Limitations of the PRODIGE 7 trial

An observational cohort of patients with colorectal peritoneal metastases or pseudomyxoma peritonei treated with CRS-HIPEC: Development and first results of the Dutch CRS-HIPEC quality registry

INTRODUCTION

To improve care for patients with colorectal peritoneal metastases (CRC-PM) or pseudomyxoma peritonei (PMP), the Dutch CRS-HIPEC quality registry was initiated in 2019. The aims are to describe the development and content of this registry and to give insight into the data collected during the first years.

MATERIALS AND METHODS

The registry is an observational cohort in the Netherlands. All patients with CRC-PM or PMP who intend to undergo cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) from 6 hospitals are included. Clinical data and outcomes (including hospital variation) were analyzed.

RESULTS

In 2019-2022, 889 patients were included in the CRS-HIPEC quality registry: 749 (84 %) with CRC-PM and 140 (16 %) with PMP. Peritoneal metastases were diagnosed synchronously in 51 % of CRC-PM patients and in 94 % of PMP patients. In patients undergoing complete CRS, the median peritoneal cancer index was 8 (IQR 4-13) for CRC-PM and 15 (IQR 6-26) for PMP. Complete cytoreduction was achieved in 639 CRC-PM patients (97 %) and 108 PMP patients (82 %). HIPEC was mainly performed with mitomycin C (CRC-PM: 94 %, PMP: 92 %). Major postoperative complications (Clavien-Dindo grade ≥3) occurred in 148 CRC-PM patients (22 %) and 30 PMP patients (23 %) with 90-day mortality rates of 2 %. In CRC-PM, differences between hospitals were observed regarding proportions of diagnostic laparoscopies/laparotomies, (neo)adjuvant treatment, ostomy formations and re-admissions.

CONCLUSION

The CRS-HIPEC quality registry provides insight into the outcomes of CRS-HIPEC and enables clinical auditing and observational cohort studies aiming to improve treatment outcomes for patients with CRC-PM and PMP.

Continuous manual agitation significantly improves temperature distribution during closed hyperthermic intraperitoneal chemotherapy: Results of a porcine model

BACKGROUND

Debate persists regarding the need for shaking during hyperthermic intraperitoneal chemotherapy. Studies assessing the thermal behaviors of the perfusate throughout the abdomen during hyperthermic intraperitoneal chemotherapy are limited.

METHODS

A closed hyperthermic intraperitoneal chemotherapy technique was performed in an institutional International Animal Care and Use Committee approved porcine model targeting a 41°C outflow temperature. Continuous temperature monitoring was conducted. Abdominal shaking was performed for 60 second intervals and temperatures were allowed to equilibrate without shaking between intervals. Temperature distributions and changes due to shaking were evaluated. These findings were validated against human subjects' data.

RESULTS

The experimental procedure was conducted in 2 different animals and with 6 total shaking intervals assessed. Without shaking, temperatures were highly variable ranging between 38.0 to 42.2°C. Shaking the abdomen reduced the mean range of temperatures across all locations observed from 3.9°C to 0.8°C (P < .01). The locations of the most divergent temperatures varied based on perfusion cannula position. The point of minimum temperature heterogeneity was achieved in 28.3 (19.1-37.5) seconds. After shaking stopped, heterogeneity equal to the baseline measurements was seen on average within 25.7 (13.3-38.0) seconds. The outflow catheter differed from the system mean temperature by 1.4°C and from the coldest-reading probe by 2.8°C and outperformed the inflow catheter for all time points. With shaking these were significantly reduced to 0.4°C (P < .01) and 0.6°C (P < .01). The patient data mirrored that of the pig data.

CONCLUSION

Shaking significantly reduces temperature variability within the abdomen during hyperthermic intraperitoneal chemotherapy, and significantly improves the ability of the outflow catheter to estimate internal temperatures.

[Current status of surgical treatment of peritoneal metastases from colorectal cancer]

Cytoreductive surgery, often in combination with hyperthermic intraperitoneal chemotherapy (HIPEC), has been instrumental in improving the survival of patients with peritoneal metastases from colorectal cancer. Recent studies have highlighted the benefits of complete cytoreduction, while the role of the HIPEC treatment remains unclear. An oxaliplatin-based HIPEC over 30 min could not achieve any clear benefits in studies on colorectal cancer, neither in the therapeutic nor in the prophylactic setting, but caused relevant side effects and increased the morbidity. The negative results of these studies with respect to oxaliplatin-based HIPEC require critical appraisal; however, they should by no means be regarded as a general setback for surgical treatment of peritoneal metastases and be misunderstood as a general failure of this treatment. While HIPEC after complete surgical cytoreduction of peritoneal metastases from colorectal cancer requires further research, cytoreductive surgery should still be regarded as a highly effective treatment for suitable patients with limited abdominal tumor dissemination.

Management of peritoneal surface metastases from colorectal cancer: Cytoreductive surgery, hyperthermic intraperitoneal chemotherapy, pressurized intraperitoneal chemotherapy, and beyond

This article provides a contemporary review of the current surgical management of peritoneal surface malignancy (PSM) of colorectal origin. A brief review of the founding history of surgical intervention for PSM is followed by a focused review of the level I evidence, current clinical questions, and evolving advancements. While not intended to address all the facets of PSM, this review aims to provide the reader with the essential knowledge and resources to effectively provide surgical care for carcinomatosis due to colorectal malignancies.

Prolonged Exposure to Oxaliplatin during HIPEC Improves Effectiveness in a Preclinical Micrometastasis Model

Simple Summary

Absence of survival benefits when adding hyperthermic intraperitoneal chemotherapy (HIPEC) with oxaliplatin to cytoreductive surgery in peritoneal metastasis from colorectal cancer has recently been shown in the randomized controlled PRODIGE 7 trial. We therefore aimed to investigate the effects of this treatment modality in a preclinical micrometastasis model. Cancer cells were incubated with either patient samples obtained during HIPEC procedures or with defined oxaliplatin-containing solutions prepared according to clinically established HIPEC protocols. Our results demonstrate a limited effectiveness of short-term HIPEC in simulations with oxaliplatin to eliminate micrometastases, although we used platinum-sensitive cell lines for our model. Since these results are in line with findings from current research, our studies might offer further convincing evidence and potential explanations for HIPEC futility observed in clinical application.

Abstract

Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC) was considered a promising treatment for patients with peritoneal metastasis from colorectal cancer. However, the recently published randomized controlled PRODIGE 7 trial failed to demonstrate survival benefits through the addition of short-term oxaliplatin-based HIPEC. Constituting a complex multifactorial treatment, we investigated HIPEC in a preclinical model concerning the elimination of minimal tumor residues, thereby aiming to better understand the size of effects and respective clinical trial results. Patient samples of peritoneal perfusates obtained during HIPEC treatments and oxaliplatin-containing solutions at clinically relevant dosages, conforming with established HIPEC protocols, were assessed regarding their ability to eliminate modelled ~100 µm thickness cancer cell layers. Impedance-based real-time cell analysis and classical end-point assays were used. Flow cytometry was employed to determine the effect of different HIPEC drug solvents on tumor cell properties. Effectiveness of peritoneal perfusate patient samples and defined oxaliplatin-containing solutions proved limited but reproducible. HIPEC simulations for 30 min reduced the normalized cell index below 50% with peritoneal perfusates from merely 3 out of 9 patients within 72 h, indicating full-thickness cytotoxic effects. Instead, prolonging HIPEC to 1 h enhanced these effects and comprised 7 patients’ samples, while continuous drug exposure invariably resulted in complete cell death. Further, frequently used drug diluents caused approximately 25% cell size reduction within 30 min. Prolonging oxaliplatin exposure improved effectiveness of HIPEC to eliminate micrometastases in our preclinical model. Accordingly, insufficient penetration depth, short exposure time, and the physicochemical impact of drug solvents may constitute critical factors.