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

Importance: Studies on the prognostic role of hyperthermic intraperitoneal chemotherapy (HIPEC) in pseudomyxoma peritonei (PMP) are currently not available. Objectives: To evaluate outcomes after cytoreductive surgery (CRS) and HIPEC compared with CRS alone in patients with PMP. Design, Setting, and Participants: This cohort study analyzed data from the Peritoneal Surface Oncology Group International (PSOGI) registry, including 1924 patients with histologically confirmed PMP due to an appendiceal mucinous neoplasm. Eligible patients were treated with CRS with or without HIPEC from February 1, 1993, to December 31, 2017, and had complete information on the main prognostic factors and intraperitoneal treatments. Inverse probability treatment weights based on the propensity score for HIPEC treatment containing the main prognostic factors were applied to all models to balance comparisons between the CRS-HIPEC vs CRS-alone groups in the entire series and in the following subsets: optimal cytoreduction, suboptimal cytoreduction, high- and low-grade histologic findings, and different HIPEC drug regimens. Data were analyzed from March 1 to June 1, 2018. Interventions: HIPEC including oxaliplatin plus combined fluorouracil-leucovorin, cisplatin plus mitomycin, mitomycin, and other oxaliplatin-based regimens. Main Outcomes and Measures: Overall survival, severe morbidity (determined using the National Cancer Institute Common Terminology for Adverse Events, version 3.0), return to operating room, and 30- and 90-day mortality. Differences in overall survival were compared using weighted Kaplan-Meier curves, log-rank tests, and Cox proportional hazards multivariable models. A sensitivity analysis was based on the E-value from the results of the main Cox proportional hazards model. Differences in surgical outcomes were compared using weighted multivariable logistic models. Results: Of the 1924 patients included in the analysis (997 [51.8%] men; median age, 56 [interquartile range extremes (IQRE), 45-65] years), 376 were in the CRS-alone group and 1548 in the CRS-HIPEC group. Patients with CRS alone were older (median age, 60 [IQRE, 48-70] vs 54 [IQRE, 44-63] years), had less lymph node involvement (14 [3.7%] vs 119 [7.7%]), received more preoperative systemic chemotherapy (198 [52.7%] vs 529 [34.2%]), and had higher proportions of high-grade disease (179 [47.6%] vs 492 [31.8%]) and suboptimal cytoreduction residual disease (grade 3, 175 [46.5%] vs 117 [7.6%]). HIPEC was not associated with a higher risk of worse surgical outcomes except with mitomycin, with higher odds of morbidity (1.99; 95% CI, 1.25-3.19; P = .004). HIPEC was associated with a significantly better overall survival in all subsets (adjusted hazard ratios [HRs], 0.60-0.68, with 95% CIs not crossing 1.00). The weighted 5-year overall survival was 57.8% (95% CI, 50.8%-65.7%) vs 46.2% (95% CI, 40.3%-52.8%) for CRS-HIPEC and CRS alone, respectively (weighted HR, 0.65; 95% CI, 0.50-0.83; P < .001; E-value, 2.03). Such prognostic advantage was associated with oxaliplatin plus fluorouracil-leucovorin (HR, 0.42; 95% CI, 0.19-0.93; P = .03) and cisplatin plus mitomycin (HR, 0.57; 95% CI, 0.42-0.78; P = .001) schedules. Conclusions and Relevance: In this cohort study, HIPEC was associated with better overall survival when performed after CRS in PMP, generally without adverse effects on surgical outcomes.

Upregulated Heat Shock Proteins After Hyperthermic Chemotherapy Point to Induced Cell Survival Mechanisms in Affected Tumor Cells From Peritoneal Carcinomatosis.

In patients with peritoneal carcinomatosis cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC) represents a promising treatment strategy. Here, we studied the role of hyperthermic chemotherapy on heat shock protein (HSP) expression and induction of tumor cell death and survival. HSP27, HSP70, and HSP90 combined with effects on tumor cell proliferation and chemosensitivity were analyzed in human colon cancer. Hyperthermic chemotherapy resulted in significant HSP27/HSP70 and HSP90 gene/protein overexpression in analyzed HT-29/SW480/SW620 colon cancer cells and peritoneal metastases from patients displaying amplified expression of proliferation markers, proliferating cell nuclear antigen and antiapoptotic protein Bcl-xL. Moreover, functionally increased chemoresistance against 5-fluorouracil/mitomycin C and oxaliplatin after hyperthermic chemotherapy points to induced survival mechanisms in cancer cells. In conclusion, the results indicate that intracellular HSP-associated antiapoptotic and proliferative effects after hyperthermic chemotherapy negatively influence beneficial effects of hyperthermic chemotherapy-induced cell death. Therefore, blocking HSPs could be a promising strategy to further improve the rate of tumor cell death and outcome of patients undergoing HIPEC therapy.

The American Society of Peritoneal Surface Malignancies evaluation of HIPEC with Mitomycin C versus Oxaliplatin in 539 patients with colon cancer undergoing a complete cytoreductive surgery.

BACKGROUND: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) are gaining acceptance as treatment for selected patients with colorectal cancer with peritoneal carcinomatosis (CRCPC). Tremendous variations exist in the HIPEC delivery. METHODS: The American Society of Peritoneal Surface Malignancies (ASPSM) examined the overall survival in patients with CRCPC who underwent a complete cytoreduction and HIPEC with Oxaliplatin vs. Mitomycin C (MMC), stratifying them by the Peritoneal Surface Disease Severity Score (PSDSS). RESULTS: Median overall survival (OS) of 539 patients with complete cytoreduction was 32.6 months, 32.7 months for the MMC group and 31.4 months for the Oxaliplatin group (P = 0.925). However, when stratified by PSDSS, median OS rates in PSDSS I/II patients were 54.3 months in those receiving MMC vs. 28.2 months in those receiving oxaliplatin (P = 0.012), whereas in PSDSS III/IV patients, median OS rates were 19.4 months in those receiving MMC vs. 30.4 months in those receiving Oxaliplatin (P = 0.427). CONCLUSION: These data suggest that MMC might be a better agent for HIPEC delivery than Oxaliplatin in patients with CRCPC, favorable histologies and low burden of disease (PSDSS I/II) undergoing complete cytoreduction. Prospective studies are warranted, which stratify patients by their PSDSS and randomize them to HIPEC with MMC vs. Oxaliplatin.

The American Society of Peritoneal Surface Malignancies (ASPSM) Multiinstitution Evaluation of the Peritoneal Surface Disease Severity Score (PSDSS) in 1,013 Patients with Colorectal Cancer with Peritoneal Carcinomatosis.

BACKGROUND: Extensive clinical experience suggests that hyperthermic intraperitoneal chemotherapy (HIPEC) may play an important role in the management of colorectal cancer patients with peritoneal carcinomatosis (CRCPC). However, there remains no established nonsurgical process to rationally select patients for this management, either for inclusion/stratification in clinical trials or as a component of standard of care. The Peritoneal Surface Disease Severity Score (PSDSS) was introduced as a basis to improve patient selection. METHODS: The American Society of Peritoneal Surface Malignancies conducted a retrospective review of 1,013 CRCPC patients. The PSDSS was evaluated on 3 specific criteria obtained before surgery (symptoms, extent of peritoneal dissemination, and primary tumor histology). Overall survival was analyzed according to four tiers of disease severity, and a comparison was made between patients who underwent cytoreductive surgery + HIPEC and those who did not. RESULTS: The PSDSS was calculated on 884 patients (87 %). The median survival of 275 patients not undergoing CRS/HIPEC based on their PSDSS-I (n = 8), II (n = 80), III (n = 55), and IV (n = 132)-was 45, 19, 8, and 6 months, respectively. The median survival of 609 patients who underwent CRS/HIPEC based on their PSDSS-I (n = 75), II (n = 317), III (n = 82), and IV (n = 135)-was 86, 43, 29, and 28 months, respectively. CONCLUSIONS: These data support that the PSDSS, undertaken before surgery, is capable of defining CRCPC populations who have a statistically defined high or considerably lower likelihood of long-term survival after CRS/HIPEC. The PSDSS can be quite useful in the decision to enter CRCPC patients into, and their stratification within, clinical trials.

Hyperthermic intraperitoneal chemotherapy in patients with peritoneal carcinomatosis: role of heat shock proteins and dissecting effects of hyperthermia.

BACKGROUND: In patients with isolated peritoneal carcinomatosis (PC) of gastrointestinal cancer, hyperthermic intraperitoneal chemotherapy (HIPEC) represents a promising treatment option integrated into multimodal concepts. Heat shock proteins (HSP) seem to play a major role in cellular stress during HIPEC therapy. We analyzed differentially hyperthermic conditions and HSPs responsible for cell stress-mediated repair mechanisms in tumor tissues from patients who underwent HIPEC therapy and in an in vitro hyperthermic model. METHODS: Tumor tissues from our patient cohort with isolated PC were selected for further analysis when representative material was available before and after HIPEC therapy. To further dissect the role of HSPs under conditions of hyperthermia, gene and protein expression was additionally determined, together with cellular apoptosis and proliferation in human HT-29 colon cancer cells. RESULTS: Differently up-regulated HSP70/72 and HSP90 gene and protein expression was found in all investigated patient tumors. In vitro studies confirmed observations from clinical tumor analysis as underlying HSP-mediated cell stress mechanisms. Moreover, results from proliferation and apoptosis assays combined with differentiated HSP expression analysis demonstrated the relevance of preselecting specific target temperatures to achieve optimal toxic effects on remaining tumor cells in vivo. CONCLUSIONS: Therapeutic approaches like HIPEC to achieve antiproliferative and apoptosis-inducing cellular effects in patients with PC are negatively influenced by highly conserved HSP mechanisms in tumor cells. This study shows for the first time that specific hyperthermic conditions are necessary to be established to achieve optimal toxic effects on tumor cells during HIPEC therapy, a finding that opens potentially new therapeutic strategies.

Summary of current therapeutic options for peritoneal metastases from colorectal cancer.

BACKGROUND: Peritoneal metastases remain an under addressed problem for which this review serves to investigate the efficacy of systemic chemotherapy and radical surgical treatments in this disease entity. METHODS: The literature between 1995 and June 2009 was surveyed systematically through a review of published studies on the treatment outcomes of metastatic colorectal cancer to the peritoneum on the Medline and PubMed databases. RESULTS: A total of 2,492 patients from 19 studies were reviewed. One thousand and eighty-four patients treated with complete cytoreductive surgery (CCS) and hyperthermic intraperitoneal chemotherapy (HIPEC) and 1,408 patients were treated with palliative surgery and/or systemic chemotherapy. For CCS HIPEC, the overall survival ranged between 20 and 63 (median 33) months, and 5-year survival ranged between 17% and 51% (median 40%). For palliative surgery and/or systemic chemotherapy, the overall survival ranged between 5 and 24 (median 12.5) months, and 5-year survival ranged between 13% and 22% (median 13%). CONCLUSION: Systemic therapies have not proved effective and randomised clinical trials have not sufficiently addressed patient subpopulations with metastatic disease of this entity. Current evidence have demonstrated the efficacy associated with CCS HIPEC for which should now be embraced as the standard of care.

Early- and long-term outcome data of patients with pseudomyxoma peritonei from appendiceal origin treated by a strategy of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

PURPOSE: Pseudomyxoma peritonei (PMP) originating from an appendiceal mucinous neoplasm remains a biologically heterogeneous disease. The purpose of our study was to evaluate outcome and long-term survival after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) consolidated through an international registry study. PATIENTS AND METHODS: A retrospective multi-institutional registry was established through collaborative efforts of participating units affiliated with the Peritoneal Surface Oncology Group International. RESULTS: Two thousand two hundred ninety-eight patients from 16 specialized units underwent CRS for PMP. Treatment-related mortality was 2% and major operative complications occurred in 24% of patients. The median survival rate was 196 months (16.3 years) and the median progression-free survival rate was 98 months (8.2 years), with 10- and 15-year survival rates of 63% and 59%, respectively. Multivariate analysis identified prior chemotherapy treatment (P < .001), peritoneal mucinous carcinomatosis (PMCA) histopathologic subtype (P < .001), major postoperative complications (P = .008), high peritoneal cancer index (P = .013), debulking surgery (completeness of cytoreduction [CCR], 2 or 3; P < .001), and not using HIPEC (P = .030) as independent predictors for a poorer progression-free survival. Older age (P = .006), major postoperative complications (P < .001), debulking surgery (CCR 2 or 3; P < .001), prior chemotherapy treatment (P = .001), and PMCA histopathologic subtype (P < .001) were independent predictors of a poorer overall survival. CONCLUSION: The combined modality strategy for PMP may be performed safely with acceptable morbidity and mortality in a specialized unit setting with 63% of patients surviving beyond 10 years. Minimizing nondefinitive operative and systemic chemotherapy treatments before definitive cytoreduction may facilitate the feasibility and improve the outcome of this therapy to achieve long-term survival. Optimal cytoreduction achieves the best outcomes.

Surgery for colorectal peritoneal carcinomatosis.

Peritoneal carcinomatosis occurs in patients with advanced gastrointestinal and gynecological malignancies and also in patients who experience recurrence after treatment failure of the primary tumor. Malignant disease in the peritoneal cavity is a morbid and significant predictor of a diminished survival in a cancer patient. Systemic chemotherapy alone will not be adequate to palliate or treat patients with peritoneal carcinomatosis. Cytoreductive surgery is a new surgical technique that is performed using peritonectomy procedures to allow total eradication of peritoneal tumors. Intraperitoneal chemotherapy regimens such as intraoperative hyperthermic intraperitoneal chemotherapy (HIPEC) and early postoperative intraperitoneal chemotherapy (EPIC) are effective adjuvant treatment to treat the minimal residual disease after cytoreductive surgery to reduce the risk of locoregional recurrence. A substantial body of evidence available in the current literature has documented the survival benefits of combining cytoreductive surgery and intraperitoneal chemotherapy to treat a previously fatal phase of malignancy. This review provides a summary of the developments in the understanding and treatment of peritoneal surface malignancy from colorectal cancer.

Optimizing of preoperative computed tomography for diagnosis in patients with peritoneal carcinomatosis.

BACKGROUND AND OBJECTIVE: This study evaluates whether Computer Tomography is an effective procedure for preoperative staging of patients with Peritoneal Carcinomatosis. METHOD: A sample of 37 patients was analyzed with contrast enhanced abdominal Computer Tomography, followed by surgical staging. All Computer Tomography scans were evaluated 3 times by 2 radiologists with one radiologist reviewing 2 times. The efficacy of Computer Tomography was evaluated using the Spearman correlation coefficient. Correlations were analyzed by abdominopelvic region to assess results of the Peritoneal Carcinomatosis Index (PCI) aggregating the 13 regions. Surgical findings were compared to radiological findings. RESULTS: Results indicate high correlations between the surgical and radiological Peritoneal Carcinomatosis Indices. Analyses of the intra-class correlation between the first and second reading of one radiologist suggest high intra-observer reliability. Correlations by abdominopelvic region show higher values in the upper and middle regions and relatively lower values in the lower regions and the small bowel (correlation coefficients range between 0.418 and 0.726, p < 0.010; sensitivities range between 50% and 96%; and specificities range between 62% and 100%). CONCLUSION: Computer Tomography represents an effective procedure in the preoperative staging of patients with PC. However, results by abdominopelvic region show lower correlation, therefore suggest lower efficacy. These results are supported by analyses of sensitivity and accuracy by lesion size. This suggests that Computer Tomography is an effective procedure for pre-operative staging but less for determining a tumor's accurate extent.

Development of a Bayesian Belief Network Model for personalized prognostic risk assessment in colon carcinomatosis.

Multimodality therapy in selected patients with peritoneal carcinomatosis is gaining acceptance. Treatment-directing decision support tools are needed to individualize care and select patients best suited for cytoreductive surgery +/- hyperthermic intraperitoneal chemotherapy (CRS +/- HIPEC). The purpose of this study is to develop a predictive model that could support surgical decisions in patients with colon carcinomatosis. Fifty-three patients were enrolled in a prospective study collecting 31 clinical-pathological, treatment-related, and outcome data. The population was characterized by disease presentation, performance status, extent of peritoneal cancer (Peritoneal Cancer Index, PCI), primary tumor histology, and nodal staging. These preoperative parameters were analyzed using step-wise machine-learned Bayesian Belief Networks (BBN) to develop a predictive model for overall survival (OS) in patients considered for CRS +/- HIPEC. Area-under-the-curve from receiver-operating-characteristics curves of OS predictions was calculated to determine the model's positive and negative predictive value. Model structure defined three predictors of OS: severity of symptoms (performance status), PCI, and ability to undergo CRS +/- HIPEC. Patients with PCI < 10, resectable disease, and excellent performance status who underwent CRS +/- HIPEC had 89 per cent probability of survival compared with 4 per cent for those with poor performance status, PCI > 20, who were not considered surgical candidates. Cross validation of the BBN model robustly classified OS (area-under-the-curve = 0.71). The model's positive predictive value and negative predictive value are 63.3 per cent and 68.3 per cent, respectively. This exploratory study supports the utility of Bayesian classification for developing decision support tools, which assess case-specific relative risk for a given patient for oncological outcomes based on clinically relevant classifiers of survival. Further prospective studies to validate the BBN model-derived prognostic assessment tool are warranted.

Single-port laparoscopic cholecystectomy with the x-cone: a feasibility study in 9 pigs.

OBJECTIVE: Virtually any port system for single-port laparoscopic surgery is for single usage only. The aim of this study was to trial the novel and completely reusable port X-Cone in order to perform a cholecystectomy by one infraumbilical incision. METHODS: Single access cholecystectomies were performed in 9 anesthetized domestic pigs in nonsurvival studies. Only one infraumbilical incision was performed for placing the reusable, multichannel steel port system. A newly developed angulated forceps was used besides regularly used instruments in laparoscopic surgery. RESULTS: The gallbladder was successfully removed in 9 pigs. At postmortem examination, the clips placed on the cystic duct and the cystic artery. No bile leakage was found at the operative field. CONCLUSION: Single-port cholecystectomy with the reusable X-Cone single-port system is safe and feasible. No additional incisions were needed. The system is ergonomically designed, easy to handle, and the learning curve for cholecystectomy is steep.

Influence of modern systemic therapies as adjunct to cytoreduction and perioperative intraperitoneal chemotherapy for patients with colorectal peritoneal carcinomatosis: a multicenter study.

BACKGROUND: To evaluate the role of modern systemic therapies and its role as palliative or curative therapy for patients with colorectal peritoneal carcinomatosis with an emphasis on patient selection with the colorectal Peritoneal Surface Disease Severity Score (PSDSS). METHODS: From three specialized treatment centers, patients with colorectal peritoneal carcinomatosis were identified between December 1988 to December 2009 to receive best supportive care, standard, or modern systemic therapies. Intent was classified as palliative or curative (if treated by cytoreductive surgery combined with perioperative intraperitoneal chemotherapy). Patients were stratified according to the PSDSS. Survival was estimated by the Kaplan-Meier method. RESULTS: Palliative and curative treatment achieved a median survival of 9 (95% confidence interval [95% CI] 5.9-12.8) and 38 (95% CI 30.2-45.2) months, respectively (P < 0.001). The type of chemotherapy in the palliative and curative group influenced outcome (P < 0.001, P = 0.011, respectively). In the palliative group, PSDSS I/II had a median survival of 24 (95% CI 15.6-32.6) and PSDSS III/IV had a median survival of 6 (95% CI 4.9-8.0) months (P < 0.001). In the curative group, PSDSS I/II had a median survival of 49 (95% CI 40.0-58.3) and PSDSS III/IV had a median survival of 31 (95% CI 20.4-40.9) months (P = 0.002). CONCLUSIONS: Modern systemic therapies were associated with improved outcome in patients with colorectal peritoneal carcinomatosis treated systemically alone or with cytoreductive surgery combined with perioperative intraperitoneal chemotherapy. Preoperative evaluation with the PSDSS may improve patient selection and optimize outcomes.

Evaluation of best supportive care and systemic chemotherapy as treatment stratified according to the retrospective peritoneal surface disease severity score (PSDSS) for peritoneal carcinomatosis of colorectal origin.

BACKGROUND: We evaluate the long-term survival of patients with peritoneal carcinomatosis (PC) treated with systemic chemotherapy regimens, and the impact of the of the retrospective peritoneal disease severity score (PSDSS) on outcomes. METHODS: One hundred sixty-seven consecutive patients treated with PC from colorectal cancer between years 1987-2006 were identified from a prospective institutional database. These patients either received no chemotherapy, 5-FU/Leucovorin or Oxaliplatin/Irinotecan-based chemotherapy. Stratification was made according to the retrospective PSDSS that classifies PC patients based on clinically relevant factors. Survival analysis was performed using the Kaplan-Meier method and comparison with the log-rank test. RESULTS: Median survival was 5 months (95% CI, 3-7 months) for patients who had no chemotherapy, 11 months (95% CI, 6-9 months) for patients treated with 5 FU/LV, and 12 months (95% CI, 4-20 months) for patients treated with Oxaliplatin/Irinotecan-based chemotherapy. Survival differed between patients treated with chemotherapy compared to those patients who did not receive chemotherapy (p = 0.026). PSDSS staging was identified as an independent predictor for survival on multivariate analysis [RR 2.8 (95%CI 1.5-5.4); p < 0.001]. CONCLUSION: A trend towards improved outcomes is demonstrated from treatment of patients with PC from colorectal cancer using modern systemic chemotherapy. The PSDSS appears to be a useful tool in patient selection and prognostication in PC of colorectal origin.

The importance of radiological controls of anastomoses after upper gastrointestinal tract surgery - a retrospective cohort study.

INTRODUCTION: This study was designed to analyze whether routine radiological controls of anastomoses in the upper gastrointestinal tract an early detection of anastomotic leaks. PATIENTS AND METHODS: 135 patients who underwent upper gastrointestinal tract surgery were retrospectively analyzed. Patients in the first group (n = 55) underwent routine radiological control of the anastomoses. In the second group (n = 80) the radiological control was only performed in case of clinical symptoms or signs of anastomotic leaks. RESULTS: The incidence of anastomotic leaks in the patients seen by us was 5.2%, equivalent to 7 of 135 patients In Group 1 leaks were seen in 4 of 55 patients (7,2%) in group 2 leaks were seen in 3 of 80 (3,8%). The radiological control of the anastomoses with contrast swallow showed the leakage in two cases. Twice the results were false negative. The sensitivity of computed tomography was 100%. DISCUSSION: Routine radiological control of anastomoses with contrast swallow only has low sensitivity. This procedure should not be performed routinely any more.The radiological control should be used in cases with signs of anastomotic leakage or with postoperatively impaired gastrointestinal passage.

Critical analysis of 33 patients with peritoneal carcinomatosis secondary to colorectal and appendiceal signet ring cell carcinoma.

BACKGROUND: Primary signet-ring cell carcinoma (SRC) of colorectal and appendiceal origin is a rare entity with an aggressive biology and clinical behavior. The majority of patients develop peritoneal carcinomatosis (PC) early in the disease. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) may potentially improve survival. METHODS: An observational study of 33 patients with SRC of colorectal or appendiceal origin was identified through a retrospective review of two peritoneal surface malignancy databases between January 1997 and December 2008. Survival analysis was performed using the Kaplan-Meier method. RESULTS: Thirty-three patients (18 women (55%); mean age at diagnosis of carcinomatosis, 49 (standard deviation = 12) years) were identified to have SRC, with 15 cases of colorectal and 18 of appendiceal origin. For patients with colonic SRC who underwent complete CRS and HIPEC versus systemic chemotherapy only, the median survival was 13 and 18 months (P = 0.75). For patients with appendiceal SRC who underwent complete CRS and HIPEC versus systemic chemotherapy only, the median survival was 27 and 15 months (P = 0.12). CONCLUSIONS: There seems to be less survival benefits after a complete CRS and HIPEC as a curative treatment for PC from colorectal SRC compared with that for non-SRC colorectal adenocarcinoma. However, in patients with appendiceal SRC, long-term survival is a reality after treatment.

Evaluation of a peritoneal surface disease severity score in patients with colon cancer with peritoneal carcinomatosis.

INTRODUCTION: Systemic therapy and cytoreduction (CRS) with hyperthermic intra-peritoneal chemotherapy (HIPEC) may benefit selected patients with carcinomatosis from colon cancer (PC). This study presents the results of a consecutive series of patients evaluated under a single strategy. PATIENTS AND METHODS: Forty patients with PC referred for CRS were evaluated. Evaluation of their treatment was determined according to disease severity scored on a 3-point scale including: (1) symptoms, (2) extent of peritoneal dissemination (PCI), and (3) primary tumor histology. Overall survival (OS) was analyzed using Kaplan-Meier product-limit method and log rank testing according to four tiers of estimated disease severity based on the above parameters. RESULTS: For patients with disease severity score I, II, III, and IV, 2-year OS following treatment was 100%, 80%, 80%, and 0%, respectively. Median OS with most advanced disease (IV: n = 20) was 5 months versus 36 months for disease of lesser severity (I-III: n = 20; P < 0.001; RR = 0.2; 95%CI 0.1-0.5). Advanced disease (IV) was an independent predictor of adverse outcome on multivariate analysis with 2.6-fold increased likelihood of mortality. CONCLUSION: A treatment strategy based on disease severity determined at time of diagnosis, stratifies patients into prognostic groups and may improve selection of patients for appropriate therapy.

Histological response of peritoneal carcinomatosis after hyperthermic intraperitoneal chemoperfusion (HIPEC) in experimental investigations.

BACKGROUND: In selected patients with peritoneal carcinomatosis from colorectal cancer prognosis can be improved by hyperthermic intraperitoneal chemotherapy (HIPEC) after cytoreductive surgery. The aim of this study was to evaluate the tumor response of peritoneal carcinomatosis in tumor-bearing rats treated with HIPEC. METHODS: CC531 colon carcinoma (2,5 x 106 cells), implanted intraperitoneally in Wag/Rija rats, was treated by hyperthermic intraperitoneal chemotherapy. After 10 days of tumor growth the animals were randomized into five groups of six animals each: group I: control (n = 6), group II: sham operated animals (n = 6), group III: hyperthermic intraperitoneal perfusion (HIP) without cytostatic drugs, group IV: HIPEC with mitomycin C in a concentration of 15 mg/m2 (n = 6), group V: mitomycin C i.p. alone in a concentration of 10 mg/m2 (n = 6). After 10 days the extent of tumor spread and histological outcome were analysed by autopsy. RESULTS: All control animals developed extensive intraperitoneal tumor growth. Histological tumor load was significantly reduced in group III and group V and was lowest in group IV. In group II tumor load was significantly higher than in group I. Implanted metastases were significantly decreased in group IV compared with group I and group II. CONCLUSION: These findings indicate that HIPEC is an effective treatment for peritoneal carcinomatosis in this animal model. HIPEC reduced macroscopic and microscopic intraperitoneal tumor spread.

A new survival model for hyperthermic intraperitoneal chemotherapy (HIPEC) in tumor-bearing rats in the treatment of peritoneal carcinomatosis.

BACKGROUND: Cytoreduction followed by hyperthermic intraperitoneal chemotherapy (HIPEC) improves survival in patients with peritoneal carcinomatosis of colorectal origin. Animal models are important in the evaluation of new treatment modalities. The purpose of this study was to devise an experimental setting which can be routinely used for the investigation of HIPEC in peritoneal carcinomatosis. METHODS: A new peritoneal perfusion system in tumor bearing rats were tested. For this purpose CC531 colon carcinoma cells were implanted intraperitoneally in Wag/Rija rats. After 10 days of tumor growth the animals were randomized into three groups of six animals each: group 1: control (n = 6), group 2: HIPEC with mitomycin C in a concentration of 15 mg/m2 (n = 6), group III: mitomycin C i.p. as monotherapy in a concentration of 10 mg/m2 (n = 6). After 10 days, total tumor weight and the extent of tumor spread, as classified by the modified Peritoneal Cancer Index (PCI), were assessed by autopsy of the animals. RESULTS: No postoperative deaths were observed. Conjunctivitis, lethargy and loss of appetite were the main side effects in the HIPEC group. No severe locoregional or systemic toxity was observed. All control animals developed massive tumor growth. Tumor load was significantly reduced in the treatment group and was lowest in group II. CONCLUSION: The combination of hyperthermia with MMC resulted in an increased tumoricidal effect in the rat model. The presented model provides an opportunity to study the mechanism and effect of hyperthermic intraperitoneal chemotherapy and new drugs for this treatment modality.

The impact of surgery and mild hyperthermia on tumor response and angioneogenesis of malignant melanoma in a rat perfusion model.

BACKGROUND: The aim of this experimental study was to determine the effect of mild hyperthermia on tumor response and angioneogenesis in an isolated limb perfusion model with a human melanoma xenograft. METHODS: A human melanoma xenograft was implanted into the hindlimbs of 30 athymic nude rats. The animals were randomized into five groups: group I: control, group II: sham group, group III: external hyperthermia with a tissue temperature of 41.5 degrees C for 30 minutes without ILP, group IV: normothermic ILP (tissue temperature 37 degrees C for 30 minutes, group V: hyperthermic ILP (tissue temperature 41.5 degrees C for 30 minutes). Tumor response was evaluated by tumor size determination and immunohistochemical analysis 6 weeks postoperatively. Tissue sections were investigated for expression of CD34 and basic fibroblast growth factor (bFGF). RESULTS: Average tumor volumes of the controls (I) increased from 105 mm3 to 1388 mm3. In the sham operated group (II) tumor volumes were significantly larger than in group I. Tumor volumes in group IV were significantly smaller than in group I and lowest in group V. There were no significant differences in size between group I and group III after six weeks. In group III and IV each, 5 animals showed tumor progression and one had a partial tumor response. In group V only 2 animals showed tumor progression. Immunhistochemical analysis of the tissue sections demonstrated that angioneogenesis was more pronounced in group II than in group I and less pronounced in group IV and V compared with group I. CONCLUSIONS: Our results suggest that even a surgical manipulation such as a skin incision promotes tumor growth, probably by induction of growth factors like bFGF. External hyperthermia of 41.5 degrees C tissue temperature for 30 minutes only has no impact on tumor growth and angioneogenesis in vivo.