Impact of Primary Tumor Location and Genomic Alterations on Survival Following Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemoperfusion for Colorectal Peritoneal Metastases.

BACKGROUND: Colorectal cancer leads to peritoneal metastases (CRPM) in 10% of cases. Cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC) improves survival. Primary tumor location and abnormalities in RAS, BRAF, and mismatch repair/microsatellite stability (MMR/MSI) may affect post-CRS-HIPEC survival, but studies have not been consistent. We estimated the effects of primary tumor site and genomic alterations on post-CRS-HIPEC survival. METHODS: This retrospective cohort study included CRS-HIPEC cases for CRPM at a high-volume center from 2001 to 2020. Next-generation sequencing and microsatellite testing defined the RAS, BRAF, and MMR/MSI genotypes. Adjusted effects of tumor sidedness and genomics on survival were evaluated using a multivariable Cox proportional hazards model. We analyzed these variables' effects on progression-free survival and the effects of immune checkpoint-inhibitors. RESULTS: A total of 250 patients underwent CRS-HIPEC with testing for RAS, BRAF, and MMR/MSI; 50.8% of patients were RAS-mutated, 12.4% were BRAF-mutated, and 6.8% were deficient-MMR/MSI-high (dMMR/MSI-H). Genomic alterations predominated in right-sided cancers. After adjustment for comorbidities and oncological and perioperative variables, rectal origin [hazard ratio (HR) 1.9, p = 0.01], RAS mutation (HR 1.6, p = 0.01), and BRAF mutation (HR 1.7, p = 0.05) were associated with worse survival. RAS mutation was also associated with shorter progression-free survival (HR 1.6, p = 0.01 at 6 months post-operatively), and dMMR/MSI-H status was associated with superior survival (HR 0.3, p = 0.01 at 2 years). dMMR/MSI-H patients receiving immune checkpoint-inhibitors trended toward superior survival. CONCLUSIONS: Rectal origin, RAS mutations, and BRAF mutations are each associated with poorer survival after CRS-HIPEC for CRPM. Patients with CRPM and dMMR/MSI-H status have superior survival. Further research should evaluate benefits of immune checkpoint-inhibitors in this subgroup.

Improved chemosensitivity following mucolytic therapy in patient-derived models of mucinous appendix cancer.

Abundant intraperitoneal (IP) accumulation of extracellular mucus in patients with appendiceal mucinous carcinoma peritonei (MCP) causes compressive organ dysfunction and prevents delivery of chemotherapeutic drugs to cancer cells. We hypothesized that reducing extracellular mucus would decrease tumor-related symptoms and improve chemotherapeutic effect in patient-derived models of MCP. Mucolysis was achieved using a combination of bromelain (BRO) and N-acetylcysteine (NAC). Ex vivo experiments of mucolysis and chemotherapeutic drug delivery/effect were conducted with MCP and non-MCP tissue explants. In vivo experiments were performed in mouse and rat patient-derived xenograft (PDX) models of early and late (advanced) MCP. MCP tumor explants were less chemosensitive than non-MCP explants. Chronic IP administration of BRO + NAC in a mouse PDX model of early MCP and a rat PDX model of late (advanced) MCP converted solid mucinous tumors into mucinous ascites (mucolysis) that could be drained via a percutaneous catheter (rat model only), significantly reduced solid mucinous tumor growth and improved the efficacy of chemotherapeutic drugs. Combination of BRO + NAC efficiently lyses extracellular mucus in clinically relevant models of MCP. Conversion of solid mucinous tumors into mucinous ascites decreases tumor bulk and allows for minimally invasive drainage of liquified tumors. Lysis of extracellular mucus removes the protective mucinous coating surrounding cancer cells and improves chemotherapeutic drug delivery/efficacy in cancer cells. Our data provide a preclinical rationale for the clinical evaluation of BRO + NAC as a therapeutic strategy for MCP.

Surveillance of Low-Grade Appendiceal Mucinous Neoplasms With Peritoneal Metastases After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: Are 5 Years Enough? A Multisite Experience.

BACKGROUND: Low-grade appendiceal mucinous neoplasms (LAMNs) are tumors that often present with widespread mucin in the peritoneal cavity (pseudomyxoma peritonei [PMP]). Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are effective treatment, but no published recommendations exist regarding surveillance. METHODS: Data from prospective databases of patients who underwent CRS-HIPEC from 2001 to 2017 at two high-volume institutions were retrospectively analyzed. Patients who underwent complete CRS-HIPEC for PMP secondary to LAMN were included in the analysis. Pathologic examination confirmed the diagnosis of LAMN. Cases of mucinous adenocarcinomas and neuroendocrine tumors (goblet cell carcinoids) were excluded. RESULTS: The study enrolled 156 patients. The median peritoneal cancer index (PCI) was 18 (interquartile range IQR1-3, 12-23), and 125 patients (80.1%) had a CC0 cytoreduction. According to American Joint Committee on Cancer (AJCC) grading, 152 patients (97.4%) presented with acellular mucin or G1 implants, 2 patients (1.3%) presented with G2 disease, and 2 patients (1.3%) presented with G3 disease. During the follow-up period (median, 45 months; IQR1-3 23-76 months), 23 patients (14.7%) experienced recurrence. All the recurrences were peritoneal and occurred within 5 years. The 1-, 3-, and 5-year disease-free survival (DFS) rates were respectively 95.5%, 83.4%, and 78.3%. Univariate Cox regression analysis showed that higher PCI scores (p < 0.001), a CC1 cytoreduction (p = 0.005), and higher preoperative levels of carcinoembryonic antigen (CEA) (p = 0.012) and CA-125 (p = 0.032) correlated with a shorter DFS. Only higher PCI scores independently predicted earlier recurrences (p < 0.001). CONCLUSION: Most patients had recurrence within 3 years after CRS-HIPEC, and none after 5 years. High PCI was the only independently significant variable. The study findings support intensive surveillance (every 3-6 months) with tumor markers and imaging methods during the first 3 years, and annual surveillance thereafter, with follow-up assessment after 5 years yielding limited benefit.

Discrimination of low- and high-grade appendiceal mucinous neoplasms by targeted sequencing of cancer-related variants.

DNA was obtained from matching micro-dissected, primary tumor cells, paired metastases, and peripheral blood mononuclear cells (germline) from patients with appendiceal mucinous neoplasms. We compared specimens from patient cohorts comprising low-grade adenomucinous neoplasm versus high-grade mucinous adenocarcinoma using a targeted, amplicon sequencing panel of 409 cancer related genes (Ion Torrent Comprehensive Cancer Panel, Thermo-Fisher, Waltham, MA). Copy number variants, single nucleotide variants and small insertions/deletions were identified using a multiplex algorithm pipeline (GATK, VarScan2, MuTect2, SIFT, SIFT-INDEL, PolyPhen-2, Provean). There were significantly more damaging variants in high-grade versus low-grade tumor cohorts. Both cohorts contained damaging, heterozygous germline variants (catenin ß1; notch receptor 1 and 4) in pathways associated with cell-lineage specification (WNT, NOTCH). Damaging, somatic KRAS proto-oncogene, GTPase mutations were present in both cohorts, while somatic GNAS complex locus mutations were confined to low-grade neoplasms. Variants predominantly affected transcription factors, kinases, and stem cell signaling molecules in canonical pathways including epithelial to mesenchymal transition, stem cell pluripotency, p53, PTEN, and NF-қB signaling pathways. High-grade tumors demonstrated MYC proto-oncogene, bHLH transcription factor (MYC) and death domain associated protein (DAXX) amplification and damaging somatic variants in tumor protein p53 (TP53), likely to amplify an aggressive phenotype. Damaging APC, WNT signaling pathway regulator (APC) deletions were identified in metastatic tissue of both cohorts suggesting a role in invasive disease. Our data suggest that germline dysregulation of WNT and/or NOTCH pathways predisposes patients toward a secretory cell phenotype (i.e., goblet-like cells) upon acquisition of somatic KRAS mutations. Additional somatically acquired variants activating oncogenes MYC and DAXX and inhibiting the critical tumor suppressor, tumor protein TP53, were consistent with manifestation of a high-grade phenotype. These additional changes within the epithelial to mesenchymal transition signaling network (WNT, NOTCH, RAS/ERK/PI3K, PTEN, NF-қB), produce aggressive high-grade tumor characteristics by actively driving cells towards dedifferentiation, proliferation, and migration.

Repeat Cytoreductive Surgery-Hyperthermic Intraperitoneal Chemoperfusion is Feasible and Offers Survival Benefit in Select Patients with Peritoneal Metastases.

INTRODUCTION: We hypothesized that repeat cytoreductive surgery-hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC) for peritoneal metastases (PM) may be associated with suboptimal resection, more frequent postoperative complications, and worse oncologic outcomes. METHODS: Using a prospectively maintained database, we compared clinicopathologic, perioperative, and oncologic outcome data in patients undergoing single or repeat CRS-HIPEC procedures. The Kaplan-Meier method was used to estimate survival. Multivariate analyses identified associations with perioperative and oncologic outcomes. RESULTS: Of the 1294 patients undergoing CRS-HIPEC procedures at our institution, only one CRS-HIPEC procedure (single HIPEC cohort) was performed in 1169 patients (90.3%), whereas 125 patients (9.7%) underwent repeat CRS-HIPEC procedures (repeat HIPEC cohort). Of the 1440 CRS-HIPEC procedures at our institution, a first CRS-HIPEC procedure was performed in 1294 patients (89.9%), whereas subsequent second, third, and fourth CRS-HIPEC procedures were performed in 125 patients (8.7%), 18 patients (1.3%), and 3 patients (0.2%), respectively. Progression-free survival (PFS) following the second CRS-HIPEC procedure was negatively impacted by shorter PFS following the first CRS-HIPEC procedure, independent of other significant variables related to the second procedure, including completeness of cytoreduction and postoperative complications. Patients undergoing multiple CRS-HIPEC procedures were not at higher risk for suboptimal resection or postoperative complications and demonstrated equivalent PFS following each successive procedure compared to the first procedure. CONCLUSIONS: Repeat CRS-HIPEC procedures for PM were not associated with suboptimal perioperative and oncologic outcomes. Our data confirmed our ability to select patients appropriately for repeat CRS-HIPEC procedures.

Pleuropulmonary Recurrence Following Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemoperfusion for Appendiceal Pseudomyxoma Peritonei.

BACKGROUND: The aim of this study was to identify factors associated with pleuropulmonary disease recurrence following cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion (CRS/HIPEC) for appendiceal pseudomyxoma peritonei (PMP) and to evaluate the oncologic impact of pleuropulmonary disease recurrence compared with isolated peritoneal recurrence. METHODS: From a prospective database, we identified patients who developed pleuropulmonary recurrence, isolated peritoneal recurrence, or no recurrence following CRS/HIPEC for appendiceal PMP. Clinicopathologic, perioperative, and oncologic data associated with the index CRS/HIPEC procedure were reviewed. The Kaplan-Meier method was used to estimate survival. Multivariate analyses identified associations with recurrence and survival. RESULTS: Of 382 patients undergoing CRS/HIPEC, 61 (16%) developed pleuropulmonary recurrence. Patients who developed a pleuropulmonary recurrence were more likely to have high-grade (American Joint Committee on Cancer [AJCC] grade 2/3) tumors (74% vs. 56%, p = 0.02) and increased operative blood loss (1651 vs. 1201 ml, p = 0.05) and were more likely to have undergone diaphragm stripping/resection (79% vs. 48%, p < 0.01) compared with patients with an abdominal recurrence. In a multivariate analysis, pleuropulmonary recurrence after CRS/HIPEC was associated with diaphragm stripping/resection, incomplete cytoreduction, and higher AJCC tumor grade. There was a trend towards reduced survival in patients with pleuropulmonary recurrence compared with patients with isolated peritoneal recurrence (median overall survival 45 vs. 53 months, p = 0.87). CONCLUSION: Pleuropulmonary recurrence of appendiceal PMP following CRS/HIPEC is common and may negatively impact survival. Formal protocols for surveillance and therapeutic intervention need to be studied and implemented to improve oncologic outcomes.

Impact of Cellularity on Oncologic Outcomes Following Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemoperfusion for Pseudomyxoma Peritonei.

BACKGROUND: The Peritoneal Surface Oncology Group International (PSOGI) recommends pathologic reporting of tumor cellularity in patients with pseudomyxoma peritonei (PMP) undergoing cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC). We investigated the prognostic significance of PMP cellularity, or lack thereof (acellular mucin), following CRS-HIPEC. METHODS: We reviewed clinical data for 310 CRS-HIPEC procedures in low-grade (American Joint Committee on Cancer grade G1) PMP with acellular mucin (n = 19), scant cellularity (n = 30), or moderate cellularity (n = 242). Kaplan-Meier survival curves and multivariate Cox regression models identified prognostic factors affecting oncologic outcomes. RESULTS: Compared with patients with acellular mucin, those with scant and moderate cellularity had higher PCI and less-frequent complete macroscopic resection. After an estimated median follow-up of 49 months, 4 patients (14%) with scant cellularity and 127 patients (56%) with moderate cellularity progressed, while none of the patients with acellular mucin progressed. While the median progression-free survival (PFS) was not reached for patients with acellular mucin or scant cellularity (estimated 5-year PFS probability of 100 and 83%, respectively), patients with moderate cellularity demonstrated a median PFS of 32 months (estimated 5-year PFS probability of 27%). In a multivariate model, degree of disease cellularity, or lack thereof (acellular mucin), was an independent predictor of PFS but not overall survival. CONCLUSIONS: Early disease progression is unlikely in patients with acellular mucin undergoing CRS-HIPEC, as opposed to a 14% recurrence rate with scant cellularity. Thorough pathologic assessment for cellularity, or lack thereof (acellular mucin), is vital for accurate prognostication of disease progression for patients with low-grade PMP undergoing CRS-HIPEC.

Institutional Experience with Ostomies Created During Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemoperfusion.

BACKGROUND: Cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC) is a complex procedure that often requires ostomy creation to protect high-risk anastomoses. This study aimed to evaluate the authors' institutional experience with CRS-HIPEC-associated ostomies, determine predictors of ostomy creation and reversal, and assess their impact on survival. METHODS: The study analyzed clinicopathologic, perioperative, and oncologic data from a prospective database of 1435 CRS-HIPEC procedures for peritoneal metastases. The Kaplan-Meier method was used to estimate survival. Multivariate analyses identified associations with ostomy creation/reversal and survival. RESULTS: Ostomies were created in 34% of the patients, most commonly loop ileostomies (82%). Loop ileostomies were reversed in the majority of patients (83%), whereas non-loop ileostomies were infrequently reversed (< 10% reversal rate). In a multivariate logistic regression model, intermediate or high tumor grade, colectomy/proctectomy, longer operative time, and lower Charlson comorbidity index were associated with loop ileostomy creation, whereas incomplete macroscopic resection, colorectal histology, and major postoperative complications were associated with non-reversal of loop ileostomy. In a multivariate Cox proportional hazards model, intermediate or high tumor grade and non-reversal of loop ileostomy were associated with worse overall survival. CONCLUSIONS: Loop ileostomies were almost always reversed, whereas non-loop ileostomies were almost always permanent. Hospital readmissions for loop ileostomy-related complications were common. Therefore, formal outpatient protocols for prevention and management should be implemented. Non-reversal of loop ileostomy was associated with very poor survival.

Safety and efficacy of combined resection of colorectal peritoneal and liver metastases.

BACKGROUND: To determine if a select subgroup of patients with combined liver and peritoneal colorectal metastases would derive oncologic benefit from surgical resection as a component of multimodality treatment. MATERIALS AND METHODS: We retrospectively compared 32 patients with combined colorectal peritoneal and liver metastases (CRLM) and 173 patients with peritoneal metastases only (CRPM) undergoing cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC). Kaplan-Meier survival curves and multivariate Cox-regression models identified prognostic factors affecting survival. RESULTS: Major postoperative complications (Clavien-Dindo grades 3-5) occurred in 32% (CRLM) and 17% (CRPM) of patients (P = 0.08). After an estimated median follow-up from surgery of 57 mo, propensity score-adjusted median progression-free survival was 5.1 mo (CRLM) and 7.6 mo (CRPM), whereas median overall survival was 13 mo (CRLM) and 21 mo (CRPM). Multivariate Cox-regression analysis of the CRLM group identified number of liver metastases to be the only independent predictor of poor survival (hazard ratio: 2.3, P = 0.03), with a dramatic decrease in survival in patients with more than three liver metastases. CONCLUSIONS: Simultaneous resection of colorectal liver metastases at the time of cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion for peritoneal metastases may be associated with worse survival, especially in patients with more than three liver metastases.

Hyperthermic intraperitoneal chemoperfusion as a component of multimodality therapy for ovarian and primary peritoneal cancer.

BACKGROUND AND OBJECTIVES: The role of hyperthermic intraperitoneal chemoperfusion (HIPEC) in the multimodality treatment of ovarian peritoneal metastases (OPM) and primary peritoneal cancer (PPC) remains controversial. We hypothesized that cytoreductive surgery (CRS) and HIPEC would provide meaningful survival benefit without excessive morbidity. METHODS: We reviewed clinicopathologic and perioperative data following 96 CRS-HIPEC procedures for primary or recurrent OPM and PPC. Kaplan-Meier survival curves and multivariate Cox-regression models identified prognostic factors affecting oncologic outcomes. RESULTS: CRS-HIPEC was mostly performed for recurrent disease (56.3%) and high-grade serous carcinoma (72.9%). Platinum-based systemic chemotherapy was administered to 89.5% of patients, with 75.5% having platinum-sensitive disease at CRS-HIPEC. Complete macroscopic resection was achieved in 70.8% of patients. Clavien-Dindo grade 3/4 morbidity occurred in 23.4% of patients; three patients died within 60-days postoperatively. Median overall survival from diagnosis of peritoneal metastases and CRS-HIPEC was 78 and 38 months, respectively. Completeness of cytoreduction, pathologic subtype, and 30-day morbidity were independent predictors of survival in multiple regression analysis. CONCLUSIONS: Our study demonstrates promising survival data and supports the role of HIPEC in the multimodality treatment algorithm for primary or recurrent OPM and PPC. However definite indications and timing of HIPEC need to be clarified by prospective studies.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemoperfusion in Adolescent and Young Adults with Peritoneal Metastases.

BACKGROUND: Several studies suggest that young patients may derive less oncologic benefit from surgical resection of cancers compared with older patients. We hypothesized that young patients may have worse outcomes following cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion (CRS/HIPEC) for peritoneal metastases. METHODS: Perioperative and oncologic outcomes in adolescent and young adults (AYA), defined as younger than age 40 years (n = 135), undergoing CRS/HIPEC between 2001 and 2015 were reviewed and compared with middle-aged adults, defined as aged 40-65 years (n = 684). RESULTS: The two groups were similar with regards to perioperative characteristics except that AYA were more likely to be symptomatic at presentation (65.2 vs. 50.9%, p = 0.003), had lower Charleson comorbidity index (median 6 vs. 8, p < 0.001), were less likely to receive neoadjuvant chemotherapy (32.8 vs. 42.5%, p = 0.042), and had longer operative times (median 543 vs. 493 min, p = 0.010). Postoperative Clavien-Dindo grade 3-4 morbidity was lower in AYA (17 vs. 26%, p = 0.029), and they required fewer reoperations for complications (3.7 vs. 10.4%, p = 0.014). AYA had longer median overall survival (103.6 vs. 73.2 months, p = 0.053). In a multivariate Cox regression analysis, age was an independent predictor of improved overall survival [hazard ratio 0.705; 0.516-0.963, p = 0.028]. CONCLUSIONS: Young patients with peritoneal metastases derive similar benefits from CRS/HIPEC as middle-aged patients. Young age should not be a deterrent to consideration of CRS/HIPEC for peritoneal metastases.

Curative Surgical Resection as a Component of Multimodality Therapy for Peritoneal Metastases from Goblet Cell Carcinoids.

BACKGROUND: The impact of histopathologic features on oncologic outcomes for patients with peritoneal metastases from goblet cell carcinoid (GCC) undergoing multimodality therapy, including cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC), is unknown. METHODS: This study prospectively analyzed 43 patients with GCC undergoing CRS-HIPEC between 2005 and 2013. Pathology slides were re-reviewed to classify GCC into histologic subtypes according to the Tang classification. Kaplan-Meier survival curves and multivariate Cox-regression models identified prognostic factors affecting oncologic outcomes. RESULTS: The 43 patients in this study underwent 50 CRS-HIPEC procedures for peritoneal metastases from GCC, and the majority received neoadjuvant and/or adjuvant systemic chemotherapy. The GCC demonstrated an aggressive phenotype with frequent lymph node and peritoneal metastases without systemic dissemination. The majority of the patients had Tang B GCC. The estimated median overall survival times after surgery for the patients with Tang A, B, and C GCC were respectively 59, 22, and 13 months. In a multivariate Cox-regression analysis, poor survival was associated with patients who had Tang B or C GCC, those undergoing incomplete macroscopic resection, and those with symptoms at the time of CRS-HIPEC. The patients with Tang A GCC demonstrated oncologic outcomes similar to those with intermediate-grade (American Joint Committee on Cancer [AJCC] grade 2) disseminated mucinous appendiceal neoplasms, whereas the patients with Tang B and C GCC demonstrated survival rates similar to or worse than those with high-grade (AJCC grade 3) disseminated mucinous appendiceal neoplasms. CONCLUSIONS: Tang classification is an independent prognostic factor for poor survival after multimodality therapy for GCC. Patients with Tang C GCC demonstrate limited survival and are not ideal candidates for a surgical approach.

Oncologic Risk Stratification Following Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Appendiceal Carcinomatosis.

INTRODUCTION: Patients with peritoneal carcinomatosis (PC) of appendiceal origin demonstrate variable oncologic outcomes, despite aggressive cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). We sought to devise a prognostic risk stratification system for oncologic outcomes following CRS-HIPEC. METHODS: A total of 197 patients undergoing CRS-HIPEC for the treatment of appendiceal PC were reviewed from a prospective database. Kaplan-Meier survival curves and multivariate Cox regression models were used to identify prognostic factors affecting oncologic outcomes. Clinicopathologic variables affecting overall survival (OS) were utilized to develop a prognostic staging system and nomograms. RESULTS: Univariate and multivariate Cox regression analysis indicated that high-grade tumor histology, lymph node metastasis, and incomplete cytoreduction were high-risk features, adversely affecting OS. Patients were stratified on the presence of high-risk features as follows: low-risk patients had no risk factors (n = 102); intermediate-risk patients had one risk factor (n = 49); and high-risk patients had more than one risk factor (n = 46). Median OS for low-risk patients was not reached, and was 43 and 22 months for intermediate-risk and high-risk patients, respectively. Five-year OS was 72, 43, and 13 % for low-, intermediate- and high-risk patients, respectively (p < 0.0003 for low vs. intermediate risk, and p = 0.06 for intermediate vs. high risk). CONCLUSIONS: We propose a three-tier staging system for appendiceal PC following CRS-HIPEC, based on histologic grade, lymph node involvement, and completeness of cytoreduction. The presence of any one or more of these high-risk features significantly decreased survival in our single-institution database and provided the basis for a prognostic staging system and corresponding nomograms.

Outcomes of Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemoperfusion in Patients with High-Grade, High-Volume Disseminated Mucinous Appendiceal Neoplasms.

BACKGROUND: High-grade (HG) mucinous appendiceal neoplasms (MAN) have a worse prognosis than low-grade histology. Our objective was to assess the safety and efficacy of cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion (CRS/HIPEC) in patients with high-grade, high-volume (HG-HV) peritoneal metastases in whom the utility of this aggressive approach is controversial. METHODS: Prospectively collected perioperative data were compared between patients with peritoneal metastases from HG-HV MAN, defined as simplified peritoneal cancer index (SPCI) ≥12, and those with high-grade, low-volume (HG-LV; SPCI <12) disease. Kaplan-Meier curves and multivariate Cox regression models identified prognostic factors affecting oncologic outcomes. RESULTS: Overall, 54 patients with HG-HV and 43 with HG-LV peritoneal metastases underwent CRS/HIPEC. The HG-HV group had longer operative time, increased blood loss/transfusion, and increased intensive care unit length of stay (p < 0.05). Incomplete macroscopic cytoreduction (CC-1/2/3) was higher in the HG-HV group compared with the HG-LV group (68.5 vs. 32.6 %; p = 0.005). Patients with HG-HV disease demonstrated worse survival than those with HG-LV disease (overall survival [OS] 17 vs. 42 m, p = 0.009; time to progression (TTP) 10 vs. 14 m, p = 0.024). However, when complete macroscopic resection (CC-0) was achieved, the OS and progression-free survival of patients with HG-HV disease were comparable with HG-LV disease (OS 56 vs. 52 m, p = 0.728; TTP 20 vs. 19 m, p = 0.393). In a multivariate Cox proportional hazard regression model, CC-0 resection was the only significant predictor of improved survival for patients with HG-HV disease. CONCLUSIONS: Although patients with HG-HV peritoneal metastases from MAN have worse prognosis compared with patients with HG-LV disease, their survival is comparable when complete macroscopic cytoreduction is achieved.

Targeting hypoxia-mediated mucin 2 production as a therapeutic strategy for mucinous tumors.

Excessive accumulation of mucin 2 (MUC2; a gel-forming secreted mucin) protein in the peritoneal cavity is the major cause of morbidity and mortality in pseudomyxoma peritonei (PMP). Hypoxia (hypoxia-inducible factor-1α; HIF-1α) has been shown to regulate the expression of similar mucins (eg, MUC5AC). We hypothesized that hypoxia (HIF-1α) drives MUC2 expression in PMP and is therefore a novel target to reduce mucinous tumor growth. The regulation of MUC2 by 2% hypoxia (HIF-1α) was evaluated in MUC2-secreting LS174T cells. The effect of BAY 87-2243, an inhibitor of HIF-1α, on MUC2 expression and mucinous tumor growth was evaluated in LS174T cells, PMP explant tissue, and in a unique intraperitoneal murine xenograft model of PMP. In vitro exposure of LS174T cells to hypoxia increased MUC2 messenger RNA (mRNA) and protein expression and increased HIF-1α binding to the MUC2 promoter. Hypoxia-mediated MUC2 protein overexpression was downregulated by transfected HIF-1α small interfering RNA (siRNA) compared with scrambled siRNA in LS174T cells. BAY 87-2243 inhibited hypoxia-induced MUC2 mRNA and protein expression in LS174T cells and PMP explant tissue. In a murine xenograft model of PMP, chronic oral therapy with BAY 87-2243 inhibited mucinous tumor growth and MUC2, HIF-1α expression in the tumor tissue. Our data suggest that hypoxia (HIF-1α) induces MUC2 promoter activity to increase MUC2 expression. HIF-1α inhibition decreases MUC2 production and mucinous tumor growth, providing a preclinical rationale for the use of HIF-1α inhibitors to treat patients with PMP.

Institutional learning curve of cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion for peritoneal malignancies.

BACKGROUND: Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemoperfusion (HIPEC) is routinely used to treat certain peritoneal carcinomatoses (PC), but it can be associated with relatively high complication rates, prolonged hospital length of stay, and potential mortality. Our objective was to determine the learning curve (LC) of CRS/HIPEC in our high-volume institution. METHODS: A total of 370 patients with PC from mucinous appendiceal neoplasms (MAN = 282), malignant peritoneal mesothelioma (MPM = 60), and gastric cancer (GC = 24) were studied. Outcomes analyzed included incomplete cytoreduction (IC), severe morbidity (SM), 60-day mortality, progression-free survival (PFS), and overall survival (OS). Risk-adjusted sequential probability ratio test (RA-SPRT) was employed to assess the LC of CRS/HIPEC for IC and SM using prespecified odds ratio (OR) boundaries derived from previously published data. Risk adjusted-cumulative average probability (RA-CAP) was used to analyze 1-year PFS and 2-year OS. RESULTS: Complete cytoreduction, severe morbidity, and 60-day mortality were 84.2, 30, and 1.9 % respectively. Higher simplified peritoneal cancer index was the major independent risk factor for IC, whereas high-grade histology, IC, and diagnosis of MPM and GC (compared with MAN) were predictors of SM after CRS/HIPEC (p < 0.05). RA-SPRT showed that approximately 180 cases are needed to achieve the lowest risk of IC and SM. Ninety cases were needed to achieve a steady 1-year PFS and 2-year OS in RA-CAP plots. CONCLUSIONS: The completeness of cytoreduction, morbidity, and mortality rates for CRS/HIPEC at our institution are comparable to previously reported data. Approximately 180 and 90 procedures are required to improve operative and oncologic outcomes respectively.

A comparative analysis of postoperative pancreatic fistulas after surgery with and without hyperthermic intraperitoneal chemoperfusion.

BACKGROUND: Postoperative pancreatic fistulas (POPFs) are potentially morbid complications that often require therapeutic interventions. Distal pancreatectomy performed during cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemoperfusion (HIPEC) puts patients at risk for POPF. The authors hypothesized that POPFs are more severe after CRS/HIPEC than after pancreatectomy alone. METHODS: Clinicopathologic and perioperative details, including POPF by International Study Group of Pancreatic Fistula criteria (ISGPF), and oncologic outcomes for patients undergoing distal pancreatectomy during CRS/HIPEC for peritoneal carcinomatosis of appendiceal (n = 31) or colorectal (n = 23) origin (HIPEC group) were compared with those for patients undergoing minimally invasive or open distal pancreatectomy without HIPEC (n = 66) for locally resectable pancreatic adenocarcinoma (non-HIPEC group). RESULTS: The incidence of POPF was similar between the HIPEC and non-HIPEC groups (26 %). The severity of POPF according to the ISGPF criteria was significantly worse in the HIPEC group. The HIPEC patients had 13 grade B fistulas and 1 grade C fistula compared with 12 grade A fistulas and 4 grade B fistulas in the non-HIPEC group. The HIPEC patients with POPF did not differ in the extent of their CRS, peritoneal cancer index, length of hospital stay, or other postoperative complications from the the HIPEC patients without POPF. The HIPEC patients with colorectal carcinomatosis who experienced POPF had higher disease recurrence in the first year after CRS/HIPEC than those without POPF. CONCLUSION: The findings showed that POPFs are more severe when distal pancreatectomy is combined with CRS/HIPEC. Moreover, selective use of distal pancreatectomy is important during CRS/HIPEC because POPFs may increase early disease recurrence for patients with colorectal carcinomatosis.

Does obesity affect outcomes of cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion for disseminated mucinous appendiceal neoplasms?

BACKGROUND: Obesity has been described as a risk factor for surgical complications and may play a prominent role in the progression, recurrence, and survival rates of various cancers. Our objective was to investigate the impact of being overweight or obese on perioperative and oncologic outcomes after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemoperfusion (HIPEC) for peritoneal carcinomatosis (PC) from mucinous appendiceal neoplasms (MAN). METHODS: From a prospectively maintained database (2001-2010) of CRS/HIPEC for PC from MAN, we evaluated the body mass index (BMI) of patients, categorizing them into normal weight (NW < 25 kg/m(2)), overweight (OW = 25 to 29.9 kg/m(2)), and obese (OB ≥ 30 kg/m(2)). We compared the perioperative and oncologic outcomes among groups. RESULTS: Of the 282 patients in the database, 234 had BMI data available, and 81, 79, and 74 patients were categorized as NW, OW, and OB, respectively. Although there was a trend toward increased risk of overall complications, wound infections, deep vein thrombosis, respiratory and renal complications, and anastomotic leaks in the OW and OB groups, these differences only achieved statistical significance for renal (p = 0.03) and pulmonary (p = 0.02) complications in the OW and OB groups, respectively. The 5-year survival rate for NW, OW, and OB patients was 63.9, 48, and 54.4 %, respectively (p = 0.63). The median time to progression was 21.1 (NW), 21.7 (OW), and 23.9 (OB) months (p = 0.83). CONCLUSIONS: OW and OB patients may have an increased risk of renal and pulmonary complications, respectively. Obesity has no major impact on perioperative mortality and long-term oncologic outcomes in patients undergoing CRS/HIPEC for MAN.

Malignant peritoneal mesothelioma: prognostic factors and oncologic outcome analysis.

BACKGROUND: Most patients with malignant peritoneal mesothelioma (MPM) present with late-stage, unresectable disease that responds poorly to systemic chemotherapy while, at the same time, effective targeted therapies are lacking. We assessed the efficacy of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemoperfusion (HIPEC) in MPM. METHODS: We prospectively analyzed 65 patients with MPM undergoing CRS/HIPEC between 2001 and 2010. Kaplan-Meier survival curves and multivariate Cox-regression models identified prognostic factors affecting oncologic outcomes. RESULTS: Adequate CRS was achieved in 56 patients (CC-0 = 35; CC-1 = 21), and median simplified peritoneal cancer index (SPCI) was 12. Pathologic assessment revealed predominantly epithelioid histology (81 %) and biphasic histology (8 %), while lymph node involvement was uncommon (8 %). Major postoperative morbidity (grade III/IV) occurred in 23 patients (35 %), and 60-day mortality rate was 6 %. With median follow-up of 37 months, median overall survival was 46.2 months, with 1-, 2-, and 5-year overall survival probability of 77, 57, and 39 %, respectively. Median progression-free survival was 13.9 months, with 1-, 2-, and 5-year disease failure probability of 47, 68, and 83 %, respectively. In a multivariate Cox-regression model, age at surgery, SPCI >15, incomplete cytoreduction (CC-2/3), aggressive histology (epithelioid, biphasic), and postoperative sepsis were joint significant predictors of poor survival (chi square = 42.8; p = 0.00001), while age at surgery, SPCI >15, incomplete cytoreduction (CC-2/3), and aggressive histology (epithelioid, biphasic) were joint significant predictors of disease progression (Chi square = 30.6; p = 0.00001). CONCLUSIONS: Tumor histology, disease burden, and the ability to achieve adequate surgical cytoreduction are essential prognostic factors in MPM patients undergoing CRS/HIPEC.