Correlation between PSOGI pathological classification and survival outcomes of patients with pseudomyxoma peritonei treated using cytoreductive surgery and HIPEC: national referral centre experience and literature review

Objectives

The Peritoneal Surface Oncology Group International (PSOGI) consensus subdivided pseudomyxoma peritonei (PMP) into four groups according to histopathological features. The aim of this paper is to report survival outcomes after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) from a national referral centre and to correlate the PSOGI classification with survival.

Methods

A retrospective study of a prospectively maintained database was performed. Consecutive patients treated with CRS + HIPEC for PMP of appendiceal origin were included (September-2013 to December-2021). Pathological features of the peritoneal disease were used to classify patients into the four groups proposed by PSOGI. Survival analysis was performed to evaluate the correlation of pathology on overall survival (OS) and disease-free survival (DFS).

Results

Overall, 104 patients were identified; 29.6 % were reclassified as acellular mucin (AM), 43.9 % as low-grade mucinous carcinoma peritonei (LGMCP), 22.4 % as high-grade MCP (HGMCP) and 4.1 % as HGMCP with signet ring cells (HGMCP-SRC). Median PCI and rate of optimal cytoreduction were 19 and 82.7 %, respectively. Median OS and DFS were not reached, 5-year OS and DFS were 88.6(SD 0.04) % and 61.6(SD 0.06) %, respectively. Log-Rank test revealed significant differences in terms of OS and DFS across the different histological subgroups (p<0.001 in both cases). However, histology did not retain its significance in the multivariate analysis for OS or DFS (p=0.932 and p=0.872, respectively).

Conclusions

Survival outcomes after CRS + HIPEC for PMP are excellent. The PSOGI pathological classification correlates with OS and DFS, but differences were not significant at multivariate analysis when adjusted for other prognostic factors.

Rectal neuroendocrine tumours and the role of emerging endoscopic techniques

Rectal neuroendocrine tumours represent a rare colorectal tumour with a 10 fold increased prevalence due to incidental detection in the era of colorectal screening. Patient outcomes with early diagnosis are excellent. However endoscopic recognition of this lesion is variable and misdiagnosis can result in suboptimal endoscopic resection with subsequent uncertainty in relation to optimal long-term management. Endoscopic techniques have shown particular utility in managing this under-recognized neuroendocrine tumour.

Rates and outcomes of testing for lynch syndrome in a national colorectal cancer screening programme

BACKGROUND

Lynch Syndrome (LS), the most common cause of hereditary colorectal cancer (CRC), is characterised by pathogenic variants in mismatch repair (MMR) genes. Universal testing of all CRCs for LS can increase detection. Rates and outcomes of testing in Ireland's national CRC screening programme have not been examined previously.

METHODS

CRCs diagnosed at two screening sites between 2015 and 2020 were identified. Patient records were used to determine if CRCs had been tested for MMR deficiency and if detected, what downstream testing to rule out LS or genetic testing to confirm LS was undertaken.

RESULTS

Over five years, 206 CRCs were diagnosed. Testing for LS was carried out for 100% of CRCs at site A and 69% of CRCs at site B. Of CRCs tested for LS, 14 (8%) were MMR deficient. After downstream testing for BRAF mutation or hypermethylation of MLH1, three CRCs were identified as potentially LS-related. Of these two individuals declined genetic testing and one was lost to follow-up.

CONCLUSIONS

By 2020 both sites had implemented universal testing of all CRCs for LS. A small number of individuals were identified as being eligible for genetic testing for LS, however those offered declined testing and one individual was lost to follow up. This highlights the importance of universal testing and the need for referral pathways to ensure all appropriate individuals are referred onwards to genetic services.

Examination of the functional and diagnostic potential of methylation-sensitive enhancers in metastatic colorectal cancer

TPS237

Background: Molecular characterisation of colorectal cancer (CRC) has demonstrated the regulatory role of epigenetic alterations, such as DNA methylation, in CRC tumorigenesis(1). Robust molecular profiling of CRC has the potential to provide critical diagnostic and prognostic information. The establishment of 4 consensus molecular subtypes (CMSs), developed initially for primary CRC tumours, resulted in the evolving framework for molecularly targeted interventions; the molecular genetic profile characterising mCRC is less well defined(3, 4). Previous pilot work identified a unique tumour-specific methylation sequence, at 376 sites within the DNA of mCRC cells(5). This study will assess whether this methylation sequence drives mCRC pathogenesis and underpins disease phenotype. The primary aim of this study is validation of the diagnostic utility of this novel enhancer signature and identification of key enhancers with the potential to direct targeted treatment development. Secondary aims include CRISPR knockdown library development targeting the enhancers in CRC cells in vitro, evaluating the impact of the knockdown on phenotype in vitro, and identifying the mechanisms by which methylation-sensitive enhancers regulate the mCRC phenotype. Methods: This is a retrospective, non-interventional, single-centre clinical study, including patients > 18 years, with (group A) de novo mCRC (n = 100), (group B) stage III colorectal cancer that subsequently relapsed (n = 100) or (group C) stage III colorectal cancer without radiological evidence of relapse at study enrolment (n = 100). Formalin-fixed, paraffin-embedded ( FFPE) tissue obtained at diagnosis will be analysed. Additionally, 50 stage III patients who have relapsed (group B) will have blood samples collected prospectively at time of consent to enable assessment for the presence of the methylation signature on ctDNA. The presence or absence of the novel methylation signature will be evaluated via the application of a targeted bisulfite sequencing panel consisting of the previously identified differentially methylated enhancer (DME) signature to both tissue and plasma samples; results will be correlated with conventional histological parameters, systemic therapy, and overall survival. Quantitative statistical analysis will be performed using SPSS with linear regression analysis for survival data. Ethical approval was obtained from the MMUH Institutional Review Board; reference 1/378/2188. This study is open and recruiting. Clinical trial information: 1/378/2188.

Pragmatic use of short-course radiotherapy, chemotherapy and surgery for stage IV rectal cancer with locally advanced or symptomatic primary tumours

INTRODUCTION

We assessed management of patients with de novo metastatic rectal cancer, referred for radiotherapy to the rectum, who were candidates for short-course radiotherapy (SCRT) and chemotherapy, followed by resection of all disease. We assessed surgical outcomes, overall survival (OS) and progression-free survival (PFS).

METHODS

Retrospective review of patients meeting criteria: (i) treatment with SCRT to rectum; (ii) locally advanced primary rectal cancer; and (iii) resectable distant metastases at diagnosis. Data were collected from charts, correspondence and electronic patient records. OS and PFS were calculated using the Kaplan-Meier method.

RESULTS

Between 2016 and 2020, 48 patients with stage IV rectal cancer at diagnosis were treated with SCRT. Only 15 patients (31%) had resectable metastatic disease and were intended for SCRT (25 Gy/5#), then chemotherapy, followed by resection of all sites of disease and are included in our study. 12 of the 15 surgical candidates (80%) had rectal surgery as planned, and 11 of the 15 (73%) had resection of the rectal primary and all metastatic disease. One patient had a pathological complete response (pCR), and 50% of surgical patients had a Mandard TRG of 1 or 2. Median PFS and OS for the 15 surgical candidates were 12.6 and 25.2 months, respectively, with a median FU of 21.2 months.

CONCLUSION

For this cohort of patients, our treatment paradigm is pragmatic and results in excellent pathological response. However, the effectiveness of this approach should be the subject of future prospective studies.

The incidence of Epstein-Barr Virus-associated gastric cancer in an Irish population

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Background: Gastric adenocarcinoma is the fourth most frequent cancer worldwide and the second leading cause of cancer deaths. According to The Cancer Genome Atlas (TCGA) 9% of gastric carcinomas are associated with Epstein-Barr Virus (EBV). EBV- associated gastric carcinoma (EBV-GC) has distinct clinicopathological features, with a marked lymphocytic infiltrate, a generally diffuse histological type and a better prognosis. The immune cell infiltration in EBV-GC suggests a role for immune checkpoint inhibition, which currently has modest activity in unselected gastric cancer. Methods: All cases of gastric or junctional adenocarcinoma diagnosed between Jan 2019 and March 2020 in Mater Misericordiae University Hospital (MMUH) and Jan 2017 and Jan 2019 in Cork University Hospital (CUH) were identified. Electronic medical records were retrospectively reviewed to collect demographic and clinicopathological data such as AJCC TNM stage, tumour subtype and grade, HER-2 status, MMR proficiency and EBV status as determined by EBV-encoded RNA in situ hybridization. Results: N = 103 cases of gastric or junctional adenocarcinoma were identified. 67 male, 36 female, median age 64.5 (range 34 – 95). 40/103 had undergone surgical resection. EBER-ISH was assessed in all patients. 8 of 103 (7.8%) patients showed EBV positivity. These cases were all male patients, median age 62 (range 51-73). The tumours were located as follows; 2 in the cardia, 5 in the body and 1 not documented. The specimens were graded as; 87.5% (7/8) tumours being poorly differentiated and 1/8 moderate to poorly differentiated. The tumour subtypes were specified as; 62.5% (5/8) diffuse, 12.5% (1/8) intestinal and 25% (2/8) mixed intestinal and diffuse. 5/8 patients were locally confined and underwent resection for N0 disease. 3/8 (37.5%) patients had metastatic disease. None of the 8 EBV-GC cases were identified as being HER-2 positive or MMR-deficient. Conclusions: EBV-GC accounted for 7.8% of all gastric cancers in two large tertiary referral centres in Ireland. 37.5% of these patients had metastatic disease. Given this frequency and a possible predictive role in selecting for immunotherapy we conclude that routine assessment of EBV status is feasible in advanced gastric cancer.

Linking Circulating Serum Proteins with Clinical Outcomes in Esophageal Adenocarcinoma-An Emerging Role for Chemokines

Simple Summary

Cancer of the esophagus (food pipe) is an aggressive type of cancer with poor prognosis and rates are increasing. Current treatments help to prolong survival but only for a minority of patients, therefore there is an urgent need to discover why some people do not respond and to develop new and improved treatments. Newer treatments targeting the immune system show promise but the anti-tumor immune response in esophageal cancer is not well understood. This study measured levels of 54 immune markers in serum of patients with esophageal cancer and evaluated a link with patient clinical outcomes, e.g., survival time, response to treatment, and adverse events. We found that certain chemokines, proteins which control immune cell trafficking, were particularly high in patients who survived longer (CCL22 and CCL26) and responded to treatment (CCL4), suggesting the importance of immune cell movement in orchestrating an effective immune response to esophageal cancer.

Abstract

Esophageal adenocarcinoma (EAC) is an aggressive cancer with poor prognosis and incidence is increasing rapidly in the Western world. Multi-modal treatment has improved survival outcomes but only for a minority of patients. Currently no markers have been identified to predict treatment response. This study investigated the association between clinical outcomes and pre-treatment levels of 54 serum proteins in n = 80 patients with EAC. Low tumor regression grade (TRG), corresponding to a favorable treatment response, was linked to prolonged overall survival (OS). CCL4 was higher in patients with a favorable treatment response, while Tie2 and CRP were higher in poor responders. Elevated CCL22 and CCL26 was associated with improved OS, while elevated IL-10 showed a negative association. CCL3, CCL4, IL-1α and IL-12/IL23p40 were highest in individuals with no adverse features of tumor biology, whereas levels of Tie2 and VEGF were lowest in this cohort. CCL4 was also elevated in patients with high tumor lymphocyte infiltration. Comparison of matched pre- and post-treatment serum (n = 28) showed a large reduction in VEGFC, and a concomitant increase in other cytokines, including CCL4. These data link several serum markers with clinical outcomes, highlighting an important role for immune cell trafficking in the EAC antitumor immune response.

A pilot study of avelumab in Epstein-Barr virus-associated gastric cancer

TPS473

Background: Gastric Cancer (GC) is the third most common cause of cancer related deaths worldwide. The median overall survival of patients with stage 4 disease is approximately 1 year. Current accepted treatment approach with chemotherapy is applied with little consideration for known genetic or biologic heterogeneity. Whilst immune-based approaches in GC look promising it is clear that single-agent PD1/PDL1 inhibition benefit a minority. We must clarify a means of identifying prospectively those patients who may benefit from this treatment. A recent landmark paper by The Cancer Genome Atlas (TCGA) proposed a classification of GC into four subtypes: Epstein-Barr-virus (EBV)-positive, microsatellite instable (MSI), chromosomal instable (CI), and genomically stable (GS). Two of the four – EBV and MSI subtypes – are likely to be immunogenic and amenable to PD1/PDL1 inhibition. Recent advances have shown EBV-positive tumors to be infiltrated by lymphocytes and be enriched for PDL1. Methods: This single centre single-arm pilot study in gastric or junctional adenocarcinoma will explore the hypothesis that administering anti-PDL1 therapy (Avelumab) in a prospectively identified population enriched for potential responders will result in improved outcomes. The anticipated frequency of EBV associated-GC (c10%) means that approximately N = 100 patients will be screened to identify N = 10 participants. If a positive signal for efficacy is seen this will provide a basis for a larger, multicentre study. Previously treated Patients with confirmation of stage 4 EBV- positive gastric or oesophago-gastric adenocarcinoma meeting eligibility criteria will be enrolled. Avelumab will be administered at a dose of 10mg/kg IV every 14days. Primary endpoint is to determine the 6-month progression free survival (PFS) of Avelumab in EBV-associated GC. Secondary endpoints include overall response rate, overall survival, median PFS time and feasibility/accrual rate at 12 months. Exploratory endpoints will be to evaluate changes in immune parameters in the peripheral blood over time. Kaplan-Meier methods for primary efficacy endpoint with two-tailed one-sample proportion test will be used to evaluate the evidence to reject the null hypothesis. Clinical trial information: 2018-002085-39.

Comprehensive transcriptome analysis reveals link between epigenetic dysregulation, endogenous retrovirus expression and immunogenicity in metastatic colorectal carcinoma

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Background: Endogenous retrovirus (ERV) elements represent genomic footprints of ancestral retroviral infections within the human genome. Previous studies have demonstrated increases in ERV mRNA as a result of DNA hypomethylation, and ERV transcription has been associated with increased immunogenicity in metastatic renal cell carcinoma. We performed comprehensive bioinformatics analysis of ERV transcription in metastatic colorectal carcinoma (mCRC), to identify novel links between ERV transcription, epigenetic dysregulation and immunogenicity in metastatic colorectal carcinoma (mCRC). Methods: Tumour samples from 63 patients with mCRC were subjected to RNA sequencing as part of the Personalized OncoGenomics program (POG; NCT02155621) at BC Cancer. Patients were enrolled between 07/2012-07/2017. ERV transcription was quantified across 702,533 distinct loci. Tumors were classified ERV-hi if their total ERV expression (RPKM) was greater than the mean across all samples. High antiviral gene expression tumors (AVG-hi) were designated as having a mean expression of IFIH1, DDX58, TLR3, TANK, TBKBP1, TBK1, IRF3 and IRF7 that was greater than the mean across all samples. All pairwise comparisons of gene expression were subjected to multiple hypothesis correction. Results: Median age was 59 years, with 34 (54%) male and 1 tumor microsatellite unstable. ERV-hi tumors showed increased expression of DNA demethylators TET2 ( q=0.0045) and TET3 ( q<0.0001). Significant overlap existed between ERV-hi and AVG-hi tumors (18/27, p=0.016). Tumors both ERV-hi and AVG-hi trended towards increased PD-L1 expression (p=0.055) and showed a significant increase in survival compared to tumors with high antiviral expression in the absence of high ERV transcription (p=0.0043). Conclusions: Our results suggest DNA demethylation drives increased ERV transcription and ERV-associated immunogenicity in mCRC. Moreover, we provide novel insight into the impact of ERV transcription on the biology of mCRC, highlighting ERV transcription as a potential biomarker and target for precision immunotherapy. Clinical trial information: NCT02155621.

RNAs as Candidate Diagnostic and Prognostic Markers of Prostate Cancer-From Cell Line Models to Liquid Biopsies

The treatment landscape of prostate cancer has evolved rapidly over the past five years. The explosion in treatment advances has been witnessed in parallel with significant progress in the field of molecular biomarkers. The advent of next-generation sequencing has enabled the molecular profiling of the genomic and transcriptomic architecture of prostate and other cancers. Coupled with this, is a renewed interest in the role of non-coding RNA (ncRNA) in prostate cancer biology. ncRNA consists of several different classes including small non-coding RNA (sncRNA), long non-coding RNA (lncRNA), and circular RNA (circRNA). These families are under active investigation, given their essential roles in cancer initiation, development and progression. This review focuses on the evidence for the role of RNAs in prostate cancer, and their use as diagnostic and prognostic markers, and targets for treatment in this disease.

Carcinogenesis in prostate cancer: The role of long non-coding RNAs

LncRNAs appear to play a considerable role in tumourigenesis through regulating key processes in cancer cells such as proliferative signalling, replicative immortality, invasion and metastasis, evasion of growth suppressors, induction of angiogenesis and resistance to apoptosis. LncRNAs have been reported to play a role in prostate cancer, particularly in regulating the androgen receptor signalling pathway. In this review article, we summarise the role of 34 lncRNAs in prostate cancer with a particular focus on their role in the androgen receptor signalling pathway and the epithelial to mesenchymal transition pathway.

Does human immunodeficiency virus status affect early wound healing in open surgically stabilised tibial fractures?: A prospective study

We compared early post-operative rates of wound infection in HIV-positive and -negative patients presenting with open tibial fractures managed with surgical fixation. The wounds of 84 patients (85 fractures), 28 of whom were HIV positive and 56 were HIV negative, were assessed for signs of infection using the ASEPIS wound score. There were 19 women and 65 men with a mean age of 34.8 years. A total of 57 fractures (17 HIV-positive, 40 HIV-negative) treated with external fixation were also assessed using the Checkett score for pin-site infection. The remaining 28 fractures were treated with internal fixation. No significant difference in early post-operative wound infection between the two groups of patients was found (10.7% (n = 3) vs 19.6% (n = 11); relative risk (RR) 0.55 (95% confidence interval (CI) 0.17 to 1.8); p = 0.32). There was also no significant difference in pin-site infection rates (17.6% (n = 3) vs 12.5% (n = 5); RR 1.62 (95% CI 0.44 to 6.07); p = 0.47). The study does not support the hypothesis that HIV significantly increases the rate of early wound or pin-site infection in open tibial fractures. We would therefore suggest that a patient's HIV status should not alter the management of open tibial fractures in patients who have a CD4 count > 350 cells/μl.

The effect of HIV on early wound healing in open fractures treated with internal and external fixation

There are 33 million people worldwide currently infected with human immunodeficiency virus (HIV). This complex disease affects many of the processes involved in wound and fracture healing, and there is little evidence available to guide the management of open fractures in these patients. Fears of acute and delayed infection often inhibit the use of fixation, which may be the most effective way of achieving union.

This study compared fixation of open fractures in HIV-positive and -negative patients in South Africa, a country with very high rates of both HIV and high-energy trauma. A total of 133 patients (33 HIV-positive) with 135 open fractures fulfilled the inclusion criteria. This cohort is three times larger than in any similar previously published study.

The results suggest that HIV is not a contraindication to internal or external fixation of open fractures in this population, as HIV is not a significant risk factor for acute wound/implant infection. However, subgroup analysis of grade I open fractures in patients with advanced HIV and a low CD4 count (< 350) showed an increased risk of infection; we suggest that grade I open fractures in patients with advanced HIV should be treated by early debridement followed by fixation at an appropriate time.

Rural palliative care volunteer education and support program

The present paper looks at the challenges of palliative care delivery in rural and remote areas and proposes the establishment, education and coordination of a network of palliative care volunteers to assist in the delivery of non-clinical services. The development of a rural palliative care volunteer education and support training package is documented, together with details of the trailing of the package and its evaluation. Possible benefits of the program and some key issues to be considered when establishing a volunteer network are raised.

Thymus dependence of the immune response: response to the haptenic determinant NIP in mice

Normal, deprived (thymectomized, irradiated) and reconstituted (thymectomized, irradiated, thymus grafted) CBA mice were immunized with either a polyvalent or a mainly monovalent conjugate of the hapten 3-iodo-4-hydroxy-5-nitrophenylacetic acid and bovine serum albumin. The humoral antibody response to the hapten was determined by the phage inactivation technique.

The response of deprived mice was always significantly lower than the response of either normal or reconstituted animals. However, by increasing the dose of antigen in these mice it was possible to elicit some degree of responsiveness, but only in those groups which had received the polyvalent conjugate.