Characterizing the Immune Environment in Peritoneal Carcinomatosis: Insights for Novel Immunotherapy Strategies.

BACKGROUND OR PURPOSE: Carcinomatosis, a distinct pattern of metastatic cancer in the peritoneal cavity, poses challenges for treatment and has limited therapeutic options. Understanding the immune environment of peritoneal surface malignancies is crucial for developing effective immunotherapeutic approaches. This study characterizes soluble immune mediators in the peritoneal fluid of patients with and without carcinomatosis to identify targets for novel treatment strategies. PATIENTS AND METHODS: Serum and peritoneal fluid samples were collected from surgical patients, and a multianalyte analysis was performed using the Luminex platform. Patient characteristics, tumor sites, and sample collection details were recorded. Soluble immune mediator levels were measured and compared between peritoneal fluid and serum samples and among clinical subgroups. Statistical analysis was conducted to assess differences in analyte concentrations and correlations between samples. RESULTS: There were 39 patients included in the study, with varying surgical indications. Significant differences were observed in soluble immune mediator levels between peritoneal fluid and serum, with peritoneal fluid exhibiting lower concentrations. Carcinomatosis was associated with elevated levels of proinflammatory mediators, including IL-6 and IL-8, while adaptive immune response markers were low in peritoneal fluid. CONCLUSIONS: The peritoneal immune microenvironment in carcinomatosis favors innate immunity, presenting a challenging environment for effective antitumor response. High levels of proinflammatory mediators suggest potential targets for intervention, such as the IL-6 axis, FGF2, IL-8, and CCL2; these could be explored as potential mitigators of malignant ascites and enhance anti-tumor immune responses. These findings provide valuable insights for developing immunotherapy strategies and improving outcomes in patients with peritoneal carcinomatosis.

Normal CEA Levels After Neoadjuvant Chemotherapy and Cytoreduction with Hyperthermic Intraperitoneal Chemoperfusion Predict Improved Survival from Colorectal Peritoneal Metastases.

BACKGROUND: Normal carcinoembryonic antigen (CEA) levels (≤ 2.5 ng/ml) after resection of localized colorectal cancer or liver metastases are associated with improved survival, however, these trends are understudied for colorectal peritoneal metastases (CRPM). PATIENTS AND METHODS: We conducted a retrospective single-institution study of patients with CRPM undergoing cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion (CRS/HIPEC) with and without neoadjuvant chemotherapy (NACT). CEA was measured before and after NACT and within 3 months after CRS/HIPEC. RESULTS: A total of 253 patients (mean age 55.3 years) with CRPM undergoing CRS/HIPEC had complete CEA data and 191 also underwent NACT with complete data. The median peritoneal carcinomatosis index score (PCI) of the overall cohort was 12 and 82.7% of patients had complete cytoreduction (CC0). In total, 64 (33.5%) patients had normal CEA levels after NACT with a median overall survival (OS) of 45.2 months compared with those with an elevated CEA (26.4 months, p = 0.004). Patients with normal CEA after NACT had a lower PCI found at the time of surgery than those with elevated CEA (10 versus 14, p < 0.001), 68 (26.9%) patients with an elevated preoperative CEA level experienced normalization after CRS/HIPEC, and 118 (46.6%) patients had elevated CEA after CRS/HIPEC. Patients who experienced normalization demonstrated similar OS to patients that had normal CEA levels pre- and post-surgery and improved OS compared with those with elevated postop CEA (median 41.9 versus 47 months versus 17.1 months, respectively, p < 0.001). CONCLUSIONS: Normal CEA levels after NACT and/or CRS/HIPEC are associated with improved survival for patients with CRPM. Patients that normalize CEA levels after surgery have similar survival to those with normal preoperative levels.

Detection of Residual Peritoneal Metastases Following Cytoreductive Surgery Using Pegsitacianine, a pH-Sensitive Imaging Agent: Final Results from a Phase II Study.

BACKGROUND: For patients with peritoneal carcinomatosis, extent of disease and completeness of cytoreductive surgery (CRS) are major prognostic factors for long-term survival. Assessment of these factors could be improved using imaging agents. Pegsitacianine is a pH-sensitive polymeric micelle conjugated to the fluorophore indocyanine green. The micelle disassembles in acidic microenvironments, such as tumors, resulting in localized fluorescence unmasking. We assessed the utility of pegsitacianine in detecting residual disease following CRS. PATIENTS AND METHODS: NCT04950166 was a phase II, non-randomized, open-label, multicenter US study. Patients eligible for CRS were administered an intravenous dose of pegsitacianine at 1 mg/kg 24-72 h before surgery. Following CRS, the peritoneal cavity was reexamined under near-infrared (NIR) illumination to evaluate for fluorescent tissue. Fluorescent tissue identified was excised and evaluated by histopathology. The primary outcome was the rate of clinically significant events (CSE), defined as detection of histologically confirmed residual disease excised with pegsitacianine or a revision in the assessment of completeness of CRS. Secondary outcomes included acceptable safety and pegsitacianine performance. RESULTS: A total of 53 patients were screened, 50 enrolled, and 40 were evaluable for CSE across six primary tumor types. Residual disease was detected with pegsitacianine in 20 of 40 (50%) patients. Pegsitacianine showed high sensitivity and was well tolerated with no serious adverse events (SAEs). Transient treatment-related, non-anaphylactic infusion reactions occurred in 28% of patients. CONCLUSIONS: Pegsitacianine was well tolerated and facilitated the recognition of occult residual disease following CRS. The high rate of residual disease detected suggests that the use of pegsitacianine augmented surgeon assessment and performance during CRS.

Assessing the long-term priorities of pancreaticoduodenectomy survivors.

BACKGROUND: This study assessed the long-term quality of life (QOL) and priorities of pancreaticoduodenectomy (PD) survivors. METHODS: Survivors were surveyed via internet-based support groups. The relative importance of longevity, experience, costs, and QOL were assessed. RESULTS: The PD cohort (n = 247, 35%) was 60 ± 12 years, 71% female, and 93% white. With moderate agreement, patients ranked survival most important, followed by functional and emotional well-being; costs and experience were least important (W = 35.7%, p < 0.001). Well-being improved throughout survivorship (P-QOL: 39 ± 12 at ≤3 mo vs 43 ± 12 at >10 y, p = 0.170; M-QOL: 38 ± 13 at ≤3 mo vs 44 ± 16 at >10 y; p = 0.015) but remained below the general population (p < 0.001). PD patients with benign diagnoses ranked functional independence as most important (2.00 ± 1.13 vs 2.63 ± 1.19, p < 0.001, W = 41.1%); PD patients with malignant diagnoses regarded overall survival most important (2.10 ± 1.20 vs 1.82 ± 1.22, p < 0.16, W = 35.1%). The mean rank order of priorities remained concordant between short-term (<1 year) and long-term (>5 years) survivors. CONCLUSION: PD survivors experience long-term mental and physical health impairments, underscoring the importance of functional and emotional support. Survivors place paramount importance on overall survival, functional independence, and emotional well-being. Cancer survivors prioritize longevity, while survivors of chronic benign conditions prioritize functional independence.

Defining the Values and Quality of Life of Cancer Survivors Following Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: An International Survey Study.

BACKGROUND: Advances in treatment of peritoneal surface malignancies including cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS±HIPEC) have led to long-term survivorship, yet the subsequent quality of life (QOL) and values of these patients are unknown. PATIENTS AND METHODS: Survivors were offered surveys via online support groups. Novel items assessed how patients prioritized experience, costs, longevity, and wellbeing. RESULTS: Of the 453 gastrointestinal/hepatobiliary (GI/HPB) surgical patients that responded, 74 underwent CRS±HIPEC and were 54±12 years old, 87% female, and 93% white. Respondents averaged 29 months from diagnosis, with a maximum survival of 20 years. With a moderate level of agreement (W = 39%), rankings of value metrics among respondents were predictable (p < 0.001). Longevity and functional independence were ranked highest; treatment experience and cost of treatment were ranked lowest (p < 0.001). Those who underwent CRS±HIPEC or other GI/HPB surgeries reported the same rank order. QOL in CRS±HIPEC survivors, both mental (M-QOL) (44±13) and physical (P-QOL) (41±11) were lower than in the general population (50±10); p < 0.001. Impairments persisted throughout survivorship, but M-QOL improved over time (p < 0.05). When comparing CRS±HIPEC with other GI/HPB cancer surgery survivors, M-QOL (43±13 versus 43±14, p = 0.85) and P-QOL (40±11 versus 42±12, p = 0.41) were similar. CONCLUSIONS: Although CRS±HIPEC survivors experience long-term mental and physical health impairments, they were similar to those experienced by survivors of other GI/HPB cancer surgeries, and their QOL improved significantly throughout survivorship. As CRS±HIPEC survivors prioritize longevity above all other metrics, survival benefit may outweigh a temporary reduction in QOL.

Predicting Severe Complications from Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy: A Data-Driven, Machine Learning Approach to Augment Clinical Judgment.

BACKGROUND: CRS-HIPEC provides oncologic benefit in well-selected patients with peritoneal carcinomatosis; however, it is a morbid procedure. Decision tools for preoperative patient selection are limited. We developed a risk score to predict severity of 90 day complications for cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). PATIENTS AND METHODS: Adults who underwent CRS-HIPEC at the University of Pittsburgh Medical Center (March 2001-April 2020) were analyzed as part of this study. Primary endpoint was severe complications within 90 days following CRS-HIPEC, defined using Comprehensive Complication Index (CCI) scores as a dichotomous (determined using restricted cubic splines) and continuous variable. Data were divided into training and test sets. Several machine learning and traditional algorithms were considered. RESULTS: For the 1959 CRS-HIPEC procedures included, CCI ranged from 0 to 100 (median 32.0). Adjusted restricted cubic splines model defined severe complications as CCI > 61. A minimum of 20 variables achieved optimal performance of any of the models. Linear regression achieved the highest area under the receiving operator characteristic curve (AUC, 0.74) and outperformed the NSQIP Surgical Risk calculator (AUC 0.80 vs. 0.66). Factors most positively associated with severe complications included peritoneal carcinomatosis index score, symptomatic status, and undergoing pancreatectomy, while American Society of Anesthesiologists 2 class, appendiceal diagnosis, and preoperative albumin were most negatively associated with severe complications. CONCLUSIONS: This study refines our ability to predict severe complications within 90 days of discharge from a hospitalization in which CRS-HIPEC was performed. This advancement is timely and relevant given the growing interest in this procedure and may have implications for patient selection, patient and referring provider comfort, and survival.

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.

Targeted Next-Generation Sequencing Improves the Prognostication of Patients with Disseminated Appendiceal Mucinous Neoplasms (Pseudomyxoma Peritonei).

BACKGROUND: Appendiceal mucinous neoplasms (AMNs) with disseminated disease (pseudomyxoma peritonei) are heterogeneous tumors with variable clinicopathologic behavior. Despite the development of prognostic systems, objective biomarkers are needed to stratify patients. With the advent of next-generation sequencing (NGS), it remains unclear if molecular testing can improve the evaluation of disseminated AMN patients. METHODS: Targeted NGS was performed for 183 patients and correlated with clinicopathologic features to include American Joint Committee on Cancer/World Health Organization (AJCC/WHO) histologic grade, peritoneal cancer index (PCI), completeness of cytoreduction (CC) score, and overall survival (OS). RESULTS: Genomic alterations were identified for 179 (98%) disseminated AMNs. Excluding mitogen-activated protein kinase genes and GNAS due to their ubiquitous nature, collective genomic alterations in TP53, SMAD4, CDKN2A, and the mTOR genes were associated with older mean age, higher AJCC/WHO histologic grade, lymphovascular invasion, perineural invasion, regional lymph node metastasis, and lower mean PCI (p < 0.040). Patients harboring TP53, SMAD4, ATM, CDKN2A, and/or mTOR gene alterations were found to have lower OS rates of 55% at 5 years and 14% at 10 years, compared with 88% at 5 years and 88% at 10 years for patients without the aforementioned alterations (p < 0.001). Based on univariate and multivariate analyses, genomic alterations in TP53, SMAD4, ATM, CDKN2A, and/or the mTOR genes in disseminated AMNs were a negative prognostic factor for OS and independent of AJCC/WHO histologic grade, PCI, CC score, and hyperthermic intraperitoneal chemotherapy treatment (p = 0.006). CONCLUSIONS: Targeted NGS improves the prognostic assessment of patients with disseminated AMNs and identifies patients who may require increased surveillance and/or aggressive management.

Significance of Uncinate Duct Dilatation in IPMNs: A New High-risk Criterion?

OBJECTIVE: To evaluate the significance of UDD in IPMNs. BACKGROUND: The uncinate process of the pancreas has an independent ductal drainage system. International consensus guidelines of IPMNs still consider it as a branch-duct, even though it is the main drainage system for the uncinate process. METHODS: A retrospective review of all surgically treated IPMNs at our institution after 2008 was performed. Preoperative radiological studies were reviewed by an abdominal radiologist who was blinded to the pathological results. In addition to the Fukuoka criteria, presence of UDD was recorded. Using multivariate analysis, the pathological significance of UDD in predicting advanced neoplasia [high grade dysplasia or invasive carcinoma (HGD/ IC)] was determined. RESULTS: Two hundred sixty patients were identified (mean age at diagnosis was 68 years and 49% were females): 122 (47%) had HGD/IC. UDD was noted in 59 (23%), of which 36 (61%) had HGD/IC (P < 0.003). On multivariate analysis, UDD was an independent predictor of HGD/IC (odds ratio = 2.99, P < 0.04). Subgroup analysis on patients with IPMNs confined to the dorsal portion of the gland (n = 161), also demonstrated UDD to be a significant predictor of HGD/IC in those remote lesions (odds ratio: 4.41, P = 0.039). CONCLUSIONS: This is the largest study to evaluate the significance of UDD in IPMNs and shows it to be a high-risk feature. This association persisted for remote IPMNs limited to the dorsal pancreas, suggesting UDD may be associated with an aggressive phenotype even in remote IPMN lesions.

Failure to Thrive Following Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy: Causes and Consequences.

BACKGROUND: Failure to thrive (FTT) is a complex syndrome of nutritional failure and functional decline. Readmission for FTT following cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS HIPEC) is common but underexamined. This study aims to determine features, risk factors, and prognostic significance of FTT following CRS HIPEC. PATIENTS AND METHODS: We reviewed patients who underwent CRS HIPEC from 2010 to 2018 at our institution. Patients were categorized into no readmission, FTT readmission, and other readmission. FTT was determined by coding and chart review. We compared baseline characteristics, oncologic data, perioperative outcomes, and survival among the three cohorts. RESULTS: Of 1068 discharges examined, 379 patients (36%) were readmitted within 90 days, of which 134 (12.5%) were labeled as FTT. Patients with FTT readmission had worse preoperative functional status, higher rates of malnutrition, more complex resections, longer hospital stays, and more postoperative complications (all p < 0.001). Ostomy creation [relative risk ratio (RRR) 4.06], in-hospital venous thromboembolism (VTE), discharge to nursing home (RRR 2.48), pre-CRS HIPEC chemotherapy (RRR 1.98), older age (RRR 1.84), and female gender (RRR 1.69) were all independent predictors for FTT readmission on multinomial regression (all p < 0.01). FTT readmission was associated with worse median overall survival on multivariate analysis [hazard ratio (HR) 1.60, p < 0.001] after controlling for oncologic, perioperative, and baseline factors. CONCLUSIONS: FTT is common following CRS HIPEC and appears to be associated with baseline patient characteristics, operative burden, and postoperative complications. Perioperative strategies for improving nutrition and activity, along with early recognition and intervention in FTT may improve patient outcomes.

Time to Surgery and Colon Cancer Survival in the United States.

PURPOSE: Time to surgery (TTS) is of concern to patients diagnosed with cancer and their physicians. Controversy surrounds the impact of TTS on colon cancer survival. There are limited national data evaluating the association; thus, our aim was to estimate the overall survival (OS) impact from increasing TTS for patients with colon cancer. METHODS: Using the National Cancer Data Base (NCDB), we assessed OS as a function of time between diagnosis and surgery by evaluating intervals encompassing <7, 7 to 30, 31 to 60, 61 to 90, 91 to 120, and 121 to 180 days in length. All patients were diagnosed with nonmetastatic colon cancer and underwent surgery as initial treatment. Our main outcome was OS as a function of time between diagnosis and surgery, after adjusting for patient, demographic, and tumor-related factors using Cox regression models and propensity score-based weighting. RESULTS: A total of 514,103 patients diagnosed between 1998 and 2012 were included. Individuals having <7, 7 to 30, 31 to 60, 61 to 90, 91 to 120, and 121 to 180 days between diagnosis and surgery comprised 35.4%, 45%, 15.1%, 2.9%, 1%, and 0.6% of the patients, respectively. There was a steady increase in median TTS across the years. On multivariable analysis, TTS >30 days or within the first week independently increased mortality risk. There was a significant increase in mortality with TTS 31 to 60 [hazard ratio (HR) 1.13], 61 to 90 (HR 1.49), <7 (HR 1.56), 91 to 120 (HR 2.28), and 121 to 180 (HR 2.46) compared to surgery performed 7 to 30 days after diagnosis (P < 0.001). CONCLUSIONS: TTS is independently associated with OS and this represents a public health issue that should be addressed at a national level. Although time is required for evaluation before surgery, efforts to reduce TTS should be pursued.

500 Minimally Invasive Robotic Pancreatoduodenectomies: One Decade of Optimizing Performance.

OBJECTIVES: This study aims to present the outcomes of our decade-long experience of robotic pancreatoduodenectomy and provide insights into successful program implementation. BACKGROUND: Despite significant improvement in mortality over the past 30 years, morbidity following open pancreatoduodenectomy remains high. We implemented a minimally invasive pancreatic surgery program based on the robotic platform as one potential method of improving outcomes for this operation. METHODS: A retrospective review of a prospectively maintained institutional database was performed to identify patients who underwent robotic pancreatoduodenectomy (RPD) between 2008 and 2017 at the University of Pittsburgh. RESULTS: In total, 500 consecutive RPDs were included. Operative time, conversion to open, blood loss, and clinically relevant postoperative pancreatic fistula improved early in the experience and have remained low despite increasing complexity of case selection as reflected by increasing number of patients with pancreatic cancer, vascular resections, and higher Charlson Comorbidity scores (all P<0.05). Operating room time plateaued after 240 cases at a median time of 391 minutes (interquartile rang 340-477). Major complications (Clavien >2) occurred in less than 24%, clinically relevant postoperative pancreatic fistula in 7.8%, 30- and 90-day mortality were 1.4% and 3.1% respectively, and median length of stay was 8 days. Outcomes were not impacted by integration of trainees or expansion of selection criteria. CONCLUSIONS: Structured implementation of robotic pancreatoduodenectomy can be associated with excellent outcomes. In the largest series of RPD, we establish benchmarks for the surgical community to consider when adopting this approach.

Recurrent Rearrangements in PRKACA and PRKACB in Intraductal Oncocytic Papillary Neoplasms of the Pancreas and Bile Duct.

BACKGROUND & AIMS: Intraductal oncocytic papillary neoplasms (IOPNs) of the pancreas and bile duct contain epithelial cells with numerous, large mitochondria and are cystic precursors to pancreatic ductal adenocarcinoma (PDAC) and cholangiocarcinoma (CCA), respectively. However, IOPNs do not have the genomic alterations found in other pancreatobiliary neoplasms. In fact, no recurrent genomic alterations have been described in IOPNs. PDACs without activating mutations in KRAS contain gene rearrangements, so we investigated whether IOPNs have recurrent fusions in genes. METHODS: We analyzed 20 resected pancreatic IOPNs and 3 resected biliary IOPNs using a broad RNA-based targeted sequencing panel to detect cancer-related fusion genes. Four invasive PDACs and 2 intrahepatic CCAs from the same patients as the IOPNs, were also available for analysis. Samples of pancreatic cyst fluid (n = 5, collected before surgery) and bile duct brushings (n = 2) were analyzed for translocations. For comparison, we analyzed pancreatobiliary lesions from 126 patients without IOPN (controls). RESULTS: All IOPNs evaluated were found to have recurring fusions of ATP1B1-PRKACB (n = 13), DNAJB1-PRKACA (n = 6), or ATP1B1-PRKACA (n = 4). These fusions also were found in corresponding invasive PDACs and intrahepatic CCAs, as well as in matched pancreatic cyst fluid and bile duct brushings. These gene rearrangements were absent from all 126 control pancreatobiliary lesions. CONCLUSIONS: We identified fusions in PRKACA and PRKACB genes in pancreatic and biliary IOPNs, as well as in PDACs and pancreatic cyst fluid and bile duct cells from the same patients. We did not identify these gene fusions in 126 control pancreatobiliary lesions. These fusions might be used to identify patients at risk for IOPNs and their associated invasive carcinomas.

IL-36γ-armed oncolytic virus exerts superior efficacy through induction of potent adaptive antitumor immunity.

In this study, we aimed to apply the cytokine IL-36γ to cancer immunotherapy by constructing new oncolytic vaccinia viruses (OV) expressing interleukin-36γ (IL-36γ-OVs), leveraging unique synergism between OV and IL-36γ's ability to promote antitumor adaptive immunity and modulate tumor microenvironment (TME). IL-36γ-OV had dramatic therapeutic efficacies in multiple murine tumor models, frequently leading to complete cancer eradication in large fractions of mice. Mechanistically, IL-36-γ-armed OV induced infiltration of lymphocytes and dendritic cells, decreased myeloid-derived suppressor cells and M2-like tumor-associated macrophages, and T cell differentiation into effector cells. Further study showed that IL-36γ-OV increased the number of tumor antigen-specific CD4+ and CD8+ T cells and the therapeutic efficacy depended on both CD8+ and CD4+ T cells. These results demonstrate that these IL36γ-armed OVs exert potent therapeutic efficacy mainly though antitumor immunity and they may hold great potential to advance treatment in human cancer patients.

Phase II Trial of Adjuvant Dendritic Cell Vaccine in Combination with Celecoxib, Interferon-α, and Rintatolimod in Patients Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Metastases.

BACKGROUND: Peritoneal metastases portend poor prognosis in the setting of standard chemotherapy. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) improves outcomes, but relapse is common. We report a phase II trial evaluating the safety and efficacy of adjuvant αDC1 vaccination with chemokine modulation (CKM) after CRS/HIPEC. METHODS: Patients undergoing CRS/HIPEC for appendiceal cancer, colorectal cancer, or peritoneal mesothelioma were enrolled. In addition to standard adjuvant chemotherapy, patients received intranodal and intradermal injections of autologous tumor-loaded αDC1 vaccine. After each vaccine booster, patients received CKM over 4 days, consisting of celecoxib, interferon (IFN)-α, and rintatolimod. RESULTS: Forty-six patients underwent CRS/HIPEC followed by αDC1 treatment, including 24 appendiceal primaries, 20 colorectal, and 2 mesotheliomas. DC maturation was successful, with 97% expressing HLA-DR and CD86. Tumor cell recovery from peritoneal tumors was challenging, resulting in only 17% of patients receiving the target dose of αDC1. The αDC1 and CKM regimen was well tolerated. CKM successfully modulated serum inflammatory cytokine and chemokine levels. Median progression-free survival (PFS) for appendiceal primaries was 50.4, 34.2, and 8.9 months for grade 1, 2, and 3 tumors, respectively, while median PFS for colorectal cancer was 20.5 and 8.9 months for moderately and poorly differentiated tumors, respectively. CONCLUSIONS: Adjuvant autologous tumor antigen-loaded αDC1 vaccine and CKM is well tolerated. The mucinous nature of peritoneal metastases limits the feasibility of obtaining adequate autologous tumor cells. The improvement in median PFS did not meet our predefined thresholds, leading us to conclude that αDC1 vaccination is not appropriate for patients undergoing CRS/HIPEC for peritoneal metastases.

Impact of Neoadjuvant Therapy on Survival Following Margin-Positive Resection for Pancreatic Cancer.

INTRODUCTION: A positive microscopic margin (R1) following resection of pancreatic ductal adenocarcinoma (PDAC) can occur in up to 80% of patients and is associated with reduced survival and increased recurrence. Our aim was to characterize the impact of neoadjuvant therapy (NAT) on survival and recurrence in patients with PDAC following an R1 resection. METHODS: A retrospective analysis of patients with PDAC who underwent pancreatectomy from 2008 to 2017 was performed. Patients were staged according to the American Joint Committee on Cancer 8th edition and stratified based on resection margin (R0 vs. R1) and treatment sequence (NAT vs. surgery first [SF]). Conditional survival analysis was performed using Cox regression and inverse probability weighted estimates. RESULTS: Among 580 patients, 59% received NAT and 41% underwent SF. On final pathology, the NAT cohort had smaller tumors and less lymph node (LN) positivity (p < 0.05). NAT was not associated with an R1 resection (50%, p = 0.653). Compared with the R1 cohort, the R0 cohort had a higher median overall survival (OS; 39.6 vs. 22.8 months; hazard ratio [HR] 1.6, p < 0.001) and disease-free survival (DFS; 19 vs. 13 months; HR 1.35, p = 0.004). After risk adjustment, NAT was not associated with OS, regardless of margin status (R0, 95% confidence interval [CI] (-)7.31-27.07, p = 0.26; or R1, 95% CI (-)36.99-15.25, p = 0.42). However, NAT was associated with improved DFS in the R1 cohort (95% CI 1.79-11.91, p = 0.008) but not in the R0 cohort (95% CI (-)11.22-10.54, p = 0.95). CONCLUSION: An R0 resection remains an important determinant of overall and disease-free survival, even when NAT is administered. For patients with an R1 resection, receipt of NAT may prolong DFS.

Optimal Management of Resectable Pancreatic Head Cancer in the Elderly Patient: Does Neoadjuvant Therapy Offer a Survival Benefit?

INTRODUCTION: Neoadjuvant therapy (NAT) is a growing strategy for patients with resectable pancreatic ductal adenocarcinoma (PDAC). Elderly patients are at increased risk of treatment withdrawal due to functional decline, and the benefit of NAT in this cohort remains to be studied. OBJECTIVE: The objective of this study was to compare outcomes of elderly patients with resectable head PDAC who underwent NAT or a surgery-first (SF) approach. METHODS: All patients 75 years of age and older with radiographically resectable (National Comprehensive Cancer Network criteria) PDAC who underwent pancreaticoduodenectomy at a single institution from 2008 to 2017 were analyzed. Baseline characteristics and perioperative outcomes were compared between the SF and NAT cohorts. Recurrence-free survival and overall survival (OS) were analyzed by treatment strategy. RESULTS: Overall, 158 patients were identified: SF cohort = 90 (57%) and NAT cohort = 68 (43%). Patients in the SF cohort were older (80 vs. 78 years; p = 0.01) but there were no differences in preoperative comorbidities or frailty indices. SF patients had a trend toward higher rates of major complications (38% vs. 24%; p = 0.06) with higher Comprehensive Complication Index totals (20.9 vs. 20; p = 0.03). There were similar rates of adjuvant therapy. NAT was associated with significantly longer OS (24.6 vs. 17.6 months; p = 0.01) in both the intent-to-treat and resected cohorts. On multivariable analysis (MVA), NAT remained an independent predictor of OS (hazard ratio 0.60; p = 0.02). CONCLUSION: NAT is safe and effective for elderly patients with PDAC. This study suggests NAT is associated with fewer complications after surgery, equal rates of adjuvant therapy receipt, and increased OS over a surgery-first approach.

Predischarge Prediction of Readmission After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: Derivation and Validation of a Risk Prediction Score.

BACKGROUND: Ninety-day hospital readmission rates following cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) range from 20 to 40%. OBJECTIVE: The aim of this study was to develop and validate a simple score to predict readmissions following CRS/HIPEC. STUDY DESIGN: Using a prospectively maintained database, we retrospectively reviewed clinicopathologic, perioperative, and day-of-discharge data for patients undergoing CRS/HIPEC for peritoneal surface malignancies between 2010 and 2018. In-hospital mortalities and discharges to hospice were excluded. Multivariate logistic regression was utilized to identify predictors of unplanned readmission, with three-quarters of the sample randomly selected as the derivation cohort and one-quarter as the validation cohort. Using regression coefficient-based scoring methods, we developed a weighted 7-factor, 10-point predictive score for risk of readmission. RESULTS: Overall, 1068 eligible discharges were analyzed; 379 patients were readmitted within 90 days (35.5%). Seven factors were associated with readmission: stoma creation, Peritoneal Cancer Index score ≥ 15, hyponatremia, in-hospital major complication, preoperative chemotherapy, anemia, and discharge to nursing home. In the validation cohort, 25 patients (9.2%) were categorized as high risk for readmission, with a predicted rate of readmission of 69.3% and an observed rate of 76.0%. The score had fair discrimination (area under the curve 0.70) and good calibration (Hosmer-Lemeshow goodness-of-fit p-value of 0.77). CONCLUSION: Our proposed risk score, easily obtainable on day of discharge, distinguishes patients at high risk for readmission over 90 days following CRS/HIPEC. This score has the potential to target high-risk individuals for intensive follow-up and other interventions.

Neoadjuvant Chemotherapy for Pancreatic Adenocarcinoma Lessens the Deleterious Effect of Omission of Adjuvant Chemotherapy.

BACKGROUND: Despite controversy regarding the role of neoadjuvant chemotherapy (NAC) in pancreatic adenocarcinoma, nearly half of resected patients do not receive chemotherapy postoperatively. This study aimed to examine whether use of NAC compensates for omission of adjuvant chemotherapy (AC) for resected pancreatic adenocarcinoma. METHODS: Adults with resected stages 1 to 3 pancreatic adenocarcinoma were enrolled from the National Cancer Database NCDB (2006-2016). Overall survival (OS) analyses were used to examine the impact of NAC on those who did not receive AC. RESULTS: The study analyzed a national cohort of 56,286 patients: 30% without chemotherapy, 11% with NAC, 54% with AC, and 5% with NAC plus AC. Use of NAC increased by more than 400% from 2006 to 2016, whereas the rates for omission of chemotherapy remained unchanged. The OS rates were similar between the patients who received NAC and those who received AC (hazard ratio, 0.97; p = 0.21). Among the patients who did not receive AC, NAC was associated with improved OS (26.7 vs. 18.4 months; p < 0.0001). The patients who did not receive AC but underwent NAC had a median OS comparable with the OS of those who received AC alone (26.9 vs. 24.7 months). In the adjusted analysis, the use of NAC for those without AC was significantly associated with improved OS (estimate, - 0.24; p < 0.0001). CONCLUSIONS: Although data are limited regarding the survival benefit derived from neoadjuvant versus adjuvant chemotherapy in pancreatic adenocarcinoma, nearly half of patients do not receive adjuvant chemotherapy. This study demonstrates that the use of NAC lessens the survival disadvantage caused by omission of AC. Despite controversy, NAC may be considered for pancreatic adenocarcinoma patients given the high likelihood that adjuvant chemotherapy will be omitted.

Definition and Prediction of Early Recurrence and Mortality Following Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Colorectal Peritoneal Metastases: Towards Predicting Oncologic Futility Preoperatively.

INTRODUCTION: Early recurrence (ER) is a significant challenge for patients with colorectal peritoneal metastases (CRPM) following cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS HIPEC). Preoperative risk stratification for ER would improve preoperative decision making. METHODS: We conducted a retrospective study examining patients who underwent CRS HIPEC for CRPM from 2000 to 2018. Optimal definition of ER was determined via minimum p-value approach based on differentiation of post-recurrence survival. Risk factors for ER were assessed in a derivation cohort by uni- and multivariate logistic regression. A predictive score for ER was generated using preoperative variables and validated in an independent cohort. RESULTS: 384 patients were analyzed, 316 (82%) had documented recurrence. Optimal length of post-operative RFS to distinguish ER (n = 144, 46%) vs. late recurrence (LR) (n = 172, 63%) was 8 mos (p<0.01). ER patients had shorter median OS post-CRS-HIPEC (13.6 vs. 39.4 mos, p<0.01). Preoperative BMI (OR 1.88), liver lesions (OR 1.89), progression on chemotherapy (OR 2.14), positive lymph nodes (OR 2.47) and PCI score (16-20: OR 1.7; >20: OR 4.37) were significant predictors of ER (all p<0.05). Using this model, patients were assigned risk scores from 0 to 9. Intermediate (scores 4-6) and high-risk patients (score 7-9) had observed rates of ER of 56% and 79% and overall 2-year survival rates of 27% and 0% respectively. The model showed fair discrimination (AUC 0.72) and good calibration (Hosmer-Lemeshow GOF p = 0.68). CONCLUSIONS: ER predicts markedly worse OS following surgery. Preoperative factors can accurately stratify risk for ER and identify patients in whom CRS-HIPEC for CPRM is futile.