Hyperthermic intraperitoneal chemotherapy with cisplatin and mitomycin C for colorectal cancer peritoneal metastases: A systematic review of the literature

Determination of mitomycin C in rat plasma by liquid chromatography-tandem mass spectrometry and its application for determining pharmacokinetics in rat

To develop the liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for measuring mitomycin C in rat plasma, samples were processed using solid-phase extraction, with the internal standard being carbamazepine. A reversed phased C18 column was utilized for the LC-MS/MS study, and mobile phases consisting of 0.1 % formic acid in acetonitrile and water were injected into it at a rate of 0.3 mL/min. Multiple reaction monitoring in positive-ion mode with precursor-product ion pairs 335.3 → 242.3 (mitomycin C) and 237.1 → 194.1 (carbamazepine) was employed to quantify the compounds. The linear range in plasma was found to be 10-4000 ng/mL (r2 = 0.992). The inter-batch and intra-batch precision were <14.3 % (LLOQ: 14.7 %) and 13.4 % (LLOQ: 16.1 %), respectively. The recovery and the matrix effect of mitomycin C in plasma were 113 % and 111 %, respectively. Mitomycin C was stable under the conditions of this assay method. In the end, this approach proved effective in a pharmacokinetic investigation with the intravenous and oral administration of mitomycin C to rats.

Hyperthermic intraperitoneal chemotherapy in colorectal cancer

BACKGROUND

This study evaluated the efficacy of hyperthermic intraperitoneal chemotherapy (HIPEC) in colorectal cancer with peritoneal metastases (pmCRC) in a large international data set of patients.

PATIENTS AND METHODS

Patients with pmCRC from 39 centres who underwent cytoreductive surgery with HIPEC between 1991 and 2018 were selected and compared for the HIPEC protocols received-oxaliplatin-HIPEC versus mitomycin-HIPEC. Following analysis of crude data, propensity-score matching (PSM) and Cox-proportional hazard modelling were performed. Outcomes of interest were overall survival (OS), recurrence-free survival (RFS) and the HIPEC dose-response effects (high versus low dose, dose intensification and double drug protocols) on OS, RFS and 90-day morbidity. Furthermore, the impact of the treatment time period was assessed.

RESULTS

Of 2760 patients, 2093 patients were included. Median OS was 43 months (95% c.i. 41 to 46 months) with a median RFS of 12 months (95% c.i. 12 to 13 months). The oxaliplatin-HIPEC group had an OS of 47 months (95% c.i. 42 to 53 months) versus 39 months (95% c.i. 36 to 43 months) in the mitomycin-HIPEC group (P = 0.002), aHR 0.77, 95% c.i. 0.67 to 0.90, P < 0.001. The OS benefit persisted after PSM of the oxaliplatin-HIPEC group and mitomycin-HIPEC group (48 months (95% c.i. 42 to 59 months) versus 40 months (95% c.i. 37 to 44 months)), P < 0.001, aHR 0.78 (95% c.i. 0.65 to 0.94), P = 0.009. Similarly, matched RFS was significantly higher for oxaliplatin-HIPEC versus others (13 months (95% c.i. 12 to 15 months) versus 11 months (95% c.i. 10 to 12 months, P = 0.02)). High-dose mitomycin-HIPEC protocols had similar OS compared to oxaliplatin-HIPEC. HIPEC dose intensification within each protocol resulted in improved survival. Oxaliplatin + irinotecan-HIPEC resulted in the most improved OS (61 months (95% c.i. 51 to 101 months)). Ninety-day mortality in both crude and PSM analysis was worse for mitomycin-HIPEC. There was no change in treatment effect depending on the analysed time period.

CONCLUSIONS

Oxaliplatin-based HIPEC provided better outcomes compared to mitomycin-based HIPEC. High-dose mitomycin-HIPEC was similar to oxaliplatin-HIPEC. The 90-day mortality difference favours the oxaliplatin-HIPEC group. A trend for dose-response between low- and high-dose HIPEC was reported.

2022 Peritoneal Surface Oncology Group International Consensus on HIPEC Regimens for Peritoneal Malignancies: Colorectal Cancer

BACKGROUND

Selected patients with peritoneal metastases of colorectal cancer (PM-CRC) can benefit from potentially curative cytoreductive surgery (CRS) ± hyperthermic intraperitoneal chemotherapy (HIPEC), with a median overall survival (OS) of more than 40 months.

OBJECTIVE

The aims of this evidence-based consensus were to define the indications for HIPEC, to select the preferred HIPEC regimens, and to define research priorities regarding the use of HIPEC for PM-CRC.

METHODS

The consensus steering committee elaborated and formulated pertinent clinical questions according to the PICO (patient, intervention, comparator, outcome) method and assessed the evidence according to the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) framework. Standardized evidence tables were presented to an international expert panel to reach a consensus (4-point, weak and strong positive/negative) on HIPEC regimens and research priorities through a two-round Delphi process. The consensus was defined as ≥ 50% agreement for the 4-point consensus grading or ≥ 70% for either of the two combinations.

RESULTS

Evidence was weak or very weak for 9/10 clinical questions. In total, 70/90 eligible panelists replied to both Delphi rounds (78%), with a consensus for 10/10 questions on HIPEC regimens. There was strong negative consensus concerning the short duration, high-dose oxaliplatin (OX) protocol (55.7%), and a weak positive vote (53.8-64.3%) in favor of mitomycin-C (MMC)-based HIPEC (preferred choice: Dutch protocol: 35 mg/m2, 90 min, three fractions), both for primary cytoreduction and recurrence. Determining the role of HIPEC after CRS was considered the most important research question, regarded as essential by 85.7% of the panelists. Furthermore, over 90% of experts suggest performing HIPEC after primary and secondary CRS for recurrence > 1 year after the index surgery.

CONCLUSIONS

Based on the available evidence, despite the negative results of PRODIGE 7, HIPEC could be conditionally recommended to patients with PM-CRC after CRS. While more preclinical and clinical data are eagerly awaited to harmonize the procedure further, the MMC-based Dutch protocol remains the preferred regimen after primary and secondary CRS.

Ursolic Acid Suppresses Colorectal Cancer by Down-Regulation of Wnt/β-Catenin Signaling Pathway Activity

Overwhelming evidence points to an abnormally active Wnt/β-catenin signaling as a key player in colorectal cancer (CRC) pathogenesis. Ursolic acid (UA) is a pentacyclic triterpenoid that has been found in a broad variety of fruits, spices, and medicinal plants. UA has been shown to have potent bioactivity against a variety of cancers, including CRC, with the action mechanism obscure. Our study tried to learn more about the efficacy of UA on CRC and its functional mechanism amid the Wnt/β-catenin signaling cascade. We determined the efficacy of UA on CRC SW620 cells with respect to the proliferation, migration, clonality, apoptosis, cell cycle, and Wnt/β-catenin signaling cascade, with assessment of the effect of UA on normal colonic NCM460 cells. Also, the effects of UA on the tumor development, apoptosis, cell cycle, and Wnt/β-catenin signaling axis were evaluated after a subcutaneous SW620 xenograft tumor model was established in mice. In this work, we showed that UA drastically suppressed proliferation, migration, and clonality; induced apoptosis; and arrested the cell cycle at the G0/G1 phase of SW620 cells, without the influence on NCM460 cells, accompanied by weakened activity of the Wnt/β-catenin signaling pathway. Besides, UA markedly deterred the growth of the xenograft tumor, ameliorated pathological features, triggered apoptosis, and arrested the cell cycle in xenograft CRC tissue, by lessening the Wnt/β-catenin signaling cascade. Overall, UA may inhibit the malignant phenotype, induce apoptosis, and arrest the cell cycle of CRC, potentially by attenuating the Wnt/β-catenin signaling axis, providing insights into the mechanism for the potency of UA on CRC.

Colorectal Cancer with Peritoneal Metastases: The Impact of the Results of PROPHYLOCHIP, COLOPEC, and PRODIGE 7 Trials on Peritoneal Disease Management

HIPEC is a potentially useful locoregional treatment combined with cytoreduction in patients with peritoneal colorectal metastases. Despite being widely used in several cancer centers around the world, its role had never been investigated before the results of three important RCTs appeared on this topic. The PRODIGE 7 trial clarified the role of oxaliplatin-based HIPEC in patients treated with radical surgery. Conversely, the PROPHYLOCHIP and the COLOPEC were designed to chair the role of HIPEC in patients at high risk of developing peritoneal metastases. Although all three trials demonstrated the relative ineffectiveness of HIPEC for treating or preventing peritoneal metastases, these results are not sufficient to abandon this technique. In addition to some criticisms relating to the design of the trials and their statistical value, the oxaliplatin-based HIPEC was found to be ineffective in preventing or treating peritoneal colorectal metastases, especially in patients already treated with systemic platinum-based chemotherapy. Several studies are ongoing investigating further HIPEC drugs and regimens. The review deeply discussed all the aspects and relapses of this new evidence.

Peritoneal Metastases of Colorectal Origin Treated with Complete Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy: The Efficiency of Mitomycin C

BACKGROUND

Survival of patients affected by colorectal cancer peritoneal metastases (CRC-PM) can be improved with combined complete cytoreductive surgery (CCRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Two chemotherapeutic agents are mainly used: mitomycin C (MMC) and oxaliplatin. A recent prospective randomized clinical trial showed that oxaliplatin-based HIPEC does not improve survival compared with CCRS alone. The purpose of our study was to compare the survival effectiveness of MMC versus oxaliplatin-based HIPEC using a homogeneous surgical technique and drug protocol.

METHODS

This retrospective monocentric study included all patients prospectively registered for having undergone CCRS and HIPEC using MMC or oxaliplatin for CRC-PM in Strasbourg University Hospital, France, from December 2004 until December 2019. MMC-based HIPEC and oxaliplatin-based HIPEC groups were compared with an inverse probability of treatment weighting.

RESULTS

A total of 137 patients were included. Groups were comparable for all baseline characteristics except for peritoneal carcinomatosis index. In the weighted multivariate analysis, disease-free survival (DFS) and peritoneal disease-free survival (PDFS) were significantly higher in the MMC-based HIPEC group compared with the oxaliplatin-based HIPEC group with a hazard ratio of 0.74 (CI 95% 0.56-0.98), p = 0.035 and 0.59 (CI 95% 0.40-0.98), p = 0.0084, respectively. There was no difference in overall survival or postoperative morbidity between groups.

CONCLUSIONS

These results favor a superiority of MMC for DFS and PDFS in comparison with oxaliplatin in HIPEC after CCRS in treatment with curative intent for CRC-PM.

Postoperative bleeding and venous thromboembolism in colorectal cancer patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy: a systematic review and meta-analysis

PURPOSE

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has improved survival for selected patients with peritoneal metastases from colorectal cancer. Previous studies report conflicting rates of postoperative bleeding and venous thromboembolism (VTE) after CRS + HIPEC. The aim of the present study was to systematically review the literature and to estimate the overall 30-day incidence of postoperative bleeding and the overall 90-day incidence of VTE after CRS + HIPEC.

METHODS

Studies were identified in PubMed, Embase, and Web of Science on 29 April 2021. Data were extracted for a qualitative synthesis and to estimate an overall mean incidence in the meta-analysis.

RESULTS

Fourteen studies with a total of 3268 patients were included in the systematic review. Postoperative bleeding incidence rates within 30 days ranged from 1.7 to 8.3% with an overall 30-day postoperative bleeding incidence with [95% CI] at 4.2 [2.6;6.2]%. VTE incidence rates within 90 days ranged from 0.2 to 13.6% with an overall 90-day VTE incidence with [95% CI] at 2.7 [1;5.2]% after CRS + HIPEC.

CONCLUSION

This systematic review and meta-analysis indicate a low risk for postoperative bleeding within 30 days and VTE within 90 days after CRS + HIPEC for peritoneal metastases from colorectal cancer.

The impact of PRODIGE 7 on the current worldwide practice of CRS-HIPEC for colorectal peritoneal metastases: A web-based survey and 2021 statement by Peritoneal Surface Oncology Group International (PSOGI)

INTRODUCTION

The PRODIGE 7-trial investigated the additional value of Hyperthermic Intraperitoneal Chemotherapy (HIPEC) to cytoreductive surgery (CRS) for patients with colorectal peritoneal metastases (CPM). The results of PRODIGE 7 were presented at the 2018 ASCO meeting showing that 30 min oxaliplatin-based HIPEC did not improve overall survival. The current study investigated the impact of PRODIGE 7 on the worldwide practice of CRS and HIPEC.

MATERIALS AND METHODS

CRS-HIPEC experts from 19 countries were invited through the Peritoneal Surface Oncology Group International (PSOGI) to complete an online survey concerning the current CRS-HIPEC practice in their hospital and country, and were asked to appraise the effect of PRODIGE 7.

RESULTS

The survey was completed by 18/19 experts. Although their personal opinions of CRS-HIPEC were barely influenced by PRODIGE 7, they reported a substantial impact on daily practice. This included a switch towards Mitomycin-C based HIPEC-regimens and prolongation of HIPEC perfusion time, a reduction in the number of referrals from non-HIPEC centers, a reduction in national consensus, the removal of HIPEC from national guidelines, and a reduced reimbursement rate.

CONCLUSION

The PRODIGE 7 has had a major impact on the practice of CRS-HIPEC for CPM worldwide. HIPEC remains an attractive option with potential for control and eradication of disease and further studies into the optimal HIPEC-regimen are urgently needed. Meanwhile, given the complexity of the treatment of patients with CPM, and the proven benefits of optimal CRS, referral of patients with potentially resectable CPM to expert centers is recommended whilst the precise role of HIPEC is further evaluated.

10 ns PEFs induce a histological response linked to cell death and cytotoxic T-lymphocytes in an immunocompetent mouse model of peritoneal metastasis

PURPOSE

The application of nanosecond pulsed electric fields (nsPEFs) could be an effective therapeutic strategy for peritoneal metastasis (PM) from colorectal cancer (CRC). The aim of this study was to evaluate in vitro the sensitivity of CT-26 CRC cells to nsPEFs in combination with chemotherapeutic agents, and to observe the subsequent in vivo histologic response.

METHODS

In vitro cellular assays were performed to assess the effects of exposure to 1, 10, 100, 500 and 1000 10 ns pulses in a cuvette or bi-electrode system at 10 and 200 Hz. nsPEF treatment was applied alone or in combination with oxaliplatin and mitomycin. Cell death was detected by flow cytometry, and permeabilization and intracellular calcium levels by fluorescent confocal microscopy after treatment. A mouse model of PM was used to investigate the effects of in vivo exposure to pulses delivered using a bi-electrode system; morphological changes in mitochondria were assessed by electron microscopy. Fibrosis was measured by multiphoton microscopy, while the histological response (HR; hematoxylin-eosin-safran stain), proliferation (KI67, DAPI), and expression of immunological factors (CD3, CD4, CD8) were evaluated by classic histology.

RESULTS

10 ns PEFs exerted a dose-dependent effect on CT-26 cells in vitro and in vivo, by inducing cell death and altering mitochondrial morphology after plasma membrane permeabilization. In vivo results indicated a specific CD8+ T cell immune response, together with a strong HR according to the Peritoneal Regression Grading Score (PRGS).

CONCLUSIONS

The effects of nsPEFs on CT-26 were confirmed in a mouse model of CRC with PM.

Rosemary oil nano-emulsion potentiates the apoptotic effect of mitomycin C on cancer cells in vitro

Purpose: To formulate nano-emulsified rosemary oil (REO/NE) and determine its effect on the anticancer agent, mitomycin C (MC) when used as a carrier for the drug.

Methods: The droplet size of REO/NE was markedly enlarged when mixed with MC. The cytotoxicity of the formulations on HeLa and MCF-7 cells was determined using MTT assay. The combination index (CI) values were estimated with CompuSyn software, while apoptosis was determined using DAPI fluorescent dye.

Results: Treatment of MCF-7 cells and HeLa cells with REO/NE (1% v:v and 1.33% v:v, respectively) reduced the IC50 of MC 33 and 15 folds, respectively. Under fluorescent microscopy, cells treated with REO/NE+MC had more marked reduction of the nuclear area than MC-treated cells.

Conclusion: These results indicate that REO/NE is an efficient carrier for MC since it enhanced MC delivery and increased its effect on the cells through the induction of apoptosis at low concentrations of MC.

Oxaliplatin versus mitomycin C in HIPEC for peritoneal metastasis from colorectal cancer: a systematic review and meta-analysis of comparative studies

BACKGROUND

Hyperthermic intraperitoneal perfusion chemotherapy (HIPEC) following cytoreductive surgery (CRS) has been applied for peritoneal metastasis (PM) from colorectal cancer (CRC). This study aimed to compare oxaliplatin (OX) with mitomycin C (MMC) in HIPEC for PM from CRC in surgical and survival outcomes.

METHODS

A systematic literature search was performed in PubMed and Ovid databases for studies comparing OX with MMC in HIPEC for PM from CRC. The last search was performed on June 21, 2020.

RESULTS

Eleven articles published between 2006 and 2020 with 2091 patients were included. When compared with MMC group, the OX group showed significantly higher rate of major complications (P = 0.006, OR = 1.57, 95% CI [1.14, 2.16], I² = 0%). Besides, no significant difference was observed between the two groups for survival outcomes, regardless of 3-year overall survival (P = 0.98, OR = 1.00, 95% CI [0.83, 1.22], I² = 0%), 3-year disease-free survival (P = 0.98, OR = 1.00, 95% CI [0.83, 1.22], I² = 0%), or 5-year overall survival (P = 0.91, OR = 1.01, 95% CI [0.81, 1.26], I² = 0%).

CONCLUSION

OX and MMC could achieve comparable survival in HIPEC for PM from CRC. However, in consideration of the high incidence of major complication in OX group, MMC might be the safer one in clinical routines.

Oxaliplatin versus Mitomycin C following complete cytoreduction for colorectal peritoneal metastases: a comparative study

BACKGROUND AND OBJECTIVES

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) can offer selected patients with colorectal peritoneal metastases (CRPM) a favorable long-term survival. While cytoreductive techniques are standardized, there remains great variability in HIPEC drugs with mitomycin C or oxaliplatin use based largely on institute preference. In this study, we compared outcomes based on mitomycin C or oxaliplatin use after complete cytoreduction.

METHODS

This is a retrospective analysis over a 7-year period of all patients undergoing complete cytoreduction with HIPEC.

RESULTS

Seventy-eight patients underwent complete cytoreduction with HIPEC during this time. Forty-six patients received oxaliplatin as HIPEC, and 32 received mitomycin C. There was no difference in patient characteristics, resections, or major morbidity between the two groups. Superficial wound infections were higher in the mitomycin C group (37.5% v 15.2%, p = 0.02). Median overall and disease-free survival for the entire cohort was 40 and 14 months, respectively. There was no difference in overall survival or disease-free survival between the two HIPEC groups (HR 0.50, 95% CI 0.11-2.28).

CONCLUSION

Complete cytoreduction and HIPEC can offer selected patients a favorable survival. The choice of mitomycin C or oxaliplatin for HIPEC had no influence on survival. Prospective studies are needed to explore this important issue.

Comparison of hyperthermic intraperitoneal chemotherapy regimens for treatment of peritoneal-metastasized colorectal cancer

BACKGROUND

Cytoreductive surgery (CRS) in combination with hyperthermic intraperitoneal chemotherapy (HIPEC) improves patient survival in colorectal cancer (CRC) with peritoneal carcinomatosis (PC). Commonly used cytotoxic agents include mitomycin C (MMC) and oxaliplatin. Studies have reported varying results, and the evidence for the choice of the HIPEC agent and uniform procedure protocols is limited.

AIM

To evaluate therapeutic benefits and complications of CRS + MMC vs oxaliplatin HIPEC in patients with peritoneal metastasized CRC as well as prognostic factors.

METHODS

One hundred and two consecutive patients who had undergone CRS and HIPEC for CRC PC between 2007 and 2019 at the Medical Center of the University Freiburg regarding interdisciplinary cancer conference decision were retrospectively analysed. Oxaliplatin and MMC were used in 68 and 34 patients, respectively. Each patient’s demographics and tumour characteristics, operative details, postoperative complications and survival were noted. Complications were stratified and graded using Clavien/Dindo analysis. Prognostic outcome factors were identified using univariate and multivariate analysis of survival.

RESULTS

The two groups did not differ significantly regarding baseline characteristics. We found no difference in median overall survival between MMC and oxaliplatin HIPEC. Regarding postoperative complications, patients treated with oxaliplatin HIPEC suffered increased complications (66.2% vs 35.3%; P = 0.003), particularly intestinal atony, intraabdominal infections and urinary tract infection, and had a prolonged intensive care unit stay compared to the MMC group (7.2 d vs 4.4 d; P = 0.035). Regarding univariate analysis of survival, we found primary tumour factors, nodal positivity and resection margins to be of prognostic value as well as peritoneal cancer index (PCI)-score and the completeness of cytoreduction regarding peritoneal carcinomatosis. Multivariate analysis of survival confirmed primary distant metastasis and primary tumour resection status to have a significant impact on survival and likewise peritoneal cancer index-scoring regarding peritoneal carcinomatosis.

CONCLUSION

In this single-institution retrospective review of patients undergoing CRS with either oxaliplatin or MMC HIPEC, overall survival was not different, though oxaliplatin was associated with a higher postoperative complication rate, indicating treatment favourably with MMC. Further studies comparing HIPEC regimens would improve evidence-based decision-making.

Integrating Loco-Regional Hyperthermia Into the Current Oncology Practice: SWOT and TOWS Analyses

Moderate hyperthermia at temperatures between 40 and 44°C is a multifaceted therapeutic modality. It is a potent radiosensitizer, interacts favorably with a host of chemotherapeutic agents, and, in combination with radiotherapy, enforces immunomodulation akin to “in situ tumor vaccination.” By sensitizing hypoxic tumor cells and inhibiting repair of radiotherapy-induced DNA damage, the properties of hyperthermia delivered together with photons might provide a tumor-selective therapeutic advantage analogous to high linear energy transfer (LET) neutrons, but with less normal tissue toxicity. Furthermore, the high LET attributes of hyperthermia thermoradiobiologically are likely to enhance low LET protons; thus, proton thermoradiotherapy would mimic ¹²C ion therapy. Hyperthermia with radiotherapy and/or chemotherapy substantially improves therapeutic outcomes without enhancing normal tissue morbidities, yielding level I evidence reported in several randomized clinical trials, systematic reviews, and meta-analyses for various tumor sites. Technological advancements in hyperthermia delivery, advancements in hyperthermia treatment planning, online invasive and non-invasive MR-guided thermometry, and adherence to quality assurance guidelines have ensured safe and effective delivery of hyperthermia to the target region. Novel biological modeling permits integration of hyperthermia and radiotherapy treatment plans. Further, hyperthermia along with immune checkpoint inhibitors and DNA damage repair inhibitors could further augment the therapeutic efficacy resulting in synthetic lethality. Additionally, hyperthermia induced by magnetic nanoparticles coupled to selective payloads, namely, tumor-specific radiotheranostics (for both tumor imaging and radionuclide therapy), chemotherapeutic drugs, immunotherapeutic agents, and gene silencing, could provide a comprehensive tumor-specific theranostic modality akin to “magic (nano)bullets.” To get a realistic overview of the strength (S), weakness (W), opportunities (O), and threats (T) of hyperthermia, a SWOT analysis has been undertaken. Additionally, a TOWS analysis categorizes future strategies to facilitate further integration of hyperthermia with the current treatment modalities. These could gainfully accomplish a safe, versatile, and cost-effective enhancement of the existing therapeutic armamentarium to improve outcomes in clinical oncology.

Neutropenia in colorectal cancer treated with oxaliplatin-based hyperthermic intraperitoneal chemotherapy: An observational cohort study

BACKGROUND

The implications of neutropenia after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) treatment have never been investigated.

AIM

To evaluate the occurrence of neutropenia and its effect on the risk of increased Clavien-Dindo morbidity as well as its effect on overall or disease-free survival.

METHODS

All patients with colorectal peritoneal metastases (1996-2015) completing cytoreductive surgery and oxaliplatin-based HIPEC treatment from a bi-institutional database (Uppsala and Sydney) were included in the study. Clavien-Dindo grade 3-4 morbidity differences between the neutropenia group vs non-neutropenia group were calculated and Kaplan-Meier curves with log rank test were rendered. Univariate and multivariable Cox regression models for disease-free survival were implemented.

RESULTS

Two hundred and forty-six patients were identified – 32 postoperative any-grade neutropenia patients and 214 non-neutropenia patients. The neutropenia group had more combination oxaliplatin + irinotecan treatment than the non-neutropenia group (66% vs 13%, P = 0.0001). The neutropenia group was not associated with increased Clavien-Dindo grade 3-4 morbidity. Median overall survival was 53 mo vs 37 mo for the neutropenia and non-neutropenia group, P = 0.07. Median disease-free survival was 16 mo vs 11 mo, respectively, P = 0.02. Neutropenia was an independent prognostic factor for disease-free survival with hazard ratio: 0.58, 95% confidence interval: 0.36-0.95, P = 0.03.

CONCLUSION

13% of patients developed neutropenia which was not associated with increased Clavien-Dindo grade 3-4 morbidity. Neutropenia was an independent positive prognostic factor for disease-free survival and was associated with more intense HIPEC treatment. This is in direct contrast to the current paradigm of decreasing the treatment intensity.