Consensus guidelines from The American Society of Peritoneal Surface Malignancies on standardizing the delivery of hyperthermic intraperitoneal chemotherapy (HIPEC) in colorectal cancer patients in the United States

Peritoneal Cancer Index Correlates with Radiographic Assessment of Colorectal Carcinomatosis

BACKGROUND

The Peritoneal Cancer Index (PCI), calculated intraoperatively, has previously yielded mixed results when correlated with computed tomography. This study aimed to quantify variation in this scoring method comparing radiologists' and surgeons' radiologic PCI (rPCI) assessment.

METHODS

The rPCI of 104 patients treated at a single institution for peritoneal carcinomatosis was calculated by an abdominal radiologist and a surgeon. An additional 36-patient cohort was studied to compare preoperative rPCI with intraoperative gold standard PCI. Agreement was compared using kappa statistics.

RESULTS

The rPCI of the 104 patients studied ranged from 2 to 39 (median, 12; interquartile range [IQR], 6-23) by the radiologist's analysis and 2 to 37 (median, 9; IQR, 6-15) by the surgeon's analysis. There was good agreement for PCI cutoffs of 15 (77.48%; kappa, 0.40) and 20 (78.63%; kappa, 0.24). The 36-patient cohort undergoing surgical exploration showed a median rPCI of 4 (IQR, 2-5.75) and a median intraoperative PCI of 11 (IQR, 6-12), with a significant difference in score by method (p < 0.001, Wilcoxon signed-rank test).

CONCLUSIONS

For rPCI cutoffs greater than 15 and 20, the surgeon's and radiologist's rPCI showed strong concordance, denoting the interobserver reproducibility of rPCI. Moreover, concordance with intraoperative PCI translated to radiographic assessment. The rPCI consistently underestimated intraoperative PCI, suggesting that rPCI may be a useful conservative tool for assessing peritoneal burden. Although surgical exploration is needed to "rule in" patients as candidates for CRS, the authors suggest that rPCI can be used to "rule out" patients as CRS candidates based on institutional PCI cutoffs.

An Organoid Model for the Therapeutic Effect of Hyperthermic Intraperitoneal Chemotherapy for Colorectal Cancer

BACKGROUND

Consensus regarding the hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal cancer (CRC) regimen remains elusive. In this study, patient-derived tumor organoids from CRC were utilized as a preclinical model for in vitro drug testing of HIPEC regimens commonly used in clinical practice. This approach was used to facilitate the clinical formulation of HIPEC.

METHOD

Tumor tissues and corresponding clinical data were obtained from patients diagnosed with CRC at the Sixth Affiliated Hospital of Sun Yat-Sen University. Qualified samples were cultured and passaged. We aimed to assess the sensitivity of in vitro hyperthermic perfusion using five different regimens, i.e. mitomycin C, mitomycin C combined with cisplatin, mitomycin C combined with 5-fluorouracil, oxaliplatin, and oxaliplatin combined with 5-fluorouracil.

RESULTS

Tumor organoids obtained from 46 patients with CRC were cultured, and in vitro hyperthermic perfusion experiments were conducted on 42 organoids using five different regimens. The average inhibition rate of mitomycin C was 85.2% (95% confidence interval [CI] 80.4-89.9%), mitomycin C combined with cisplatin was 85.5% (95% CI 80.2-90.7%), mitomycin C combined with 5-fluorouracil was 65.6% (95% CI 59.6-71.6%), oxaliplatin was 37.9% (95% CI 31.5-44.3%), and oxaliplatin combined with 5-fluorouracil was 40.7% (95% CI 33.9-47.5%).

CONCLUSION

In vitro hyperthermic perfusion demonstrates that the inhibition rate of mitomycin C, both alone and in combination with cisplatin, surpasses that of the combination of mitomycin C with 5-fluorouracil and oxaliplatin. In clinical practice, the combination of mitomycin C and cisplatin can be regarded as the optimal choice for HIPEC in CRC.

Pharmacokinetics of cisplatin in the systemic versus hyperthermic intrathoracic or intraperitoneal chemotherapy

OBJECTIVE

To compare the pharmacokinetics and adverse effects of cisplatin administered via intravenous infusion for systemic chemotherapy (SC) versus injection into the perfusate during hyperthermic intrathoracic chemotherapy (HITHOC) or hyperthermic intraperitoneal chemotherapy (HIPEC).

METHODS

Total 60 patients who received SC, HITHOC, or HIPEC in the Department of Oncology, Tangdu Hospital, were enrolled into this study. After administering same dose of cisplatin (40 mg) via either intravenous infusion (SC group) or injection into the perfusate during the HITHOC or HIPEC procedure, concentration of cisplatin in the plasma as well as in the hyperthermic perfusate at various time points was quantified by HPLC analysis. The area under the plasma or perfusate concentration-time curve over the last 24h dosing interval (AUC0-24h), mean residence time over the 24 h (MRT0-24h), terminal elimination half-life (t1/2z), time to peak concentration (Tmax), apparent clearance (Clz/F), and peak concentration (Cmax) in the perfusate and plasma were compared.

RESULTS

In the perfusate, the AUC0-24h (64.32 ± 27.12 µg/mL·h) and Cmax (21.62 ± 5.88 µg/mL) were significantly higher in the HITHOC group compared to that in the HIPEC group (31.68 ± 13.29 µg/mL·h and 16.96 ± 5.54 µg/mL, respectively, p ≤ 0.01). In contrast, MRT0-∞, t1/2z, and Clz/F were significantly lower in the HITHOC group compared to that in the HIPEC group (p < 0.01). In the plasma, average AUC0-24h and Cmax of the HITHOC group were 2.57 ± 0.55 µg/mL·h and 0.26 ± 0.08 µg/mL, respectively, which were significantly lower than that of systemic chemotherapy (SC) group (3.26 ± 0.56 µg/mL·h and 0.69 ± 0.14 µg/mL, respectively, p < 0.01), but no difference compared to that of HIPEC group (3.02 ± 0.52 µg/mL·h and 0.40 ± 0.15 µg/mL, respectively, p > 0.05). In contrast, MRT0-24h and Tmax in the plasma of HITHOC group were significantly longer compared to that of SC group (p < 0.05), but no significant difference compared to that of HIPEC group (p > 0.05). Absolute bioavailability of cisplatin in the thoracic (HITHOC group) and abdominal (HIPEC group) cavities was 20 and 10 times higher than that in the blood administered intravenously (SC group), respectively. There was no significant difference in the incidence of adverse events among the three groups (p < 0.05).

CONCLUSION

The current study demonstrated that, in the perfusate, AUC0-24h and Cmax of cisplatin was significantly higher in the group of HITHOC compared to that of HIPEC, and that, in the plasma, AUC0-24h and Cmax of cisplatin was lower in the group of HITHOC compared to that of HIPEC or SC group. This study provided pharmacokinetic evidence to further support the concept that topical application of chemotherapeutic drug through minimally invasive HITHOC or HIPEC may enhance local exposure compared to systemic chemotherapy for the patients with malignant pleural effusion or ascites.

Abdominal compartment syndrome during intraoperative hyperthermic intraperitoneal chemotherapy following debulking surgery for colorectal cancer: A case report

INTRODUCTION

Colorectal cancer leads to peritoneal metastasis in 8-15 % of cases and necessitates treatments, such as hyperthermic intraperitoneal chemotherapy (HIPEC). However, HIPEC may result in perioperative complications, some often overlooked, such as abdominal compartment syndrome.

CASE PRESENTATION

A 52-year-old female with colorectal cancer and peritoneal metastasis underwent debulking surgery followed by HIPEC. During HIPEC, a sudden increase in airway pressure and severe hypotension were noted. Pneumothorax with abdominal compartment syndrome (ACS) was suspected and HIPEC was terminated. Despite intravenous fluids and vasopressors, she experienced circulatory and respiratory collapse. Laparotomy sutures were promptly removed, which effectively alleviated the intra-abdominal hypertension and immediately restored the vital signs. An inadequately repaired diaphragm defect was identified and repaired. A chest tube was inserted for pleural effusion.

DISCUSSION

ACS is characterized by an increase in abdominal cavity pressure above 20 mmHg, leading to end-organ damage. It can mimic physiological effects of HIPEC and result in adverse outcomes. Early detection of ACS is essential, especially when complicated by pneumothorax from diaphragmatic tumor dissection. The closed technique for HIPEC, while efficient, can increase the risk of ACS and requires careful management.

CONCLUSIONS

This case underscores the complexity of HIPEC and the importance of promptly identifying and managing ACS during the procedure. Monitoring intra-abdominal pressure during HIPEC is essential. Thoroughly check for iatrogenic injuries, including the diaphragm, is crucial before starting before HIPEC.

Efficacy and safety of cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy in patients with pancreatic cancer peritoneal metastasis

OBJECTIVES

Pancreatic cancer with peritoneal metastasis presents a challenging prognosis, with limited effective treatment options available. This study aims to evaluate the efficacy and safety of combining cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) as a treatment strategy for this patient group.

METHODS

A retrospective analysis was conducted on patients with peritoneal metastasis of pancreatic cancer who underwent CRS + HIPEC treatment at Beijing Shijitan Hospital from March 2017 to December 2023. The study focused on assessing clinical features, the incidence of sever adverse events (SAEs), and overall survival (OS).

RESULTS

A total of 10 patients were enrolled in this study. The median OS was 24.2 months, suggesting an improvement over traditional therapies. While SAEs were noted, including two cases of severe complications necessitating additional surgical interventions, no perioperative fatalities were recorded. The overall survival time for patients with CC0/1 was not significantly different from that of patients with CC2/3, and no prognostic predictors were identified.

CONCLUSIONS

The combination of CRS and HIPEC appears to be a viable and promising treatment modality for patients with peritoneal metastasis of pancreatic cancer, offering an improved survival rate with manageable safety concerns. Further research is needed to refine patient selection criteria and to explore the long-term benefits of this approach.

Thromboelastogram changes are associated with postoperative complications after cytoreductive surgery

Objectives

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is used to treat peritoneal surface malignancies. However, surgical morbidity is high, and prediction of severe postoperative complications (SPC) is limited. We hypothesized that the changes in thromboelastogram (TEG) values following CRS could be associated with SPC.

Methods

We retrospectively analyzed a cohort of CRS and HIPEC patients who had TEG measured before and after CRS. Clinical and postoperative data were retrieved from a prospectively maintained database.

Results

Our 37-patient cohort was comprised of 24 men and 13 women with an age (median, [interquartile range, IQR]) 55 (47-65) years, of whom six had SPC. The ones with SPC did not differ from the others in age, sex, tumor histology or preoperative chemotherapy. The extent of surgery as measured by the peritoneal carcinomatosis index and the number of organs resected was comparable between SPC group vs. no SPC [9 (3-10.5) vs. 9 (5-14), p=1.0; 2 (0.75-2.25) vs. 2 (1-3), p=0.88, respectively]. The TEG parameters showed increased R- and K- time for the patients with SPC compared to those without (6 ± 3.89 vs. 4.05 ± 1.24, p=0.01; 1.65 ± 0.63 vs. 1.25 ± 0.4, p=0.03, respectively). The TEG values were significantly associated with SPC in the multivariable analysis (odds ratio=1.53, p=0.05).

Conclusions

TEG changes are associated with SPC. Intra-operative markers of SPC could guide intraoperative decisions, such as stool diversion and postoperative triage of patients to an appropriate level of care.

Has the open surgical approach in colorectal cancer really become uncommon?

Colorectal cancer is the third most common cancer in the world. Surgery is mandatory to treat patients with colorectal cancer. Can colorectal cancer be treated in laparoscopy? Scientific literature has validated the oncological quality of laparoscopic approach for the treatment of patients with colorectal cancer. Randomized non-inferiority trials with good remote control have answered positively to this long-debated question. Early as 1994, first publications demonstrated technical feasibility and compliance with oncological imperatives and, as far as short-term outcomes are concerned, there is no difference in terms of mortality and post-operative morbidity between open and minimally invasive surgical approaches, but only longer operating times at the beginning of the experience. Subsequently, from 2007 onwards, long-term results were published that demonstrated the absence of a significant difference regarding overall survival, disease-free survival, quality of life, local and distant recurrence rates between open and minimally invasive surgery. In this editorial, we aim to summarize the clinical and technical aspects which, even today, make the use of open surgery relevant and necessary in the treatment of patients with colorectal cancer.

Long-term survival outcomes following cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for peritoneal metastasis of hepatocellular carcinoma patients

BACKGROUND

Hepatocellular carcinoma with peritoneal metastasis (HCC-PM) has a poor outlook. Traditional treatments have limited effect on survival. The safety and efficacy of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) have been shown in other peritoneal cancers. This study evaluates the role of CRS + HIPEC in HCC-PM.

METHODS

A retrospective analysis of HCC-PM patients treated with CRS + HIPEC at Beijing Shijitan Hospital from March 2017 to December 2023 was conducted, assessing clinical features, severe adverse events (SAEs), and overall survival (OS) rates.

RESULTS

The study population comprised 10 HCC-PM patients who underwent CRS + HIPEC. The median peritoneal cancer index (PCI) was 25, and complete cytoreduction (CC0 ~ 1) was achieved in half of the patients. Three patients experienced SAEs within 30 days postoperatively. The 1-year, 3-year, and 5-year OS rates were recorded as 89.0%, 89.0%, and 21.0% respectively, with a median OS1 of 107.8 months and OS2 of 49.9 months. The median progression-free survival (PFS) was 5.0 months.

CONCLUSION

The application of CRS + HIPEC offers significant benefits to patients with HCC-PM. A selected group of patients may achieve prolonged PFS. Incorporating CRS + HIPEC into the treatment paradigm can thus be considered a strategic therapeutic option for patients with HCC-PM.

Progress in Biological Research and Treatment of Pseudomyxoma Peritonei

Pseudomyxoma peritonei (PMP) is a rare disease characterized by extensive peritoneal implantation and mass secretion of mucus after primary mucinous tumors of the appendix or other organ ruptures. Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is currently the preferred treatment, with excellent efficacy and safety, and is associated with breakthrough progress in long-term disease control and prolonged survival. However, the high recurrence rate of PMP is the key challenge in its treatment, which limits the clinical application of multiple rounds of CRS-HIPEC and does not benefit from conventional systemic chemotherapy. Therefore, the development of alternative therapies for patients with refractory or relapsing PMP is critical. The literature related to PMP research progress and treatment was searched in the Web of Science, PubMed, and Google Scholar databases, and a literature review was conducted. The overview of the biological research, treatment status, potential therapeutic strategies, current research limitations, and future directions associated with PMP are presented, focuses on CRS-HIPEC therapy and alternative or combination therapy strategies, and emphasizes the clinical transformation prospects of potential therapeutic strategies such as mucolytic agents and targeted therapy. It provides a theoretical reference for the treatment of PMP and the main directions for future research.

Genomic Characterization and Clinical Outcomes of Patients with Peritoneal Metastases from the AACR GENIE Biopharma Collaborative Colorectal Cancer Registry

Peritoneal metastases (PM) are common in metastatic colorectal cancer (mCRC). We aimed to characterize patients with mCRC and PM from a clinical and molecular perspective using the American Association of Cancer Research Genomics Evidence Neoplasia Information Exchange (GENIE) Biopharma Collaborative (BPC) registry. Patients' tumor samples underwent targeted next-generation sequencing. Clinical characteristics and treatment outcomes were collected retrospectively. Overall survival (OS) from advanced disease and progression-free survival (PFS) from start of cancer-directed drug regimen were estimated and adjusted for the left truncation bias. A total of 1,281 patients were analyzed, 244 (19%) had PM at time of advanced disease. PM were associated with female sex [OR: 1.67; 95% confidence interval (CI): 1.11-2.54; P = 0.014] and higher histologic grade (OR: 1.72; 95% CI: 1.08-2.71; P = 0.022), while rectal primary tumors were less frequent in patients with PM (OR: 0.51; 95% CI: 0.29-0.88; P < 0.001). APC occurred less frequently in patients with PM (N = 151, 64% vs. N = 788, 79%) while MED12 alterations occurred more frequently in patients with PM (N = 20, 10% vs. N = 32, 4%); differences in MED12 were not significant when restricting to oncogenic and likely oncogenic variants according to OncoKB. Patients with PM had worse OS (HR: 1.45; 95% CI: 1.16-1.81) after adjustment for independently significant clinical and genomic predictors. PFS from initiation of first-line treatment did not differ by presence of PM. In conclusion, PM were more frequent in females and right-sided primary tumors. Differences in frequencies of MED12 and APC alterations were identified between patients with and without PM. PM were associated with shorter OS but not with PFS from first-line treatment.

SIGNIFICANCE

Utilizing the GENIE BPC registry, this study found that PM in patients with colorectal cancer occur more frequently in females and right-sided primary tumors and are associated with worse OS. In addition, we found a lower frequency of APC alterations and a higher frequency in MED12 alterations in patients with PM.

Amplifying Curcumin's Antitumor Potential: A Heat-Driven Approach for Colorectal Cancer Treatment

Introduction

Peritoneal metastases from colorectal cancer (CRC) present a significant clinical challenge with poor prognosis, often unresponsive to systemic chemotherapy. Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is a treatment approach for select patients. The use of curcumin, a natural compound with antitumor properties, in HIPEC is of interest due to its lower side effects compared to conventional drugs and potential for increased efficacy through direct delivery to the peritoneal cavity.

Methods

An in vitro hyperthermic model was developed to simulate clinical HIPEC conditions. Three colon cancer cell lines (SK-CO-1, COLO205, SNU-C1) representing different genetic mutations (p53, KRAS, BRAF) were treated with either curcumin (25 µM) or mitomycin-C (1 µM) for 1, 2, or 3 hours. Post-treatment, cells were incubated at 37°C (normothermia) or 42°C (hyperthermia). Cell viability and proliferation were assessed at 24, 48 and 72 hours post-treatment using Annexin V/PI, MTT assay, trypan blue exclusion, and Hoffman microscopy.

Results

Hyperthermia significantly enhanced the antitumor efficacy of curcumin, evidenced by a two-fold reduction in cell viability compared to normothermia across all cell lines. In the SNU-C1 cell line, which harbors a p53 mutation, mitomycin-C failed to significantly impact cell viability, unlike curcumin, suggesting mutation-specific differences in treatment response.

Discussion

The findings indicate that hyperthermia augments the antitumor effects of curcumin in vitro, supporting the hypothesis that curcumin could be a more effective HIPEC agent than traditional drugs like mitomycin-C. Mutation-associated differences in response to treatments were observed, particularly in p53 mutant cells. While further studies are needed, these preliminary results suggest that curcumin in HIPEC could represent a novel therapeutic strategy for CRC patients with peritoneal metastases. This approach may offer improved outcomes with fewer side effects, particularly in genetically distinct CRC subtypes.

Cost Analysis and Financial Implications of a Peritoneal Surface Malignancy Program in the USA

BACKGROUND

We aimed to describe the financial implications of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) in the USA.

MATERIALS AND METHODS

We conducted a retrospective cost analysis of 100 CRS/HIPEC procedures to examine the impact of patient and procedural factors on hospital costs and reimbursement. A comparison of surgeons' work relative value units (wRVUs) between CRS/HIPEC and a representative sample of complex surgical oncology procedures was made to assess the physicians' compensation rate. Univariable and multivariable backward logistic regression was used to analyze the association between perioperative variables and high direct cost (HDCs).

RESULTS

The median direct cost per CRS/HIPEC procedure was US $44,770. The median hospital reimbursement was US $43,066, while professional reimbursement was US $8608, resulting in a positive contribution margin of US $7493/procedure. However, the contribution margin significantly varied with the payer mix. Privately insured patients had a positive median contribution margin of US $23,033, whereas Medicare-insured patients had a negative contribution margin of US $13,034. Length of stay (LOS) had the most significant association with HDC, and major complications had the most significant association with LOS. Finally, CRS/HIPEC procedures generated a median of 13 wRVU/h, which is significantly lower than the wRVU/h generated by open pancreatoduodenectomies, open gastrectomies, and hepatectomies. However, higher operation complexity and multiple visceral resections help compensate for the relatively low wRVU/h.

CONCLUSIONS

CRS/HIPEC is an expensive operation, and prolonged LOS has the most significant impact on the total cost of the procedure. High-quality care is essential to improve patient outcomes and maintain the economic sustainability of the procedure.

Peritoneal-directed chimeric oncolytic virus CF17 prevents malignant ascites and improves survival in gastric cancer peritoneal metastases

Gastric cancer (GC) peritoneal metastasis (PM) is fatal without effective therapy. We investigated CF17, a new replication-competent chimeric poxvirus, against GC cell lines in vitro and PM in an aggressive GCPM mouse model. We performed viral proliferation and cytotoxicity assays on intestinal-type and diffuse-type human GC cell lines following CF17 treatment. At lower MOIs of 0.01, 0.1, there was >80% killing in most cell lines, while in the more aggressive cell lines, killing was seen at higher MOIs of 1.0 and 10.0. We observed reduced peritoneal tumor burden and prolonged survival with intraperitoneal (i.p.) CF17 treatment in nude mice implanted with the resistant GC cell line. At day 91 after treatment, seven of eight mice were alive in the CF17-treated group vs. one of eight mice in the control group. CF17 treatment inhibited ascites formation (0% vs. 62.5% with PBS). Thus, CF17 efficiently infected, replicated in, and killed GC cells in a dose- and time-dependent manner in vitro. In vivo, i.p. CF17 treatment exhibited robust antitumor activity against an aggressive GCPM model to decrease tumor burden, improve survival, and prevent ascites formation. These preclinical results inform the design of future clinical trials of CF17 for peritoneal-directed therapy in GCPM patients.

Consensus statement and clinical pathway for the management of colon cancer with peritoneal metastases in the state of Delaware

BACKGROUND

Increasing data suggests that the combination of modern systemic therapies and Cytoreductive surgery with or without Hyperthermic Intraperitoneal Chemotherapy (HIPEC) may improve the outcome of patients with colon cancer with peritoneal metastases. Patient selection and sequence of treatments remains ill-defined.

MATERIALS AND METHODS

A working group, the State of Delaware Peritoneal Surface Malignancies Task Force (DE-PSM-TF), was created including representatives from medical and surgical oncology from the acute care hospitals in Delaware. An extensive review of all available literature was carried out. Virtual meetings were held, and interpretation and discussion of the data was conducted.

RESULTS

A clinical pathway that includes a multidisciplinary evaluation at the time of diagnosis of colon cancer with peritoneal metastases and reflects a consensus from the Task Force on 7 key points that suggest the management of these patients based on the severity of their peritoneal metastases and incorporates all currently available therapies was created. The sequence of therapies of this multimodality treatment was determined by the Peritoneal Surface Disease Severity Score (PSDSS) (Fig. 1).

CONCLUSION

The current pathway represents a comprehensive, team effort that should improve the outcome of patients with Colon Cancer with peritoneal metastases in the state of Delaware by having multidisciplinary discussions at the time of diagnosis, selecting the best order of sequence of currently available therapies in order to maximize benefits and minimize morbidity.

Progress in the Treatment of Peritoneal Metastatic Cancer and the Application of Therapeutic Nanoagents

Peritoneal metastatic cancer is a cancer caused by the direct growth of cancer cells from the primary site through the bloodstream, lymph, or peritoneum, which is a difficult part of current clinical treatment. In the abdominal cavity of patients with metastatic peritoneal cancer, there are usually nodules of various sizes and malignant ascites. Among them, nodules of different sizes can obstruct intestinal movement and form intestinal obstruction, while malignant ascites can cause abdominal distension and discomfort, and even cause patients to have difficulty in breathing. The pathology and physiology of peritoneal metastatic cancer are complex and not fully understood. The main hypothesis is "seed" and "soil"; i.e., cells from the primary tumor are shed and implanted in the peritoneal cavity (peritoneal metastasis). In the last two decades, the main treatment modalities used clinically are cytoreductive surgery (CRS), systemic chemotherapy, intraperitoneal chemotherapy, and combined treatment, all of which help to improve patient survival and quality of life (QOL). However, the small-molecule chemotherapeutic drugs used clinically still have problems such as rapid drug metabolism and systemic toxicity. With the rapid development of nanotechnology in recent years, therapeutic nanoagents for the treatment of peritoneal metastatic cancer have been gradually developed, which has improved the therapeutic effect and reduced the systemic toxicity of small-molecule chemotherapeutic drugs to a certain extent. In addition, nanomaterials have been developed not only as therapeutic agents but also as imaging agents to guide peritoneal tumor CRS. In this review, we describe the etiology and pathological features of peritoneal metastatic cancer, discuss in detail the clinical treatments that have been used for peritoneal metastatic cancer, and analyze the advantages and disadvantages of the different clinical treatments and the QOL of the treated patients, followed by a discussion focusing on the progress, obstacles, and challenges in the use of therapeutic nanoagents in peritoneal metastatic cancer. Finally, therapeutic nanoagents and therapeutic tools that may be used in the future for the treatment of peritoneal metastatic cancer are prospected.

A real-word study: is normothermic intraoperative intraperitoneal chemotherapy impactful as we expect?

Background

Patients with gastric cancer have a poor prognosis. Currently, intraperitoneal chemotherapy has been considered a therapeutic option to improve prognosis due to its appealing theoretical rationales. But there is no consensus on the choice of chemotherapeutic agents used in intraperitoneal chemotherapy for gastric cancer. The real-world efficacy of applying intraoperative chemotherapy in gastric cancer still remains undefined.

Methods

Patients with gastric cancer who underwent radical gastrectomy at the Gastrointestinal Department of The First Affiliated Hospital of Anhui Medical University between 2012 and 2019 were enrolled in this study. Patients were divided into two groups based on whether they received intraperitoneal chemotherapy. The t-test (mean of two samples) was conducted to compare the difference in measurement data between the two groups, and the chi-square test was used to compare the difference in count data. Kaplan-Meier method with log-rank test was performed to analyze the overall survival of patients. Kaplan-Meier method with log-rank test was also performed in various subgroups to respectively compare the survival of patients. Multivariate Cox analysis was performed to analyze the prognosis factors of these patients.

Results

A total of 1253 patients were included in the final analysis, in which 861 patients received intraperitoneal chemotherapy and 352 not received intraperitoneal chemotherapy. The clinicopathological features of the participants in the two groups were comparable. There was no significant difference between the two groups in overall survival (P > 0.05). Consistently, no significant difference was found between the two groups in each subgroup (P > 0.05). The multivariate Cox analysis demonstrated that only age, BMI, pathological type, TNM stage, and differentiation grade were independent risk factors of survival.

Conclusion

Intraoperative intraperitoneal chemotherapy usage did not improve survival in patients with gastric cancer undergoing radical gastrectomy.

The 2022 PSOGI International Consensus on HIPEC Regimens for Peritoneal Malignancies: Methodology

BACKGROUND

A group of experts from the Peritoneal Surface Oncology Group International (PSOGI) and the BIG-RENAPE group carried out a consensus among surgeons experienced in treating peritoneal malignancies from around the world to derive recommendations on indications of hyperthermic intraperitoneal chemotherapy (HIPEC), choice and details of HIPEC regimens, and areas for future research. This manuscript describes the methodology of achieving this consensus and the degree of participation of experts.

METHODS

The Delphi technique was used and the questionnaire comprised three categories: evidence-based recommendations using the GRADE (Grades of Recommendation, Assessment, Development, and Evaluation) system with the PICO (patient, intervention, comparison, and outcome) method, an opinion survey, and research recommendations. A consensus was achieved if any one option had >50% of votes, or positive or negative recommendations combined had > 70% of votes.

RESULTS

Of the 145 experts solicited, 71.1% in round I and 72.2% in round II took the survey. Participation was highest among surgeons treating both gastrointestinal and gynecological malignancies. Of 113 questions, after round I, a consensus was achieved for 72 (63.7%) questions, and after the second round, consensus was achieved for another 22 (19.4%) questions, making a total of 94 (83.1%) questions for which a consensus was achieved.

CONCLUSION

This consensus was carried out using a thorough review of literature and robust rating of evidence, and included key experts and opinion leaders from across the world. The results could guide clinicians on the use of HIPEC, both in their day-to-day clinical practice and in designing clinical trials.

Current Research and Development in Hyperthermic Intraperitoneal Chemotherapy (HIPEC)-A Cross-Sectional Analysis of Clinical Trials Registered on ClinicalTrials.gov

INTRODUCTION

Over the past two decades, cytoreductive surgery and HIPEC has improved outcomes for selected patients with peritoneal metastasis from various origins. This is a cross-sectional study with descriptive analyses of HIPEC trials registered on ClinicalTrials.gov. This study aimed to characterize clinical trials on HIPEC registered on ClinicalTrials.gov with the primary objective of identifying a trial focus and to examine whether trial results were published.

METHODS

The search included trials registered from 1 January 2001 to 14 March 2022. We examined the associations of exposure variables and other trial features with two primary outcomes: therapeutic focus and results reporting.

RESULTS

In total, 234 clinical trials were identified; 26 (11%) were already published, and 15 (6%) trials have reported their results but have not been published as full papers. Among ongoing nonpublished trials, 81 (39%) were randomized, 30 (14%) were blinded, n = 39 (20%) were later phase trials (i.e., phases 3 and 4), n = 152 (73%) were from a single institution, and 91 (44%) had parallel groups. Most of the trials were recruiting at the time of this analysis (75, 36%), and 39 (20%) were completed but had yet to publish results. In total, 68% of the trials focused on treatment strategies, and 53% investigated the oncological outcome. The most studied neoplasms for HIPEC trials were peritoneally metastasized colorectal cancer (32%), gastric cancer (29%), and ovarian cancer (26%). Twenty different drugs were analyzed in these clinical trials.

CONCLUSIONS

Many study results are awaited from ongoing HIPEC trials. Most HIPEC trials focused on gastric, colorectal, or ovarian cancer. Many clinical trials were identified involving multiple entities and chemotherapeutic agents.

Immunological effects of heated intraperitoneal chemotherapy can be augmented by thymosin α1

BACKGROUND

Peritoneal metastases of colorectal carcinoma origin (PM-CRC) are treated by cytoreductive surgery and heated intraperitoneal chemotherapy (HIPEC). However, the majority of patients recur, calling for novel treatments. We explored the immunogenic changes induced by HIPEC and the possibility to use thymosin α1 (Tα1) as an immune-stimulatory agent.

METHODS

We used an experimental murine model of PM-CRC combined with mitomycin (MMC)-based HIPEC. We determined immune cell infiltration into tumor metastases after HIPEC administration by means of immunohistochemistry, and determined immunogenic cell death signals in tumor cells by real-time polymerase chain reaction.

RESULTS

Mice with PM-CRC treated by HIPEC had increased overall survival (OS) compared to sham-treated mice (median OS 22.8 vs 18.9 days, respectively; P < 0.001). HIPEC induced increased infiltration of CD4+, CD8+, CD68 + and CD20 + cells into omental and visceral metastases at a magnitude of 40-100 %. We searched for potential immune signals induced by HIPEC by determining its effects on known immunogenic cell death proteins (heat-shock protein [HSP]-70, HSP-90 and calreticulin). HIPEC significantly increased HSP-90 mRNA expression (2.37 ± 1.5 vs 1-fold change, P < 0.05). The OS of Tα1 treated mice significantly improved compared to HIPEC-treated mice (16.3 ± 0.8 vs 14.1 ± 0.6 days, respectively, P = 0.02) and vs sham (11.8 ± 0.8 days, P = 0.007).

CONCLUSIONS

HIPEC induced immunogenic changes that led to increased immune cell infiltration. These changes were further augmented by Tα1 treatment. Future studies aimed at optimizing Tα1 treatment should focus upon the immune response it evokes.

Surgical Options for Peritoneal Surface Metastases from Digestive Malignancies-A Comprehensive Review

The peritoneum is a common site for the dissemination of digestive malignancies, particularly gastric, colorectal, appendix, or pancreatic cancer. Other tumors such as cholangiocarcinomas, digestive neuroendocrine tumors, or gastrointestinal stromal tumors (GIST) may also associate with peritoneal surface metastases (PSM). Peritoneal dissemination is proven to worsen the prognosis of these patients. Cytoreductive surgery (CRS), along with systemic chemotherapy, have been shown to constitute a survival benefit in selected patients with PSM. Furthermore, the association of CRS with hyperthermic intraperitoneal chemotherapy (HIPEC) seems to significantly improve the prognosis of patients with certain types of digestive malignancies associated with PSM. However, the benefit of CRS with HIPEC is still controversial, especially due to the significant morbidity associated with this procedure. According to the results of the PRODIGE 7 trial, CRS for PSM from colorectal cancer (CRC) achieved overall survival (OS) rates higher than 40 months, but the addition of oxaliplatin-based HIPEC failed to improve the long-term outcomes. Furthermore, the PROPHYLOCHIP and COLOPEC trials failed to demonstrate the effectiveness of oxaliplatin-based HIPEC for preventing peritoneal metastases development in high-risk patients operated for CRC. In this review, we discuss the limitations of these studies and the reasons why these results are not sufficient to refute this technique, until future well-designed trials evaluate the impact of different HIPEC regimens. In contrast, in pseudomyxoma peritonei, CRS plus HIPEC represents the gold standard therapy, which is able to achieve 10-year OS rates ranging between 70 and 80%. For patients with PSM from gastric carcinoma, CRS plus HIPEC achieved median OS rates higher than 40 months after complete cytoreduction in patients with a peritoneal cancer index (PCI) ≤6. However, the data have not yet been validated in randomized clinical trials. In this review, we discuss the controversies regarding the most efficient drugs that should be used for HIPEC and the duration of the procedure. We also discuss the current evidence and controversies related to the benefit of CRS (and HIPEC) in patients with PSM from other digestive malignancies. Although it is a palliative treatment, pressurized intraperitoneal aerosolized chemotherapy (PIPAC) significantly increases OS in patients with unresectable PSM from gastric cancer and represents a promising approach for patients with PSM from other digestive cancers.

Comparative Study of Short-Term Efficacy and Safety of Mitomycin versus Lobaplatin for Hyperthermic Intraperitoneal Chemotherapy after Radical Surgery in Colorectal Cancer with High-Risk Factors for Peritoneal Carcinomatosis: A Propensity Score Matching Analysis

BACKGROUND

The drug selection of radical surgery (RS), with hyperthermic intraperitoneal chemotherapy (HIPEC), in pT4 colorectal cancer (CRC) remains controversial.

METHODS

Adverse events after HIPEC were estimated by common terminology criteria for adverse events version 5.0. The efficacy was evaluated using overall survival (OS) and recurrence-free rate (RFR). Propensity score matching (PSM) was used to reduce the influence of confounders between Mitomycin and Lobaplatin groups.

RESULTS

Of the 146 patients, from April 2020 to March 2021, 47 were managed with mitomycin and 99 with lobaplatin. There was no significant difference in the incidence of all adverse events between the two groups after PSM. OS and RFR were not significantly different between the two groups at 22 months (p = 0.410; p = 0.310). OS and RFR of the two groups also showed no significant difference for patients with T4a or T4b stage, tumor size < or ≥ 5 cm. Among patients with colon cancer, RFR at 22 months of the two groups was significantly different (100.0% vs. 63.2%, p = 0.028).

CONCLUSIONS

In summary, the safety of mitomycin and lobaplatin for HIPEC was not different. Compared with lobaplatin, mitomycin for HIPEC after RS could benefit patients with colon cancer in RFR.

PD-1 Blockade Combined with Heated Intraperitoneal Chemotherapy Improves Outcome in Experimental Peritoneal Metastases from Colonic Origin in a Murine Model

BACKGROUND

Heated intraperitoneal chemotherapy (HIPEC) was shown to induce immunogenicity of peritoneal metastases from colorectal cancer (PM-CRC) by induction of immunogenic cell death. We aimed to explore whether the addition of a checkpoint inhibitor would augment the effect of HIPEC in an experimental murine model of PM-CRC.

METHODS

PM-CRC was established in C57BL mice by intraperitoneal inoculation of MC38 colon cancer cells. HIPEC was administered using the closed technique with mitomycin C (MMC). Clinical and immunological parameters were compared between animals treated with HIPEC alone and those treated with HIPEC + anti-programmed death receptor-1 (aPD-1).

RESULTS

MMC-based HIPEC increased the overall survival of animals compared with sham-treated animals (22.8; 95% confidence interval [CI] 21.14-24.53 vs. 18.9 days; 95% CI 17.6-20.3, p < 0.001). The extent of peritoneal disease as measured by the modified peritoneal carcinomatosis index was also reduced by HIPEC. This clinical benefit was accompanied by increased infiltration of CD8⁺, CD68⁺, and CD20⁺ cells into tumor metastases in HIPEC-treated animals compared with sham-treated animals. We identified heat shock protein (HSP) 90 as a potential immunogenic cell death protein whose expression is increased under HIPEC conditions (fold change: 2.37 ± 1.5 vs. 1 without HIPEC, p < 0.05). Combined HIPEC + PD-1 treatment ameliorated survival compared with HIPEC alone and sham treatment (24.66; 95% CI 20.13-29.2 vs. 19; 95% CI 15.85-22.14 and 14.33 days; 95% CI 9.6-19.04, respectively; p = 0.008). This clinical effect was accompanied by increased CD8⁺ tumor infiltration.

CONCLUSIONS

HIPEC induced the expression of immunogenic cell death signals that can support an anti-tumor immune response. This response can be further exploited by a checkpoint inhibitor.

Hyperthermic intrathoracic/intraperitoneal chemotherapy versus conventional intrapleural/intraperitoneal chemotherapy for the malignant effusion: a multi-center randomized clinical trial

OBJECTIVE

To compare the efficacy and safety of hyperthermic intrathoracic/intraperitoneal chemotherapy versus conventional intrapleural/intraperitoneal chemotherapy in the treatment of malignant pleural or peritoneal effusion.

METHODS

A randomized clinical trial was carried out in 8 cancer centers across China. Patients with malignant pleural or peritoneal effusion were randomly assigned to the study group or control group. Patients in the study group were treated with cisplatin-based hyperthermic intrathoracic chemotherapy (HITHOC) or hyperthermic intraperitoneal chemotherapy (HIPEC), while the control group was treated with conventional intrapleural or intraperitoneal chemotherapy using same chemotherapeutic regime as the study group. The objective response rate (ORR) was analyzed as primary outcome. Quality-of-life (QOL) score was recorded as secondary outcome using the questionnaire 30 (QLQ-C30) of the European Organization for Research and Treatment of Cancer (EORTC). The efficacy and safety of the two treatments were compared.

RESULTS

Total 135 patients were recruited and randomized in this study, with 67 patients in the study group and 68 patients in the control group. The ORR in the study group (80.70%) was significantly higher than that in the control group (31.03%, p < 0.001). However, neither changes of QOL scores, nor incidence rates of adverse events were significantly different between the two groups (p = 0.076 and 0.197, respectively).

CONCLUSION

Efficacy of HITHOC or HIPEC is superior to that of conventional modality for the treatment of malignant effusion with comparable side effects.

The Development of Investigator-Initiated Clinical Trials in Surgical Oncology

Investigator-initiated trials (IITs) are designed by principal investigators who identify important, unaddressed clinical gaps and opportunities to answer these questions through clinical trials. Surgical oncologists are poised to lead IITs due to their multidisciplinary clinical practice and substantial research background. The process of developing, organizing, and implementing IITs is multifaceted and involves important steps including (but not limited to) navigating regulatory requirements, obtaining funding, and meeting enrollment targets. Here, the authors explore the steps, methodology, and barriers of IIT development by surgical oncologists and highlight the importance of IITs in oncology.

[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.

Hyperthermic Intraperitoneal Chemotherapy Following Cytoreductive Surgery for Colorectal Peritoneal Carcinomatosis Patients: A Review

Colorectal peritoneal carcinomatosis (CPC) is an advanced malignancy and is typically associated with a poor prognosis. Hyperthermic intraperitoneal chemotherapy (HIPEC) following complete cytoreductive surgery (CRS) is a novel, advanced loco-regional treatment for colorectal cancer that is currently being used to treat peritoneal carcinomatosis (PC). The present review aims to describe the evidence-based literature on the efficacy and safety of this treatment approach in patients with PC originating from colorectal cancer and to summarize its complications. All published literature regarding the efficacy of HIPEC for the treatment of CPC was reviewed; 16 studies were included in this paper. The overall survival rate for the HIPEC group ranged from 63% to 93%. The overall median survival for the HIPEC and non-HIPEC groups ranged from 13 to 60.1 months and 12.6 to 41.2 months, respectively. The overall median survival of patients in the HIPEC group was comparatively better than those in the non-HIPEC group. There was insufficient evidence to suggest whether this treatment regimen was associated with a high or low morbidity rate in comparison to other groups. However, the mortality rate associated with this treatment regimen was low. In conclusion, the present data provide insufficient evidence regarding the beneficial effects of using HIPEC following CRS treatment. Therefore, further studies are required to determine the benefits of HIPEC for CPC patients.

An Ex Vivo Organotypic Culture Platform for Functional Interrogation of Human Appendiceal Cancer Reveals a Prominent and Heterogenous Immunological Landscape

PURPOSE

Epithelial neoplasms of the appendix are difficult to study preclinically given their low incidence, frequent mucinous histology, and absence of a comparable organ in mice for disease modeling. Although surgery is an effective treatment for localized disease, metastatic disease has a poor prognosis as existing therapeutics borrowed from colorectal cancer have limited efficacy. Recent studies reveal that appendiceal cancer has a genomic landscape distinct from colorectal cancer and thus preclinical models to study this disease are a significant unmet need.

EXPERIMENTAL DESIGN

We adopted an ex vivo slice model that permits the study of cellular interactions within the tumor microenvironment. Mucinous carcinomatosis peritonei specimens obtained at surgical resection were cutoff using a vibratome to make 150-μm slices cultured in media.

RESULTS

Slice cultures were viable and maintained their cellular composition regarding the proportion of epithelial, immune cells, and fibroblasts over 7 days. Within donor specimens, we identified a prominent and diverse immune landscape and calcium imaging confirmed that immune cells were functional for 7 days. Given the diverse immune landscape, we treated slices with TAK981, an inhibitor of SUMOylation with known immunomodulatory functions, in early-phase clinical trials. In 5 of 6 donor samples, TAK981-treated slices cultures had reduced viability, and regulatory T cells (Treg). These data were consistent with TAK981 activity in purified Tregs using an in vitro murine model.

CONCLUSIONS

This study demonstrates an approach to study appendiceal cancer therapeutics and pathobiology in a preclinical setting. These methods may be broadly applicable to the study of other malignancies.

Long-term outcomes of elderly patients with peritoneal metastases of colorectal origin after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

INTRODUCTION

Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) were reportedly safe for the elderly. However, long-term survival data in this subgroup of patients are scarce. Our aim was to evaluate the peri-operative and long-term outcomes of CRS + HIPEC in colorectal peritoneal metastases (CRC-PM) in patients ≥70 years of age.

MATERIAL AND METHODS

We retrospectively analyzed our combined institutional databases for patients who underwent CRS + HIPEC for CRC-PM. Clinical and pathological characteristics, as well as overall survival (OS) and progression-free survival (PFS) were compared between the groups. Tumor extent was measured by the peritoneal carcinomatosis index (PCI) and completeness of cytoreduction by the CCR score. Major morbidity was defined according to Clavien-Dindo classification.

RESULTS

The dataset of 159 patients included 33 elderly and 126 non-elderly patients. Clinical characteristics between the groups differed only in medical comorbidities (Charlson comorbidity index 10 vs. 7, P < 0.001) and delivery of post-HIPEC adjuvant treatment (12.5% vs. 43.8%, P = 0.004). Overall PCI and CCR0 rates were similar between the groups, as were length of stay and major morbidity and mortality rates. Long-term outcomes in the elderly group were lower than those of the non-elderly (median OS: 21.8 vs. 40.5 months, P < 0.001; median PFS: 6 vs. 8 months, P = 0.02, respectively).

CONCLUSIONS

CRS + HIPEC in selected elderly patients can be safe in terms of postoperative morbidity and mortality. However, despite the same surgical extents and radicality, their long-term outcomes are inferior, possibly due to under-usage of systemic chemotherapy.

Thymosin alpha 1 as an adjuvant to hyperthermic intraperitoneal chemotherapy in an experimental model of peritoneal metastases from colonic carcinoma

INTRODUCTION

Heated intraperitoneal chemotherapy (HIPEC) is currently implemented in the treatment of peritoneal metastases from colorectal carcinoma (PM-CRC) origin. However, recurrence is common and the effectiveness of HIPEC has been questioned. The aim of this study was to evaluate the use of thymosin alpha 1 (Tα1), an immunomodulatory molecule, as an adjuvant to HIPEC treatment.

METHODS

We developed an experimental model of HIPEC by the induction of PM-CRC in C57BL mice and intra-abdominal perfusion of mitomycin C (MMC). Mice were treated with Tα1 at 0.6 mg/kg for 5 days after HIPEC. Clinical and immunological parameters were compared between HIPEC and HIPEC + Tα1 groups.

RESULTS

Treatment with Tα1 increased overall survival of mice compared to HIPEC treatment alone and sham-treated animals (16.1 ± 0.8 vs. 14.1 ± 0.6 and 11.8 ± 0.8, respectively, p = 0.02). Tα1 had no direct anti-tumor effect, as seen by lack of inhibition of tumor cell proliferation. Tα1 treatment induced a T helper (Th) 1 immune response in tumor metastases as evidenced by a significant increase of the Th1-specific markers IFN-γ and T-bet (1.21 ± 0.3 vs. 0.52 ± 0.08, p < 0.05; 0.88 ± 0.04 vs. 0.64 ± 0.14, p < 0.05, respectively). This Th1 skew was accompanied by increased CD8⁺ infiltration into omental and visceral metastases by Tα1 treatment compared to sham and HIPEC-treated animals (21.24 ± 2.16 vs. 10.45 ± 0.89 and 7.7 ± 1.3, p < 0.001; 14.12 ± 1.54 vs. 12.12 ± 0.01 and 6.64 ± 0.87, p < 0.01, respectively).

CONCLUSIONS

Tα1 augments the effect of HIPEC by the induction of a Th1 anti-tumor immune response. Further experiments should evaluate Tα1 and other novel immunomodulators in order to exploit the immunological opportunities created by HIPEC.

Current Trends in Cytoreductive Surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for Peritoneal Disease from Appendiceal and Colorectal Malignancies

Peritoneal carcinomatosis (PC) is a poor prognostic factor for all malignancies. This extent of metastatic disease progression remains difficult to treat with systemic therapies due to poor peritoneal vascularization resulting in limited drug delivery and penetration into tissues. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are surgical interventions that directly target peritoneal tumors and have improved outcomes for PC resulting from appendiceal and colorectal cancer (CRC). Despite these radical therapies, long-term survival remains infrequent, and recurrence is common. The reasons for these outcomes are multifactorial and signal the need for the continued development of novel therapeutics, techniques, and approaches to improve outcomes for these patients. Here, we review landmark historical studies that serve as the foundation for current recommendations, recent discoveries, clinical trials, active research, and areas of future interest in CRS/HIPEC to treat PC originating from appendiceal and colorectal malignancies.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Management of Colorectal Cancer with Peritoneal Dissemination: 30 Years of Experience at a Single Institution

BACKGROUND

Cytoreductive surgery (CRS) is at the forefront of treatment for colorectal cancer with peritoneal metastasis or "carcinomatosis" (CRC-PC). We report outcomes of the operative management of CRC-PC at a single center.

STUDY DESIGN

We retrospectively reviewed our database from 1992 through 2021. The Kaplan-Meier method was used to estimate survival. Proportional hazards regression and multivariable models were used for assessments.

RESULTS

This study included 345 patients with mean age 53.5 years. Multivariate analysis revealed performance and resection status were associated with overall survival (OS; p < 0.001). Within the R0/R1 group, adverse impact on OS was found with increasing Peritoneal Cancer Index (PCI) score starting at 9 (hazard ratio [HR] = 1.98, CI 1.39-2.82, p = 0.0001) with the most significant hazard noted at PCI >14 (HR = 2.35, CI 1.52-3.63, p = 0.0001). Incomplete resection (R2) had significantly worse OS compared with complete CRS 33.4 (n = 206) vs R2: 12.7 months (n = 139; p < 0.0001. When stratified by PCI for the R0/R1 group, median OS for PCI less than 10, 10 to 15, and greater than 15 was 38.2, 19.7, and 22.2 m, respectively (p = 0.0007 comparing PCI less than 10 and greater than 15). Ten-year increments-1991 through 2000, 2001 through 2010, 2011 through 2020-revealed improvement in median OS (13.4 [n = 66], 19.3 [n = 139], and 29.1 months [n = 140]). However, by resection status, median OS remained stable for R0/R1 (32.3 [n = 23], 31.1 [n = 76], and 34.1 months [n = 107]) and improved for R2 (5.2 [n = 43], 14.4 [n = 63], and 14.6 months [n = 33]). Clavien-Dindo complication rate (greater than or equal to grade III) was 29.4%.

CONCLUSION

CRS improves outcomes for CRC-PC compared with historic outcomes with nonoperative management. This benefit is greatest with complete resection and lower disease burden. Results of CRS (with or without heated intraperitoneal chemotherapy) are improving, and surgery for CRC-PC should be routinely considered.

Peritoneal Metastasis: Current Status and Treatment Options

Simple Summary

Surgical and locoregional treatments of peritoneal metastasis, e.g., from colorectal cancer, has gained increasing acceptance after the publication of excellent patient outcomes from many groups around the world. Apart from systemic chemotherapy and surgical removal of the tumor, locoregional therapies such as HIPEC or PIPAC may improve tumor control. Understanding the molecular characteristics of peritoneal metastasis is crucial to evolve future therapeutic strategies for peritoneal metastasis. This includes the genetic background of PM, which is often different from other sites of metastasis, and promotes peritoneal dissemination and the growth of tumor cells. Growing knowledge and insight into the physiology of the peritoneal tumor microenvironment and the specific role of the immune system in this compartment may provide a critical step to move locoregional therapy to the next level. This review summarizes the current knowledge and highlights the molecular characteristics of peritoneal metastasis.

Abstract

Peritoneal metastasis (PM) originating from gastrointestinal cancer was considered a terminal disease until recently. The advent of better systemic treatment, a better understanding of prognostic factors, and finally, the advent of novel loco-regional therapies, has opened the door for the multimodal treatment of PM. These strategies, including radical surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) showed surprisingly good results, leading to the prolonged survival of patients with peritoneal metastasis. This has triggered a significant body of research, leading to the molecular characterization of PM, which may further help in the development of novel treatments. This review summarizes current evidence on peritoneal metastasis and explores potential novel mechanisms and therapeutic approaches to treat patients with peritoneal metastasis.

Risk of Intraoperative Hyperthermia and Outcomes in Adults Undergoing Cytoreductive Surgery (CRS) with Hyperthermic Intraperitoneal Chemotherapy (HIPEC)

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) is commonly used to treat peritoneal surface malignancies. We aimed to identify risk factors of intraoperative patient hyperthermia and the postoperative outcome of adults undergoing HIPEC PATIENTS AND METHODS: A retrospective, IRB approved, single center cohort study was conducted. Adults treated with cytoreductive surgery and HIPEC between 2006 and 2021 were included. The primary outcome was bladder hyperthermia during perfusion, stratified by severity and duration. Secondary outcomes were postoperative complications and recurrence-free (RFS) and overall (OS) survival. Multivariable logistic regression models were fit to estimate the effects of important covariates.

RESULTS

Out of 214 patients, 114 had mild hyperthermia (≥ 38 °C) at any time, and in 73 of these it lasted for ≥ 30 min. Independent prognostic factors of mild hyperthermia ≥ 30 min were age (OR = 0.958, 95% CI 0.933-0.984), body mas index (BMI; OR = 0.959 95% CI 0.917-1.002), gender (OR = 0.199, 95% CI 0.092-0.431), and type of chemotherapy [cisplatin versus mitomycin (OR = 0.186, 95% CI 0.070-0.491; oxaliplatin versus mitomycin (OR = 0.430, 95% CI 0.163-1.139)]. Prognostic factors of moderate-to-severe hyperthermia (≥ 39 °C) at any time were perfusion duration (OR = 1.094, 95% CI 1.018-1.177) and blood transfusion (OR = 5.689, 95% CI 1.784-18.137). Intraoperative hyperthermia was not associated with increased postoperative complications but was associated with better RFS and OS.

CONCLUSIONS

Our study demonstrates age, gender, BMI, and chemotherapy type to be associated with hyperthermia ≥ 38 °C for ≥ 30 min, whereas longer perfusion time and blood transfusion were associated with hyperthermia ≥ 39 °C. Mild hyperthermia at the end of perfusion is associated with better RFS and OS.

Lymph Node Metastases from Visceral Peritoneal Colorectal Metastases are Associated with Systemic Recurrence

BACKGROUND

Visceral peritoneal colorectal metastases (VPCMs) may further metastasize to lymph nodes that drain those organs. The rate of lymph node metastases (LNMs) from VPCMs and their clinical and prognostic significance are unknown.

METHODS

This study retrospectively analyzed the authors' institutional databases of 160 patients with peritoneal colorectal metastases who underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. Patients with LNM-VPCM (n = 12) were identified by pathologic reports, and both their short- and long-term outcomes were compared with those of patients without LNM-VPCM.

RESULTS

The clinical presentation and primary tumor pathologic characteristics did not differ between the two groups. The patients with LNM-VPCM had a higher tumor burden (measured by the peritoneal carcinomatosis index [PCI]) and visible remnant disease compared with those who had no LNM-VPI (10 vs 5.5 [p = 0.03] vs 33.3% vs 6.8% [p = 0.007], respectively). The postoperative outcomes also were comparable. The patients with LNM-VPCM had a shorter overall survival (OS) than those without LNM-VPCM (median OS, 22.5 months; 95% confidence interval [CI], 15.1-29.9 months vs 40.1 months; 95% CI, 38.1-42 months; p = 0.02). However, only tumor grade and PCI were predictors of OS in the multivariate analysis (hazard ratio [HR], 2.33 [p = 0.001]; 1.77 [p = 0.03], respectively). The study showed that LNM-VPCM was associated with systemic but not peritoneal recurrence compared with non-LNM-VPCM (81.8% vs 51.6% for systemic recurrence, respectively; p = 0.05).

CONCLUSION

The small distinct group of patients defined by LNM-VPCM were prone to systemic recurrence. Given its correlation with systemic recurrence, LNM-VPCM may indicate the need for adjuvant treatment.

Variable Molecular Weight Polymer Nanoparticles for Detection and Hyperthermia-Induced Chemotherapy of Colorectal Cancer

Simple Summary

The purpose of this work was to evaluate the development of polymer-based nanoparticles that can both generate heat and be used for fluorescence detection. The nanoparticles were used against luminescent colorectal cancer cells that were either sensitive or resistant to the chemotherapy drug, oxaliplatin. The fluorescence of the nanoparticles indicates that they are internalized within the cells for heat generation. Mild heating makes oxaliplatin-resistant cancer cells responsive to chemotherapy, and the nanoparticle-induced hyperthermia causes cell death in a few minutes, compared to classical bulk heating, which takes a few hours. Changes in the luminescence of the cancer cells can be used to determine the thermal dose induced by the nanoparticles, which may be correlated with the cell viability and therapeutic response.

Abstract

Oxaliplatin plays a significant role as a chemotherapeutic agent for the treatment of colorectal cancer (CRC); however, oxaliplatin-resistant phenotypes make further treatment challenging. Here, we have demonstrated that rapid (60 s) hyperthermia (42 °C), generated by the near-infrared stimulation of variable molecular weight nanoparticles (VMWNPs), increases the effectiveness of oxaliplatin in the oxaliplatin-resistant CRC cells. VMWNP-induced hyperthermia resulted in a higher cell death in comparison to cells exposed to chemotherapy at 42 °C for 2 h. Fluorescence from VMWNPs was observed inside cells, which allows for the detection of CRC. The work further demonstrates that the intracellular thermal dose can be determined using cell luminescence and correlated with the cell viability and response to VMWNP-induced chemotherapy. Mild heating makes oxaliplatin-resistant cancer cells responsive to chemotherapy, and the VMWNPs-induced hyperthermia can induce cell death in a few minutes, compared to classical bulk heating. The results presented here lay the foundation for photothermal polymer nanoparticles to be used for cell ablation and augmenting chemotherapy in drug-resistant colorectal cancer cells.

Quality Standards for Surgery of Colorectal Peritoneal Metastasis After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND

The standardization of surgical outcomes throughout surgical procedures is mandatory. Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) should provide proficient oncological and surgical outcomes.

STUDY DESIGN

The aim of this study was to identify clinically relevant quality indicators and their quality standard, and to determine their acceptable quality limit. A systematic review on cytoreductive results from 2000 to 2018 was performed focusing on clinical guidelines, consensus conferences, and publications. After the selection of quality indicators, a systematic review of indexed references was performed in order to calculate the quality standard for each indicator.

STUDY SELECTION

Unicentric/multicentric series, comparative studies, and clinical trials. Studies were to include outcomes after cytoreduction of colorectal origin and series with more than 50 patients. Quality indicators with at least 10 series were mandatory and objective measurements were also mandatory for inclusion.

MAIN OUTCOME MEASUREMENTS

Quality indicators selected were 1- to 5-year survival, overall disease-free survival, 1- to 5-year disease-free survival, complete surgical resection, duration of surgery, length of stay, overall morbimortality, major morbidity, re-intervention, postoperative hemorrhage, intestinal fistula, anastomotic leakage, wound infection, postoperative medical complications, overall recurrence, and failure to rescue.

RESULTS

The most relevant quality indicators and critical quality limits were overall disease-free survival and 5-year overall disease-free survival (14 months and <10 months, and 14% and <4%, respectively), completeness of surgical resection (89% and <80%, respectively), overall mortality (3% and >8%, respectively), overall morbidity (47% and >63%, respectively), failure to rescue (12% and <30%, respectively), reintervention (13 and <22%, respectively), anastomotic leakage (6% and <13%, respectively), and overall recurrence (60% and <74%, respectively).

CONCLUSION

This is the first study to assess quality standards in CRS + HIPEC for colorectal peritoneal metastases. The current data are of particular relevance for future studies to control the variability of this surgery.

The role of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in the treatment of peritoneal carcinomatosis: a systematic review including evidence from Japan

The prognosis of peritoneal carcinomatosis is poor. However, the emergence of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) as a treatment option has prolonged survival and it can even potentially cure patients with peritoneal carcinomatosis. Randomized controlled studies and other observational studies indicated that this combined therapy potentially improved the prognosis of patients with colon, gastric, and ovarian cancers with acceptable morbidity and mortality rates. Even in rarer diseases, such as pseudomyxoma peritonei and malignant peritoneal mesothelioma, CRS + HIPEC markedly improved the prognoses over those with conventional treatment. Based on the accumulated evidence, clinical guidelines recommend CRS + HIPEC for selected patients with peritoneal carcinomatosis. However, several issues still need to be overcome. A standard method for HIPEC has not yet been established. Furthermore, the criteria employed for patient selection need to be clarified to achieve real benefits. The peritoneal cancer index, chemo-sensitivity and several biological markers are considered to be key factors.

HIPEC Methodology and Regimens: The Need for an Expert Consensus

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) is performed with a wide variation in methodology, drugs, and other elements vital to the procedure. Adoption of a limited number of regimens could increase the collective experience of peritoneal oncologists, make comparison between studies more meaningful, and lead to a greater acceptance of results from randomized trials. This study aimed to determine the possibility of standardizing HIPEC methodology and regimens and to identify the best method of performing such a standardization.

METHODS

A critical review of preclinical and clinical studies evaluating the pharmacokinetic aspects of different HIPEC drugs and drug regimens, the impact of hyperthermia, and the efficacy of various HIPEC regimens as well as studies comparing different regimens was performed.

RESULTS

The preclinical and clinical data were limited, and studies comparing different regimens were scarce. Many of the regimens were neither supported by preclinical rationale or data nor validated by a dose-escalating formal phase 1 trial. All the regimens were based on pharmacokinetic data and did not take chemosensitivity of peritoneal metastases into account. Personalized medicine approaches such as patient-derived tumor organoids could offer a solution to this problem, although clinical validation is likely to be challenging.

CONCLUSIONS

Apart from randomized trials, more translational research and phases 1 and 2 studies are needed. While waiting for better preclinical and clinical evidence, the best way to minimize heterogeneity is by an expert consensus that aims to identify and define a limited number of regimens for each indication and primary site. The choice of regimen then can be tailored to the patient profile and its expected toxicity and the methodology according regional factors.

Nanosecond pulsed electric fields impair viability and mucin expression in mucinous colorectal carcinoma cell

Nanosecond pulsed electric fields (nsPEFs) are a non-thermal technology that can induce a myriad of biological responses and changes in cellular physiology. nsPEFs have gained significant attention as a novel cancer therapy. However, studies investigating the application of nsPEF in mucinous carcinomas are scarce. In this study, we explored several biological responses in two mucinous colorectal adenocarcinoma cell lines, LS 174T and HT-29, to nsPEF treatment. We determined the overall cell survival and viability rates following nsPEF treatment using CCK-8 and colony formation assays. We measured the intracellular effects of nsPEF treatment by analyzing cell cycle distribution, cell apoptosis and mitochondrial potential. We also analyzed mucin production at both mRNA and protein levels. Our results showed that nsPEF treatment significantly reduced mucinous cell viability in a dose-dependent manner. nsPEF treatment increased cell cycles arrest at G₀/G₁ while the proportion of G₂/M cells gradually decreased. Cell apoptosis increased following nsPEF treatment with a clear loss in mitochondrial membrane potential. Furthermore, the protein expression of functional mucin family members decreased after nsPEF treatment. In conclusion, nsPEF treatment reduced MCRC cell viability, cell proliferation, and mucin protein production while promoted apoptosis. Our work is a pilot study that projects some insights into the potential clinical applications of nsPEFs in treating mucinous colorectal carcinoma.

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.

The Role of Hyperthermic Intraperitoneal Chemotherapy in Pseudomyxoma Peritonei After Cytoreductive Surgery

Importance

Studies on the prognostic role of hyperthermic intraperitoneal chemotherapy (HIPEC) in pseudomyxoma peritonei (PMP) are currently not available.

Objectives

To evaluate outcomes after cytoreductive surgery (CRS) and HIPEC compared with CRS alone in patients with PMP.

Design, Setting, and Participants

This cohort study analyzed data from the Peritoneal Surface Oncology Group International (PSOGI) registry, including 1924 patients with histologically confirmed PMP due to an appendiceal mucinous neoplasm. Eligible patients were treated with CRS with or without HIPEC from February 1, 1993, to December 31, 2017, and had complete information on the main prognostic factors and intraperitoneal treatments. Inverse probability treatment weights based on the propensity score for HIPEC treatment containing the main prognostic factors were applied to all models to balance comparisons between the CRS-HIPEC vs CRS-alone groups in the entire series and in the following subsets: optimal cytoreduction, suboptimal cytoreduction, high- and low-grade histologic findings, and different HIPEC drug regimens. Data were analyzed from March 1 to June 1, 2018.

Interventions

HIPEC including oxaliplatin plus combined fluorouracil-leucovorin, cisplatin plus mitomycin, mitomycin, and other oxaliplatin-based regimens.

Main Outcomes and Measures

Overall survival, severe morbidity (determined using the National Cancer Institute Common Terminology for Adverse Events, version 3.0), return to operating room, and 30- and 90-day mortality. Differences in overall survival were compared using weighted Kaplan-Meier curves, log-rank tests, and Cox proportional hazards multivariable models. A sensitivity analysis was based on the E-value from the results of the main Cox proportional hazards model. Differences in surgical outcomes were compared using weighted multivariable logistic models.

Results

Of the 1924 patients included in the analysis (997 [51.8%] men; median age, 56 [interquartile range extremes (IQRE), 45-65] years), 376 were in the CRS-alone group and 1548 in the CRS-HIPEC group. Patients with CRS alone were older (median age, 60 [IQRE, 48-70] vs 54 [IQRE, 44-63] years), had less lymph node involvement (14 [3.7%] vs 119 [7.7%]), received more preoperative systemic chemotherapy (198 [52.7%] vs 529 [34.2%]), and had higher proportions of high-grade disease (179 [47.6%] vs 492 [31.8%]) and suboptimal cytoreduction residual disease (grade 3, 175 [46.5%] vs 117 [7.6%]). HIPEC was not associated with a higher risk of worse surgical outcomes except with mitomycin, with higher odds of morbidity (1.99; 95% CI, 1.25-3.19; P = .004). HIPEC was associated with a significantly better overall survival in all subsets (adjusted hazard ratios [HRs], 0.60-0.68, with 95% CIs not crossing 1.00). The weighted 5-year overall survival was 57.8% (95% CI, 50.8%-65.7%) vs 46.2% (95% CI, 40.3%-52.8%) for CRS-HIPEC and CRS alone, respectively (weighted HR, 0.65; 95% CI, 0.50-0.83; P < .001; E-value, 2.03). Such prognostic advantage was associated with oxaliplatin plus fluorouracil-leucovorin (HR, 0.42; 95% CI, 0.19-0.93; P = .03) and cisplatin plus mitomycin (HR, 0.57; 95% CI, 0.42-0.78; P = .001) schedules.

Conclusions and Relevance

In this cohort study, HIPEC was associated with better overall survival when performed after CRS in PMP, generally without adverse effects on surgical outcomes.

Consensuses and controversies on pseudomyxoma peritonei: a review of the published consensus statements and guidelines

Background

Pseudomyxoma peritonei (PMP) is a clinical malignant syndrome mainly originating from the appendix, with an incidence of 2–4 per million people. As a rare disease, an early and accurate diagnosis of PMP is difficult. It was not until the 1980s that the systematic study of this disease was started.

Main body

As a result of clinical and basic research progress over the last 4 decades, a comprehensive strategy based on cytoreductive surgery (CRS) + hyperthermic intraperitoneal chemotherapy (HIPEC) has been established and proved to be an effective treatment for PMP. Currently, CRS + HIPEC was recommended as the standard treatment for PMP worldwide. There are several consensuses on PMP management, playing an important role in the standardization of CRS + HIPEC. However, controversies exist among consensuses published worldwide. A systematic evaluation of PMP consensuses helps not only to standardize PMP treatment but also to identify existing controversies and point to possible solutions in the future. The controversy underlying the consensus and vice versa promotes the continuous refinement and updating of consensuses and continue to improve PMP management through a gradual and continuous process. In this traditional narrative review, we systemically evaluated the consensuses published by major national and international academic organizations, aiming to get a timely update on the treatment strategies of CRS + HIPEC on PMP.

Conclusion

Currently, consensuses have been reached on the following aspects: pathological classification, terminology, preoperative evaluation, eligibility for surgical treatment, maximal tumor debulking, CRS technical details, and severe adverse event classification system. However, controversies still exist regarding the HIPEC regimen, systemic chemotherapy, and early postoperative intraperitoneal chemotherapy.

Thirty-three long-term survivors after cytoreductive surgery in patients with peritoneal metastases from colorectal cancer: a retrospective descriptive study

BACKGROUND

Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) improves survival in selected patients with peritoneal metastasis (PM) from colorectal cancer (CRC). However, little has been reported on characteristics and clinical course of long-term survivors with CRC-PM beyond 5 years. The objective of this study was to identify the clinical and oncological features affecting long-term survival of CRC-PM after comprehensive treatment.

METHODS

Between January 1990 and April 2015, CRC-PM patients who underwent CRS with or without HIPEC in two Japanese tertiary hospitals were analyzed. Clinicopathological parameters and therapeutic details for long-term survivors (patients surviving ≥ 5 years after CRS) were described and compared with those for non-survivors (patients surviving < 5 years).

RESULTS

The study identified 236 patients with CRC-PM who underwent CRS, with a median follow-up period of 2.5 years. Thirty-three patients (14.0%) were considered as long-term survivors. Compared with non-survivors, long-term survivors had a lower median peritoneal cancer index (PCI) [4 (1-27) vs 9 (0-39), p < 0.001]. Complete cytoreduction (CCR-0) was achieved in all long-term survivors, with a significantly higher rate [33/33 (100%) vs 141/203 (69.8%), p < 0.001]. Metachronous onsets of PM were more frequently observed in the long-term survivor group [26/33 (78.8%) vs 103/203 (50.3%), p = 0.018]. Regarding histopathology, long-term survivors more frequently had mucinous adenocarcinoma than non-survivors [8/33 (24.2%) vs 27/203 (13.3%)] and less likely exhibited poorly differentiated or signet ring cell carcinoma [2/33 (6.1%) vs 48/203 (23.7%)] (p < 0.001).

CONCLUSIONS

One in seven patients with CRC-PM achieved the long-term milestone after CRS. A long-term survival was associated with the presence of low PCI, CCR-0, metachronous onset, and mucinous histology.

The role of molecular biomarkers in outcomes and patient selection for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for peritoneal metastases of colorectal origin

BACKGROUND

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is effective in select patients with peritoneal metastases of colorectal (CRC) origin. The impact of different biomarkers in predicting recurrence after CRS/HIPEC is unclear.

METHODS

Retrospective review of patients who underwent CRS/HIPEC for PC of CRC origin from 03/2007-08/2017. Molecular profile of the primary tumor was obtained from pathology reports, whenever available.

RESULTS

Overall, 100 patients underwent CRS/HIPEC for peritoneal metastases of CRC origin. Most patients presented high grade tumor histology (G2/G3, n = 97, 97%), and a majority showed mucinous features (n = 61, 61%). At a median follow-up of 18 months, median DFS for the overall population was 13 months (95% CI 9.6, 16.4). Data reporting at least one mutational analysis was available in 64 patients. Microsatellite stability was detected in 42/50 (84%) patients, mKRAS in 25/51 (49%), and mBRAF in 5/35 (14.3%). On Kaplan-Meier analysis, BRAF was the only mutation associated with poor DFS (16 months, CI 95% 11.7-43.3 vs. 7 months, CI 95% 2.1-11.9, p = .008). On multivariate analysis, mBRAF independently predicted earlier recurrence (p = .032).

CONCLUSIONS

In this analysis, mBRAF was independently associated with earlier recurrence in patients undergoing CRS/HIPEC for CRC, leading to dismal median DFS (7 months). Strict patient selection is advisable in these patients.

CSN7B defines a variant COP9 signalosome complex with distinct function in DNA damage response

Mammalian COP9 signalosome (CSN) exists as two variant complexes containing either CSN7A or CSN7B paralogs of unknown functional specialization. Constructing knockout cells, we found that CSN7A and CSN7B have overlapping functions in the deneddylation of cullin-RING ubiquitin ligases. Nevertheless, CSN^CSN7B has a unique function in DNA double-strand break (DSB) sensing, being selectively required for ataxia telangiectasia mutated (ATM)-dependent formation of NBS1^S343p and γH2AX as well as DNA-damage-induced apoptosis triggered by mitomycin C and ionizing radiation. Live-cell microscopy revealed rapid recruitment of CSN7B but not CSN7A to DSBs. Resistance of CSN7B knockout cells to DNA damage is explained by the failure to deneddylate an upstream DSB signaling component, causing a switch in DNA repair pathway choice with increased utilization of non-homologous end joining over homologous recombination. In mice, CSN7B knockout tumors are resistant to DNA-damage-inducing chemotherapy, thus providing an explanation for the poor prognosis of tumors with low CSN7B expression.

Updated staging and patient outcomes in low-grade appendiceal mucinous neoplasms

Low-grade appendiceal mucinous neoplasms (LAMNs) exhibit drastically different clinical course and prognosis depending on tumor stage, particularly as it relates to the extent and cellularity of peritoneal involvement. In this context, recent changes in staging guidelines have sought to clarify criteria for pT and pM categories. This study's aim was to identify clinicopathological features associated with patient outcomes, especially as they pertain to updated stage groups. We reviewed LAMNs from 192 patients (mean age: 56.9 years, 119 (62.0%) women). The tumors consisted of 66 (34.4%) pTisM0, 16 (8.3%) pT3M0, 16 (8.3%) pT4aM0, 27 (14.1%) pTxM1a, and 67 (34.9%) pTxM1b cases. In multivariate analysis, only gross perforation was significantly associated with higher TNM group stage (p = 0.001; OR 3.3, 95% CI: 1.7-6.4). Of 165 (85.9%) patients with clinical follow-up, 51 (30.9%) had disease progression (over a mean 33.7 months, range: 4.7-121.7), whereas over significantly longer follow-up (mean 48.7 months, range: 3.1-143.9; p = 0.004), 114 (69.1%) patients did not. In multivariate analysis, higher TNM stage was significantly associated with disease progression (p = 0.029; OR 18.3, 95% CI: 1.4-246.0). In Kaplan-Meier analysis, none of 74 patients with disease limited to the appendix (pM0), 6 of 27 (22.2%) cases with peritoneal involvement by acellular mucin only (pM1a), and 45 of 64 (70.3%) tumors with intraperitoneal deposits containing neoplastic cells (pM1b) showed disease progression (p < 0.001). These differences in progression-free survival among TNM groups persisted when limiting the analysis to patients who had undergone successful cytoreductive surgery (p = 0.050). Finally, in four patients (all with pM1b disease) death was attributed to disease progression whereas there was no disease-specific mortality in the pM0 and pM1a groups (p = 0.020). These data support the designation of LAMNs with acellular peritoneal mucin as having an intermediate prognosis between cases limited to the appendix and those with intraperitoneal deposits containing neoplastic epithelium.