Immunological effects of heated intraperitoneal chemotherapy can be augmented by thymosin α1.

BACKGROUND: Peritoneal metastases of colorectal carcinoma origin (PM-CRC) are treated by cytoreductive surgery and heated intraperitoneal chemotherapy (HIPEC). However, the majority of patients recur, calling for novel treatments. We explored the immunogenic changes induced by HIPEC and the possibility to use thymosin α1 (Tα1) as an immune-stimulatory agent. METHODS: We used an experimental murine model of PM-CRC combined with mitomycin (MMC)-based HIPEC. We determined immune cell infiltration into tumor metastases after HIPEC administration by means of immunohistochemistry, and determined immunogenic cell death signals in tumor cells by real-time polymerase chain reaction. RESULTS: Mice with PM-CRC treated by HIPEC had increased overall survival (OS) compared to sham-treated mice (median OS 22.8 vs 18.9 days, respectively; P < 0.001). HIPEC induced increased infiltration of CD4+, CD8+, CD68 + and CD20 + cells into omental and visceral metastases at a magnitude of 40-100 %. We searched for potential immune signals induced by HIPEC by determining its effects on known immunogenic cell death proteins (heat-shock protein [HSP]-70, HSP-90 and calreticulin). HIPEC significantly increased HSP-90 mRNA expression (2.37 ± 1.5 vs 1-fold change, P < 0.05). The OS of Tα1 treated mice significantly improved compared to HIPEC-treated mice (16.3 ± 0.8 vs 14.1 ± 0.6 days, respectively, P = 0.02) and vs sham (11.8 ± 0.8 days, P = 0.007). CONCLUSIONS: HIPEC induced immunogenic changes that led to increased immune cell infiltration. These changes were further augmented by Tα1 treatment. Future studies aimed at optimizing Tα1 treatment should focus upon the immune response it evokes.

PD-1 Blockade Combined with Heated Intraperitoneal Chemotherapy Improves Outcome in Experimental Peritoneal Metastases from Colonic Origin in a Murine Model.

BACKGROUND: Heated intraperitoneal chemotherapy (HIPEC) was shown to induce immunogenicity of peritoneal metastases from colorectal cancer (PM-CRC) by induction of immunogenic cell death. We aimed to explore whether the addition of a checkpoint inhibitor would augment the effect of HIPEC in an experimental murine model of PM-CRC. METHODS: PM-CRC was established in C57BL mice by intraperitoneal inoculation of MC38 colon cancer cells. HIPEC was administered using the closed technique with mitomycin C (MMC). Clinical and immunological parameters were compared between animals treated with HIPEC alone and those treated with HIPEC + anti-programmed death receptor-1 (aPD-1). RESULTS: MMC-based HIPEC increased the overall survival of animals compared with sham-treated animals (22.8; 95% confidence interval [CI] 21.14-24.53 vs. 18.9 days; 95% CI 17.6-20.3, p < 0.001). The extent of peritoneal disease as measured by the modified peritoneal carcinomatosis index was also reduced by HIPEC. This clinical benefit was accompanied by increased infiltration of CD8+, CD68+, and CD20+ cells into tumor metastases in HIPEC-treated animals compared with sham-treated animals. We identified heat shock protein (HSP) 90 as a potential immunogenic cell death protein whose expression is increased under HIPEC conditions (fold change: 2.37 ± 1.5 vs. 1 without HIPEC, p < 0.05). Combined HIPEC + PD-1 treatment ameliorated survival compared with HIPEC alone and sham treatment (24.66; 95% CI 20.13-29.2 vs. 19; 95% CI 15.85-22.14 and 14.33 days; 95% CI 9.6-19.04, respectively; p = 0.008). This clinical effect was accompanied by increased CD8+ tumor infiltration. CONCLUSIONS: HIPEC induced the expression of immunogenic cell death signals that can support an anti-tumor immune response. This response can be further exploited by a checkpoint inhibitor.

Long-term outcomes of elderly patients with peritoneal metastases of colorectal origin after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

INTRODUCTION: Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) were reportedly safe for the elderly. However, long-term survival data in this subgroup of patients are scarce. Our aim was to evaluate the peri-operative and long-term outcomes of CRS + HIPEC in colorectal peritoneal metastases (CRC-PM) in patients ≥70 years of age. MATERIAL AND METHODS: We retrospectively analyzed our combined institutional databases for patients who underwent CRS + HIPEC for CRC-PM. Clinical and pathological characteristics, as well as overall survival (OS) and progression-free survival (PFS) were compared between the groups. Tumor extent was measured by the peritoneal carcinomatosis index (PCI) and completeness of cytoreduction by the CCR score. Major morbidity was defined according to Clavien-Dindo classification. RESULTS: The dataset of 159 patients included 33 elderly and 126 non-elderly patients. Clinical characteristics between the groups differed only in medical comorbidities (Charlson comorbidity index 10 vs. 7, P < 0.001) and delivery of post-HIPEC adjuvant treatment (12.5% vs. 43.8%, P = 0.004). Overall PCI and CCR0 rates were similar between the groups, as were length of stay and major morbidity and mortality rates. Long-term outcomes in the elderly group were lower than those of the non-elderly (median OS: 21.8 vs. 40.5 months, P < 0.001; median PFS: 6 vs. 8 months, P = 0.02, respectively). CONCLUSIONS: CRS + HIPEC in selected elderly patients can be safe in terms of postoperative morbidity and mortality. However, despite the same surgical extents and radicality, their long-term outcomes are inferior, possibly due to under-usage of systemic chemotherapy.

Thymosin alpha 1 as an adjuvant to hyperthermic intraperitoneal chemotherapy in an experimental model of peritoneal metastases from colonic carcinoma.

INTRODUCTION: Heated intraperitoneal chemotherapy (HIPEC) is currently implemented in the treatment of peritoneal metastases from colorectal carcinoma (PM-CRC) origin. However, recurrence is common and the effectiveness of HIPEC has been questioned. The aim of this study was to evaluate the use of thymosin alpha 1 (Tα1), an immunomodulatory molecule, as an adjuvant to HIPEC treatment. METHODS: We developed an experimental model of HIPEC by the induction of PM-CRC in C57BL mice and intra-abdominal perfusion of mitomycin C (MMC). Mice were treated with Tα1 at 0.6 mg/kg for 5 days after HIPEC. Clinical and immunological parameters were compared between HIPEC and HIPEC + Tα1 groups. RESULTS: Treatment with Tα1 increased overall survival of mice compared to HIPEC treatment alone and sham-treated animals (16.1 ± 0.8 vs. 14.1 ± 0.6 and 11.8 ± 0.8, respectively, p = 0.02). Tα1 had no direct anti-tumor effect, as seen by lack of inhibition of tumor cell proliferation. Tα1 treatment induced a T helper (Th) 1 immune response in tumor metastases as evidenced by a significant increase of the Th1-specific markers IFN-γ and T-bet (1.21 ± 0.3 vs. 0.52 ± 0.08, p < 0.05; 0.88 ± 0.04 vs. 0.64 ± 0.14, p < 0.05, respectively). This Th1 skew was accompanied by increased CD8+ infiltration into omental and visceral metastases by Tα1 treatment compared to sham and HIPEC-treated animals (21.24 ± 2.16 vs. 10.45 ± 0.89 and 7.7 ± 1.3, p < 0.001; 14.12 ± 1.54 vs. 12.12 ± 0.01 and 6.64 ± 0.87, p < 0.01, respectively). CONCLUSIONS: Tα1 augments the effect of HIPEC by the induction of a Th1 anti-tumor immune response. Further experiments should evaluate Tα1 and other novel immunomodulators in order to exploit the immunological opportunities created by HIPEC.

Lymph Node Metastases from Visceral Peritoneal Colorectal Metastases are Associated with Systemic Recurrence.

BACKGROUND: Visceral peritoneal colorectal metastases (VPCMs) may further metastasize to lymph nodes that drain those organs. The rate of lymph node metastases (LNMs) from VPCMs and their clinical and prognostic significance are unknown. METHODS: This study retrospectively analyzed the authors' institutional databases of 160 patients with peritoneal colorectal metastases who underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. Patients with LNM-VPCM (n = 12) were identified by pathologic reports, and both their short- and long-term outcomes were compared with those of patients without LNM-VPCM. RESULTS: The clinical presentation and primary tumor pathologic characteristics did not differ between the two groups. The patients with LNM-VPCM had a higher tumor burden (measured by the peritoneal carcinomatosis index [PCI]) and visible remnant disease compared with those who had no LNM-VPI (10 vs 5.5 [p = 0.03] vs 33.3% vs 6.8% [p = 0.007], respectively). The postoperative outcomes also were comparable. The patients with LNM-VPCM had a shorter overall survival (OS) than those without LNM-VPCM (median OS, 22.5 months; 95% confidence interval [CI], 15.1-29.9 months vs 40.1 months; 95% CI, 38.1-42 months; p = 0.02). However, only tumor grade and PCI were predictors of OS in the multivariate analysis (hazard ratio [HR], 2.33 [p = 0.001]; 1.77 [p = 0.03], respectively). The study showed that LNM-VPCM was associated with systemic but not peritoneal recurrence compared with non-LNM-VPCM (81.8% vs 51.6% for systemic recurrence, respectively; p = 0.05). CONCLUSION: The small distinct group of patients defined by LNM-VPCM were prone to systemic recurrence. Given its correlation with systemic recurrence, LNM-VPCM may indicate the need for adjuvant treatment.

Neoadjuvant FOLFIRINOX for locally advanced and borderline resectable pancreatic cancer: An intention to treat analysis.

OBJECTIVE: To assess clinical and pathologic efficacy of neoadjuvant FOLFIRINOX for locally advanced (LAPC) and borderline resectable pancreatic cancer (BRPC). METHODS: Patients receiving neoadjuvant FOLFIRINOX for LAPC and BRPC treated between 2014 and 2017 were identified. Post-treatment patients achieving resectability were referred for surgery, whereas unresectable patients continued chemotherapy. Clinical and pathological data were retrospectively compared with control group consisting of 47 consecutive patients with BRPC undergoing pancreatic and portal vein resection between 2008 and 2017. RESULTS: Thirty LAPC and 23 BRPC patients were identified. Reasons for unresectability included disease progression (70%), locally unresectable disease (18%), and poor performance status (11%). Three patients (10%) with LAPC, and 20 (87%) with BRPC underwent curative surgery. Compared with control group, perioperative complication rate (4.3% versus 28.9%, p = 0.016), and pancreatic fistula rate (0 versus 14.8%, p = 0.08) were lower. Peripancreatic fat invasion (52.2% vs 97.8%, p = 0.001), lymph node involvement (22% vs 54.3%, p = 0.01), and surgical margin involvement (0 vs 17.4%, p = 0.04) were higher in the control group. Median survival was 34.3 months in BRPC patients operated after FOLFIRINOX and 26.1 months in the control group (p = 0.07). Three patients (13%) with complete pathological response are disease-free after mean follow-up of 19 months. CONCLUSIONS: Whereas neoadjuvant FOLFIRINOX rarely achieves resectability in patients with LAPC (10%), most BRPC undergo resection (87%). Neoadjuvant FOLFIRINOX leads to complete pathological response in 13% of cases, tumor downstaging, and a trend towards improved survival compared with patients undergoing up-front surgery.

Perioperative complications after neoadjuvant chemotherapy with and without bevacizumab for colorectal liver metastases.

PURPOSE: Bevacizumab has been shown to increase progression free and overall survival in patients with metastatic colorectal cancer. Neoadjuvant bevacizumab is commonly used in patients undergoing liver resection. Our purpose was to evaluate whether bevacizumab is associated with increased rate of perioperative complications in patients undergoing hepatic resection for colorectal liver metastases (CRLM). METHODS: Retrospective analysis of patients undergoing hepatic resection for CRLM who received chemotherapy and bevacizumab (group 1, n = 134), or chemotherapy alone (group 2, n = 57). We compared demographics, surgical characteristics, and perioperative course. RESULTS: Perioperative complications developed in 35 % of patients in group 1, and 47 % in group 2 (p = 0.11). Of those complications, 15 (11.2 %) in group 1, and 5 (8.8 %) in group 2 were considered major (p = 0.617). Four patients, all of whom received preoperative bevacizumab, developed enteric leaks following combined liver and bowel resection. The rate of anastomotic leak in group 1 was 10 %, compared with 0 in group 2, p = 0.56. CONCLUSION: Neoadjuvant chemotherapy along with bevacizumab was not associated with an increased risk of postoperative complications after hepatic resection. Possible association of increased morbidity with simultaneous bowel and liver resections following bevacizumab administration was found and we recommend avoiding such treatment combination.

Multifocality in retroperitoneal sarcoma: a prognostic factor critical to surgical decision-making.

OBJECTIVE: To evaluate the significance of multifocality on overall survival (OS) in patients with retroperitoneal sarcoma (RPS) and establish a data-derived, prognostically and therapeutically useful definition of sarcomatosis. SUMMARY BACKGROUND DATA: The incidence, clinical features, and prognostic significance of multifocality in RPS is unknown. No current standardized definition for sarcomatosis is available. METHODS: We conducted a retrospective analysis of 393 patients with primary or recurrent nonmetastatic RPS treated at a comprehensive cancer center between 1996 and 2006. Baseline and treatment variables were compared in patients with unifocal and multifocal disease. A multivariate model was used to evaluate the association of multifocality and OS and identify additional prognostic factors in patients with multifocal disease. RESULTS: The median follow-up time for all patients was 69 months; 79 patients (20%) presented with multifocal disease. The 5-year OS rate was less in the multifocal group compared with the unifocal group (31% vs. 60%, respectively; P < 0.0001). After multivariate analysis, multifocality remained an independent predictor of worse OS {hazard ratio (HR) 1.7 (95% confidence interval (CI), 1.2-2.5); P = 0.004}. Additionally, patients with more tumors had significantly worse prognosis (>7 tumors, HR 2.1 (95% CI, 1.1-3.9); P = 0.03), with a 5-year OS rate of 7%. CONCLUSIONS: Multifocal RPS is associated with worse OS in patients with either primary or recurrent RPS; Patients with >7 tumors had the worst prognosis. This criterion can be used to define sarcomatosis, thereby identifying patients whose survival will ultimately depend on effective systemic therapy.

Immunomodulatory effects of ciprofloxacin in TNBS-induced colitis in mice.

BACKGROUND: Crohn's exacerbation and pouchitis are commonly treated with ciprofloxacin and metronidazole. Few studies have shown an advantage of this regimen compared with other antibiotics. Most attributed the effect to its better antibacterial coverage. Others have shown an apparent anti-inflammatory effect of quinolones in several in vitro and in vivo models of inflammation other than inflammatory bowel diseases (IBD). Our objective was to test the hypothesis that ciprofloxacin may act as an anti-inflammatory agent rather than just an antibacterial drug using a model of chemical colitis. METHODS: TNBS colitis was induced in BALB/c mice. The anti-inflammatory effect of ciprofloxacin compared with ceftazidime and dexamethasone was assessed. RESULTS: Mice treated with ciprofloxacin (7.5 mg/kg or 15 mg/kg) had significant reductions in clinical signs, body weight loss, splenic and colonic weight increase compared with saline-treated and ceftazidime-treated mice. Histologic analysis showed mild inflammation in ciprofloxacin-treated mice with a mean score of 3.8 +/- 0.5 points compared with moderate colitis scored 7.8 +/- 1.3 and 9.5 +/- 0.5 points in saline and ceftazidime-treated mice, respectively. Analysis of cytokine levels in colon homogenates showed a significant decrease of IL-1beta, IL-8, and TNFalpha levels in ciprofloxacin-treated animals. Immunohistochemistry for NFkappaB showed strong positivity in saline and ceftazidime-treated mice in contrast to weak focal stain in ciprofloxacin- and dexamethasone-treated mice. CONCLUSIONS: These findings imply that ciprofloxacin has an anti-inflammatory effect, rather than just an antibacterial one, making its use favorable in IBD patients.