Platelet Dynamics in Peritoneal Carcinomatosis Patients Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Oxaliplatin

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.

Population pharmacokinetics of oxaliplatin after intraperitoneal administration with hyperthermia in Wistar rats

BACKGROUND

The evaluation of the efficacy and toxicity of hyperthermic intraoperative peritoneal chemotherapy presents some difficulties, due in part to the lack of information about the pharmacokinetic behavior of the drugs administered in this procedure. The aim of this study was to characterize the population pharmacokinetics of hyperthermic intraoperative peritoneal oxaliplatin in Wistar rats and to evaluate the effect of treatment-related covariates dose, instillation time and temperature on the pharmacokinetic parameters.

METHODS

Oxaliplatin peritoneal and plasma concentrations from 37 rats treated by either intravenous or intraperitoneal oxaliplatin administrations under different instillation times, temperatures and doses were analyzed according to a population pharmacokinetic approach using the software NONMEM V7.3®.

RESULTS

Intraperitoneal (n = 115) and plasma (n = 263) concentrations were successfully described according to a two-compartment model with first order absorption. No significant effect of dose, temperature and instillation time on pharmacokinetic parameters was found. However, an abrupt decrease in the elimination process was observed, reflected in the structural pharmacokinetic model through a modification in clearance. The typical parameters values and the interindividual variability (CV %) in clearance, central and peripheral volume of distribution were 3.25 mL/min (39.1%), 53.6 mL (37.8%) and 54.1 mL (77.3%), respectively. Clearance decreased to 0.151 mL/min (39.1%) when the instillation was still ongoing, at 31.4 min. One of the possible reasons behind the clearance decrease would be an alteration of renal function due to surgery and/or hyperthermia.

CONCLUSIONS

This study described the deterioration of the drug elimination process due to the procedure, and estimated the time at which this deterioration is most likely to occur. In addition, dose, instillation time and temperature had no influence in the PK parameters.

Thrombin generation and platelet activation in cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy - A prospective cohort study

Background and objectives

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal peroperative chemotherapy (HIPEC), indicated for patients with peritoneal metastases from digestive or gynecological malignancies alike, demonstrates a considerable impact on hemostatic metabolism, both on platelet and on coagulation level. The potential hemostatic interference in CRS and HIPEC is phase dependent. The hypothesis of this prospective cohort study is that the procedure exposed an increased thrombotic risk, resulting in a faster and increased thrombin generation and hyper platelet function.

Methods

This study explores the combined use of ROTEM (rotational thromboelastometry), PACT (platelet activation test) and CAT (thrombin generation test) assays during CRS and HIPEC with a follow-up of 7 days postoperative in 27 patients with confirmed histological diagnosis of peritoneal disease.

Results

Platelet reactivity (relative to before incision values) to CRP (collagen-related peptide) (p value 0.02) and TRAP (thrombin receptor activator peptide) (p value 0.048) seems to be slightly reduced during CRS and HIPEC with regard to αIIbβ3 activation, while P-selectin expression is not affected. During surgery, CAT demonstrates that, the LT (lagtime) (p value 0.0003) and TTP (time-to-thrombin peak) values (p value 0.002) decrease while and the TP (thrombin peak) (p value 0.004) and ETP (endogenous thrombin potential) (p value 0.02) increase. Subsequently, after surgery, the LT and TTP increase and ETP and TP decrease in time. ROTEM EXTEM (extrinsic) MCF (maximum clot firmness) (p value 0.005), INTEM (intrinsic) MCF (p value 0.003) and FIBTEM (fibrinogen) MCF (p value <0.001) decreased during CRS. At day 7 INTEM and FIBTEM MCF values (p values of 0.004 and <0.001) were significantly higher than before surgery. No considerable changes in platelet count and hemoglobin concentration and absence of leukopenia are noticed.

Conclusion

This approach detects changes in coagulation much earlier than noticed by standard coagulation tests.

Neutropenia and thrombocytopenia after cytoreductive surgery and heated intraperitoneal chemotherapy

Background

Neutropenia and thrombocytopenia are well-recognised complications of systemic chemotherapy. In cytoreductive surgery and heated intraperitoneal chemotherapy (HIPEC), the interplay between surgical factors and systemic toxicity of chemotherapeutics must be considered when considering post-operative haematological outcomes. We sought to quantify the incidence of these events in cytoreductive surgery and HIPEC at our institution.

Methods

We conducted a single centre, a retrospective cohort study of 50 consecutive patients who underwent cytoreductive surgery and HIPEC from 2002 to 2015. Routine haematological data were analysed and complications classified according to CTCAE 4.0. Subgroup analysis was undertaken to compare those who received or not perioperative systemic chemotherapy.

Results

The rate of all-grade post-procedure neutropenia was 4 % (n=2/50); one grade 1, and one grade 4 neutropenia. The patient with grade 4 neutropenia died day 57 post-operatively, despite subsequent growth factor support. Eight percent (n=4/50) of patients had thrombocytopenia preoperatively. The overall rate of post-procedure thrombocytopenia was 46 % with grade 3-4 thrombocytopenia of 4 %. If not present preoperatively, thrombocytopenia onset was on day 1 or 2 post-operatively, with a median duration of 3 days.

Conclusions

Intraperitoneal delivery of chemotherapy as HIPEC can cause haematological toxicity with potentially fatal outcomes. However, the incidence of neutropenia and thrombocytopenia after CRS and HIPEC is low.