival of tumor-bearing mice. Our results suggested that Doc+LL37 NPs–hydrogel may have potential clinical applications.

Breakthrough therapy for peritoneal carcinomatosis of gastric cancer: Intraperitoneal chemotherapy with taxanes

The effect of chemotherapy on peritoneal carcinomatosis (PC) of gastric cancer remains unclear. Recently, the intraperitoneal (IP) administration of taxanes [e.g., paclitaxel (PTX) and docetaxel (DOC)] during the perioperative period has shown promising results. Herein, we summarized the rationale and methodology for using IP chemotherapy with taxanes and reviewed the clinical results. IP administered taxanes remain in the IP space at an extremely high concentration for 48-72 h. The drug directly infiltrates peritoneal metastatic nodules from the surface and then produces antitumor effects, making it ideal for IP chemotherapy. There are two types of perioperative IP chemotherapy with taxanes: neoadjuvant intraperitoneal and systemic chemotherapy and sequential perioperative intraperitoneal chemotherapy (SPIC). In SPIC, patients receive neoadjuvant IP chemotherapy and the same regimen of IP chemotherapy after cytoreductive surgery (CRS) until disease progression. Usually, a taxane dissolved in 500-1000 mL of saline at ordinary temperature is administered through an IP access port on an outpatient basis. According to phase I studies, the recommended doses (RD) are as follows: IP DOC, 45-60 mg/m²; IP PTX [without intravenous (IV) PTX], 80 mg/m²; and IP PTX (with IV PTX), 20 mg/m². Phase II studies have reported a median survival time of 14.4-24.6 mo with a 1-year overall survival of 67%-78%. A phase III study comparing S-1 in combination with IP and IV PTX to S-1 with IV cisplatin started in 2011. The prognosis of patients who underwent CRS was better than that of those who did not; however, this was partly due to selection bias. Although several phase II studies have shown promising results, a randomized controlled study is needed to validate the effectiveness of IP chemotherapy with taxanes for PC of gastric cancer.

Selection of chemotherapy for hyperthermic intraperitoneal use in gastric cancer

PURPOSE

Several studies have shown the potential benefit of cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC) in gastric cancer patients. At present the most effective chemotherapeutic regime in HIPEC for gastric cancer is unknown. The aim of this review was to provide a comprehensive overview of chemotherapeutic agents used for HIPEC in gastric cancer.

METHODS

A literature search was conducted using the PubMed database to identify studies on chemotherapy used for HIPEC in gastric cancer patients.

RESULTS AND CONCLUSION

The chemotherapeutic regime of choice in HIPEC for gastric cancer has yet to be determined. The wide variety in studies and study parameters, such as chemotherapeutic agents, dosage, patient characteristics, temperature of perfusate, duration of perfusion, carrier solutions, intraperitoneal pressure and open or closed perfusion techniques, warrant more experimental and clinical studies to determine the optimal treatment schedule. A combination of drugs probably results in a more effective treatment.

The efficacy and toxicity of paclitaxel plus S-1 compared with paclitaxel plus 5-FU for advanced gastric cancer: a PRISMA systematic review and meta-analysis of randomized controlled trials

The standard treatment for patients with advanced gastric cancer (AGC) is still a matter of debate. The chemotherapy regimen of paclitaxel (PTX) combined with S-1 has been used to treat AGC or metastatic gastric cancer.We conducted a meta-analysis to compare oral S-1 and infusional 5-fluorouracil (5-FU) to determine which agent was more efficacious and less toxic in combination with PTX. A systematic review with a meta-analysis was performed. PubMed, EmBase, the Cochrane Central Register of Controlled Trials, and the China National Knowledge Infrastructure databases were searched to select randomized controlled trials (RCTs) comparing PTX plus S-1 and PTX plus 5-FU in patients with AGC.Three RCTs were eligible and 352 patients were analyzed. PTX plus S-1 increased the disease control rate (risk ratio [RR] = 1.14, 95% confidence interval [CI] = 1.00-1.30, P = 0.04) and reduced the progressive disease rate (RR = 0.62, 95% CI] = 0.39-0.98, P = 0.04) compared with PTX plus 5-FU. There was a significant decrease in nausea (RR = 0.60, 95% CI = 0.43-0.82, P = 0.001) and vomiting (RR = 0.55, 95% CI = 0.33-0.91, P = 0.02) in patients treated with PTX plus S-1.PTX plus S-1 was associated with almost equivalent safety and a lower progressive disease rate compared with PTX plus 5-FU. PTX plus S-1 is a good alternative strategy for patients who cannot tolerate a continuous intravenous infusion.

Prognostic information derived from RT-PCR analysis of peritoneal fluid in gastric cancer patients: results from a prospective multicenter clinical trial

OBJECTIVE

The purpose of this study is to define the clinical significance of the molecular analysis of peritoneal lavage fluid in patients with gastric cancer in a multicenter prospective trial.

METHODS

Quantitative RT-PCR with CEA and CK-20 mRNA as target markers was introduced for peritoneal lavage diagnosis in 141 patients with clinically advanced gastric cancer from 9 different institutes. We then evaluated the prognostic factors in patients and also evaluated predictive markers for peritoneal recurrence in 124 patients without peritoneal metastasis at surgery

RESULTS

Out of the 141 cases, 140 patients were successfully analyzed by RT-PCR of peritoneal lavage fluids. According to multivariate analysis, the combined results of RT-PCR (CEA and CK-20) and CK-20 alone in addition to pathological N (pN)-stage were significantly correlated with overall survival. Multivariate analysis showed that the RT-PCR (CEA and CK-20) and CEA alone in addition to pathological T-stage, pN-stage, and histological grade were significantly correlated with peritoneal recurrence after surgery.

CONCLUSION

This is the first multicenter prospective study to show that RT-PCR analysis of peritoneal lavage fluid with the combination of CEA and CK-20 markers was useful for predicting overall survival and peritoneal recurrence in patients with clinically advanced gastric cancer.

The clinical importance of a transcription reverse-transcription concerted (TRC) diagnosis using peritoneal lavage fluids in gastric cancer with clinical serosal invasion: a prospective, multicenter study

PURPOSE

We have developed a novel molecular method of diagnosis using the technique of transcriptase-reverse transcriptase concerted reaction (TRC) for the detection of cancer micrometastasis. This study prospectively examined the clinical importance of the TRC diagnosis with peritoneal lavage fluids collected from gastric cancer operations at multiple institutes.

METHODS

TRC amplification targeting carcinoembryonic antigen mRNA was applied to detect gastric cancer cells in peritoneal lavage fluids obtained during gastric cancer resections from nine different hospitals. A total of 137 patients with a clinical diagnosis of serosa-invading neoplasms were enrolled to investigate the correlation between the TRC diagnosis and patient prognosis.

RESULTS

Of the 137 patients, 27 (20%) were positive by cytologic examination. In contrast, TRC targeting carcinoembryonic antigen mRNA was positive in 59 of 137 (54%) patients. TRC positivity was associated with a poorer overall survival in all patients and in the 104 patients who underwent a curative operation. TRC positivity also was associated with the peritoneal recurrence-free survival rate in the 104 curative cases. Multivariate analysis showed that TRC positivity and the pathologic N factor were prognostic factors for the overall survival time.

CONCLUSION

Our prospective multicenter study showed that the TRC test using peritoneal lavage fluids could be a potential prognostic factor to predict patient survival and peritoneal recurrence with clinically diagnosed, serosa-invading gastric cancer.

Randomized phase II study comparing paclitaxel with S-1 vs. S-1 as first-line treatment in patients with advanced gastric cancer

PURPOSE

This randomized phase II study was conducted to compare the efficacy and safety of paclitaxel with S-1 (PS) vs. S-1 in patients with advanced gastric cancer (AGC).

METHODS

Eighty-two (82) patients were 1:1 randomly assigned to oral S-1 (daily for 2 weeks, every 4 weeks' cycle) or S-1 (daily for 2 weeks, every 4 weeks' cycle) plus paclitaxel (on day 1, 8 and 15 of a 4 weeks' cycle). S-1 was orally administered with a fixed quantity according to body surface area (BSA), while paclitaxel was given 60 mg/m(2) i.v. daily through an implanted catheter. The primary endpoint was overall survival (OS). Secondary endpoints included progression-free survival (PFS), overall responsible rates and safety.

RESULTS

The median OS with PS versus S-1 monotherapy was 14.0 versus 11.0 months (P = 0.02), survival at 12 months was 61.0 % in the PS group and 46.3 % in the S-1 group. Median PFS was also significantly longer in the PS group (6.0 months) than in the S-1 group (4.0 months). The overall response rate was determined in 82 evaluable patients, and was significantly higher (P = 0.04) with PS (19 patients, 46.3 %) than with S-1 monotherapy (10 patients, 24.4 %). PS was well tolerated with no treatment-related deaths, all were grade 3-4 gastrointestinal toxicities, including anorexia, nausea, and diarrhea developed in less than 10 % of the patients.

CONCLUSIONS

Combination chemotherapy of paclitaxel with S-1 is well tolerated and active in AGC patients. Further investigation with comparative trials is needed for confirmation.

Establishing a peritoneal dissemination xenograft mouse model for survival outcome assessment of experimental gastric cancer

BACKGROUND

Peritoneal dissemination of gastric cancer is a common reason for unresectability, a frequent recurrence mechanism, and a common cause for death. The present study was performed to test peritoneal dissemination gastric cancer xenografts mouse models that would support survival outcome analyses.

MATERIALS AND METHODS

Human gastric cancer cell lines AGS, NCI-N87, and SNU-16 were intraperitoneally injected into nude mice and severe combined immunodeficiency (SCID) mice. The peritoneal tumor formation and mouse survival were compared among different groups. Mice were treated with oxaliplatin (5 mg/kg) and NVP-BEZ235 (10 mg/kg).

RESULTS

The formation rate of peritoneal cancer after intraperitoneal injection of 5 × 10(6) SNU16, NCI-N87, and AGS cells was 2/8, 6/8, and 0/8 in nude mice, and 6/6, 6/6, and 0/6 in SCID mice, respectively. Median animal survival with peritoneal dissemination was 74 d for NCI-N87 cells (10 × 10(6)), 95 d for SNU16 cells (10 × 10(6)), 78 d for SNU16 cells (20 × 10(6)), and 44 d for SNU16 cells (40 × 10(6)). In a therapeutic experiment with 40 × 10(6) SNU16 cells, animal survival was significantly improved by oxaliplatin treatment compared with the control group (58.5 d versus 45 d, P < 0.001), but not by NVP-BEZ235 (48 d versus 45 d, P = 0.249) treatment. In the accompanying subcutaneous SNU16 mouse model, relative tumor volume compared with controls was not significantly decreased by oxaliplatin treatment (P = 0.151) but by NVP-BEZ235 therapy (P = 0.008).

CONCLUSIONS

Peritoneal gastric cancer xenografts were successfully established after intraperitoneal injection NCI-N87 and SNU16 cells. These findings provide a useful survival outcome assessment model for experimental gastric cancer research.

Effects of neoadjuvant intraperitoneal/systemic chemotherapy (bidirectional chemotherapy) for the treatment of patients with peritoneal metastasis from gastric cancer

Novel multidisciplinary treatment combined with neoadjuvant intraperitoneal-systemic chemotherapy protocol (NIPS) and peritonectomy was developed. Ninety-six patients were enrolled. Peritoneal wash cytology was performed before and after NIPS through a port system. Patients were treated with 60 mg/m(2) of oral S-1 for 21 days, followed by a 1-week rest. On days 1, 8, and 15, 30 mg/m(2) of Taxotere and 30 mg/m(2) of cisplatin with 500 mL of saline were introduced through the port. NIPS is done 2 cycles before surgery. Three weeks after NIPS, 82 patients were eligible to intend cytoreductive surgery (CRS) by gastrectomy + D2 dissection + periotnectomy to achieve complete cytoreduction. Sixty-eight patients showed positice cytology before NIPS, and the positive cytology results became negative in 47 (69%) patients after NIPS. Complete pathologic response on PC after NIPS was experienced in 30 (36.8%) patients. Stage migration was experienced in 12 patients (14.6%). Complete cytoreduction was achieved in 58 patients (70.7%). By the multivariate analysis, complete cytoreduction and pathologic response became a significantly good survival. However the high morbidity and mortality, stringent patient selection is important. The best indications of the therapy are patients with good pathologic response and PCI ≤ 6, which are supposed to be removed completely by peritonectomy.

Disposition kinetics of taxanes in peritoneal dissemination

Treatment of cancers in the abdominal cavity, such as peritoneal dissemination, is difficult, but in principle intraperitoneal administration of anticancer drugs is expected to be preferable to systemic administration. Taxane anticancer drugs are used to treat gastric cancer patients with peritoneal dissemination. They are administered as micellar preparations, Taxol and Taxotere, which consist of paclitaxel in Cremophor EL (crEL) and docetaxel in Polysorbate-80 (PS-80), respectively. In this paper we review the disposition kinetics of taxane anticancer drugs after intraperitoneal administration in peritoneal dissemination patients and animal models and also discuss the effect of the surfactant vehicle on the behavior of taxanes.

Intraperitoneal infusion of paclitaxel with S-1 for peritoneal metastasis of advanced gastric cancer: phase I study

BACKGROUND

Intraperitoneal administration of taxanes revealed excellent anti-tumor effect for peritoneal metastasis of gastric cancer in some experimental models. The aim of this study is to determine maximum tolerated dose (MTD), dose limiting toxicity (DLT) and recommended dose (RD) of intraperitoneally infused paclitaxel (PTX) with S-1 as a phase I study.

PATIENTS AND METHODS

Eighteen patients with advanced gastric cancer in addition to confirmed peritoneal metastasis using laparoscopy were enrolled in this study. The regimen consists of oral administration of S-1 (Dose 80 mg: BSA<1.25 m(2), 100 mg: 1.25<BSA<1.5 m(2), 120 mg: BSA>1.5 m(2)) for 14 days and intraperitoneal infusion of PTX (Dose escalation: level I: 40, II: 60, III: 80, level IV: 90, V: 100 mg/m(2)) at day 1 and 14. PTX concentrations in serum and ascites were determined at 4, 8, 12, 24, 48 hours after the infusion, which was repeated twice every 4 weeks.

RESULTS

The number of patients were as follows: Level I: 3, Level II: 6, Level III: 3, Level IV: 3, Level V: 3. Grade 3 leukocytopenia was confirmed in 1 (Level II) and 2 (Level V). MTD is 90 mg/m(2), RD is 80 mg/m(2) and DLT is Grade 3 leukocytopenia. The average serum PTX concentrations remained in optimal range except for all 3 of level V patients. In all cohorts, the PTX concentrations in the ascites were approximately 1000 folds higher than those in serum for 48 hours after the infusion.

CONCLUSIONS

MTD and RD were PTX 90 mg/m(2), 80 mg/m(2), respectively. These findings were supported by pharmocokinetics of PTX.

Systematic review of intraperitoneal chemotherapy for gastric cancer

BACKGROUND

Gastric cancer with peritoneal carcinomatosis has a poor prognosis. Intraperitoneal chemotherapy has been proposed as a treatment option. This systematic review examined recent literature to determine the role of intraperitoneal chemotherapy in gastric cancer.

METHODS

Four electronic databases were searched between January 2004 and January 2010 for relevant studies. Defined outcomes of interest were treatment-related morbidity and mortality, long-term survival and sites of recurrence.

RESULTS

Fourteen studies were identified involving 914 patients with gastric cancer, of whom 819 (89·6 per cent) received intraperitoneal chemotherapy. There were two randomized controlled trials, two case-control studies and ten observational studies. Methodological quality was rated as poor in 12 studies, with selection and observer bias apparent in most non-randomized cohorts. Studies were often small and varied in terms of intraperitoneal timing of chemotherapy, chemotherapeutic agents, treatment temperature, and the use of adjuvant therapies. In the better conducted studies, survival was longer in patients receiving intraperitoneal chemotherapy and surgery than in those having surgery alone.

CONCLUSION

There is limited good-quality evidence to determine the role of intraperitoneal chemotherapy in gastric cancer. Intraperitoneal chemotherapy in gastric cancer is worthy of further appraisal. However, the quality of trials must be improved, and studies must be conducted more uniformly to minimize bias and aid comparison between centres.

Pilot study of a combination of S-1 and paclitaxel for patients with peritoneal metastasis from gastric cancer

BACKGROUND

This pilot study was carried out to evaluate the efficacy of chemotherapy for patients with peritoneal dissemination from gastric cancer or positive lavage cytology diagnosed by staging laparoscopy.

METHODS

Sixteen patients were enrolled. Paclitaxel was administered at 120 mg/m(2) on day 1 and S-1 was administered orally at 80 mg/m(2) for 14 consecutive days, followed by a 1-week rest, as one course. After five courses of this therapy, the primary gastric tumors were evaluated and second-look laparoscopy was performed for patients showing partial response or stable disease with clinical benefit.

RESULTS

Partial response or stable disease with clinical benefit was confirmed in seven and five patients, respectively, and these patients underwent second-look laparoscopy. No viable cancer cells were detected on cytopathological investigation during second-look laparoscopy in 9 patients who underwent surgical treatment. The intent-to-treat response rate for gastric tumor was 44% and the rate of disappearance of peritoneal metastasis was 38% (6 cases) at surgery. The median survival time was 555 days. Leucopenia of grade 3 and neutropenia of grade 3 were recognized in two and three patients, respectively.

CONCLUSION

This chemotherapy regimen may be an acceptable option for patients with peritoneal dissemination. We plan to study this regimen further in gastric cancer patients with peritoneal dissemination.

Phase I study of intraperitoneal irinotecan in patients with gastric adenocarcinoma with peritoneal seeding

PURPOSE

The objectives of this phase I study were to determine the maximum-tolerated dose (MTD), dose-limiting toxicities (DLTs), and preliminary efficacy of intraperitoneally administered irinotecan (CPT-11) in gastric cancer patients with peritoneal seeding.

EXPERIMENTAL DESIGN

Gastric adenocarcinoma patients with surgical biopsy proven peritoneal seeding were enrolled at the time of surgery. Prior to IP chemotherapy, patients underwent palliative gastrectomy and CAPD catheter insertion in which CPT-11 was administered on postoperative day 1. The IP CPT-11 was initiated at 50 mg/m(2), which was escalated to 100, 150, 200, 250, and 300 mg/m(2). IP CPT-11 chemotherapy was repeated every 3 weeks.

RESULTS

Seventeen patients received a total of 56 cycles at five different CPT-11 dose levels. The DLTs were neutropenic fever, neutropenia, and diarrhea. At the dose level 2 (100 mg/m(2)), there were one DLTs in one of the first cohort of three patients, but no DLTs at the second cohort of this level. At the dose level 5 (250 mg/m(2)), two DLTs were detected in the first two patients; thus, the accrual was stopped resulting in the recommended dose of IP CPT-11 of 200 mg/m(2). Median progression-free survival was 8.6 months (95% CI, 5.9,11.2), and median overall survival was 15.6 months (95% CI, 8.4,22.8). Pharmacokinetic results of the study showed that the C (max) of peritoneal SN-38 was achieved earlier than that of plasma SN-38.

CONCLUSIONS

Intraperitoneally administered CPT-11 was feasible and tolerable. Further, phase II study of IP CPT-11 in gastric cancer patients with peritoneal seeding is warranted.

Pharmacokinetic advantage of intraperitoneal injection of docetaxel in the treatment for peritoneal dissemination of cancer in mice

Intraperitoneal administration of docetaxel has been used to treat peritoneal dissemination of cancer, but its safety has not yet been confirmed. We have compared the pharmacokinetic behaviour of docetaxel after intravenous and intraperitoneal administration in CD-1-nu/nu mice bearing MKN-45P, a gastric cancer variant line producing peritoneal dissemination. Docetaxel (8mg kg−1) was intravenously or intraperitoneally injected into the mice and at designated times the drug concentration was measured in plasma, ascites fluid, and abdominal tissues (liver, kidney, intestine and spleen, solid cancer, and suspended free cancer). The pharmacokinetic behaviour of docetaxel was similar in control mice and cancer-bearing mice after administration via either route, except that the transfer of docetaxel from the abdominal cavity to systemic blood (plasma) was slower in cancer-bearing mice than in control mice. As expected, the intraperitoneal drug concentration was much higher (approximately 100-fold) and was maintained for a longer time in the intraperitoneal injection group than in the intravenous injection group. The drug concentrations in peritoneal solid cancer tissue and suspended free cancer cells were also significantly higher for a longer time in the intraperitoneal injection group than in the intravenous injection group. The values of the plasma area under concentration-time curves (AUC) were similar for both administration routes. The ratio of AUC ascite/AUC plasma after intraperitoneal administration was higher than after intravenous administration. The drug concentration in abdominal organs after intraperitoneal injection was lower during the first 2 h, then became similar to those after intravenous injection. These results indicated that the intraperitoneal administration of docetaxel for peritoneal dissemination was likely to be an effective treatment method, without causing any increase in systemic toxicity.

Multidisciplinary therapy for treatment of patients with peritoneal carcinomatosis from gastric cancer

There is no standard treatment for peritoneal carcinomatosis (PC) from gastric cancer. A novel multidisciplinary treatment combining bidirectional chemotherapy [neoadjuvant intraperitoneal-systemic chemotherapy protocol (NIPS)], peritonectomy, hyperthermic intraperitoneal chemoperfusion (HIPEC) and early postoperative intraperitoneal chemotherapy has been developed. In this article, we assess the indications, safety and efficacy of this treatment, review the relevant studies and introduce our experiences. The aims of NIPS are stage reduction, the eradication of peritoneal free cancer cells, and an increased incidence of complete cytoreduction (CC-0) for PC. A complete response after NIPS was obtained in 15 (50%) out of 30 patients with PC. Thus, a significantly high incidence of CC-0 can be obtained in patients with a peritoneal cancer index (PCI) ≤ 6. Using a multivariate analysis to examine the survival benefit, CC-0 and NIPS are identified as significant indicators of a good outcome. However, the high morbidity and mortality rates associated with peritonectomy and perioperative chemotherapy make stringent patient selection important. The best indications for multidisciplinary therapy are localized PC (PCI ≤ 6) from resectable gastric cancer that can be completely removed during a peritonectomy. NIPS and complete cytoreduction are essential treatment modalities for improving the survival of patients with PC from gastric cancer.

Multidisciplinary therapy for treatment of patients with peritoneal carcinomatosis from gastric cancer

There is no standard treatment for peritoneal carcinomatosis (PC) from gastric cancer. A novel multidisciplinary treatment combining bidirectional chemotherapy [neoadjuvant intraperitoneal-systemic chemotherapy protocol (NIPS)], peritonectomy, hyperthermic intraperitoneal chemoperfusion (HIPEC) and early postoperative intraperitoneal chemotherapy has been developed. In this article, we assess the indications, safety and efficacy of this treatment, review the relevant studies and introduce our experiences. The aims of NIPS are stage reduction, the eradication of peritoneal free cancer cells, and an increased incidence of complete cytoreduction (CC-0) for PC. A complete response after NIPS was obtained in 15 (50%) out of 30 patients with PC. Thus, a significantly high incidence of CC-0 can be obtained in patients with a peritoneal cancer index (PCI) ≤ 6. Using a multivariate analysis to examine the survival benefit, CC-0 and NIPS are identified as significant indicators of a good outcome. However, the high morbidity and mortality rates associated with peritonectomy and perioperative chemotherapy make stringent patient selection important. The best indications for multidisciplinary therapy are localized PC (PCI ≤ 6) from resectable gastric cancer that can be completely removed during a peritonectomy. NIPS and complete cytoreduction are essential treatment modalities for improving the survival of patients with PC from gastric cancer.

Pilot study of intraperitoneal administration of paclitaxel and oral S-1 for patients with peritoneal metastasis due to advanced gastric cancer

BACKGROUND

There is no standard treatment for peritoneal dissemination from gastric cancer. A novel combination chemotherapy has been introduced for patients with advanced gastric cancer with peritoneal metastasis.

METHODS

This pilot study was performed on four patients to confirm safety and efficacy. They were diagnosed with unresectable gastric cancer with severe peritoneal dissemination by staging laparoscopy, or with metastasis to the transverse colon. We selected combined chemotherapy with both paclitaxel and S-1. Paclitaxel at 60 mg/m(2) or 60 mg/body was administered intraperitoneally on days 1 and 8 and S-1, at 80-120 mg/body, was administered orally for 14 days followed by 7 days' rest, as one course. After five courses of this therapy, the primary gastric tumors were evaluated by conventional examinations, and second-look laparoscopy was performed to assess the efficacy of the treatment against the peritoneal metastases.

RESULTS

After five courses, primary tumor reductions were confirmed, and no cancer cells were detected on pathocytological investigation during second-look laparoscopy in any of the patients. Three patients underwent total gastrectomy with lymph node dissection and one underwent left upper abdominal evisceration. Final histological staging showed two stage 3 and two stage 4 patients. The intraperitoneal administration of paclitaxel and the oral administration of S-1 were well tolerated. Three patients died, at 8, 15, and 29 months, respectively, after the initial treatment, and one has been alive for 54 months without recurrence.

CONCLUSION

This chemotherapy can be used in the treatment of patients with peritoneal metastasis of gastric cancer.

Different tissue distribution of paclitaxel with intravenous and intraperitoneal administration

PURPOSE

Paclitaxel is considered to be suitable for disseminated cancer in the peritoneal cavity because of its high molecular weight and lipophilic characteristics. However, the difference in pharmacokinetics of paclitaxel after intraperitoneal (i.p.) and intravenous (i.v.) administration is not fully defined. Here, we investigated the tissue concentration of paclitaxel in various organs at various time points after i.p. or i.v. administration.

METHODS

Paclitaxel (5 mg/kg) was administrated in an ear vein or in the abdominal cavity of rabbits. At 0.5, 6, 24, and 48 h after administration, the rabbits were sacrificed, and organs as well as peripheral blood were harvested. The serum and tissue concentrations of paclitaxel were measured by HPLC procedure.

RESULT

The concentration of paclitaxel was high in the i.v. group at 0.5 h, whereas it was significantly higher in the i.p. group at 6 and 24 h. The AUC (area under the curve) was markedly higher in the omentum, mesenteric lymph nodes as well as ovary and stomach in the i.p. group.

CONCLUSION

Compared with i.v. administration, paclitaxel concentration was maintained at a high level in the whole body by i.p. administration. Repeated i.p. paclitaxel can produce more marked clinical effects than i.v. administration for metastatic lymph nodes and primary lesions as well as peritoneal dissemination.

Treatment of peritoneal chemotherapy in combination with tocetaxel and cisplatin for advanced gastric cancer: an analysis of 45 cases

AIM: To investigate the therapeutic efficacy of peritoneal chemotherapy in combination with tocetaxel and cisplatin for advanced gastric cancer.

METHODS: Forty-five cases of advanced gastric cancer were treated with tocetaxel in combination with cisplatin by peritoneal chemotherapy. The tumor size, blood routine examination, hepatic and renal function were compared before and after peritoneal chemotherapy. The side effects were observed. All patients were followed-up and their survival time was recorded.

RESULTS: The tumor sizes of gastric cancer were decreased dramatically (72.4 ± 22.4 cm³vs 7.23 ± 2.4 cm³, t = 2.946, P < 0.01). The average survival time was 14.0 ± 1.4 months, and the short-term therapeutic efficacy was 59%. The peritoneal chemotherapy affected some indexes in blood routine examination, hepatic and renal function. The main side effects included hair loss, stomatitis, constipation and blood urine.

CONCLUSION: Peritoneal chemotherapy in combination with tocetaxel and cisplatin reduces the tumor size effectively, prolongs the survival period, and alleviates the tumor ascites in patients with advanced gastric cancer. It's convenient and safe for advanced gastric cancer treatment.

Intraperitoneal administration of paclitaxel and oral S-1 for a patient with peritoneal dissemination and hydronephrosis due to advanced gastric cancer

We report a patient with type 3 gastric cancer with peritoneal dissemination and hydronephrosis who was successfully treated with intraperitoneal infusion of paclitaxel and oral administration of S-1. He was diagnosed with unresectable gastric cancer with severe peritoneal dissemination by staging laparoscopy. We selected combined chemotherapy with both paclitaxel and S-1. Paclitaxel at 60 mg/m(2) was administered intraperitoneally on days 1 and 8, and S-1 at 100 mg/body was administered orally for 14 days, followed by 7 days' rest, as one course. After five courses, primary tumor reduction was confirmed and no cancer cells were detected on pathocytological investigation at second-look laparoscopy. The patient underwent total gastrectomy with lymph node dissection. He died from liver metastasis 29 months after the initial treatment, but he had not suffered from peritoneal metastases and had kept a good quality of life (QOL) since that treatment. This chemotherapy can be applied as one of the promising candidates for the treatment of patients with peritoneal metastasis of gastric cancer.

Feasibility study of postoperative intraperitoneal hyperthermochemotherapy by radiofrequency capacitive heating system for advanced gastric cancer with peritoneal seeding

BACKGROUND

Gastric carcinoma patients with peritoneal dissemination have an extremely poor prognosis. Attempting to improve regional control and decrease the risk of complications related to hyperthermic chemotherapy, we applied a new treatment modality using a combination of gastrectomy with postoperative intraperitoneal hyperthermo-chemotherapy (PIHC) using Thermotron RF-8. The purpose of this study was to evaluate the feasibility of PIHC in advanced gastric carcinoma patients with peritoneal seeding.

PATIENTS AND METHODS

Between March 2002 and April 2006, 20 gastric carcinoma patients with peritoneal dissemination were allocated to two groups in the patient's selection. The PIHC group (10 patients) received a 60-min PIHC with a cisplatin dose of 80 mg/m2 two weeks after surgery, and the control group (10 patients) received surgery alone. Thermotron RF-8 is a heating device that can raise temperatures in both superficial and deep-seated tumours using 8 MHz radiofrequency electromagnetic waves as a source of heat.

RESULTS

No patients in either group had life-threatening complications. The most frequent nonhaematologic toxicity (grade 3) was nausea. The one-, two-, and three-year cumulative survival rates for the PIHC group were 60%, 48%, and 36%, respectively, whereas those for the control group were 40%, 10%, and 0%, respectively. The survival rates for the PIHC group were significantly higher than those for the control group.

CONCLUSION

Although this study was conducted non-randomly with a small number of patients, the PIHC group had a higher survival rate and better prognosis compared with the control group.

Recent advances in the treatment of peritoneal dissemination of gastrointestinal cancers by nucleoside antimetabolites

Peritoneal dissemination is the most common cause of metastasis from malignancies in the abdominal cavity. There are no standard treatments for peritoneal dissemination and the results are poor. The reasons for this are as follows: (1) no effective chemotherapeutic agents have been identified or developed; (2) surgical cytoreduction has little effect on survival improvement; and (3) the molecular mechanisms of peritoneal dissemination have not been clarified and no therapy against the target molecules has been developed. However, studies on the molecular mechanisms of peritoneal dissemination have elucidated some of the target molecules and the development of new multimodal therapies has also improved survival. Early postoperative intraperitoneal chemotherapy, hyperthermic intraperitoneal perfusion chemotherapy and neoadjuvant intraperitoneal-systemic chemotherapy have been newly developed, and a novel surgical therapy named peritonectomy has been proposed to perform complete cytoreduction of peritoneal dissemination. At present, these approaches appear to be effective therapeutic modalities for peritoneal dissemination. However, TS-1 and capecitabine have shown worthwhile results in recent clinical trials for patients with advanced gastric cancer. We recently found that newly developed antitumor cytosine nucleoside analogs show a survival advantage in peritoneal dissemination models using human cancer cells. These non-fluoropyrimidine nucleosides may potentially help to improve the poor prognosis observed in patients with advanced cancers involving peritoneal dissemination.

A photon counting technique for quantitatively evaluating progression of peritoneal tumor dissemination

We recently established a mouse model of peritoneal dissemination of human gastric carcinoma, including the formation of ascites, by orthotopic transplantation of cultured gastric carcinoma cells. To clarify the processes of expansion of the tumors in this model, nude mice were sacrificed and autopsied at different points of time after the orthotopic transplantation of the cancer cells for macroscopic and histopathologic examination of the tumors. The cancer cells grew actively in the gastric submucosa and invaded the deeper layers to reach the serosal plane. The tumor cells then underwent exfoliation and became free followed by the formation of metastatic lesions initially in the greater omentum and subsequent colonization and proliferation of the tumors on the peritoneum. Although this model allowed the detection of even minute metastases, it was not satisfactory from the viewpoint of quantitative and objective evaluation. To resolve these problems, we introduced a luciferase gene into this tumor cell line with a high metastasizing potential and carried out in vivo photon counting analysis. This photon counting technique was found to allow objective and quantitative evaluation of the progression of peritoneal dissemination on a real-time basis. This animal metastatic model is useful for monitoring the responses of tumors to anticancer agents.

Treatment of ovarian cancer using intraperitoneal chemotherapy with taxanes: from laboratory bench to bedside

The combination of a taxane, paclitaxel or docetaxel, and a platinum compound has become the systemic chemotherapy of choice for primary ovarian cancer and has demonstrated high efficacy. However, ultimately most patients will die from this disease. Hence, there is a need for even more effective systemic chemotherapy or different treatment strategies. Intraperitoneal chemotherapy with taxanes is such an alternative treatment option. Ovarian cancer is theoretically an attractive malignancy for this regional treatment, because the disease remains largely confined to the peritoneal cavity. The choice of taxanes for this kind of chemotherapy is rational, because of its high activity against ovarian cancer cells and expected favourable pharmacokinetics because of limited absorption from the peritoneal cavity due to their large molecular weight and first-pass effect in the liver. In animal model and human pharmacokinetic studies, very high intraperitoneal drug concentrations and exposure and high peritoneal tumour concentrations were achieved, while systemic drug levels were low. The combination of intraperitoneal chemotherapy with hyperthermia enhances the penetration and cytotoxic activity of many drugs. Although data concerning thermal enhancement of taxane cytotoxicity are inconsistent, experimental studies show that at high locoregional concentrations there seems to be such an effect. Recently, feasibility and efficacy of this treatment have evidently been demonstrated in various clinical studies. A large randomized trial revealed improvement of outcome by intraperitoneal instillation chemotherapy with paclitaxel and cisplatin as first-line treatment. Moreover, promising results have been observed after intraoperative hyperthermic intraperitoneal chemotherapy with docetaxel for recurrent disease.