Survival difference between mucinous vs. non-mucinous colorectal cancer following cytoreductive surgery and intraperitoneal chemotherapy.

BACKGROUND: It is believed that the oncologic behavior of mucinous colorectal adenocarcinoma (MC) is different from non-mucinous adenocarcinoma (NMC). The aim of the study is to compare long-term survivals between patients with MC and those with NMC following cytoreductive surgery (CRS) and intraperitoneal chemotherapy (IPC). METHODS: This was a retrospective study of prospectively collected data of patients with peritoneal metastases of colorectal origin following CRS and IPC. Group I included patients with MC which was defined as being composed of >50% extracellular mucin. Group II included those with NMC. Subgroup analysis was performed according to the location of primary tumor. RESULTS: A total of 213 patients were included in this study. The two groups had similar hospital mortality, high dependency unit stay. MC group had a significantly longer mean intensive care unit (ICU) stay (p = .037) and total hospital stay (p = .037). There was no significant difference in overall survival (OS) and disease-free survival (DFS) between two groups (p = .657 and p = .938, respectively). Multivariate analysis showed that the presence of mucin was not an independent negative prognostic factor for OS (p = .190). CONCLUSION: In summary, patients with MC had a similar long-term survival outcome with those with NMC following CRS and IPC.

Increased Fusobacterium tumoural abundance affects immunogenicity in mucinous colorectal cancer and may be associated with improved clinical outcome.

There is currently an urgent need to identify factors predictive of immunogenicity in colorectal cancer (CRC). Mucinous CRC is a distinct histological subtype of CRC, associated with a poor response to chemotherapy. Recent evidence suggests the commensal facultative anaerobe Fusobacterium may be especially prevalent in mucinous CRC. The objectives of this study were to assess the association of Fusobacterium abundance with immune cell composition and prognosis in mucinous CRC. Our study included two independent colorectal cancer patient cohorts, The Cancer Genome Atlas (TCGA) cohort, and a cohort of rectal cancers from the Beaumont RCSI Cancer Centre (BRCC). Multiplexed immunofluorescence staining of a tumour microarray (TMA) from the BRCC cohort was undertaken using Cell DIVE technology. Our cohorts included 87 cases (13.3%) of mucinous and 565 cases (86.7%) of non-mucinous CRC. Mucinous CRC in the TCGA dataset was associated with an increased proportion of CD8 + lymphocytes (p = 0.018), regulatory T-cells (p = 0.001) and M2 macrophages (p = 0.001). In the BRCC cohort, mucinous RC was associated with enhanced CD8 + lymphocyte (p = 0.022), regulatory T-cell (p = 0.047), and B-cell (p = 0.025) counts. High Fusobacterium abundance was associated with an increased proportion of CD4 + lymphocytes (p = 0.031) and M1 macrophages (p = 0.006), whilst M2 macrophages (p = 0.043) were under-represented in this cohort. Patients with increased Fusobacterium relative abundance in our mucinous CRC TCGA cohort tended to have better clinical outcomes (DSS: likelihood ratio p = 0.04, logrank p = 0.052). Fusobacterium abundance may be associated with improved outcomes in mucinous CRC, possibly due to a modulatory effect on the host immune response. KEY MESSAGES: • Increased Fusobacterium relative abundance was not found to be associated with microsatellite instability in mucinous CRC. • Increased Fusobacterium relative abundance was associated with an M2/M1 macrophage switch, which is especially significant in mucinous CRC, where M2 macrophages are overexpressed. • Increased Fusobacterium relative abundance was associated with a significant improvement in disease specific survival in mucinous CRC. • Our findings were validated at a protein level within our own in house mucinous and non-mucinous rectal cancer cohorts.

Primary Colorectal Tumor Displays Differential Genomic Expression Profiles Associated with Hepatic and Peritoneal Metastases.

BACKGROUND: Despite improvements in characterization of CRC heterogeneity, appropriate risk stratification tools are still lacking in clinical practice. This study aimed to elucidate the primary tumor transcriptomic signatures associated with distinct metastatic routes. METHODS: Primary tumor specimens obtained from CRC patients with either isolated LM (CRC-Liver) or PM (CRC-Peritoneum) were analyzed by transcriptomic mRNA sequencing, gene set enrichment analyses (GSEA) and immunohistochemistry. We further assessed the clinico-pathological associations and prognostic value of our signature in the COAD-TCGA independent cohort. RESULTS: We identified a significantly different distribution of Consensus Molecular Subtypes between CRC-Liver and CRC-peritoneum groups. A transcriptomic signature based on 61 genes discriminated between liver and peritoneal metastatic routes. GSEA showed a higher expression of immune response and epithelial invasion pathways in CRC-Peritoneum samples and activation of proliferation and metabolic pathways in CRC-Liver samples. The biological relevance of RNA-Seq results was validated by the immunohistochemical expression of three significantly differentially expressed genes (ACE2, CLDN18 and DUSP4) in our signature. In silico analysis of the COAD-TCGA showed that the CRC-Peritoneum signature was associated with negative prognostic factors and poor overall and disease-free survivals. CONCLUSIONS: CRC primary tumors spreading to the liver and peritoneum display significantly different transcriptomic profiles. The implementation of this signature in clinical practice could contribute to identify new therapeutic targets for stage IV CRC and to define individualized follow-up programs in stage II-III CRC.

Case report: Preclinical efficacy of NEDD8 and proteasome inhibitors in patient-derived models of signet ring high-grade mucinous colorectal cancer from a Lynch syndrome patient.

High-grade mucinous colorectal cancer (HGM CRC) is particularly aggressive, prone to metastasis and treatment resistance, frequently accompanied by "signet ring" cancer cells. A sizeable fraction of HGM CRCs (20-40%) arises in the context of the Lynch Syndrome, an autosomal hereditary syndrome that predisposes to microsatellite instable (MSI) CRC. Development of patient-derived preclinical models for this challenging subtype of colorectal cancer represents an unmet need in oncology. We describe here successful propagation of preclinical models from a case of early-onset, MSI-positive metastatic colorectal cancer in a male Lynch syndrome patient, refractory to standard care (FOLFOX6, FOLFIRI-Panitumumab) and, surprisingly, also to immunotherapy. Surgical material from a debulking operation was implanted in NOD/SCID mice, successfully yielding one patient-derived xenograft (PDX). PDX explants were subsequently used to generate 2D and 3D cell cultures. Histologically, all models resembled the tumor of origin, displaying a high-grade mucinous phenotype with signet ring cells. For preclinical exploration of alternative treatments, in light of recent findings, we considered inhibition of the proteasome by bortezomib and of the related NEDD8 pathway by pevonedistat. Indeed, sensitivity to bortezomib was observed in mucinous adenocarcinoma of the lung, and we previously found that HGM CRC is preferentially sensitive to pevonedistat in models with low or absent expression of cadherin 17 (CDH17), a differentiation marker. We therefore performed IHC on the tumor and models, and observed no CDH17 expression, suggesting sensitivity to pevonedistat. Both bortezomib and pevonedistat showed strong activity on 2D cells at 72 hours and on 3D organoids at 7 days, thus providing valid options for in vivo testing. Accordingly, three PDX cohorts were treated for four weeks, respectively with vehicle, bortezomib and pevonedistat. Both drugs significantly reduced tumor growth, as compared to the vehicle group. Interestingly, while bortezomib was more effective in vitro, pevonedistat was more effective in vivo. Drug efficacy was further substantiated by a reduction of cellularity and of Ki67-positive cells in the treated tumors. These results highlight proteasome and NEDD8 inhibition as potentially effective therapeutic approaches against Lynch syndrome-associated HGM CRC, also when the disease is refractory to all available treatment options.

An Analysis of Clinicopathological Outcomes and the Utility of Preoperative MRI for Patients Undergoing Resection of Mucinous and Non-Mucinous Colorectal Cancer Liver Metastases.

Background and Aims: Mucinous colorectal cancer has traditionally been associated with high rates of recurrence and poor long-term survival. There is limited published data on outcomes for patients undergoing liver resection for metastatic mucinous colorectal cancer. The aim of this study was to compare the clinicopathological outcomes for patients with mucinous colorectal cancer liver metastases (CRCLM) undergoing liver resection to a matched group of patients with adenocarcinoma not otherwise specified (NOS) and to evaluate the accurary of preoperative magnetic resonance imaging (MRI) at detecting the presence of mucin in liver metastases. Materials and Methods: Patients with mucinous CRCLM undergoing liver resection were matched 1:3 to patients with adenocarcinoma NOS CRCLM. Clinicopathological data from the primary tumour and metastatic lesion were collected and compared between the groups. Hepatic recurrence-free, disease-free and overall survival were compared between the groups. The ability of preoperative MRI to detect mucin in CRCLM was also evaluated. Results: A total of 25 patients with mucinous CRCLM underwent surgery over the 12-year period and were matched to 75 patients with adenocarcinoma NOS. Clinicopathological findings were similar between the groups. Resection of mucinous CRCLM was feasible and safe with similar levels of morbidity to adenocarcinoma NOS. There were no differences identified in hepatic recurrence-free (p=0.85), disease-free (p=0.25) and overall survival (p=0.98) between the groups. MRI had a sensitivity of 31.3% in detecting the presence of mucin in CRCLM. Conclusion: Patients with mucinous CRCLM in this study had similar outcomes to patients with adenocarcinoma NOS. Based on our findings, histological subtype should not be taken into account when deciding on resectability of CRCLM.

Nanosecond pulsed electric fields impair viability and mucin expression in mucinous colorectal carcinoma cell.

Nanosecond pulsed electric fields (nsPEFs) are a non-thermal technology that can induce a myriad of biological responses and changes in cellular physiology. nsPEFs have gained significant attention as a novel cancer therapy. However, studies investigating the application of nsPEF in mucinous carcinomas are scarce. In this study, we explored several biological responses in two mucinous colorectal adenocarcinoma cell lines, LS 174T and HT-29, to nsPEF treatment. We determined the overall cell survival and viability rates following nsPEF treatment using CCK-8 and colony formation assays. We measured the intracellular effects of nsPEF treatment by analyzing cell cycle distribution, cell apoptosis and mitochondrial potential. We also analyzed mucin production at both mRNA and protein levels. Our results showed that nsPEF treatment significantly reduced mucinous cell viability in a dose-dependent manner. nsPEF treatment increased cell cycles arrest at G0/G1 while the proportion of G2/M cells gradually decreased. Cell apoptosis increased following nsPEF treatment with a clear loss in mitochondrial membrane potential. Furthermore, the protein expression of functional mucin family members decreased after nsPEF treatment. In conclusion, nsPEF treatment reduced MCRC cell viability, cell proliferation, and mucin protein production while promoted apoptosis. Our work is a pilot study that projects some insights into the potential clinical applications of nsPEFs in treating mucinous colorectal carcinoma.

Clinicopathological characteristics and survival outcomes for patients with mucinous colorectal cancer liver metastases undergoing hepatic resection: A systematic review and meta-analysis.

BACKGROUND: Mucinous adenocarcinoma represents a distinct histological subtype of colorectal cancer. To date there has been limited data available for patients with colorectal cancer liver metastases (CRCLM) derived from mucinous adenocarcinoma. This systematic review and meta-analysis aims to provide data on the clinicopathological and survival outcomes of this cohort. METHODS: Databases were searched for studies comparing clinicopathological and survival outcomes between patients with mucinous CRCLM and CRCLM from adenocarcinoma not otherwise specified who underwent liver resection. A random-effects model was used for analysis. RESULTS: Eight studies describing 9157 patients were included. Mucinous CRCLM were positively associated with colon tumors (OR 1⋅64, P = 0⋅01), T3/T4 tumors (OR 1⋅58, P = 0⋅02), node positive tumors (OR 1⋅55, P = 0⋅005). The review also identified a trend towards worse overall survival in patients with mucinous CRCLM. CONCLUSIONS: Despite the distinct clinicopathological characteristics and impaired long term outcomes of mucinous CRCLM, resection should remain the gold standard where possible.

Advanced mucinous colorectal carcinoma in a 14-year old male child: A case report and review of the literature.

INTRODUCTION: ColorectaI carcinoma is extremely rare in children and presents with a poor prognosis. PRESENTATION OF CASE: The present report describes the case of a 14-year old male child who presented with complaints of general weakness and recurrent abdominal pain, caused by a mucinous adenocarcinoma of the transverse colon (Dukes stage which was inoperable. DISCUSSION: Mucinous histopathological type is the most common type with increased ability to invade the adjacent stromal tissue. This biological behaviour has been reported to be attributable to its aggressive behaviour. Additionally, delay of diagnosis of colorectal carcinoma in children accounts for the advanced disease at diagnosis. CONCLUSION: Colorectal carcinoma occurring in both children and adolescents usually have poor prognosis because of not having specific symptoms which contributes to delay of diagnosis. Mimicking of its symptoms with other non-malignant conditions such as intestinal obstruction and acute appendicitis also has been found to contribute to delay of diagnosis as it was in our present case.

Thymidylate synthase, topoisomerase-1 and microsatellite instability: relationship with outcome in mucinous colorectal cancer treated with fluorouracil.

BACKGROUND: Mucinous colorectal cancer (CRC) exhibits distinct clinical and pathological features, including poorer response to fluorouracil (FU) compared with non-mucinous tumours. PATIENTS AND METHODS: We compared the expression of thymidylate synthase (TYMS) and topoisomerase-1 (TOPO1) and DNA microsatellite instability (MSI) in 87 patients (35 mucinous and 52 non-mucinous CRCs) enrolled in three randomized trials, evaluating infused FU as first-line treatment. RESULTS: Mucinous CRCs more frequently had high TOPO1 expression than did non-mucinous tumors (41% vs. 15%, p=0.028). The median overall survival was 14.2 months for patients with mucinous CRC with low TOPO1 expression compared with 9.7 months for high TOPO1-expressing cases (p=0.016). After adjusting for confounding variables, low TOPO1 expression was statistically favourably associated with overall survival (hazard ratio=0.55; p=0.041). CONCLUSION: Our data suggest the TOPO1 expression levels to be a prognostic marker in patients with mucinous CRC treated with FU. If further verified, these data might redefine therapeutic strategies by identifying categories of patients with a worse prognosis.

Polymorphism of the 5,10-Methylenetetrahydrofolate Reductase (MTHFR) Gene and Microsatellite Instability (MSI) in Mucinous Colorectal Cancer

PURPOSE: Generally, a mucinous carcinoma (Muc) of the colon show higher rates of microsatellite instability (MSI) than a non-mucinous carcinoma (non-Muc). Mutated methylenetetrahydrofolate reductase (MTHFR) brings about low enzyme activity, which may reduce genomic DNA methylation. These processes may be critical for the oncogenic transformation of human cells. We compared the relationship of MSI and MTHFR polymorphism in Muc to that in non-Muc. METHODS: From March 2003 to August 2007, genomic DNA was isolated from whole blood and tissue specimens of 285 colorectal cancer patients (Muc: 31 cases, non-Muc: 254 cases) and 448 normal control patients. These were subjected to MSI analysis and MTHFR genotyping by using PCR-based restriction fragment length polymorphism analyses. RESULTS: MSI was significantly more frequent in the Muc group (40.7%) than in the non- Muc group (14.8%). The frequencies of polymorphism of MTHFR 677C>T were CC (31.5%), CT (57%), and TT (11.5%) in the patient group and 32.4%, 53.1%, and 14.5% in the control group. In the Muc group, the frequencies of polymorphism of MTHFR 677C>T were CC (36%), CT (56%), TT (8%), and in the non-Muc group, they were 31.1%, 57%, and 11.9%. The frequencies of polymorphism of MTHFR 1298A>C were AA (73%), AC (21.3%), and CC (5.7%) in the patient group and 69.6%, 28.6%, and 1.8% in the control group. In the Muc group, the frequencies of polymorphism of MTHFR 1298A>C were AA (50%), AC (30%), and CC (20%), and in the non-Muc group, they were 76%, 20.3%, and 3.7%. The Muc group showed higher frequencies of the CC variant than the non-Muc group (P-value=0.018). No relation between MSI and MTHFR polymorphisms were seen in any comparison of the Muc and the non-Muc groups. CONCLUSIONS: The Muc group showed higher rates of MSI than the non-Muc group, but no definite difference between the Muc and the non-Muc groups was noted in the case of polymorphism of MTHFR 677C>T. However, the TT-type variant showed slightly lower frequencies in the Muc group than in the non-Muc group. On the contrary, the Muc group showed a higher rate of the CC variant in polymorphism of MTHFR 1298A>C. These inconsistent results seem to be due to the small size of the Muc group, so further study is needed.