Systemic exposure of the parent drug oxaliplatin during hyperthermic intraperitoneal perfusion

Application of HIPEC simulations for optimizing treatment delivery strategies

INTRODUCTION

Hyperthermic IntraPEritoneal Chemotherapy (HIPEC) aims to treat microscopic disease left after CytoReductive Surgery (CRS). Thermal enhancement depends on the temperatures achieved. Since the location of microscopic disease is unknown, a homogeneous treatment is required to completely eradicate the disease while limiting side effects. To ensure homogeneous delivery, treatment planning software has been developed. This study compares simulation results with clinical data and evaluates the impact of nine treatment strategies on thermal and drug distributions.

METHODS

For comparison with clinical data, three treatment strategies were simulated with different flow rates (1600-1800mL/min) and inflow temperatures (41.6-43.6 °C). Six additional treatment strategies were simulated, varying the number of inflow catheters, flow direction, and using step-up and step-down heating strategies. Thermal homogeneity and the risk of thermal injury were evaluated.

RESULTS

Simulated temperature distributions, core body temperatures, and systemic chemotherapeutic concentrations compared well with literature values. Treatment strategy was found to have a strong influence on the distributions. Additional inflow catheters could improve thermal distributions, provided flow rates are kept sufficiently high (>500 mL/min) for each catheter. High flow rates (1800 mL/min) combined with high inflow temperatures (43.6 °C) could lead to thermal damage, with CEM4310 values of up to 27 min. Step-up and step-down heating strategies allow for high temperatures with reduced risk of thermal damage.

CONCLUSION

The planning software provides valuable insight into the effects of different treatment strategies on peritoneal distributions. These strategies are designed to provide homogeneous treatment delivery while limiting thermal injury to normal tissue, thereby optimizing the effectiveness of HIPEC.

Determination of whether HIPEC is beneficial in patients with synchronous peritoneal and liver metastases from colorectal cancer (Review)

Peritoneal carcinomatosis, as well as the presence of liver metastases from colorectal cancer, has been long considered as the sign of a systemic disease, transforming the patient into a candidate for palliation and best supportive care. However, in recent decades, progress in the field of medical and surgical oncology has allowed scientists worldwide to produce curative therapeutic strategies for these cases such as hyperthermic intraperitoneal chemotherapy (HIPEC) or extended liver resection. In addition, the association of these two therapies has also been performed with encouraging results. The aim of the current study was to review articles published thus far in regard to the association of these two therapeutic strategies, in order to identify which cases can benefit the most, which is the most efficient agent or combination of agents, and whether these types of therapy should be performed as monotherapy or as a two-stage procedure.

Hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal and appendiceal peritoneal metastases: lessons learned from PRODIGE 7

The treatment for peritoneal metastases from appendiceal, colon and rectal cancer (MO1) has relied on cytoreductive surgery (CRS) to remove all visible evidence of disease plus a perioperative chemotherapy for the entire abdomen to eliminate microscopic residual disease. Using the results obtained from the PRODIGE 7 randomized controlled trial, methodological issues were discussed and possible improvements to the hyperthermic intraperitoneal chemotherapy (HIPEC) with oxaliplatin were sought. Possible methodological and pharmacologic flaws were identified. Several methodological flaws included the sample size, cross-over option, neoadjuvant chemotherapy use and timing of the peritoneal disease evaluation. The sample size issue raised the question of what the minimal clinically relevant benefit we want in future trials. Neoadjuvant FOLFOX may have induced acquired drug resistance to oxaliplatin. Several pharmacological issues were identified including limited 5-fluorouracil exposure as well as limited oxaliplatin peritoneal exposure time. Insufficient 5-fluorouracil accompanied the oxaliplatin as only a bolus dose was used and continuous 5-FU infusion has previously been an integral part of oxaliplatin treatment. Finally, only approximately one-half of the oxaliplatin entered body tissues or tumor. Three suggestions from the lessons learned from a critique of PRODIGE 7 were offered as adjustments to the HIPEC protocol. The Efficacy of HIPEC, a perioperative FOLFOX or a return to HIPEC with mitomycin C were described.

Systemic Pharmacokinetics of Oxaliplatin After Intraperitoneal Administration by Electrostatic Pressurized Intraperitoneal Aerosol Chemotherapy (ePIPAC) in Patients with Unresectable Colorectal Peritoneal Metastases in the CRC-PIPAC Trial

BACKGROUND

Electrostatic pressurized intraperitoneal aerosol chemotherapy (ePIPAC) is a palliative treatment for unresectable peritoneal metastases from various primary cancers. However, little is known about the systemic pharmacokinetics of oxaliplatin after ePIPAC.

METHODS

Twenty patients with unresectable colorectal peritoneal metastases were treated with repetitive ePIPAC monotherapy with oxaliplatin (92 mg/m²) and a simultaneous intravenous bolus of leucovorin (20 mg/m²) and 5-fluorouracil (400 mg/m²). Samples were collected during each ePIPAC: whole blood at t = 0, t = 5, t = 10, t = 20, t = 30, t = 60, t = 120, t = 240, t = 360 and t = 1080 min for plasma and plasma ultrafiltrate concentrations; urine at t = 0, t = 1, t = 3, t = 5 and t = 7 days. Samples were analyzed using atomic absorption spectrometry. Pharmacokinetics were analyzed using nonlinear mixed-effects modeling.

RESULTS

Four patients received one ePIPAC, three patients received two ePIPAC, and thirteen patients received ≥ 3 ePIPAC. The population pharmacokinetic models adequately described the pharmacokinetics of oxaliplatin after ePIPAC. The plasma ultrafiltrate C_max of oxaliplatin reached 1.36-1.90 µg/mL after 30 min with an AUC_{0-24 h} of 9.6-11.7 µg/mL * h. The plasma C_max reached 2.67-3.28 µg/mL after 90 min with an AUC_{0-24 h} of 49.0-59.5 µg/mL * h. The absorption rate constant (Ka) was 1.13/h. Urine concentrations of oxaliplatin rapidly decreased to less than 3.60 µg/mL in 90% of the samples at day 7.

DISCUSSION

Systemic exposure to oxaliplatin after ePIPAC seemed comparable to that after systemic chemotherapy, as described in other literature. Since this is an indirect comparison, future research should focus on the direct comparison between the systemic exposure to oxaliplatin after ePIPAC and after systemic chemotherapy.

TRIAL REGISTRATION

NCT03246321, Pre-results; ISRCTN89947480, Pre-results; NTR6603, Pre-results; EudraCT: 2017-000927-29, Pre-results.

Hyperthermic intraperitoneal chemotherapy with oxaliplatin for peritoneal carcinomatosis: a clinical pharmacological perspective on a surgical procedure

Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC) has become the standard of care in the treatment of patients with peritoneal carcinomatosis of colorectal origin. The use of oxaliplatin for HIPEC has gained popularity. Although the HIPEC procedure is adopted throughout the world, major differences exist between treatment protocols regarding the carrier solution, perfusate volume, use of an open or closed technique, duration of the perfusion and application of additional flushing. These differences can influence the pharmacokinetics and pharmacodynamics of oxaliplatin and might thereby have an impact on the efficacy and/or safety of the treatment. Clinicians should be aware of the clinical importance of oxaliplatin pharmacology when performing HIPEC surgery. This review adds new insights into the complex field of the pharmacology of HIPEC and highlights an important worldwide problem: the lack of standardization of the HIPEC procedure.

Comparison of open and closed abdomen techniques for the delivery of intraperitoneal pemetrexed using a murine model

BACKGROUND AND OBJECTIVES

Pemetrexed is an appealing agent to use for cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC). However, the optimal method of pemetrexed delivery still remains undefined. Using a murine model, we compared the use of open and closed abdomen techniques on the absorption of intraperitoneal (IP) pemetrexed in different compartments.

METHODS

Eleven Sprague-Dawley rats were submitted to a fixed dose of IP pemetrexed (1000 mg/m² ) at a perfusion temperature of 40°C during 25 min according to two techniques: open and closed. At the end of perfusion, samples in different compartments were harvested and the concentrations of pemetrexed were measured by high performance liquid chromatography.

RESULTS

Absorption of IP pemetrexed in portal and systemic blood was significantly higher using the open compared to the closed abdomen technique (93.17 vs 52.50 µg/mL, P < 0.001) and (76.26 vs 51.65 µg/mL, P < 0.001), respectively. No difference was found between the two techniques on the peritoneal tissue concentration of pemetrexed (18.07 vs 19.17 µg/g, P = 0.51).

CONCLUSION

Peritoneal absorption of pemetrexed is not modified by the use of either technique. However, systemic concentrations of pemetrexed increased using the open technique, suggesting it could increase systemic toxicity.

Suitability of the AUC Ratio as an Indicator of the Pharmacokinetic Advantage in HIPEC

The purpose of this study was to evaluate the area under the concentration-time curve (AUC) ratio as an optimal indicator of the pharmacokinetic advantage during hyperthermic intraperitoneal perioperative chemotherapy. The impact on the AUC ratio on the variables related to the calculation of systemic drug exposure, instillation time, and peripheral drug distribution was evaluated through simulations as well as through a retrospective analysis of studies published in the literature. Both model simulations and the retrospective analysis showed that the 3 variables evaluated had an impact on the AUC ratio value if the complete systemic exposure was not fully considered. However, when that complete systemic exposure was considered, none of these variables affected the AUC ratio value. AUC ratio is not a characteristic parameter of a drug if the calculated systemic drug exposure is not complete. Thus, AUC ratio is not valid for comparing the pharmacokinetic advantage of 2 drugs, and it should not be employed to prove whether a drug can be used in hyperthermic intraperitoneal perioperative chemotherapy safely with regard to toxicity. As an alternative, the study of the absorption rate constant and the bioavailability are proposed as the true and independent parameters that reflect the amount of drug absorbed.

Pharmacodynamics of Oxaliplatin-Derived Platinum Compounds During Hyperthermic Intraperitoneal Chemotherapy (HIPEC): An Emerging Aspect Supporting the Rational Design of Treatment Protocols

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) is used to treat peritoneal surface malignancies with application of cytostatic drugs such as oxaliplatin (OX) after cytoreductive surgery. Despite its increased use, evidence for optimal drug dosage, and notably duration of HIPEC, is scarce.

METHODS

In this study, OX distribution was comprehensively assessed in nine patients during HIPEC (300 mg OX/m² body surface area in Physioneal solution for 30 min). Oxaliplatin and its derivatives were measured in peritoneal perfusates over time by liquid chromatography coupled with mass spectrometry (LC-MS), and the resulting total platinum concentration in tissue was analyzed by atomic absorption spectrometry. Additionally, a novel impedance-based real-time cytotoxicity assay was used to evaluate the bioactivity of perfusates ex vivo.

RESULTS

Compared with amounts of OX expected in peritoneal perfusates by calculation, only 10-15% of the parent drug could be detected by LC-MS during HIPEC. Notably, the study additionally detected platinum compounds consistent with OX transformation, accounting for a further fraction of the applied drug. The cytotoxic properties of perfusates remained unchanged during HIPEC, with only a slight but significant attenuation evidenced after 30 min.

CONCLUSIONS

The bioactivity of peritoneal perfusates ex vivo is a useful parameter for evaluating the actual cytotoxic potential of OX and its derivatives used in HIPEC over time, overcoming important limitations and disadvantages associated with respective drug monitoring only. Ex vivo cytotoxicity assays may be a promising tool to aid guiding future standardization and harmonization of HIPEC protocols based on drug-mediated effects.

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.

Stability of oxaliplatin in chloride-containing carrier solutions used in hyperthermic intraperitoneal chemotherapy

PURPOSE

Oxaliplatin is increasingly becoming the chemotherapeutic drug of choice for the treatment of peritoneal malignancies using cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). Oxaliplatin is unstable in chloride-containing media, resulting in the use of 5% dextrose as the carrier solution in these procedures. Exposure of the peritoneum to 5% dextrose during perfusion times varying from 30 min to 90 min is associated with serious hyperglycemias and electrolyte disturbances. This can result in significant postoperative morbidity and mortality. In order to find out whether safer, chloride-containing carrier solutions can be used, we report the results of in-vitro analysis of oxaliplatin stability in both chloride-containing and choride-deficient carrier solutions and discuss the implications for oxaliplatin-based CRS-HIPEC procedures.

METHODS

5 mg of oxaliplatin was added to 50 mL of various carrier solutions at 42 °C: 5% dextrose, 0.9% sodium chloride, Ringer lactate, Dianeal(®) PD4 glucose 1.36% solution for peritoneal dialysis and 0.14 M sterile phosphate buffer pH 7.4. Samples were collected at standardized intervals and oxaliplatin concentration was determined using a stability indicating high-performance liquid chromatographic method, coupled to an UV detector (HPLC-UV); oxaliplatin degradation products were identified using HPLC-mass spectometry.

RESULTS

In 5% dextrose, oxaliplatin concentration remained stable over a 2-hour period. Increasing chloride concentrations were associated with increasing degradation rates; however, this degradation was limited to <10% degradation after 30 min (the standard peritoneal perfusion time in most clinical CRS-HIPEC protocols) and <20% degradation after 120 min at 42 °C. In addition, oxaliplatin degradation was associated with the formation of its active drug form [Pt(dach)Cl2].

CONCLUSIONS

The use of chloride-containing carrier solutions for oxaliplatin does not relevantly affect its concentrations under the tested in-vitro conditions. Chloride seems to promote formation of the active cytotoxic drug form of oxaliplatin and therefore could enhance its cytotoxic effect. These data show that more physiological, chloride-containing carrier solutions can be used safely and effectively as a medium for oxaliplatin in CRS-HIPEC procedures.

Oxaliplatin-based versus irinotecan-based hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with peritoneal metastasis from appendiceal and colorectal cancer: a retrospective analysis

BACKGROUND

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) provide an effective treatment option for selected patients with colorectal peritoneal metastasis with encouraging survival results. Many different drug combinations and HIPEC regimens including bidirectional, i.e. synchronous intravenous and intraperitoneal, drug application have been used. However, there is still no standardization of the HIPEC regimen.

METHODS

Between 05/2007 and 04/2010 190 patients underwent CRS and HIPEC at the University Hospital Regensburg. Thirty-two patients with peritoneal metastasis arising from colorectal or appendiceal cancer underwent complete macroscopic cytoreduction (CC-0/1) and bidirectional HIPEC and completed at least 3-year follow-up. Twenty patients received oxaliplatin-based (OX) and twelve patients received irinotecan-based HIPEC (IRI). Group-specific perioperative morbidity and 3-year survival has been determined.

RESULTS

The grade 3/4 morbidity rate according to CTCAE v4 was 35.0% in the OX group vs. 33.3% in the IRI group (p = 1.000). There was no perioperative mortality in both groups. Median survival was 26.8 months (95% CI 15.7-33.1 months) in the IRI group and has not yet been reached in the OX group during a median follow-up of 39.4 months. Three-year survival rates were 65.0% in the OX group vs. 41.7% in the IRI group (p = 0.295).

CONCLUSIONS

The morbidity and toxicity rates of bidirectional irinotecan-based and oxaliplatin-based HIPEC are comparable. Nevertheless, in the absence of contraindications oxaliplatin-based HIPEC might be preferred due to the positive trend regarding 3-year and median survival.

Population pharmacokinetics of peritoneal, plasma ultrafiltrated and protein-bound oxaliplatin concentrations in patients with disseminated peritoneal cancer after intraperitoneal hyperthermic chemoperfusion of oxaliplatin following cytoreductive surgery: correlation between oxaliplatin exposure and thrombocytopenia

PURPOSE

First, to evaluate the peritoneal (IP), plasma ultrafiltrated (UF) and protein-bound (B) pharmacokinetics (PK) of oxaliplatin after intraperitoneal hyperthermic chemoperfusion (HIPEC) following cytoreductive surgery. Second, to evaluate the relationship between oxaliplatin exposure and observed toxicity.

METHODS

IP, UF, and B concentrations from 75 patients treated by 30-min oxaliplatin-based HIPEC procedures were analysed according to a pharmacokinetic modelling approach using NONMEM. Oxaliplatin was administered in a 5 % dextrose solution (2 L/m(2)) at 360 (n = 58) or 460 mg/m(2) (n = 17). The most frequently observed toxicities were related to the peritoneal, systemic exposures and to the parameters corresponding to the oxaliplatin absorption from peritoneal cavity into plasma.

RESULTS

IP (n = 536), UF (n = 669) and B (n = 661) concentrations were simultaneously described according to a five-compartment PK model with irreversible nonlinear binding from UF to B according to a Michaelis-Menten equation. The mean (±SD) maximum fraction of dose absorbed and elimination half-life from the peritoneum was 53.7 % (±8.5) and 0.49 h (±0.1), respectively. The mean (±SD) ratio AUC(IP)/AUC(UF) was 5.3 (±2) confirming the pharmacokinetic advantage of the procedure. Haemoperitoneum (22.7 %), neuropathy (18.7 %), grade 3/4 thrombocytopenia (13.3 %) were the most frequently reported toxicities. AUC(UF) accounts for approximately 12 % of the variation in the maximum percentage of platelet decrease (r = 0.35, p = 0.002). Thrombocytopenia was correlated with higher AUCUF, partly dependent on the extent and rate of oxaliplatin absorption.

CONCLUSIONS

Despite a common dose administered, variability in peritoneal and systemic oxaliplatin exposures are observed, leading to differences in haematological toxicity between patients.

Cytoreductive surgery and hyperthermic intra-peritoneal chemotherapy treatment of colorectal peritoneal metastases: cohort analysis of high volume disease and cure rate

BACKGROUND

Cytoreductive surgery (CRS) and hyperthermic intra-peritoneal chemotherapy (HIPEC) treatment of colorectal peritoneal metastases (PM) is an established treatment alternative. The study aim was, first, to investigate the outcome of high-volume disease defined by the peritoneal cancer index (PCI) 20; second, to report the long-term disease-free survival of patients with >5 years observation.

METHODS

Consecutive patients with colorectal PM from a prospective HIPEC database between 2004 and 2010 were included, 67 patients. Clinicopathological and outcome parameters were compared between low PCI (n = 40) and high PCI (n = 27). A subgroup analysis on patients with >5 years observation was performed (n = 32). Disease-free survival after 5 years defined cure.

RESULTS

Median overall survival (OS) was 28 months, low PCI-group 33 months versus high PCI-group 17 months (P = 0.03). Median OS of patients with complete CRS (n = 56) was 30 months, low PCI-group 37 months versus high PCI-group 27 months (P = 0.2), with 5-year survival of 31% and 21%, respectively. No difference in morbidity/mortality. The cure rate was 22% in the subgroup (7/32) and 28% in those with complete CRS (7/25). Two patients in the cured group had PCI 29 and 34.

DISCUSSION

Treatment of high-volume disease may result in long-term survival and even cure. The key is to reach a complete CRS. The overall cure rate is 22%.

The use of Oxaliplatin or Mitomycin C in HIPEC treatment for peritoneal carcinomatosis from colorectal cancer: a comparative study

BACKGROUND

Oxaliplatin and Mitomycin C (MMC) are both suitable as intraperitoneal chemotherapy agents in HIPEC for peritoneal carcinomatosis (PC) of colorectal cancer (CRC).

METHODS

Patient cohorts from two different HIPEC-centers underwent cytoreductive surgery and HIPEC with Oxaliplatin (39 patients) and MMC (56 patients), respectively. They were compared for toxicity and survival data. The extent of PC was assessed using the Dutch 7-region count.

RESULTS

The median 7-region count was 4 [range 0-7] for Oxaliplatin-patients versus 2.5 [range 1-6] for MMC-patients (P = 0.004). Median intra-operative blood loss was 650 ml [0-6,000 ml] in Oxaliplatin-patients versus 1,230 ml [range 0-5,300 ml] in MMC-patients (P < 0.001). Only MMC-patients developed neutropenia/leucopenia (26.8%, P < 0.001). After statistical correction for the extent of PC, the overall postoperative complication rate was significantly higher in MMC-patients (OR = 2.68 (95% CI: 1.04-6.91), P = 0.04), with a comparable intra-abdominal complication (IAC) rate (OR = 0.78 (95% CI: 0.30-2.03), P = 0.61), but a tendency towards more extra-abdominal complications (EAC) in MMC-patients (OR = 2.23 (95% CI: 0.91-5.43), P = 0.079). Median follow-up was significantly shorter for Oxaliplatin-patients (2.8 years) than for MMC-patients (5.1 years). Median RFS was 12.2 months [IQR: 7.2-undefined] in the Oxaliplatin-group and 13.8 months [IQR: 7.0-25.8] in the MMC-group (P = 0.87). Median OS is 37.1 months [IQR: 22.4-52.8] for Oxaliplatin-patients and 26.5 months [IQR: 16.9-64.8] for MMC-patients (P = 0.45). Logistic regression analysis (corrected for extent of PC) shows RFS (HR = 1.24 (95% CI: 0.75-2.05), P = 0.39) and OS (HR = 1.37 (95% CI: 0.74-2.54), P = 0.32) are not significantly different.

CONCLUSIONS

No clear benefit in RFS and OS for HIPEC with Oxaliplatin or MMC could be demonstrated in patients with PC from CRC.

Activity ex vivo of cytotoxic drugs in patient samples of peritoneal carcinomatosis with special focus on colorectal cancer

Background

The optimal choice of cytotoxic drugs for intraperitoneal chemotherapy (IPC) in conjunction with cytoreductive surgery (CRS) for treatment of peritoneal carcinomatosis (PC) is poorly defined. We investigated drug sensitivity ex vivo in patient samples of various PC tumor types and correlated clinical outcome to drug sensitivity within the subset of PC from colorectal cancer (CRC).

Methods

PC tissue samples (n = 174) from mesothelioma, pseudomyxoma peritonei (PMP), ovarian cancer, CRC or appendix cancer were analyzed ex vivo for sensitivity to oxaliplatin, cisplatin, mitomycin C, melphalan, irinotecan, docetaxel, doxorubicin and 5-FU. Clinicopathological variables and outcome data were collected for the CRC subset.

Results

Mesothelioma and ovarian cancer were generally more drug sensitive than CRC, appendix cancer and PMP. Oxaliplatin showed the most favorable ratio between achievable IPC concentration and ex vivo drug sensitivity. Drug sensitivity in CRC varied considerably between individual samples. Ex vivo drug sensitivity did not obviously correlate to time-to-progression (TTP) in individual patients.

Conclusions

Drug-sensitivity varies considerably between PC diagnoses and individual patients arguing for individualized therapy in IPC rather than standard diagnosis-specific therapy. However, in the current paradigm of treatment according to diagnosis, oxaliplatin is seemingly the preferred drug for IPC from a drug sensitivity and concentration perspective. In the CRC subset, analysis of correlation between ex vivo drug sensitivity and TTP was inconclusive due to the heterogeneous nature of the data.

Body surface area predicts plasma oxaliplatin and pharmacokinetic advantage in hyperthermic intraoperative intraperitoneal chemotherapy

Background

Hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC) is used to treat peritoneal surface-spreading malignancies to maximize local drug concentrations while minimizing systemic effects. The pharmacokinetic advantage of HIPEC is defined as the intraperitoneal to intravascular ratio of drug concentrations. We hypothesized that body surface area (BSA) would correlate with the pharmacokinetic advantage of HIPEC. Because oxaliplatin is administered in 5 % dextrose, we hypothesized that BSA would correlate with glycemia.

Methods

We collected blood and peritoneal perfusate samples from ten patients undergoing HIPEC with a BSA-based dose of 250 mg/m² oxaliplatin, and measured drug concentrations by inductively coupled plasma mass spectrophotometry. We monitored blood glucose for 24 h postoperatively. Areas under concentration-time curves (AUC) were calculated by trapezoidal rule. Pharmacokinetic advantage was calculated by (AUC[peritoneal fluid]/AUC[plasma]). We used linear regression to test for statistical significance.

Results

Higher BSA was associated with lower plasma oxaliplatin AUC (p = 0.0075) and with a greater pharmacokinetic advantage (p = 0.0198) over the 60-minute duration of HIPEC. No statistically significant relationships were found between BSA and blood glucose AUC or peak blood glucose levels.

Conclusions

Higher BSA is correlated with lower plasma drug levels and greater pharmacokinetic advantage in HIPEC, likely because of increased circulating blood volume with inadequate time for equilibration. Plasma glucose levels after oxaliplatin HIPEC were not clearly related to BSA.

Treatment-related morbidity and toxicity of CRS and oxaliplatin-based HIPEC compared to a mitomycin and doxorubicin-based HIPEC protocol in patients with peritoneal carcinomatosis: a matched-pair analysis

INTRODUCTION

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) provide a promising therapeutic option for selected patients with peritoneal carcinomatosis. The use of intraperitoneal oxaliplatin seems to further improve the efficacy of the combined treatment concept. Nevertheless, additional toxicity might be expected.

PATIENTS AND METHODS

Between 03/2004 and 08/2010 307 patients underwent CRS and HIPEC at the University Medical Center Regensburg. Forty of these patients received oxaliplatin-based HIPEC. A matched-pair analysis was performed to compare IP oxaliplatin to our former standard HIPEC protocol with mitomycin C (MMC) and doxorubicin.

RESULTS

The mean operating time in the OX and the MMC group was 315 and 313 min, respectively. Median hospital stay was 15.5 days in the OX group and 17 days in the MMC group. The grade 3/4 morbidity rate according to CTCAEv3.0 was 42.5% versus 37.5% (P = 0.648). Perioperative mortality was 2.5% versus 0%.

CONCLUSION

Our data suggest that the use of IP oxaliplatin in the context of CRS and HIPEC does not significantly increase perioperative morbidity and/or mortality rates. Nevertheless, randomized controlled trials are required to determine the optimal intraperitoneal chemotherapeutic regimen regarding toxicity, postoperative complications, and oncological outcome.

The treatment of peritoneal carcinomatosis of colorectal cancer with complete cytoreductive surgery and hyperthermic intraperitoneal peroperative chemotherapy (HIPEC) with oxaliplatin: a Belgian multicentre prospective phase II clinical study

BACKGROUND

Up to 25% of patients with metastatic colorectal cancer (CRC) present with peritoneal carcinomatosis (PC) as the only site of metastases. Complete cytoreductive surgery (CCRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC) aims for locoregional disease control and long-term survival. Oxaliplatin is effective for treating advanced CRC. This study assesses the safety and efficacy of CCRS with HIPEC with oxaliplatin for patients with PC of CRC.

METHODS

A Belgian prospective multicenter registry was performed to monitor perioperative morbidity and assess mortality, disease-free survival (DFS), and overall survival (OS).

RESULTS

Forty-eight consecutive patients underwent CCRS (R0/1) with HIPEC (male/female ratio 17/31, median age 60 years, range 24-76 years). Median PC index was 11 (range 1-22). Median operation time was 460 (range 125-840) min, with a median blood loss of 475 (range 2-6,000) ml. Thirty-day mortality was 0%. Complication rate (any grade) was 52.1%. Anastomotic leakage occurred in 10.4% of patients, bleeding in 6.3%, and bowel perforation in 2.1%. Median hospital stay was 20 (range 5-65) days. At median follow-up of 22.7 (range 3.2-55.7) months, OS was 97.9% [95% confidence interval (CI) 86.1-99.7] at 1 year and 88.7% (95% CI 73.6-95.4) at 2 years. DFS at 1 year was 65.8% (95% CI 52.3-76.2) and 45.5% (95% CI 34.3-55.9) at 2 years. Median time until recurrence was 19.8 months (95% CI 12-upper limit not defined). Only after dichotomizing PC index was a significant difference in OS found between low and high PC index.

CONCLUSIONS

CCRS followed by HIPEC with oxaliplatin for PC from CRC can be implemented with acceptable morbidity. Long-term DFS and OS can be achieved in selected patients.

Pharmacokinetic and pharmacodynamic analysis of hyperthermic intraperitoneal oxaliplatin-induced neutropenia in subjects with peritoneal carcinomatosis

The objective of this study was to characterize the pharmacokinetics and the time course of the neutropenia-induced by hyperthermic intraperitoneal oxaliplatin (HIO) after cytoreductive surgery in cancer patients with peritoneal carcinomatosis. Data from 30 patients who received 360 mg/m(2) of HIO following cytoreductive surgery were used for pharmacokinetic-pharmacodynamic (PK/PD) analysis. The oxaliplatin plasma concentrations were characterized by an open two-compartment pharmacokinetic model after first-order absorption from peritoneum to plasma. An oxaliplatin-sensitive progenitor cell compartment was used to describe the absolute neutrophil counts in blood. The reduction of the proliferation rate of the progenitor cells was modeled by a linear function of the oxaliplatin plasma concentrations. The typical values of oxaliplatin absorption and terminal half-lives were estimated to be 2.2 and 40 h, with moderate interindividual variability. Oxaliplatin reduced the proliferation rate of the progenitor cells by 18.2% per mg/L. No patient's covariates were related to oxaliplatin PK/PD parameters. Bootstrap and visual predictive check evidenced the model was deemed appropriate to describe oxaliplatin pharmacokinetics and the incidence and severity of neutropenia. A peritoneum oxaliplatin exposure of 65 and 120 mg·L/h was associated with a 20% and 33% incidence of neutropenia grade 4. The time course of neutropenia following HIO administration was well described by the semiphysiological PK/PD model. The maximum tolerated peritoneum oxaliplatin exposure is 120 mg L/h and higher exposures should be avoided in future studies. We suggest the prophylactic use of granulocyte colony stimulating factor for patients treated with HIO exposure higher than 65 mg L/h.

Is Platinum Present in Blood and Urine from Treatment Givers during Hyperthermic Intraperitoneal Chemotherapy?

Background. In selected patients with peritoneal carcinomatosis (PC) originating from colorectal cancer (CRC) the high dosage of oxaliplatin (460 mg/m(2)) is recommended for hyperthermic intraperitoneal chemotherapy (HIPEC), which may be a health risk to those administering the drug. The aim of this study was to determine the risk of platinum (Pt) exposure for the two main people handling and administering the cytotoxic agent during HIPEC. Methods. Samples of blood and urine were collected from one male surgeon and one female perfusionist during oxaliplatin-based HIPEC treatment with open abdomen coliseum technique on six consecutive patients with PC from CRC. Results. All blood samples analysed were below the detection limit of <0.05 nmol/L Pt, and the urine samples were all below the detection limit of <0.03 nmol/L Pt. Conclusions. There appears to be little or no risk of Pt exposure during HIPEC when the recommended protective garment is used and the safety considerations are followed.

New insights into the biotransformation and pharmacokinetics of oxaliplatin

Oxaliplatin is used primarily in the treatment of metastatic colorectal cancer. In this minireview, we discuss potentially important biotransformation pathways in light of its short elimination half-life in vivo. We also highlight new information achieved using a selective analytical technique to measure intact oxaliplatin in pharmacokinetic studies (comprising intravenous, intraperitoneal, and intrahepatic administration) and compare to results obtained by measurements of total platinum. The use of selective analytical techniques is strongly recommended giving kinetic parameters of the parent compound and not only to a complex mixture of platinum containing endogenous compounds.