Gastrointestinal malignancy: rationale for adjuvant therapy using early postoperative intraperitoneal chemotherapy

Review of Options to Traditional HIPEC for Prevention and Treatment of Peritoneal Metastases

Cytoreductive surgery with HIPEC has definite application to the management of selected patients with peritoneal metastases. Patients who profit most have a complete cytoreductive surgery. Higher-grade tumors such as colorectal cancer, gastric cancer, and ovarian malignancy are benefited by CRS and HIPEC only under limited circumstances. High-grade tumor invades subperitoneal lymphatics where HIPEC is not effective. Options to traditional HIPEC for treatment of invasive intraabdominal malignancies with peritoneal metastases must be explored.

Culturing Primary Human Mesothelial Cells

Mesothelial cells line the serosal cavities and associated organs. In order to metastasize to distant organs, ovarian tumor cells must first attach and then clear the mesothelial cells. Therefore, human primary mesothelial cells (HPMCs) are necessary to effectively study ovarian cancer metastases. Here, we describe methods to obtain HPMCs from human omentum and to culture in vitro.

Sequential postoperative intraperitoneal chemotherapy for colorectal cancer with peritoneal metastases: a narrative review

Sequential postoperative intraperitoneal chemotherapy (SPIC) is a chemotherapy abdominal infusion given as a postoperative adjuvant treatment for 6 months after cytoreductive surgery (CRS) for peritoneal surface malignancies. It has most commonly been used in conjunction with ovarian cancer where the SPIC treatment has been integrated with adjuvant systemic chemotherapy. This review investigates the role of SPIC in the setting of colorectal cancer with peritoneal metastases. The focus is on the CRS+SPIC combination treatment with no systemic chemotherapy component. Several cohort studies, several comparative studies, and one randomized trial have been reported with several important endpoints. The following aspects will be covered in this review: overall survival, disease-free survival, morbidity, quality-of-life, and cost-effectiveness. In comparison to systemic chemotherapy alone for isolated resectable colorectal peritoneal metastases, CRS+SPIC is superior concerning overall survival, has no difference in morbidity, is similar in quality-of-life, and SPIC is cost-effective. In comparison to HIPEC, results are conflicting in multivariate analysis; but in a univariate analysis HIPEC (most often combined with systemic adjuvant therapy) appears superior to SPIC alone (no systemic component). The future of SPIC is uncertain. However, a combination of HIPEC and SPIC ± a systemic chemotherapy component is a possible direction to explore further.

Outcomes of neoadjuvant chemotherapy before CRS-HIPEC for patients with appendiceal cancer

BACKGROUND

Cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) is indicated for patients with peritoneal dissemination of appendiceal cancer. The role of neoadjuvant chemotherapy (NAC) before CRS-HIPEC remains controversial.

METHODS

A retrospective review of adult patients who underwent CRS ± HIPEC for metastatic appendiceal cancer between 2000-2017 was performed. Patients who received NAC followed by surgery were compared with those who underwent surgery first (SF) with and without 1:1 propensity score matching (PSM).

RESULTS

Among 803 patients with appendiceal cancer who underwent CRS ± HIPEC, 225 (28%) received NAC, and 578 (72%) underwent SF. After PSM (n = 186), median overall survival (OS) did not differ (NAC: 40 vs SF: 56 months; P = .210) but recurrence-free survival (RFS) was worse among patients who received NAC (14 vs 22 months; P = .007). NAC was independently associated with worse OS (hazards ratio [HR], 1.81; 95% confidence interval [CI], 1.03-3.18) and RFS (HR, 1.93; 95% CI, 1.25-2.99).

CONCLUSION

In this multi-institutional retrospective analysis of patients with peritoneal dissemination from appendiceal cancer, the use of NAC before CRS-HIPEC was associated with worse OS and RFS even after PSM and multivariable regression. Immediate surgery should be considered for patients with disease amenable to complete cytoreduction.

Is ascites CEA a risk factor for peritoneal carcinomatosis in colorectal cancer?: a long-term follow-up study

PURPOSE

Our previous study reported that carcinoembryonic antigen (CEA) levels in peritoneal fluid were significantly correlated with the prevalence of peritoneal carcinomatosis (PC) in colorectal cancer (CRC). The purpose of this study was a long-term follow up of the author's previous study, as well as the identification of correlations with the known risk factors of PC and the comparison of the predictive power of PC in CRC.

METHODS

A total of 495 patients without PC who underwent CRC operations at St. Mary's Hospital, The Catholic University of Korea, from January 2006 to November 2014 were included in this study. Tumor markers of peritoneal fluid sampled at the beginning of each operation were prospectively analyzed and compared with the known risk factors for PC in CRC.

RESULTS

Multivariate analysis of PC revealed that T4 cancer (OR 5.143, 95% CI 1.400-18.897, p = 0.014), T3 mucinous cancer (OR 17.480, 95% CI 1.577-193.714, p = 0.020), obstructed tumors (OR 6.030, 95% CI 1.627-22.343, p = 0.007), and peritoneal fluid CEA above 5 ng/dl (OR 4.073, 95% CI 1.315-12.615, p = 0.015) were significant risk factors. T4 cancer, obstructed tumors, and peritoneal fluid CEA above 5 ng/dl showed correlations with cancer-free survival. Generally, higher CEA levels in peritoneal fluid were correlated with previously known risk factors for PC in CRC.

CONCLUSION

Peritoneal fluid CEA has predictive value for PC and prognostic value in CRC. Therefore, we recommend routinely performing ascites CEA analysis in colorectal cancer surgery.

Concomitant intraperitoneal and systemic chemotherapy for extensive peritoneal metastases of colorectal origin: protocol of the multicentre, open-label, phase I, dose-escalation INTERACT trial

INTRODUCTION

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) has become standard of care for patients with peritoneal metastases of colorectal origin with a low/moderate abdominal disease load. In case of a peritoneal cancer index (PCI) score >20, CRS-HIPEC is not considered to be beneficial. Patients with a PCI >20 are currently offered palliative systemic chemotherapy. Previous studies have shown that systemic chemotherapy is less effective against peritoneal metastases than it is against haematogenous spread of colorectal cancer. It is suggested that patients with peritoneal metastases may benefit from the addition of intraperitoneal chemotherapy to systemic chemotherapy. Aim of this study is to establish the maximum tolerated dose of intraperitoneal irinotecan, added to standard of care systemic therapy for colorectal cancer. Secondary endpoints are to determine the safety and feasibility of this treatment and to establish the pharmacokinetic profile of intraperitoneally administered irinotecan.

METHODS AND ANALYSIS

This phase I, '3+3' dose-escalation, study is performed in two Dutch tertiary referral centres. The study population consists of adult patients with extensive peritoneal metastases of colorectal origin who have a good performance status and no extra-abdominal metastases. According to standard work-up for CRS-HIPEC, patients will undergo a diagnostic laparoscopy to score the PCI. In case of a PCI >20, a peritoneal access port will be placed in the abdomen of the patient. Through this port we will administer intraperitoneal irinotecan, in combination with standard systemic treatment consisting of 5-fluorouracil/leucovorin with oxaliplatin and the targeted agent bevacizumab. Therapy consists of a maximum of 12 cycles 2-weekly.

ETHICS AND DISSEMINATION

This study protocol is approved by a research medical ethics committee (Rotterdam, Netherlands) and the Dutch Competent Authority (CCMO, The Hague, Netherlands). The results of this trial will be submitted for publication in a peer-reviewed scientific journal.

TRAIL REGISTRATION NUMBER

NL6988 and NL2018-000479-33; Pre-results.

Early postoperative intraperitoneal chemotherapy for lower gastrointestinal neoplasms with peritoneal metastasis: a systematic review and critical analysis

Background

Early postoperative intraperitoneal chemotherapy (EPIC) can be used in combination with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) to treat patients with peritoneal carcinomatosis (PC) of multiple origins. The present study is a systematic review to evaluate the role of EPIC after CRS + HIPEC for appendiceal and colorectal cancers with PC.

Content

We conducted a systematic search in PubMed according to the PRISMA guidelines and included all studies published before June 27 of 2019 comparing EPIC to HIPEC or the combination of both. Our search found 79 articles. After excluding non-relevant articles, a total of 13 retrospective clinical studies reporting on the efficacy and safety of EPIC compared to HIPEC or as a combination therapy for lower gastrointestinal neoplasms were analyzed. Initial EPIC reports led to its declined usage because of concerns with increased postoperative morbidity and uncertain added benefit on survival. Recent retrospective studies have been promising, showing significant improvements in OS and fewer issues with complications when adding EPIC to CRS + HIPEC.

Conclusions

Current evidence is entirely retrospective and is conflicting. It is hoped that ongoing clinical trials and additional studies will clarify EPIC’s role in the treatment of patients with PC.

Prevention and Treatment of Peritoneal Metastases: a Comprehensive Review

Peritoneal metastases may occur from a majority of cancers that occur within the abdomen or pelvis. When cancer spread to the peritoneal surfaces is documented, a decision regarding palliation versus an aggressive approach using cytoreductive surgery (CRS) and hyperthermic perioperative intraperitoneal chemotherapy (HIPEC) must be made. This decision is dependent on a well-defined group of prognostic indicators. In addition to treatment, prevention of peritoneal metastases may be an option. The clinical and pathologic features of a primary cancer can be used to select perioperative treatments that may prevent cancer cells within the abdomen and pelvis from progressing to established peritoneal metastases. In some clinical situations with appendiceal and colorectal cancers, the clinical or histopathologic features may indicate that second-look surgery plus perioperative chemotherapy should occur. Peritoneal metastases should always be considered by the multidisciplinary team for treatment or prevention.

Peritoneal Metastases from Gastrointestinal Cancer

PURPOSE OF REVIEW

Peritoneal metastases may occur from a majority of cancers that occur within the abdomen or pelvis. When cancer spread to the peritoneal surfaces is documented, a decision regarding palliation vs. an aggressive approach using cytoreductive surgery (CRS) and perioperative intraperitoneal chemotherapy must be made. The perioperative chemotherapy may be hyperthermic intraperitoneal chemotherapy (HIPEC) administered in the operating room or early postoperative intraperitoneal chemotherapy (EPIC) administered in the first 4 or 5 postoperative days.

RECENT FINDINGS

This decision is dependent on a well-defined group of prognostic indicators. In addition to treatment, the clinical and pathologic features of a primary cancer can be used to select perioperative treatments that may prevent cancer cells within the abdomen and pelvis from progressing to established peritoneal metastases. In some clinical situations with appendiceal and colorectal cancers, the clinical or histopathologic features may indicate that second-look surgery plus perioperative chemotherapy should occur. Peritoneal metastases should always be considered for treatment or prevention.

Neutropenia following Perioperative Intraperitoneal Chemotherapy

Introduction

The purpose of this retrospective report was to evaluate clinical features associated with profound neutropenia in patients with peritoneal carcinomatosis who were treated with heated intraoperative intraperitoneal chemotherapy (HIIC) followed by early postoperative intraperitoneal chemotherapy (EPIC). Common clinical denominators for significant neutropenia were analyzed.

Materials and Methods

A retrospective study of all available clinical data of six patients with postoperative neutropenia out of a total of 242 was undertaken. All patients underwent cytoreductive surgery, HIIC with mitomycin C (n = 4) or cisplatin (n = 1) and EPIC with 5-fluorouracil (5-FU) for 4 (n = 1) or 5 (n = 5) days.

Results

All six patients presented with hematologic toxicity of WHO criteria grade 4; four of them died postoperatively. Two of the patients who died, and one who did not die, developed bowel perforations. Five patients had prior chemotherapy with 5-FU; three of them had toxic side effects. All patients were overweight, and three patients were anemic preoperatively. The neutropenia presented with fever, leukopenia and thrombocytopenia on postoperative days 10–15. The leukocyte count courses showed a pattern suggesting the 5-FU as the cause of leukopenia. There was no consistent warning signal for predicting severe neutropenia.

Discussion

Neutropenia following cytoreductive surgery combined with HIIC and EPIC has a high mortality (66%). Patients who are at special risk and should have a dose reduction include patients who had toxicities from prior chemotherapy, who present with obesity and anemia. The groups have an increased risk of developing postoperative profound neutropenia. This condition can result in a prohibitively high mortality and morbidity rate. Therefore, reduced doses of chemotherapy in selected patients are necessary to prevent this condition from developing.

Tissue invasion and metastasis: Molecular, biological and clinical perspectives

Cancer is a key health issue across the world, causing substantial patient morbidity and mortality. Patient prognosis is tightly linked with metastatic dissemination of the disease to distant sites, with metastatic diseases accounting for a vast percentage of cancer patient mortality. While advances in this area have been made, the process of cancer metastasis and the factors governing cancer spread and establishment at secondary locations is still poorly understood. The current article summarizes recent progress in this area of research, both in the understanding of the underlying biological processes and in the therapeutic strategies for the management of metastasis. This review lists the disruption of E-cadherin and tight junctions, key signaling pathways, including urokinase type plasminogen activator (uPA), phosphatidylinositol 3-kinase/v-akt murine thymoma viral oncogene (PI3K/AKT), focal adhesion kinase (FAK), β-catenin/zinc finger E-box binding homeobox 1 (ZEB-1) and transforming growth factor beta (TGF-β), together with inactivation of activator protein-1 (AP-1) and suppression of matrix metalloproteinase-9 (MMP-9) activity as key targets and the use of phytochemicals, or natural products, such as those from Agaricus blazei, Albatrellus confluens, Cordyceps militaris, Ganoderma lucidum, Poria cocos and Silybum marianum, together with diet derived fatty acids gamma linolenic acid (GLA) and eicosapentanoic acid (EPA) and inhibitory compounds as useful approaches to target tissue invasion and metastasis as well as other hallmark areas of cancer. Together, these strategies could represent new, inexpensive, low toxicity strategies to aid in the management of cancer metastasis as well as having holistic effects against other cancer hallmarks.

Colorectal cancer: prevention and management of metastatic disease

This paper compared the similarities and differences of the two most common types of colorectal cancer metastases. The treatment of liver metastases by surgery combined with systemic chemotherapy was explained. The different natural history of liver metastases as compared to peritoneal metastases and the possibility for prevention of peritoneal metastases were emphasized. Perioperative cancer chemotherapy or second-look surgery must be considered as individualized treatments of selected patients who have small volume peritoneal metastases or who are known to be at risk for subsequent disease progression on peritoneal surfaces. However, the fact that peritoneal metastases, when diagnosed in the follow-up of colorectal cancer patients, can be cured with a combination of cytoreductive surgery and hyperthermic perioperative chemotherapy cannot be ignored. Careful follow-up and timely intervention in colorectal cancer patients with progressive disease are a necessary part of the management strategies recommended by the multidisciplinary team. After a critical evaluation of the data currently available, these strategies for prevention and management of colorectal metastases are presented as the author's recommendations for a high standard of care. As more information becomes available, modifications may be necessary.

Proactive management of peritoneal metastases from colorectal cancer: the next logical step toward optimal locoregional control

SUMMARY Although surgery for colorectal cancer has improved over the last decade, locoregional recurrence and peritoneal metastases continue as a mechanism of surgical treatment failure in 10–20% of patients. These patients have a dismal prognosis. Clinical information is available in order to identify patients who are at high risk for locoregional recurrence and peritoneal metastases. These patients, once identified, should be offered new treatment options shown to be of benefit in selected patients. Using perioperative chemotherapy at the time of colorectal cancer resection improves locoregional control and diminishes peritoneal metastases. Also, in patients at high risk, a proactive second-look surgery utilizing peritonectomy and hyperthermic intraperitoneal chemotherapy is of benefit, with reasonable morbidity and mortality.

A proposal of a practical and optimal prophylactic strategy for peritoneal recurrence

Peritoneal metastasis, which often arises in patients with advanced gastric cancer, is well known as a miserable and ill-fated disease. Once peritoneal metastasis is formed, it is extremely difficult to defeat. We advocated EIPL (extensive intraoperative peritoneal lavage) as a useful and practical adjuvant surgical technique for those gastric cancer patients who are likely to suffer from peritoneal recurrence. In this paper, we review the effect of EIPL therapy on prevention of peritoneal recurrence on patients with peritoneal free cancer cells without overt peritoneal metastasis (CY+/P−) through the prospective randomized study, and we verified its potential as an optimal and standard prophylactic therapeutic strategy for peritoneal recurrence.

A Phase II Study of Modified FOLFOX4 for Colorectal Cancer Patients with Peritoneal Carcinomatosis

Purpose

Peritoneal carcinomatosis (PC) of colorectal cancer (CRC) is common and is the second most common cause of death. Clinical studies regarding chemotherapy for CRC with PC have been classically rather limited in scope. We evaluated the efficacy of modified oxaliplatin, leucovorin, and fluorouracil (m-FOLFOX4) regimen for PC of CRC origin.

Materials and Methods

CRC patients with PC were treated with cycles of oxaliplatin at 85 mg/m² on day 1, leucovorin 20 mg/m² followed by 5-fluorouracil (5-FU) via a 400 mg/m² bolus and a 22 hours continuous infusion of 600 mg/m² 5-FU on days 1-2 at 2-week intervals.

Results

Forty patients participated in this study. Median age was 55 years. Thirty-two patients (80.0%) received previous operation, and 60.0% of PC occurred synchronously. Thirty-five patients (87.5%) were assessable and exhibited measurable lesions. Two patients (5.7%) demonstrated complete response and five patients (14.3%) showed partial response. The median time to progression was 4.4 months (95% confidence interval, 2.5 to 6.3 months), the median overall survival time was 21.5 months (95% confidence interval, 17.2 to 25.7 months). There was no treatment related death. Presence of liver metastasis (p=0.022), performance status (p=0.039), and carcinoembryonic antigen level (p=0.016) were related to the time to progression. Patients with low carcinoembryonic antigen level (37.2 months vs. 15.6 months, p=0.001) or good performance status (22.5 months vs. 6.8 months, p=0.040) showed better overall survival.

Conclusion

The m-FOLFOX4 regimen was determined to be effective for CRC patients with PC.

Mesothelial cells can detach from the mesentery and differentiate into macrophage-like cells

Peritoneal cell suspension is composed of heterogeneous cell population. Macrophages are the most numerous cells among them. They can originate from different sources and can be resident, exudate and elicited. When we used Freund's adjuvant to elicit peritoneal macrophages, cells having large amount of caveolae on their plasma membrane appeared in the peritoneal wash. The number of these caveolae-rich cells increased by the time of the Freund's adjuvant treatment. Although their morphology was different form from the common macrophages, they were labelled with pan-macrophage antibodies. As the origin of these cells is unknown in this work, we tried to find out where they can originate from. Our interest turned towards the mesothelial cells. We found that the adjuvant treatment resulted in significant morphological changes in these cells and stimulate them to leave the surface of the mesentery. By the time of the adjuvant treatment, the macrophage markers expression increased in the mesothelial cells and more cells were found to detach from the mesentery. These results strongly suggest that under special stimuli mesothelial cells can leave the mesentery and differentiate into phagocytotic (macrophage-like) cells. These data raises the idea that mesothelial cells might not entirely differentiated and represent a multipotential cell lineage. To study whether this is the case we used anti-nestin antibody, which is a specific marker for multifunctional, multi-lineage progenitor cells. Mesothelial cells showed strong labelling with this antibody indicating that these cells really represent a 'young', not entirely differentiated cell population.

Application of stereology to study the effects of pneumoperitoneum on peritoneum

BACKGROUND

Scanning electron microscopy is unable to provide sufficient data to obtain definitive results for research into the morphologic effect of pneumoperitoneum on peritoneum. To overcome this difficulty, we adopted stereology to examine the effect of the type of gas insufflated, pressure, duration, and gas flow on morphologic alterations of peritoneum.

METHODS

Fifty SD rats were divided into ten groups. One group served as control. Pneumoperitoneum was established at 5 mmHg and 1.0 l/min gas flow for 1, 2 or 3 h with CO2 (in groups C1h, C2h, and C3h, respectively) or with He (in groups H1h, H2h, and H3h, respectively). CO2 pneumoperitoneum was further established at 8 mmHg and 1.0 l/min gas flow for 1 h (group C8p), at 5 mmHg and 2.0 l/min gas flow for 1 h (group C2f), and at 5 mmHg and 3.0 l/min gas flow for 1 h (group C3f). After the procedures, five specimens were sampled from anterior peritoneum and measured by stereological and electron-microscopic techniques.

RESULTS

Groups H1h and C1h, H2h and C2h, and H3h and C3h, respectively, were the same in terms of area fraction of basal lamina exposed and diameter of mesothelial cells (P>0.05). The magnitudes of peritoneal trauma in groups C2h, C3h, C8p, C2f, and C3f were significantly higher than that in group C1h (P<0.01), and the same result was observed in groups H2h and H3h against group H1h (P<0.01), and in group C3f against group C2f (P<0.01). Furthermore, the area fractions of basal lamina exposed in groups C3h and H3h were remarkably higher than those in groups C2h and H2h, respectively (P<0.01). The mechanism of basal lamina exposure comprises mesothelial cell desquamation and plasmatorrhexis.

CONCLUSIONS

Peritoneal morphologic trauma during pneumoperitoneum can be attributed to the pressure, duration, and gas flow instead of the type of gas insufflated.

The integrity of colonic anastomoses following the intraperitoneal administration of oxaliplatin

INTRODUCTION

The purpose of this experimental study was to determine the effect of oxaliplatin on the integrity of colonic anastomoses which were under oxaliplatin administration.

MATERIALS AND METHODS

Thirty rats were randomized to two groups. After resection of a 1-cm segment of the transverse colon, an end-to-end sutured anastomosis was performed. Rats of the control group were injected with 3 ml of 0.9% sodium chloride solution and in the oxaliplatin group with 2.4 mg/kg of oxaliplatin intraperitoneally immediately after surgery and for seven postoperative days. All rats were sacrificed on the tenth postoperative day, and the anastomoses were examined macroscopically and graded histologically. Rats were measured for anastomotic bursting pressures and tissue hydroxyproline levels.

RESULTS

The body weight changes were significantly greater in the oxaliplatin group (p = 0.005). Anastomotic dehiscence occurred only in the oxaliplatin group. The adhesion formation was significantly increased in the group of oxaliplatin compared to the control group (p = 0.001). The colonic bursting pressure was significantly lower in the oxaliplatin group compared to the control group (p < 0.001). The mean inflammatory cell infiltration was significantly lower in the oxaliplatin group (1.00 vs. 2.33, p < 0.001). The mean neoagiogenesis was significantly lower in the oxaliplatin group (0.80 vs. 2.20, p < 0.001). The mean collagen deposition was significantly lower in the oxaliplatin group and the mean fibroblast activity was significantly lower in the oxaliplatin group (1.27 vs. 2.53, p < 0.001). Hydroxyproline concentration was significantly lower in the oxaliplatin group (p < 0.001).

CONCLUSION

Intra- and postoperative intraperitoneal administration of oxaliplatin definitely impairs healing of colonic anastomoses in rats.

Effect of early preoperative 5-fluorouracil on the integrity of colonic anastomoses in rats

AIM: To determine the effect of chemotherapy on wound healing by giving early preoperative 5-fluorouracil (5-FU) to rats with colonic anastomoses.

METHODS: Sixty Albino-Wistar male rats (median weight, 235 g) were used in this study. The rats were fed with standard laboratory food and given tap water ad libitum. The animals were divided into three groups: Group 1: Control group (chemotherapy was not administered), Group 2: Intraperitoneally (IP) administered 5-FU group (chemotherapy was administered IP to animals at a dose of 20 mg/kg daily during the 5 d preceeding surgery), Group 3: Intravenously (IV) administered 5-FU group. Chemotherapy was administered via the penil vein, using the same dosing scheme and duration as the second group. After a 3-d rest to minimize the side effects of chemotherapy, both groups underwent surgery. One centimeter of colon was resected 2 cm proximally from the peritoneal reflection, then sutured intermittently and subsequently end-to-end anastomosed. In each group, half the animals were given anaesthesia on the 3rd postoperative (PO) day and the other half on the 7th PO day, for in vivo analytic procedures. The abdominal incisions in the rats were dissected, all the new and old anastomotic segments were clearly seen and bursting pressures of each anastomotic segment, tissue hydroxyproline levels and DNA content were determined to assess the histologic tissue repair process.

RESULTS: When the IV group was compared with the IP group, bursting pressures of the anastomotic segments on the 3rd and 7th PO days, were found to be significantly decreased, hydroxyproline levels at the anastomotic segment on the 7th PO day were significantly decreased (P < 0.01).

CONCLUSION: In this study, we conclude that early preoperative 5-FU, administered IV, negatively affects wound healing. However, IP administered 5-FU does not negatively affect wound healing.

Effects of oxaliplatin and 5-fluorouracil on the healing of colon anastomoses

PURPOSE

Oxaliplatin (OX) and 5-fluorouracil (5-FU) are the most widely used chemotherapeutic agents in the adjuvant treatment of colon cancer. Although the early initiation of adjuvant chemotherapy can improve the outcome of surgery, it carries potentially fatal risks. This experimental study investigates the effects of 5-FU and OX on colon anastomoses.

METHODS

We used 60 rats, divided into six groups. After being subjected to bowel resection and anastomosis, the rats were given 5-FU on days 1-3, or OX 130 mg/m(2) on days 1 or 5, or 5% dextrose as a control. The bursting pressures and hydroxyproline content of the anastomoses were measured, and complications and adhesions were recorded.

RESULTS

There were no major complications in the treatment groups. The bursting pressures of the 5-FU group were significantly lower than those of the control and OX groups. The bursting pressures of the OX groups were not significantly different from those of the control groups. The hydroxyproline levels of the rats treated with OX on day 1 were significantly lower than those of the rats treated with OX on day 5 and the 5-FU groups.

CONCLUSION

Oxaliplatin and 5-FU did not compromise wound healing of the colon significantly. Our results indicate that OX is less detrimental to the healing of colonic anastomoses, when administered on days 1 and 5 after resection, than 5-FU.

The porta hepatis as a site of recurrence of mucinous appendiceal neoplasms treated by cytoreductive surgery and perioperative intraperitoneal chemotherapy

BACKGROUND

A successful new treatment for a particular disease may change the natural history of that disease as patients go on to longer survival. The goal of this study was to investigate the porta hepatis as a site of recurrence of appendiceal mucinous neoplasms.

METHODS

A prospective database on patients with peritoneal dissemination of mucinous appendiceal neoplasms has been maintained for 21 years. In patients with complete cytoreduction, disease progression/recurrence in and around the porta hepatis has been noted as a new manifestation of this disease.

RESULTS

In 710 patients treated for mucinous appendiceal cancer with a complete cytoreduction, 140 developed recurrent disease. Seven patients (5%) had disease recurrence in and around the porta hepatis. Four of the seven had biliary obstruction and three had masses within the liver hilum not causing bile duct obstruction. Four of the seven patients were successfully palliated by surgical procedures within the liver and biliary tree. Two patients were successfully palliated using a biliary stent and one patient was not treated.

CONCLUSIONS

Progression of mucinous neoplasms within the porta hepatis may be related to imperfect cytoreduction technique. Reoperative surgical treatment and biliary stents were beneficial in some of these patients.

Effect of 5-fluorouracil and mitomycin on the healing of intestinal anastomosis

OBJECTIVE

Antineoplastic agents affect the healing of intestinal anastomosis. The aim was to evaluate the effect of 5-fluorouracil (5-FU) and mitomycin on the healing of the intestinal anastomosis and their schedule of administration.

MATERIAL AND METHODS

Eighty-nine male albino Charles Foster rats with a mean weight of 256.57 g were divided into six groups. Group A represents the control, while in others varying schedules of chemotherapy (5-FU and mitomycin) were administered. The sacrifices were made on days 7, 14 and 21 postoperatively and bursting pressure and hydroxyproline content were measured.

RESULTS

Nine rats died before completion of the experiment and were excluded. Adhesions were noted in all rats on sacrifice. The mean bursting pressure of normal intestine (group A) was 252 mm Hg. The bursting pressure was lower on day 7 (208 mm Hg) and it subsequently increased by day 21 (230 mm Hg). The mean bursting pressure in groups B, C, D and E was 174, 194, 182 and 188 mm Hg and it subsequently increased to 232, 272, 244 and 286 mm Hg. There was no difference in the pattern of bursting pressure in colon and ileum. The mean hydroxyproline content of ileum (group A) on day 7 was 34.37 mg/g tissue. The hydroxyproline content of the ileum in groups B, C, D and E was 15.08, 27.03, 7.75 and 21.04 mg/g tissue. There was a significant decrease in hydroxyproline content following anastomosis and chemotherapy.

CONCLUSIONS

The effect of chemotherapy was pronounced when administered on the day of surgery or in the immediate pre- or postoperative period. Hence administration of chemotherapy during this period may be harmful.

Effect of iloprost on impaired anastomotic healing caused by 5-fluorouracil plus leucovorin

PURPOSE

This experimental study was designed to investigate whether iloprost can reverse impaired colonic healing caused by immediate postoperative intraperitoneal administration of 5-fluorouracil plus leucovorin.

METHODS

Eighty Wistar rats were randomized into four groups. After resection of a 1-cm segment of transverse colon, an end-to-end sutured anastomosis was generated. Rats received saline solution (Group 1), 5-fluorouracil plus leucovorin (Group 2), iloprost (Group 3), and 5-fluorouracil plus leucovorin plus iloprost (Group 4) intraperitoneally from the day of operation and once daily until killing. Each group was further randomized into two subgroups. Subjects were killed on the fifth (Subgroup a) and eighth (Subgroup b) postoperative days. After killing, anastomoses were examined macroscopically and graded histologically. Rats were measured for anastomotic bursting pressures and tissue hydroxyproline levels.

RESULTS

The leakage rate of the anastomoses was significantly higher in the 5-fluorouracil plus leucovorin group compared with the other groups (P = 0.049). Bursting pressure was significantly lower in 2a subgroup (5-fluorouracil plus leucovorin, postoperative Day 5) than in 4a (5-fluorouracil plus leucovorin plus iloprost, postoperative Day 5; P < 0.001). Adhesion formation was significantly higher in all b subgroups compared with the Control b subgroup. Neoangiogenesis was significantly higher in iloprost and iloprost plus 5-fluorouracil plus leucovorin subgroups compared with the 5-fluorouracil plus leucovorin subgroups. Hydroxyproline levels, collagen deposition, fibroblasts, and white cell count were significantly higher in the iloprost plus 5-fluorouracil plus leucovorin b subgroup (postoperative Day 8) compared with the 5-fluorouracil plus leucovorin b subgroup (postoperative Day 8).

CONCLUSIONS

The immediate postoperative, intraperitoneal administration of iloprost counteracts and reverses the negative effects of 5-fluorouracil plus leucovorin chemotherapy and protects colonic healing in rats.

Effects of granulocyte-colony stimulating factor on peritoneal defense mechanisms and bacterial translocation after administration of systemic chemotherapy in rats

AIM: To investigate the effects of granulocyte-colony stimulating factor (G-CSF) on peritoneal defense mechanisms and bacterial translocation after systemic 5-Fluorouracil (5-FU) administration.

METHODS: Thirty Wistar albino rats were divided into three groups; the control, 5-FU and 5-FU + G-CSF groups. We measured bactericidal activity of the peritoneal fluid, phagocytic activity of polymorphonuclear leucocytes in the peritoneal fluid, total peritoneal cell counts and cell types of peritoneal washing fluid. Bacterial translocation was quantified by mesenteric lymph node, liver and spleen tissue cultures.

RESULTS: Systemic 5-FU reduced total peritoneal cell counts, neutrophils and macrophage numbers. It also altered bactericidal activity of the peritoneal fluid and phagocytic activity of polymorphonuclear leucocytes in the peritoneal fluid. 5-FU also caused significant increase in frequencies of bacterial translocation at the liver and mesenteric lymph nodes. G-CSF decreased bacterial translocation, it significantly enhanced bactericidal activity of the peritoneal fluid and phagocytic activity of polymorphonuclear leucocytes in the peritoneal fluid. It also increased total peritoneal cell counts, neutrophils and macrophage numbers.

CONCLUSION: Systemic 5-FU administration caused bacterial translocation, decreased the bactericidal activity of peritoneal fluid and phagocytic activity of polymorphonuclear leucocytes in the peritoneal fluid. G-CSF increased both bactericidal activity of the peritoneal fluid and phagocytic activity of polymorphonuclear leucocytes in the peritoneal fluid, and prevented the bacterial translocation. We conclude that intraperitoneal GCSF administration protects the effects of systemic 5-FU on peritoneal defense mechanisms.

The effect of octreotide on healing of injured colonic anastomosis with immediate postoperative intraperitoneal administration of 5-Fluorouracil

PURPOSE

This study was designed to investigate the effect of octreotide on side effects of immediate usage of 5-fluorouracil after colonic anastomosis.

METHODS

Forty male Wistar rats were randomly assigned into four groups and underwent standardized left colonic anastomosis. The rats served as control or received intraperitoneal 5-fluorouracil (20 mg/kg daily), subcutaneous octreotide (20 mug/kg daily), or both. Diarrhea and wound complications were noted during the experiment. The colonic anastomoses were assessed for healing on postoperative Day 7 by determining the anastomotic bursting pressure, performing histologic examination, and measuring the tissue hydroxyproline content, serum malondialdehyde, and nitric oxide levels. Intraperitoneal adhesions and anastomotic leakage were also noted.

RESULTS

No statistical significant difference was found between the control and octreotide groups for each of the parameters measured. Immediate 5-fluorouracil use resulted with higher adhesion score (P = 0.002), significant depression in anastomotic bursting pressure (P = 0.0001), histopathologic score (P = 0.0001), hydroxyproline content (P = 0.0001), and increasing nitric oxide (P = 0.0001) and malondialdehyde levels (P = 0.0001) compared with the control group. Diarrhea was seen in 80 percent of the 5-fluorouracil group but in neither the control nor octreotide groups (P = 0.0001 for each comparison). However, all these parameters were ameliorated by use of concomitant octreotide and 5-fluorouracil (P = 0.019, P = 0.023, P = 0.0001, P = 0.006, P = 0.0001, and P = 0.013, respectively). In addition, diarrhea was found to be prevented (P = 0.0001).

CONCLUSIONS

The results of this study showed that concomitant octreotide use might prevent the side effects of 5-fluorouracil, such as diarrhea, postoperative adhesion, and delaying the anastomotic healing parameters. In addition, it might reduce tissue damage and inflammation.

Adjuvant intraperitoneal chemotherapy for advanced primary gastric cancer

BACKGROUND

For gastric cancer dissemination to the peritoneal cavity is a large part of the natural history. Also, cancer dissemination caused from the trauma of cancer resection can release viable cancer cells into the free peritoneal cavity; these cells implant and then progress as peritoneal carcinomatosis.

METHODS

From the medical literature a compilation of the results of adjuvant treatment of gastric cancer were reviewed and critically analyzed. A surgical rationale for integrating intraperitoneal chemotherapy into the management of advanced primary gastric cancer was sought.

RESULTS

A theoretical basis for the application of cytotoxic effects of cancer chemotherapy within the peritoneal cavity as a part of the primary management of gastric cancer was explored. Numerous manuscripts suggested that there was an increased morbidity and mortality with perioperative intraperitoneal chemotherapy but the added number of complications was manageable. These data suggest that intraperitoneal chemotherapy is of benefit in an adjuvant setting in gastric cancer patients who have a complete resection but who are at high likelihood of local-regional recurrence.

SUMMARY

Adjuvant intraperitoneal chemotherapy for advanced primary gastric cancer has a strong rationale. Numerous reports have established benefit. Wider application of this treatment modality is necessary through education, through additional clinical trials, and through continued publications from peritoneal surface malignancy treatment centers around the world.

Effect of 5-Fluorouracil plus Interferon on the Integrity of Colonic Anastomoses Covering with Fibrin Glue

BACKGROUND

It has been well established that the immediate postoperative intraperitoneal administration of chemotherapeutic agents such as 5-fluorouracil (5-FU) after curative colon resection for colon cancer destroys disseminated cancer cells and inhibits micrometastases but also inhibits anastomotic healing. On the other hand, the application of fibrin glue constitutes a physical barrier around the anastomosis and may prevent anastomotic leakage. The purpose of this experimental study was to determine the effect of 5-FU plus interferon (IFN)-alpha-2a on the integrity of colonic anastomoses covered with fibrin glue when injected intraperitoneally immediately after colon resection.

MATERIALS AND METHODS

Sixty rats were randomized to one of four groups. After resection of a 1-cm segment of the transverse colon, an end-to-end sutured anastomosis was performed. Rats of the control and the fibrin glue groups were injected with 6 ml of 0.9% sodium chloride (NaCl) solution intraperitoneally. Rats in the 5-FU + IFN and the 5-FU + IFN + fibrin glue groups received 5-FU plus IFN intraperitoneally. The colonic anastomoses of the rats in the fibrin glue and in the 5-FU + IFN + fibrin glue groups were covered with fibrin glue. All rats were sacrificed on the 8th postoperative day, and the anastomoses were examined macroscopically. The bursting pressure measurements were recorded, and the anastomoses were graded histologically.

RESULTS

Only the 5-FU + IFN group had anastomoses rupture, and the rupture rate (33%) in this group was significantly greater than in the other groups, where there were no ruptures (P = 0.015). The adhesion formations score was, on average, significantly higher in rats of the 5-FU + IFN group compared with the control group (P = 0.006) and the 5-FU + IFN + fibrin glue group (P = 0.010). Bursting pressures were significantly lower in the control group when compared to the fibrin glue and 5-FU + IFN + fibrin glue group (P < 0.001). Rats in the 5-FU + IFN + fibrin glue group developed significantly more marked neoangiogenesis than rats in the other groups. Inflammatory cell infiltration, collagen deposition, and fibroblast activity did not differ significantly among the four groups (P = 0.856, P = 0.192 and P = 0.243, respectively).

CONCLUSION

The immediate postoperative intraperitoneal administration of 5-FU plus IFN impairs colonic healing. However, when the colonic anastomoses were covered with fibrin glue, the injection of 5-FU plus IFN had no adverse effects on the integrity of the anastomoses.

Early Postoperative Intraperitoneal Chemotherapy Following Cytoreductive Surgery in Patients with Very Advanced Gastric Cancer

BACKGROUND

The survival of patients with stage IV gastric cancer is poor due to frequent peritoneal failure. The aim of this study was to investigate the impact of early postoperative intraperitoneal chemotherapy (EPIC) after cytoreductive surgery on the long-term survival of these patients, as determined by residual disease status.

METHODS

A total of 154 patients with stage IV gastric cancer were enrolled in our study. All patients underwent potentially curative or palliative resections. After surgery, the residual disease states of the patients were recorded. All patients received EPIC.

RESULTS

Of all 154 patients, R0 resection was achieved in 37, R1 in 56, and R2 in 61. All patients received a mean of 4.3 EPIC perfusions. After a mean followup period of 29 months, 14 patients remained alive. The median survival of all 154 patients was 11.4 months. Survival times were analyzed according to the type of residual tumor; the median survival time was 25.5 months in the R0 group, 15.6 months in the R1 group, and 7.2 months in the R2 group (p < .001). Upon multivariate analysis, the residual tumor states and the cycle of EPIC perfusion were found to be independent prognostic predictors (p < .001 and p = .018, respectively).

CONCLUSIONS

The residual tumor status is the most important predictor for the survival of very advanced gastric cancer patients who received cytoreductive surgery and EPIC. Therefore, complete cytoreductive surgery yielding R0 resection is mandatory for achieving the beneficial effects of EPIC.

Intraarterial chemotherapy as an adjuvant treatment in locally advanced gastric cancer

BACKGROUND AND AIMS

D2 gastrectomy has improved survival in gastric cancer. Adjuvant intravenous chemotherapy, radiotherapy, or multimodal therapy has failed to demonstrate improved survival. The results of intraarterial chemotherapy (IARC) as an adjuvant have been encouraging in a few studies. A prospective randomized trial was designed to evaluate the toxicity and survival in locally advanced gastric cancer using IARC as an adjuvant after potentially curative gastrectomy.

PATIENTS AND METHODS

Forty patients with locally advanced gastric cancer were randomly selected to undergo either potentially curative gastrectomy and receive IARC (study group) or gastrectomy only (control group). Clinical and histopathologic data were analyzed and the toxicity related to IARC was recorded.

RESULTS

The groups were comparable (p>0.05). Three patients in the study group had minor toxicity. Five-year survival rate for the study and the control group was 52 and 54%, respectively (p>0.05). Mean survival for the study and the control group was 50+/-8 and 62+/-10 months, respectively (p>0.05). The number of recurrences and the failure sites were comparable (p>0.05).

CONCLUSION

Intraarterial chemotherapy can be safely applied to gastric cancer patients. As proposed by the protocol, the method cannot be recommended as an adjuvant treatment for locally advanced tumors because it appears that there is no survival benefit compared to potentially curative gastrectomy alone.

Icodextrin reduces postoperative adhesion formation in rats without affecting peritoneal metastasis

BACKGROUND

Peroperative peritoneal trauma activates a cascade of peritoneal defense mechanisms responsible for postoperative adhesion formation. The same cascade seems to play a role in the process of intra-abdominal tumor recurrence. Icodextrin is a glucose polymer solution that is absorbed slowly from the peritoneal cavity, allowing prolonged "hydroflotation" of the viscera, thereby decreasing adhesion formation. This study evaluated the adhesion-preventing properties of icodextrin and its effect on peritoneal metastasis.

METHODS

Reproducible rat models of peritoneal trauma were used, allowing semiquantitative scoring of adhesion formation or tumor load. In one experiment, peritoneal trauma was inflicted; one group was treated by peroperative intra-abdominal instillation of 7.5% icodextrin, one by instillation of RPMI (placebo), and one had no instillate (controls). In another experiment involving a different model of peritoneal trauma, the coloncarcinoma cell line CC531 was injected intraperitoneally to induce tumor load, again using these three groups.

RESULTS

Treatment of peritoneally traumatized rats with icodextrin caused a 51% reduction in postoperative adhesion formation ( P < .001). However, peroperative intra-abdominal treatment with icodextrin did not affect intraperitoneal tumor cell adhesion and growth of free intra-abdominal tumor cells in rats with this model of severe peritoneal trauma.

CONCLUSION

A 7.5% icodextrin solution is effective in reducing postoperative adhesions without promoting tumor recurrence and therefore may prove useful and safe in oncologic surgery.

Clinical perspective on desmoplastic small round-cell tumor

Rare diseases are often associated with uninformed medical decisions and poorly executed treatments because of inexperience of the physicians. Desmoplastic small round-cell tumor is a rare disease that is a form of peritoneal surface malignancy usually affecting young males, with a mean survival of 29 months. In order to begin to build a more knowledgeable clinical pathway all 7 patients treated at the Washington Hospital Center were studied and compared to patients described in the medical literature. Clinical and pathological data, tumor distribution, cytoreductive surgery, completeness of cytoreduction and survival were recorded and analyzed. The first most common symptoms were pain, increased abdominal girth and palpable abdominal mass in our patients and in the literature review. The overall survival did not improve with cytoreductive surgery plus intraperitoneal chemotherapy (mean survival 32 months); however, 2 long-term survivors who responded to systemic chemotherapy of 55 and 101 months were recorded. The latter may be the longest survivor reported in the literature. No consistent response to chemotherapy was observed in our patients or in any literature review. Complete surgical removal of this malignancy did not correlate with survival in our patients. The absence of improved survival of our aggressively treated patients as compared to the literature was thought to be a consequence of an advanced stage of the disease. A new comprehensive approach that uses complete clearing of cancer by surgery and perioperative systemic and perioperative intraperitoneal chemotherapy as early as is possible in the natural history of the disease emerged as goals for future management.

Mesothelial progenitor cells and their potential in tissue engineering

The mesothelium consists of a single layer of flattened mesothelial cells that lines serosal cavities and the majority of internal organs, playing important roles in maintaining normal serosal integrity and function. A mesothelial 'stem' cell has not been identified, but evidence from numerous studies suggests that a progenitor mesothelial cell exists. Although mesothelial cells are of a mesodermal origin, they express characteristics of both epithelial and mesenchymal phenotypes. In addition, following injury, new mesothelium regenerates via centripetal ingrowth of cells from the wound edge and from a free-floating population of cells present in the serosal fluid, the origin of which is currently unknown. Recent findings have shown that mesothelial cells can undergo an epithelial to mesenchymal transition, and transform into myofibroblasts and possibly smooth muscle cells, suggesting plasticity in nature. Further evidence for a mesothelial progenitor comes from tissue engineering applications where mesothelial cells seeded onto tubular constructs have been used to generate vascular replacements and grafts to bridge transected nerve fibres. These findings suggest that mesothelial cell progenitors are able to switch between different cell phenotypes depending on the local environment. However, only by performing detailed investigations involving selective cell isolation, clonal analysis together with cell labelling and tracking studies, will we begin to determine the true existence of a mesothelial stem cell.

Healing of colon anastomoses covered with fibrin glue after immediate postoperative intraperitoneal administration of 5-fluorouracil

PURPOSE

The aim of this experimental study was to investigate whether covering the colonic anastomoses with fibrin glue can protect the colonic healing from the adverse effects of 5-fluorouracil (5-FU), when it is injected intraperitoneally immediately after colon resection.

METHODS

Sixty-four rats were randomized to one of four groups. After resection of a 1-cm segment of the transverse colon, an end-to-end sutured anastomosis was performed. Rats of the control group and the fibrin glue group were injected with 6 ml of solution 0.9 percent NaCl intraperitoneally. Rats in the 5-FU and the 5-FU + fibrin glue groups received 5-FU intraperitoneally. The colonic anastomoses of the rats in the fibrin glue group and in the 5-FU + fibrin glue group were covered with fibrin glue. All rats were killed on the 8th postoperative day and the anastomoses were examined macroscopically. The bursting pressure measurements were recorded and the anastomoses were graded histologically.

RESULTS

The leakage rate of the anastomoses was significantly higher in the rats of the 5-FU group than in those of the fibrin glue group and those of the 5-FU + fibrin glue group (37.5 percent vs. 0 percent, P = 0.020). The adhesion formation score was significantly higher in rats of the 5-FU group than in the other groups. Bursting pressures were also significantly lower in the 5-FUgroup than in the other groups ( P < 0.001). Rats in the 5-FU + fibrin glue group developed significantly more marked neoagiogenesis than rats in the other groups. Rats in the 5-FU + fibrin glue group also presented significantly more fibroblast activity than those in the 5-FU group. ( P = 0.004)

CONCLUSIONS

The immediate postoperative, intraperitoneal administration of 5-FU inhibited wound healing. However, when the colonic anastomoses were covered with fibrin glue, the injection of 5-FU had no adverse effects on the healing of the anastomoses.

Gastrectomy, peritonectomy, and perioperative intraperitoneal chemotherapy: the evolution of treatment strategies for advanced gastric cancer

Gastric cancer disseminates by hematogenous, lymphatic, and transcoelomic routes. For maximal containment of the malignant process, perioperative intraperitoneal chemotherapy is necessary in two groups of patients in whom the primary cancer can be resected. Those patients who have been resected for cure and have a high likelihood of microscopic residual disease require intraperitoneal chemotherapy. This includes all T3 and T4 patients, and patients with N2 nodes present. A series of randomized and nonrandomized clinical studies have established the benefits of perioperative intraperitoneal chemotherapy in this group of patients. Patients with stage IV disease who are able to undergo a palliative resection require these treatments if peritoneal seeding is observed. Systemic chemotherapy is largely ineffective for peritoneal seeding, while intraperitoneal chemotherapy is most likely to produce a response with small volume, surgically debulked carcinomatosis. In addition, intraperitoneal chemotherapy can eliminate the future development of debilitating ascites. Sufficient data are available from the gastric cancer literature to support the use of these combined treatments on a routine basis if the primary cancer is resectable and gastrointestinal function can be reestablished.

Improved survival in patients with peritoneal metastases from colorectal cancer: a preliminary study

Patients with peritoneal or local metastases from colorectal cancer have a poor prognosis. However, aggressive treatments by debulking surgery and infusional intraperitoneal (i.p.) chemotherapy have been tried and appear to benefit selected patients. We assayed the effects of debulking surgery and i.p. chemotherapy with respect to survival and compared the results with matched control patients treated by intravenous (i.v.) chemotherapy. In all, 18 patients with peritoneal and/or local metastases from colorectal adenocarcinoma underwent debulking surgery followed by 5-fluorouracil (5-FU) 550 mg m⁻² day⁻¹ i.p. and leucovorin (LV) 60 mg m⁻² day⁻¹ i.v. The chemotherapy was started the day after surgery and was given daily for 6 days and repeated monthly for totally eight courses. The control patients, matched for age, gender, performance status and metastatic site, were randomly selected from controlled clinical chemotherapy trials and treated with i.v. 5-FU+LV or i.v. methotrexate+5-FU+LV. There was no treatment-related mortality. The median survival among i.p. patients was 32 months compared to 14 months in the control group. In all, 11 patients who underwent macroscopically radical surgery had a longer survival than those who were not radically operated (P=0.02). These results indicate that patients with peritoneal metastases and/or locally advanced cancers but without distant metastases may benefit from cytoreductive surgery combined with i.p. chemotherapy.

The mesothelial cell

Mesothelial cells form a monolayer of specialised pavement-like cells that line the body's serous cavities and internal organs. The primary function of this layer, termed the mesothelium, is to provide a slippery, non-adhesive and protective surface. However, mesothelial cells play other pivotal roles involving transport of fluid and cells across the serosal cavities, antigen presentation, inflammation and tissue repair, coagulation and fibrinolysis and tumour cell adhesion. Injury to the mesothelium triggers events leading to the migration of mesothelial cells from the edge of the lesion towards the wound centre and desquamation of cells into the serosal fluid which attach and incorporate into the regenerating mesothelium. If healing is impaired, fibrous serosal adhesions form between organs and the body wall which impede vital intrathoracic and abdominal movement. Neoplastic transformation of mesothelial cells gives rise to malignant mesothelioma, an aggressive tumour predominantly of the pleura. Although closely associated with exposure to asbestos, recent studies have implicated other factors including simian virus 40 (SV40) in its pathogenesis.

Uptake of 5-fluorouracil (5-FU) in peritoneal metastases in relation to the route of drug administration and tumour debulking surgery

Patients with peritoneal metastases from colorectal cancer have a poor prognosis. Aggressive treatment by debulking surgery and intraperitoneal (i.p.) chemotherapy has been suggested as an alternative therapy. However, the drug penetrance into the tumour in relation to the administration route and surgical reduction of the tumour is not well known. We compared locoregional administration with intravenous (i.v.) injection. Thirty-four in-bred rats with peritoneal metastases were randomly allocated into eight groups and injected with 14C-labelled 5-fluorouracil (5-FU) either through the i.v. or i.p. route, with or without a preceding tumour debulking, and were sacrificed after 2 or 8 h. Tumour radioactivity was visualised by autoradiography and quantified by a computer-based image analysis. After 8 h, 19 debulked and i.p.-injected tumours had a higher drug uptake, 63.2+/-28 (mean+/-standard deviation (SD)) kBq/g than 62 native i.p.-injected tumours (32.8+/-14) or 22 debulked and i.v.-injected tumours (18.5+/-18, P=0.002). After 8 h, 9 small tumours (<median 571 pixels) which underwent i.p. injection and tumour reduction had a higher drug uptake (77.4+/-26) than 29 non-debulked and i.p.-injected (35.1+/-17) or eight debulked and i.v. injected tumours (23.0+/-16, P=0.004). For larger tumours (>/=median 571 pixels), 16 debulked and i.p.-injected tumours had a higher radioactivity (drug uptake) (150.7+/-63) at 2 h than 49 i.p.-injected native tumours (48.5+/-59) or 11 reduced and i.v.-injected tumours (19.9+/-13, P=0.03). At 8 h, 10 debulked and i.p.-injected tumours had a higher drug uptake (50.3+/-24) than 33 native and i.p.-injected (30.8+/-10) or 14 debulked and i.v.-injected tumours (16.0+/-19, P=0.001). These results indicate that a debulking procedure and locoregional treatment of peritoneal metastases is associated with an increased level of 5-FU in the tumours.