Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for peritoneal metastasis of non-primary origin

PURPOSE

The objective of this study was to analyze the role of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy that has developed in the treatment of patients with peritoneal metastasis of non-primary origin.

METHODS

Patients who underwent treatment for secondary gastrointestinal and ovarian malignancies over a 20-year period were reviewed. Survival curves were estimated by the Kaplan-Meier product limit method and the log-rank test was used to assess differences between subgroups.

RESULTS

The study included 293 patients. The most common histology was ovarian cancer (56.3%). Median PCI was 16 and CC0-1 resection was obtained in 88.1% of cases. Grade III and IV complications occurred in 12 patients (4.1%) and 47 patients (16%), respectively. The 30- and 60-day mortality rate was 1.3% (4 patients) and 2.4% (7 patients). Five-year OS was 21.7%, 73.6%, 42.1%, and 0 for colorectal, appendiceal, ovarian, and gastric cancer (p =  < 0.0001), respectively, whereas 5-year DFS was 12.4%, 48.4%, 24.3%, and 0 (p =  < 0.0001), respectively. Survival outcomes were significantly higher for CC0 in each subgroup of patients.

CONCLUSION

Despite being a complex procedure, cytoreductive surgery with hyperthermic intraperitoneal chemotherapy should be considered a safe treatment with acceptable postoperative morbidity and mortality rates, if performed in high-volume centers. Good survival outcomes have been increasingly obtained in selected patients with peritoneal metastasis of non-primary origin.

Clinical and Molecular Features in Patients Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Carcinosis from Colorectal Cancer

PURPOSE

Careful patient selection plays a crucial role in avoiding overtreatment and further increases survival rates in patients undergoing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal cancer (CRC) with peritoneal metastases (PM).

METHODS

The clinical and molecular factors influencing survival in patients who had undergone CRS with HIPEC between January 2015 and December 2018 were analyzed.

RESULTS

Sixty-six patients underwent CRS with HIPEC during the study period. The median overall survival (OS) was 36 months, with a 3-year OS of 43%. Multivariate analysis revealed increased PCI (HR: 1.21; 95% CI: 1.02-1.41; p = 0.020), right-sided primary tumor (HR: 3.01; 95% CI: 1.27-7.13; p = 0.017), and BRAF V600E mutation (HR: 4.55; 95% CI: 1.21-17.21; p = 0.025) as independent predictors for worse OS.

CONCLUSION

In addition to confirming the prognostic role of PCI, our study extends the role of BRAF mutation and right primary tumor location as markers for worse prognosis.

Seeing the whole picture: Added value of MRI for extraperitoneal findings in CRS-HIPEC candidates

PURPOSE

In colorectal cancer (CRC) patients the selection of suitable cytoreductive surgery and hyperthermic peritoneal chemotherapy (CRS-HIPEC) candidates is based on the location and extent of peritoneal metastases (PM) and presence of extraperitoneal metastases. MRI is increasingly being used to accurately assess the extent of PM, however, the significance of extraperitoneal findings in these scans has never been evaluated before.

METHODS

CRC patients who had undergone an additional MRI scan after standard work-up with CT for preoperative staging between January 2016-January 2020 were selected. CT and MRI reports were reviewed for new abdominopelvic extra-peritoneal findings on MRI (MR-EPF) and MR-EPFs concerning lesions previously indicated as equivocal (uncertain benign/malignant) on CT. Reference standard were surgical results or follow-up imaging.

RESULTS

In 158 included patients 60 MR-EPFs (in 58/158 patients) were noted: twenty-six (43%) were new findings and thirty-four (57%) were equivocal findings on CT. Of the 34 equivocal findings 27 were 'rejected/less likely malignant' and 7 'confirmed/more likely malignant' based on MRI. In 29 patients (18%) the MR-EPFs had direct influence on treatment planning. Three patients (2%), eligible for CRS-HIPEC on CT, were deemed inoperable due to MR-EPFs.

CONCLUSION

MRI had an added value in more than a third of the patients due to abdominopelvic extraperitoneal findings that were undetected or indeterminate on CT and therefore influenced the treatment in a substantial part of the patients. Combined with the known accurate detection of peritoneal disease on MRI, MRI seems a logical addition to the diagnostic workup of potential CRS-HIPEC candidates.

EMMPRIN in extracellular vesicles from peritoneal mesothelial cells stimulates the invasion activity of diffuse-type gastric cancer cells

Peritoneal metastasis of gastric cancer (GC) results in extremely poor prognoses. The peritoneal cavity is covered by a monolayer of peritoneal mesothelial cells (PMCs). Interactions between GC cells and PMCs might play a pivotal role in peritoneal metastasis. Extracellular vesicles (EVs) correlate with intercellular communication. Although intercellular communication between cancer cells and PMCs might be associated with the peritoneal metastatic process, the role of EVs from PMCs remains unclear. We investigated the effects of EVs from PMCs on GC cells. Three GC cell lines (OCUM-12, NUGC-3, and MKN74) and four mesothelial cell lines were used. The effects of EVs derived from the PMCs on the invasion and migration of GC cells were evaluated by Matrigel invasion assay. Factors contained in the PMC EVs were analyzed; extra-cellular matrix metalloproteinase inducer (EMMPRIN) was detected in the EVs. The effects of an EMMPRIN inhibitor on the invasion-stimulating activity of EVs were examined. The EMMPRIN expressions of 110 GCs were evaluated by immunohistochemistry. PMC EVs significantly promoted the invasion of diffuse-type GC cells, i.e., OCUM-12 and NUGC-3 cells. EMMPRIN in the EVs stimulated the invasion of OCUM-12 and NUGC-3 cells. The invasion-stimulating activity of PMC EVs was inhibited by the EMMPRIN inhibitor. A high EMMPRIN expression in PMCs was significantly associated with worse cancer-specific survival and peritoneal-recurrence-free survival. EMMPRIN in EVs from PMCs might stimulate the malignant progression of diffuse-type GC. EMMPRIN might be a useful prognostic marker of recurrence in GC patients.

The Clinical Significance and Functional Role of miR-466 in Gastric Cancer Peritoneal Metastasis

The prognosis of metastasis gastric cancer patients remains poor and the identification of novel molecular markers will improve the management of gastric cancer patients. The present study aimed to investigate the clinical significance and functional role of miR-466 in gastric cancer peritoneal metastasis. miR-466 expression was confirmed by RT-qPCR. The biological functions were examined by MTT assay, Transwell migration, and invasion assays. The Kaplan-Meier survival curve and multivariate Cox regression analysis were used to investigate the clinical role of miR-466. The logistic regression analysis was performed to reveal the risk factors associated with peritoneal metastasis. miR-466 expression was downregulated in gastric cancer cell lines, tumor tissues, and peritoneal metastasis tissues compared with respective controls. Increased miR-466 expression inhibited proliferation, migration, and invasion of gastric cancer cells. Besides, the lower expression of miR-466 in gastric cancer patients was associated with peritoneal dissemination. Furthermore, multivariate Cox proportional hazard regression analyses demonstrated miR-466 expression level as an independent predictor of prognosis of gastric cancer. The present study provides novel evidence for the clinical and biological significance of miR-466 expression as a possible biomarker for the prognosis and identifying patients with peritoneal metastasis, as well as a potential therapeutic target in patients with gastric cancer.

Improved prognosis of pancreatic cancer patients with peritoneal metastasis

BACKGROUND

Peritoneal metastasis is one of the most important poor prognostic factors in advanced pancreatic cancer (PC). Whether the prognosis of PC with peritoneal metastasis has improved with the advent of gemcitabine plus nab-paclitaxel (GnP) and modified FOLFIRINOX (mFFX) is uncertain. The aim of this study was to evaluate the improvements in treatment outcomes of PC with peritoneal metastasis.

METHODS

We retrospectively investigated consecutive PC patients with peritoneal metastasis treated with chemotherapy at our institution between 2010 and 2019. We compared the clinical characteristics and survival outcomes according to the period of diagnosis (group A, 2010-2014; group B, 2015-2019) and chemotherapy regimen. We also examined the prognostic factors for overall survival (OS).

RESULTS

Among 180 patients included (GnP 88; mFFX 14; other regimens 78), distant metastasis was confined to the peritoneum in 89 patients. Although group B had a worse performance status compared to group A, median OS was significantly longer in group B. GnP and mFFX showed a significantly higher objective response rate and disease control rate in addition to longer progression free survival and OS compared to other regimens. The administration of GnP or mFFX, performance status, and neutrophil to lymphocyte ratio ≥5 were identified as independent prognostic factors for OS. Furthermore, the amount of ascites and extent of peritoneal metastasis were significantly associated with OS in patients with distant metastasis confined to the peritoneum.

CONCLUSIONS

The prognosis of PC with peritoneal metastasis has significantly improved over time with the advent of GnP and mFFX.

[Risk factors of peritoneal metastasis in primary appendiceal tumor]

Objective: To investigate the risk factors of peritoneal metastasis in primary appendiceal tumor. Methods: The clinic data of 71 patients with primary appendiceal tumor admitted in the Sixth Affiliated Hospital of Sun Yat-sen University between Dec 2012 and Jan 2019 were enrolled retrospectively. Multivariate logistic regression analysis were carried out to evaluate the risk factors of appendiceal tumor with peritoneal metastasis. Results: Of the 71 patients, 33 were peritoneal metastasis (peritoneal metastasis group) and 38 were non-peritoneal metastasis (no peritoneal metastasis group). Twenty-one patients in the peritoneal metastasis group had increased preoperative cancer embryo antigen (CEA), while 3 cases in the non-peritoneal metastasis group, with statistically significant difference (P<0.001). Sixteen cases in peritoneal metastasis group had increased preoperative carbohydrate antigen 199, while only 2 cases in the non-peritoneal metastasis group, the difference was statistically significant (P<0.001). The pathological type of 30 cases in the peritoneal metastasis group was adenocarcinoma (including mucus adenocarcinoma and colon adenocarcinoma), while 12 cases of adenocarcinoma in the non-peritoneal metastasis group, with statistically significant difference (P<0.001). Twelve cases in the peritoneal metastasis group had lymph node metastasis, while 3 cases in the non-peritoneal metastasis group, the difference is statistically significant (P=0.003). Preoperative CEA elevation and pathological type is adenocarinoma were independent risk factors for peritoneal metastasis of appendiceal cancer (P<0.05). Conclusions: The propensity of peritoneal metastasis in primary appendiceal tumor is high and the outcome is poor. Patients with increased preoperative CEA, adenocarcinoma histopathology are more inclined to have peritoneal metastasis.

Postoperative oxaliplatin-based hyperthermic intraperitoneal chemotherapy: an effective and safe palliative treatment option for colorectal cancer with peritoneal metastasis

BACKGROUND

The prognosis of patients with colorectal cancer and peritoneal metastasis (CRC-PM) after incomplete cytoreductive surgery (CRS) or palliative surgery is poor. Novel and effective therapies are urgently needed. This study aimed to assess the effects of palliative postoperative hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with CRC-PM.

METHODS

This retrospective study included patients with CRC-PM at the First Affiliated Hospital of Xi'an Jiaotong University in 05/2014-05/2019. Observation indicators included overall survival (OS), ascites-free survival, peritoneal cancer index (PCI), and completeness of cytoreduction (CC). Kaplan-Meier survival curves and multivariable Cox regression models were used to determine the factors associated with OS and ascites-free survival. The ascites-specific quality of life (QoL) was measured using the Functional Assessment of Chronic Illness Therapy-Ascites Index (FACIT-AI).

RESULTS

Eighty-two patients were included, including 37 and 45 in the HIPEC and non-HIPEC groups, respectively. Mean OS was 10.3±3.7 (95% CI 9.5-11.2) months. Multivariable Cox proportional hazard regression suggested that PCI (HR=6.086, 95% CI 3.187-11.620, P < 0.0001) was independently associated with OS. The degree of ascites (HR=2.059, 95% CI 1.412-3.005, P < 0.0001), PCI (HR=6.504, 95% CI 2.844-14.875, P < 0.0001), and HIPEC (HR=0.328, 95% CI 0.191-0.562, P < 0.0001) were independently associated with ascites-free survival. In patients with survival >6 months, postoperative ascites-specific QoL was significantly improved after HIPEC compared with the non-HIPEC group (P < 0.001). Oxaliplatin-based HIPEC significantly increased the rates of neutropenia and peripheral neurotoxicity (both P < 0.05).

CONCLUSION

These data indicate that postoperative oxaliplatin-based HIPEC might help increase ascites-free survival in CRC-PM patients after incomplete CRS or palliative surgery, with improved QoL after 6 months of follow-up.

Treatment Modality Based Survival in Gastric Carcinoma Patients with Stand-Alone Peritoneal Metastasis: a Case-Control Study

Purpose

To date, there are no promising treatments for gastric carcinoma with peritoneal metastasis. Some researchers have suggested a survival benefit of gastrectomy in select patients. This study investigated the survival of gastric carcinoma patients with stand-alone peritoneal metastasis according to the type of treatment modality.

Materials and Methods

We reviewed the data of 132 patients with gastric carcinoma and stand-alone peritoneal metastasis. We performed gastrectomy when the primary tumor was deemed resectable and systemic chemotherapy was administered. We analyzed patient survival according to the type of treatment, and the prognostic value of gastrectomy was evaluated in univariate and multivariate models.

Results

Among all patients, 70 underwent gastrectomy plus chemotherapy, 20 underwent gastrectomy alone, 36 underwent chemotherapy alone, and 6 received supportive care. The median patient survival was 13 months. Patients who underwent gastrectomy had significantly longer survival than those who did not undergo gastrectomy (14 vs. 8 months, P<0.001). Patients who received chemotherapy showed significantly longer survival than those who did not (13 vs. 7 months, P=0.032). Patients who underwent gastrectomy plus chemotherapy showed better survival than those who underwent other treatments. In multivariate analysis, gastrectomy was found to be an independent prognostic factor (hazard ratio, 0.52; 95% confidence interval, 0.33–0.82) in addition to chemotherapy.

Conclusions

Our study showed that patients who underwent gastrectomy plus chemotherapy had the best survival. Although the survival benefit of gastrectomy remains uncertain, it is a favorable prognostic indicator in patients with stand-alone peritoneal metastasis.

Assessment of workplace environmental contamination and occupational exposure to cisplatin and doxorubicin aerosols during electrostatic pressurized intraperitoneal aerosol chemotherapy

BACKGROUND

Electrostatic precipitation pressurized intraperitoneal aerosol chemotherapy (ePIPAC) is a novel approach for intraperitoneal drug delivery. As ePIPAC using cisplatin and doxorubicin is performed in an operating room, the challenge is to safely deliver the chemotherapeutic aerosol intraperitoneally while preventing exposure to healthcare workers. The objective of this study was to describe cisplatin and doxorubicin workplace environmental contamination and healthcare worker exposure during ePIPAC.

METHODS

Antineoplastic drugs concentrations of cisplatin and doxorubicin were measured in wipe samples from the operating room, and urine samples were collected from healthcare workers. The air samples were collected in order to detect Cisplatin contamination. Cisplatin was analysed by inductively coupled plasma-mass spectrometry and doxorubicin by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry.

RESULTS

No trace of cisplatin was found in the air. Cisplatin and doxorubicin were detected on the operating room floor, surfaces, devices and personal protective equipment even after a cleaning protocol. No traces of cisplatin or doxorubicin were found in the urine samples.

CONCLUSION

In this study, no internal contamination was found in the ePIPAC surgical team even after implementing two successive ePIPAC procedures. These results showed the effectiveness of the individual and collective protective measures applied. However, the cleaning procedure during ePIPAC should be respected to limit environmental exposure to chemotherapy to cisplatin and doxorubicin during ePIPAC.

Angiopoietin-like protein 2 decreases peritoneal metastasis of ovarian cancer cells by suppressing anoikis resistance

Peritoneal metastasis is a common mode of spread of ovarian cancer. Despite therapeutic advances, some patients have intractable peritoneal metastasis. Therefore, in-depth characterization of the molecular mechanism of peritoneal metastasis is a key imperative. Angiopoietin-like protein 2 (ANGPTL2) is an inflammatory factor which activates NF-κB signaling and plays an important role in the pathogenesis of various inflammatory diseases including cancers, such as lung and breast cancer. In this study, we examined the role of ANGPTL2 in ovarian cancer peritoneal metastasis. We observed no difference of cell proliferation between ANGPTL2-expressing and control cells. In the mouse intraperitoneal xenograft model, formation of peritoneal metastasis by ANGPTL2-expressing cells was significantly decreased compared to control. In the in vitro analysis, the expressions of integrin α5β1, α6, and β4, but not those of αvβ3, α3, α4, and β1, were significantly decreased in ANGPTL2-expressing cells compared to control cells. ANGPTL2-expressing cells showed significantly inhibited adherence to laminin compared to control. In addition, we observed upregulation of anoikis (a form of programmed cell death occurring under an anchorage-independent condition) and significant decrease in the expression of Bcl-2 in ANGPTL2-expressing cells as compared to control cells. These results suggest that ANGPTL2 expression in ovarian cancer cells represses peritoneal metastasis by suppressing anoikis resistance.

Impact of preoperative chemotherapy as initial treatment for advanced gastric cancer with peritoneal metastasis limited to positive peritoneal lavage cytology (CY1) or localized peritoneal metastasis (P1a): a multi-institutional retrospective study

BACKGROUND

Gastric cancer (GC) patients with peritoneal metastasis are defined as stage IV in the Japanese classification of GC. For patients with peritoneal metastasis limited to positive peritoneal lavage cytology (CY1) and/or localized peritoneal metastasis (P1a), gastrectomy followed by S1 monotherapy is one of the most widely accepted therapeutic strategy in Japan. This study investigated the efficacy of preoperative chemotherapy as initial treatment in GC patients with CY1 and/or P1a.

METHODS

We retrospectively reviewed GC patients diagnosed with CY1 and/or P1a at 34 institutions in Japan between 2008 and 2012. Selection criteria were: adenocarcinoma, no distant metastasis except CY1 or P1a, and no prior treatment. The subjects were divided into an Initial-Chemotherapy group and an Initial-Surgery group, according to the initial treatment.

RESULTS

A total of 824 patients were collected and 713 eligible patients were identified for this study. As the initial treatment, 150 patients received chemotherapy (Initial-Cx), and 563 patients underwent surgery (Initial-Sx). Initial-Cx regimens were cisplatin plus S1/docetaxel plus cisplatin plus S1/others (n = 90/37/23). Both overall survival (OS) and progression-free survival (PFS) were similar between the Initial-Cx and Initial-Sx groups (median OS 24.8 and 24.0 months, HR 1.07, 95% CI 0.87-1.3; median PFS 14.9 and 13.9 months, HR 1.04, 95% CI 0.85-1.27). The 5-year OS rates were 22.3% in the Initial-Cx group and 21.5% in the Initial-Sx group.

CONCLUSIONS

Although, the preoperative chemotherapy did not show a survival benefit for GC patients with CY1 and/or P1a, initial-Cx showed favorable survival in patients who converted to P0 and CY0.

Negative prognostic outcomes of percutaneous transhepatic biliary drainage in distal cholangiocarcinoma: a retrospective analysis using propensity score matching

BACKGROUND

The efficacy of different types of preoperative biliary drainage for cholangiocarcinoma has been debated over the past two decades. Controversy concerning the use of percutaneous transhepatic biliary drainage (PTBD) versus endoscopic biliary drainage (EBD) still exists. This study aimed to compare the long-term outcomes between PTBD and EBD in patients with distal cholangiocarcinoma.

METHODS

Data of patients diagnosed with distal cholangiocarcinoma who underwent preoperative PTBD or EBD from January 1999 to December 2017 were analyzed retrospectively. Post-surgical outcomes, including the incidence of post-operative complications, peritoneal metastasis, disease-free survival, and overall survival, were analyzed. Survival analyses were also performed after propensity score matching in the PTBD and EBD groups.

RESULTS

The incidence of post-operative complications was similar in both groups. The 5-year estimated cumulative incidences for peritoneal metastasis were 14.7% and 7.2% in the PTBD and EBD groups, respectively (p = 0.192). The 5-year disease-free survival rates were 23.7% and 47.3% in the PTBD and EBD groups, respectively (p = 0.015). In the multi-variate analysis for overall survival, PTBD was an independent poor prognostic factor. The 5-year overall survival rates were 35.9% and 56.3% in the PTBD and EBD groups, respectively (hazard ratio 1.85, confidence interval 1.05-3.26, p = 0.035). The results after propensity score matching indicated a poorer prognosis in the PTBD group, with a 5-year survival rate of 35.9% in the PTBD group vs 56.0% in the EBD group (p = 0.044).

CONCLUSION

PTBD should be considered as a negative prognostic factor in distal cholangiocarcinoma patients.

Treatment options for advanced gastric cancer with peritoneal metastasis: experience from a single institution in Korea

Purpose

This study aimed to compare treatment options and outcomes based on peritoneal cancer index (PCI) among patients with peritoneal metastasis (PM) of advanced gastric cancer (AGC).

Methods

Between January 2016 and July 2019, clinicopathological data of patients with AGC diagnosed with PM were reviewed. Different treatment methods were performed according to the PCI score: (1) group A (PCI ≤ 13) received cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) with postoperative intraperitoneal (IP) and systemic chemotherapy (n = 29), while (2) group B (PCI > 13) received IP chemotherapy with systemic chemotherapy (n = 22).

Results

Clinical outcomes of 51 patients at the Dankook University Hospital were reviewed. Group A had a significantly lower mean PCI score (9.8 ± 6.9 vs. 32.6 ± 7.1, P < 0.01) than group B, with 25 patients (86.2%) achieving complete cytoreduction. Complications occurred in 16 patients (31.4%), none of who suffered mortality (group A: 11 patients, 37.9% vs. group B: 5 patients, 22.7%; P = 0.25). Among the morbidity, 5 cases (17.2%) and 2 cases (9.1%) exhibited a Clavien-Dindo grade greater than III in groups A and B, respectively (P = 0.04). Groups A and B had an overall median survival time of 34.0 and 16.0 months, respectively (P = 0.03).

Conclusion

Patients with PM of AGC received different treatments according to their PCI score. When accompanied with careful patient selection, our approach may be considered an acceptable option for the treatment of PM of AGC.

Cytoreductive surgery and mitomycin C hyperthermic intraperitoneal chemotherapy with CO2 recirculation (HIPEC-CO2) for colorectal cancer peritoneal metastases: analysis of short-term outcomes

Peritoneal dissemination from colorectal cancer (CRC) has long been associated with unfavorable prognosis. However, in the last decades, the combination of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) was able to obtain up to 30% 5-year survival rate in selected centers. Despite the wide diffusion of CRS and HIPEC, until now, there are no clear recommendations on the drug of choice for HIPEC nor its technique, and safety and efficacy data of HIPEC regimens and techniques are lacking. We performed a retrospective analysis of a prospectively maintained database of 26 CRS and mitomycin C HIPEC with CO₂ recirculation (HIPEC-CO₂) for CRC peritoneal metastasis (PM) performed at our center. The main endpoints were morbidity, mortality, the temperature of perfusate during HIPEC and metabolic changes throughout the procedure. Morbidity was assessed by analysis of postoperative adverse events according to the Common Terminology Criteria for Adverse Events (CTCAE version 4.0). Continuous variables of Arterial Blood Gas (ABG) analysis at three time-points were compared by the Student t test. There were no postoperative deaths. The overall grade 3-4 CTCAE complications rate at 30 days was 38.4%, with ten severe adverse events occurring to six (23.0%) patients. The temperature within HIPEC perfusion maintained between 41 and 42 °C in all cases and we experienced no HIPEC-related intraoperative complications. We observed a significant difference between all baseline and pre-HIPEC ABG parameters evaluated but no statistically significant differences between pre- and post-HIPEC ABG outcomes. This study shows that mitomycin C HIPEC-CO₂ is feasible and has a safety profile comparable to that of other HIPEC techniques reported in the literature. Further research is needed to validate prospectively the safety and efficacy of this technique.

[Meta analysis of whether cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy can improve survival in patients with colorectal cancer peritoneal metastasis]

Objective: To explore whether the cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (CRS+HIPEC) can improve the survival rate of colorectal cancer patients with peritoneal metastasis. Methods: The relevant studies were systematically retrieved from PubMed, Embase, Cochrane Library, CNKI, Wanfang, VIP database, and the study of French Elias' team on peritoneal metastasis was retrieved manually. Inclusion criteria: (1) The patients were colorectal cancer peritoneal metastasis. (2) There were CRS+HIPEC treatments (treatment group) and other treatments (control group). (3) Survival analysis data of treatment group and control group were available. (4) Types of studies were randomized controlled trials, cohort studies, or case-control studies. (5) The literature was in Chinese or English. Exclusion criteria: (1) studies without full-text; (2) studies without complete data. The literature screening and data extraction were carried out by two people independently, and the third person decided on the literature with differences. The extracted data included authors, year of publication, number of patients, time of enrollment, time of follow-up, studies design, treatment regimen, hazard ratio (HR) and 95% CI of treatment group and control groups. If the HR and 95% CI of the treatment group and control group were not provided in the literature, Engauge Digitizer 11.1 software was used to extract the time of follow-up and the survival rate at the corresponding time point from the survival curves of both groups, and the HR and 95% CI of both groups were calculated by combining the number of both groups. The quality of study was evaluated by Newcastle-Ottawa scale (NOS) or Cochrane collaboration's tool for assessing risk bias. STATA 15.1 software was used for statistical analysis. HR and 95% CI of both groups were pooled and analyzed. Inter-trial heterogeneity was assessed by Q test and I(2) statistics. When there was no significant heterogeneity (Q test: P≥0.10), fixed-effect model was used for pooled analysis. When significant heterogeneity existed (Q test: P<0.10), random effect model was used for pooled analysis, and subgroup analysis was used to find out the source of heterogeneity. Sensitivity analysis was used to evaluate the stability of the pooled results. Publication bias was assessed by Egger's test and Begg's test (P<0.05 indicated publication bias) and it is reflected by the visual symmetry of Begg's funnel plot on the natural logarithm of HR. Results: A total of 10 studies were enrolled in the meta-analysis, including 1 randomized controlled trial and 9 cohort studies. The risk of bias in 1 randomized controlled trial was uncertain, and 9 cohort studies were all higher than 7 points, indicating high quality literatures. There were 781 patients in treatment group receiving CRS+HIPEC and 2452 patients in control group receiving other treatment, including tumor cytoreductive surgery (CRS), palliative chemotherapy (PC) and intraperitoneal chemotherapy (IPC). The results of pooled analysis by random effect model showed that the OS rate in treatment group was significantly higher than that in control group (HR=0.43, 95% CI: 0.34-0.54), but the heterogeneity of the study was high (P=0.024, I(2)=52.9%). The subgroup analysis of different control treatments showed that the OS rate in treatment group was significantly higher than that in CRS control group (HR=0.63, 95% CI: 0.44-0.90), in PC control group (HR=0.37, 95% CI: 0.32-0.43), in CRS+ IPC control group (HR=0.60, 95% CI: 0.37-0.96), and the heterogeneity of each subgroup was low (CRS control group: P=0.255, I(2)=22.9%; PC control group: P=0.222, I(2)=29.9%; CRS+IPC control group: P=0.947, I(2)=0). Due to the low heterogeneity of subgroups, fixed-effect models were used to pool and analysis. The results of sensitivity analysis revealed that there was little difference between the pooled analysis results after each study was deleted, suggesting that the pooled analysis results were more reliable. Publication bias detection of each study showed Begg's test (P=0.088) >0.05 and Egger's test (P=0.138)>0.05. According to the Begg's funnel plot, the scatter point distribution was basically symmetric, indicating that there was no publication bias in the included study. Conclusion: CRS+HIPEC can improve the OS of patients with colorectal cancer peritoneal metastasis.

[Strategies of chemotherapy for peritoneal metastasis of gastrointestinal cancer]

Peritoneal metastasis of gastrointestinal cancer is an independent factor that seriously affects the prognosis of patients. The "seed-soil" theory is considered to be the main theory to explain peritoneal metastasis. Because of the small size of peritoneal metastatic nodules at the initial stage, early diagnosis is particularly difficult, therefore, the risk assessment of peritoneal metastasis is very important. Recently, the diagnosis methods have gradually developed from clinicopathological factors to cytology and molecular level. In addition, the integrated assessment of multiple groups including radiomics further enriches the accurate diagnosis of peritoneal metastasis. Peritoneal metastasis is a big challenge in the treatment of gastrointestinal cancer which may also lead to refractory malignant ascites, intestinal obstruction, cachexia and other related complications. At present, the treatment is based on systemic chemotherapy. The combination of surgery, intraperitoneal chemotherapy and HIPEC is an effective treatment for peritoneal metastasis of gastrointestinal cancer. How to enrich peritoneal metastasis patients with potential benefits, how to determine the timing of conversion surgery, how to further optimize the existing treatment plan, especially how to formulate treatment plan for patients after conversion surgery, call for improved study design and prospective randomized controlled trials. The goal of continuous efforts is to effectively prolong the survival of gastrointestinal cancer trials patients with peritoneal metastasis.

[Fundamental pathological mechanisms underlying gastro-intestinal cancer peritoneal metastasis]

Gastrointestinal cancer peritoneal metastasis(GICPM) is one of the biggest challenges of clinical treatment. The ultimate solution to the problem requires the clinicians to accurately understand cytologic and molecular pathological mechanisms behind GICPM, and apply such knowledge in the clinical decision-making process for diagnosis and treatment of individual patient, so as to realize "prevention" and "treatment" proactively. The core cytopathological mechanisms behind GICPM, which are closely related to clinical treatment decisions, are as follows: (1) free cancer cells or clusters in peritoneal cavity colonize the peritoneum, resulting in irreversible pathological damage to peritoneal mesothelial cells; (2) the colonized cancer cells further invade the specific structure of the peritoneal milky spots and initiate an accelerated invasive growth process; (3) the process of peritoneal interstitial fibrosis aggravates the structural destruction of the peritoneum; (4) the interaction between cancer cells and immune cells in the milk spots forms a permissive immune microenvironment that promotes the growth of peritoneal metastatic cancer. These four core cytopathological mechanisms are mutually causal and promote each other, forming a vicious circle of GICPM development. As long as clinicians accurately understand these four points, it is possible to grasp the opportunity of clinical diagnosis and treatment, change reactive and passive treatment into preventive and proactive treatment, and improve the clinical diagnosis and treatment landscape of GICPM.

[Safety and short-term efficacy of apatinib combined with oxaliplatin and S-1 in the conversion treatment for gastric cancer with peritoneal metastasis]

Objective: To investigate the safety and short-term efficacy of apatinib combined with oxaliplatin and S-1 in the conversion treatment for gastric cancer with different types of peritoneal metastasis. Methods: A prospective study "one arm exploratory clinical study of conversion therapy of apatinib with S-1 and oxaliplatin in the treatment of advanced gastric cancer" (clinical registration ChiCTR-ONC-17010430) from medical record database was retrospectively analyzed. Patients aged 18-70 years with gastric cancer peritoneal metastasis confirmed by histology and laparoscopic exploration, and had not receive radiotherapy, chemotherapy, targeted therapy or immunotherapy before were enrolled. Before operation, the patients received 6 cycles of S-1 (80-120 mg/d, d1-d14) and oxaliplatin (130 mg/m(2), d1), and 5 cycles of apatinib (500 mg/d, d1-d21) conversion regimen. Three weeks after chemotherapy, whether the operation was performed or not depending on re-evaluation and patient preference. The main outcome were adverse reactions, and the secondary outcome were objective remission rate (ORR), disease control rate (DCR), and overall survival (OS) rate. The follow-up period was up to May 2020. Results: A total of 27 patients with gastric cancer peritoneal metastasis were enrolled in this study. There were 13 males and 14 females, with a median age of 58 (30-68) years old. There were 9 cases of P1a, 5 cases of P1b, and 13 cases of P1c. There were 14 cases with 1-5 scores of PCI (peritoneal cancer index), and 13 cases with 6 scores or above. The incidence of adverse reactions was 100%. The most common adverse reactions were hematological events including leucopenia (70.4%, 19/27) and granulocytopenia (74.1%, 20/27). Non-hematological adverse events included fatigue (51.9%, 14/27) and oral mucositis (37.0%, 10/27). One patient was withdrawn due to grade 4 thrombocytopenia. Among 26 patients with feasible efficacy evaluation, 18 (69.2%) achieved partial remission, 3 (11.5%) achieved stable disease, and 5 (19.2%) disease progression. The objective remission rate was 69.2% (18/26) and the disease control rate was 80.8% (21/26). Fourteen patients underwent surgery, including 6 patients undergoing R0 resection with the R0 resection rate of 42.9% (6/14). The postoperative pathological response rate was 64.3% (9/14). The follow-up time was 12-40 months, and the follow-up rate was 100%. The 1-year OS rate was 65.2% and the survival time was (14.0±1.7) months. The 1-year OS rates of P1a/P1b group and P1c group were 81.8% and 42.0% respectively, whose difference was statistically significant (P=0.041). The 1-year OS rates of PCI 1-5 group and PCI ≥6 group were 67.3% and 38.5% respectively, whose difference was statistically significant (P=0.022). Conclusion: In the conversion treatment of gastric cancer peritoneal metastasis, the safety of apatinib combined with oxaliplatin and S-1 is acceptable, and this regimen shows a good short-term survival efficacy in patients with P1a/P1b and PCI of 1-5.

LncRNA SPOCD1-AS from ovarian cancer extracellular vesicles remodels mesothelial cells to promote peritoneal metastasis via interacting with G3BP1

Background

Metastasis is the key cause of death in ovarian cancer patients. To figure out the biological nature of cancer metastasis is essential for developing effective targeted therapy. Here we investigate how long non-coding RNA (lncRNA) SPOCD1-AS from ovarian cancer extracellular vesicles (EVs) remodel mesothelial cells through a mesothelial-to-mesenchymal transition (MMT) manner and facilitate peritoneal metastasis.

Methods

EVs purified from ovarian cancer cells and ascites of patients were applied to mesothelial cells. The MMT process of mesothelial cells was assessed by morphology observation, western blot analysis, migration assay and adhesion assay. Altered lncRNAs of EV-treated mesothelial cells were screened by RNA sequencing and identified by qRT-PCR. SPOCD1-AS was overexpressed or silenced by overexpression lentivirus or shRNA, respectively. RNA pull-down and RNA immunoprecipitation assays were conducted to reveal the mechanism by which SPOCD1-AS remodeled mesothelial cells. Interfering peptides were synthesized and applied. Ovarian cancer orthotopic implantation mouse model was established in vivo.

Results

We found that ovarian cancer-secreted EVs could be taken into recipient mesothelial cells, induce the MMT phenotype and enhance cancer cell adhesion to mesothelial cells. Furthermore, SPOCD1-AS embedded in ovarian cancer-secreted EVs was transmitted to mesothelial cells to induce the MMT process and facilitate peritoneal colonization in vitro and in vivo. SPOCD1-AS induced the MMT process of mesothelial cells via interacting with G3BP1 protein. Additionally, G3BP1 interfering peptide based on the F380/F382 residues was able to block SPOCD1-AS/G3BP1 interaction, inhibit the MMT phenotype of mesothelial cells, and diminish peritoneal metastasis in vivo.

Conclusions

Our findings elucidate the mechanism associated with EVs and their cargos in ovarian cancer peritoneal metastasis and may provide a potential approach for metastatic ovarian cancer therapeutics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01899-6.

CD31 and D2-40 Contribute to Peritoneal Metastasis of Colorectal Cancer by Promoting Epithelial-Mesenchymal Transition

Background/Aims

Colorectal cancer (CRC) patients often exhibit peritoneal metastasis, which negatively impacts their prognosis. CD31 and D2-40 have recently been suggested to be predictors of breast cancer prognosis, but their role in colorectal peritoneal metastasis (CRPM) remains unknown.

Methods

The expression profiles of CD31 and D2-40 were analyzed in CRC patients with or without CRPM and in CRC cell lines with increasing metastatic potential. Overexpression and short hairpin RNA knockdown assays were performed in CRC cells, and the effects of these alterations on epithelial-mesenchymal transition (EMT) in vitro, growth of xenograft tumors in vivo, and peritoneal metastasis potential in a mouse model of CRPM were examined.

Results

The expressions of CD31 and D2-40 were upregulated in CRC tumor tissues and was elevated further in tumor tissues from patients with CRPM. CD31 and D2-40 expression levels exhibited increasing trends parallel to the EMT potential of CRC cells. CD31 and D2-40 are essential for CRC cell EMT in vitro as well as for xenograft tumor growth and peritoneal metastasis in vivo.

Conclusions

CD31 and D2-40 contribute to CRPM by promoting EMT and may serve as prognostic markers and therapeutic targets for CRC, particularly in patients with peritoneal metastasis.

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.