Case report: Spinal cord stimulation for pain relief in two patients with locally recurrent pelvic malignancy.

Introduction: Chronic cancer-related pain from locally recurrent infiltrative cancers within the bony confines of the pelvis is a devastating and hard to manage condition that can be refractory to many conventional pain management methods. Spinal cord stimulation (SCS) is an evolving and safe method of pain management and can be trialled in a quick and well-tolerated operation under local anaesthesia. To date, this has not been reported in the setting of locally recurrent inoperable pelvic cancers. Case description: In the present study, we report two cases of patients with severe back and lower limb pain resulting from recurrent anal and rectal cancers involving the right lumbar and sacral nerve roots as well as the bony sacrum, which severely affected quality of life and daily functioning. Discussion: Following successful SCS, effective pain relief was observed. Conclusion: SCS could represent an effective supplementary or alternative technique to conventional pain management in this challenging group of patients, especially if other available methods have been exhausted.

Empty pelvis syndrome: a systematic review of reconstruction techniques and their associated complications.

AIM: Empty pelvis syndrome is a major contributor to morbidity following pelvic exenteration. Several techniques for filling the pelvis have been proposed; however, there is no consensus on the best approach. We evaluated and compared the complications associated with each reconstruction technique with the aim of determining which is associated with the lowest incidence of complications related to the empty pelvis. METHOD: The systematic review protocol was prospectively registered with PROSPERO (CRD42021239307). PRISMA-P guidelines were used to present the literature. PubMed and MEDLINE were systematically searched up to 1 February 2021. A dataset containing predetermined primary and secondary outcomes was extracted. RESULTS: Eighteen studies fulfilled our criteria; these included 375 patients with mainly rectal and gynaecological cancer. Only three studies had a follow-up greater than 2 years. Six surgical interventions were identified. Mesh reconstruction and breast prosthesis were associated with low rates of small bowel obstruction (SBO), entero-cutaneous fistulas and perineal hernia. Findings for myocutaneous flaps were similar; however, they were associated with high rates of perineal wound complications. Omentoplasty was found to have a high perineal wound infection rate (40%). Obstetric balloons were found to have the highest rates of perineal wound dehiscence and SBO. Silicone expanders effectively kept small bowel out of the pelvis, although rates of pelvic collections remained high (20%). CONCLUSION: The morbidity associated with an empty pelvis remains considerable. Given the low quality of the evidence with small patient numbers, strong conclusions in favour of a certain technique and comparison of these interventions remains challenging.

Network Mapping of Molecular Biomarkers Influencing Radiation Response in Rectal Cancer.

Preoperative radiotherapy (RT) plays an important role in the management of locally advanced rectal cancer (RC). Tumor regression after RT shows marked variability, and robust molecular methods are needed to help predict likely response. The aim of this study was to review the current published literature and use Gene Ontology (GO) analysis to define key molecular biomarkers governing radiation response in RC. A systematic review of electronic bibliographic databases (Medline, Embase) was performed for original articles published between 2000 and 2015. Biomarkers were then classified according to biological function and incorporated into a hierarchical GO tree. Both significant and nonsignificant results were included in the analysis. Significance was binarized on the basis of univariate and multivariate statistics. Significance scores were calculated for each biological domain (or node), and a direct acyclic graph was generated for intuitive mapping of biological pathways and markers involved in RC radiation response. Seventy-two individual biomarkers across 74 studies were identified. On highest-order classification, molecular biomarkers falling within the domains of response to stress, cellular metabolism, and pathways inhibiting apoptosis were found to be the most influential in predicting radiosensitivity. Homogenizing biomarker data from original articles using controlled GO terminology demonstrated that cellular mechanisms of response to RT in RC-in particular the metabolic response to RT-may hold promise in developing radiotherapeutic biomarkers to help predict, and in the future modulate, radiation response.

Novel biomarkers for patient stratification in colorectal cancer: A review of definitions, emerging concepts, and data.

Colorectal cancer (CRC) treatment has become more personalised, incorporating a combination of the individual patient risk assessment, gene testing, and chemotherapy with surgery for optimal care. The improvement of staging with high-resolution imaging has allowed more selective treatments, optimising survival outcomes. The next step is to identify biomarkers that can inform clinicians of expected prognosis and offer the most beneficial treatment, while reducing unnecessary morbidity for the patient. The search for biomarkers in CRC has been of significant interest, with questions remaining on their impact and applicability. The study of biomarkers can be broadly divided into metabolic, molecular, microRNA, epithelial-to-mesenchymal-transition (EMT), and imaging classes. Although numerous molecules have claimed to impact prognosis and treatment, their clinical application has been limited. Furthermore, routine testing of prognostic markers with no demonstrable influence on response to treatment is a questionable practice, as it increases cost and can adversely affect expectations of treatment. In this review we focus on recent developments and emerging biomarkers with potential utility for clinical translation in CRC. We examine and critically appraise novel imaging and molecular-based approaches; evaluate the promising array of microRNAs, analyze metabolic profiles, and highlight key findings for biomarker potential in the EMT pathway.

Long non-coding RNAs within the tumour microenvironment and their role in tumour-stroma cross-talk.

Long non-coding RNAs (lncRNAs) are a diverse class of RNA transcripts which have limited protein coding potential. They perform a variety of cellular functions in health, but have also been implicated during malignant transformation. A further theme in recent years is the critical role of the tumour microenvironment and the dynamic interactions between cancer and stromal cells in promoting invasion and disease progression. Whereas the contribution of deregulated lncRNAs within cancer cells has received considerable attention, their significance within the tumour microenvironment is less well understood. The tumour microenvironment consists of cancer-associated stromal cells and structural extracellular components which interact with one another and with the transformed epithelium via complex extracellular signalling pathways. LncRNAs are directly and indirectly involved in tumour/stroma cross-talk and help stimulate a permissive tumour microenvironment which is more conducive for invasive tumour growth. Furthermore, lncRNAs play key roles in determining the phenotype of cancer associated stromal cells and contribute to angiogenesis and immune evasion pathways, extracellular-matrix (ECM) turnover and the response to hypoxic stress. Here we explore the multifaceted roles of lncRNAs within the tumour microenvironment and their putative pathophysiological effects.

Cytoreductive surgery and intraperitoneal chemotherapy for colorectal peritoneal metastases.

AIM: To systematically review the available evidence regarding cytoreductive surgery (CRS) and intraperitoneal chemotherapy (IPC) for colorectal peritoneal metastases (CPM). METHODS: An electronic literature search was carried out to identify publications reporting oncological outcome data (overall survival and/or disease free survival and/or recurrence rates) following CRS and IPC for treatment of CPM. Studies reporting outcomes following CRS and IPC for cancer subtypes other than colorectal were only included if data were reported independently for colorectal cancer-associated cases; in addition studies reporting outcomes for peritoneal carcinomatosis of appendiceal origin were excluded. RESULTS: Twenty seven studies, published between 1999 and 2013 with a combined population of 2838 patients met the predefined inclusion criteria. Included studies comprised 21 case series, 5 case-control studies and 1 randomised controlled trial. Four studies provided comparative oncological outcome data for patients undergoing CRS in combination with IPC vs systemic chemotherapy alone. The primary indication for treatment was CPM in 96% of cases (2714/2838) and recurrent CPM (rCPM) in the remaining 4% (124/2838). In the majority of included studies (20/27) CRS was combined with hyperthermic intraperitoneal chemotherapy (HIPEC). In 3 studies HIPEC was used in combination with early post-operative intraperitoneal chemotherapy (EPIC), and 2 studies used EPIC only, following CRS. Two studies evaluated comparative outcomes with CRS + HIPEC vs CRS + EPIC for treatment of CPM. The delivery of IPC was performed using an "open" or "closed" abdomen approach in the included studies. CONCLUSION: The available evidence presented in this review indicates that enhanced survival times can be achieved for CPM after combined treatment with CRS and IPC.

Molecular profiling of the invasive tumor microenvironment in a 3-dimensional model of colorectal cancer cells and ex vivo fibroblasts.

Invading colorectal cancer (CRC) cells have acquired the capacity to break free from their sister cells, infiltrate the stroma, and remodel the extracellular matrix (ECM). Characterizing the biology of this phenotypically distinct group of cells could substantially improve our understanding of early events during the metastatic cascade. Tumor invasion is a dynamic process facilitated by bidirectional interactions between malignant epithelium and the cancer associated stroma. In order to examine cell-specific responses at the tumor stroma-interface we have combined organotypic co-culture and laser micro-dissection techniques. Organotypic models, in which key stromal constituents such as fibroblasts are 3-dimensionally co-cultured with cancer epithelial cells, are highly manipulatable experimental tools which enable invasion and cancer-stroma interactions to be studied in near-physiological conditions. Laser microdissection (LMD) is a technique which entails the surgical dissection and extraction of the various strata within tumor tissue, with micron level precision. By combining these techniques with genomic, transcriptomic and epigenetic profiling we aim to develop a deeper understanding of the molecular characteristics of invading tumor cells and surrounding stromal tissue, and in doing so potentially reveal novel biomarkers and opportunities for drug development in CRC.

Intraoperative radiotherapy in colorectal cancer: systematic review and meta-analysis of techniques, long-term outcomes, and complications.

BACKGROUND: The precise contribution of IORT to the management of locally advanced and recurrent colorectal cancer (CRC) remains uncertain. We performed a systematic review and meta-analysis to assess the value of IORT in this setting. METHODS: Studies published between 1965 and 2011 that reported outcomes after IORT for advanced or recurrent CRC were identified by an electronic literature search. Studies were assessed for methodological quality and design, and evaluated for technique of IORT delivery, oncological outcomes, and complications following IORT. Outcomes were analysed with fixed-effect and random-effect model meta-analyses and heterogeneity and publication bias examined. RESULTS: 29 studies comprising 14 prospective and 15 retrospective studies met the inclusion criteria and were assessed, yielding a total of 3003 patients. The indication for IORT was locally advanced disease in 1792 patients and locally recurrent disease in 1211 patients. Despite heterogeneity in methodology and reporting practice, IORT is principally applied for the treatment of close or positive margins. When comparative studies were evaluated, a significant effect favouring improved local control (OR 0.22; 95% CI = 0.05-0.86; p = 0.03), disease free survival (HR 0.51; 95% CI = 0.31-0.85; p = 0.009), and overall survival (HR 0.33; 95% CI = 0.2-0.54; p = 0.001) was noted with no increase in total (OR 1.13; 95% CI = 0.77-1.65; p = 0.57), urologic (OR 1.35; 95% CI = 0.84-2.82; p = 0.47), or anastomotic complications (OR 0.94; 95% CI = 0.42-2.1; p = 0.98). Increased wound complications were noted after IORT (OR 1.86; 95% CI = 1.03-3.38; p = 0.049). CONCLUSIONS: Despite methodological weaknesses in the studies evaluated, our results suggest that IORT may improve oncological outcomes in advanced and recurrent CRC.

Short- and long-term outcomes after laparoscopic and open hepatic resection: systematic review and meta-analysis.

BACKGROUND: Laparoscopic liver resection (LLR) is now considered a feasible alternative to open liver resection (OLR) in selected patients. Nevertheless studies comparing LLR and OLR are few and concerns remain about long-term oncological equivalence. The present study compares outcomes with LLR vs. OLR using meta-analytical methods. METHODS: Electronic literature searches were conducted to identify studies comparing LLR and OLR. Short-term outcomes evaluated included operating time, blood loss, length of hospital stay, peri-operative morbidity and resection margin status. Longer-term outcomes included local and distant recurrence, and overall (OS) and disease-free survival (DFS). Meta-analyses were performed using the Mantel-Haenszel method and Cohen's d method, with results expressed as odds ratio (OR) or standardized mean difference (SMD), respectively, with 95% confidence intervals (CI). RESULTS: Twenty-six studies met the inclusion criteria with a population of 1678 patients. LLR resulted in longer operating time, but reduced blood loss, portal clamp time, overall and liver-specific complications, ileus and length of stay. No difference was found between LLR and OLR for oncological outcomes. DISCUSSION: LLR has short-term advantages and seemingly equivalent long-term outcomes and can be considered a feasible alternative to open surgery in experienced hands.

Increased local recurrence and reduced survival from colorectal cancer following anastomotic leak: systematic review and meta-analysis.

OBJECTIVE: To examine the long-term oncological impact of anastomotic leakage (AL) after restorative surgery for colorectal cancer using meta-analytical methods. Outcomes evaluated were local recurrence, distant recurrence, and survival. BACKGROUND: Recurrence after potentially curative surgery for colorectal cancer remains a significant clinical problem and has a poor prognosis. AL may be a risk factor for disease recurrence, however available studies have been conflicting. A meta-analysis was conducted to investigate the impact of AL on disease recurrence and long-term survival. METHODS: Studies published between 1965 and 2009 evaluating the long-term oncological impact of AL were identified by an electronic literature search. Outcomes evaluated included local recurrence, distant recurrence, and cancer specific survival. Meta-analysis was performed using the DerSimonian-Laird random-effects model to compute odds ratio and 95% confidence intervals. Study heterogeneity was evaluated using Q statistics and I and publication bias assessed with funnel plots and Egger's test. RESULTS: Twenty-one studies comprising 13 prospective nonrandomized studies, 1 prospective randomized, and 7 retrospective studies met the inclusion criteria, yielding a total of 21,902 patients. For rectal anastomoses, the odd ratios (OR) of developing a local recurrence when there was AL was 2.05 (95% CI = 1.51-2.8; P = 0.0001). For studies describing both colon and rectal anastomoses, the OR of local recurrence when there was an AL was 2.9 (95% CI = 1.78-4.71; P < 0.001). The OR of developing a distant recurrence after AL was 1.38 (95% CI = 0.96-1.99; P = 0.083). Long term cancer specific mortality was significantly higher after AL with an OR of 1.75 (95% CI = 1.47-2.1; P = 0.0001). CONCLUSIONS: AL has a negative prognostic impact on local recurrence after restorative resection of rectal cancer. A significant association between colorectal AL and reduced long-term cancer specific survival was also noted. No association between AL and distant recurrence was found.

Clinical algorithms for the surgical management of locally recurrent rectal cancer.

PURPOSE: Advances in surgical practice have helped expand the options for patients with locally recurrent rectal cancer through improvements in reconstructive options, management of operative complications, addition of intraoperative adjuvant therapies, and postoperative care. This review outlines the presentation and management of patients with locally recurrent rectal cancer, and it describes easy-to-apply clinical algorithms to aid management. METHODS: The electronic literature was searched for studies reporting outcomes for locally recurrent rectal cancer limited to the English language. RESULTS: Prospective and retrospective case series and single-center experiences were identified. A total of 106 articles were selected for full-text review of which 82 fulfilled the inclusion criteria. No randomized studies were identified. We found that multimodality treatment of locally recurrent rectal cancer can improve 5-year survival from 0% to over 40%, and selected patients may survive up to 10 years. A mixture of imaging modalities is used in patient selection for surgery. An R0 resection is consistently a favorable prognostic factor. R1 resection and surgery in the setting of oligometastases compare favorably with nonoperative palliation. Although mortality figures remain low, morbidity is significant and mostly wound related. CONCLUSIONS: Improvements in radiological imaging modalities and technical improvements in surgical and reconstructive options have facilitated more accurate staging, better selection of patients for surgery, reduced morbidity and mortality, and higher R0 resections. Optimal management is in specialist units with a multidisciplinary approach with the use of multimodal therapy.

Role of the unique N-terminal domain of CtBP2 in determining the subcellular localisation of CtBP family proteins.

BACKGROUND: CtBP1 and CtBP2 are transcriptional co-repressors that modulate the activity of a large number of transcriptional repressors via the recruitment of chromatin modifiers. Many CtBP-regulated proteins are involved in pathways associated with tumorigenesis, including TGF-beta and Wnt signalling pathways and cell cycle regulators such as RB/p130 and HDM2, as well as adenovirus E1A. CtBP1 and CtBP2 are highly similar proteins, although evidence is emerging that their activity can be differentially regulated, particularly through the control of their subcellular localisation. CtBP2s from diverse species contain a unique N-terminus, absent in CtBP1 that plays a key role in controlling the nuclear-cytoplasmic distribution of the protein. RESULTS: Here we show that amino acids (a.a.) 4-14 of CtBP2 direct CtBP2 into an almost exclusively nuclear distribution in cell lines of diverse origins. Whilst this sequence contains similarity to known nuclear localisation motifs, it cannot drive nuclear localisation of a heterologous protein, but rather has been shown to function as a p300 acetyltransferase-dependent nuclear retention sequence. Here we define the region of CtBP2 required to co-operate with a.a. 4-14 to promote CtBP2 nuclear accumulation as being within a.a. 1-119. In addition, we show that a.a. 120-445 of CtBP2 can also promote CtBP2 nuclear accumulation, independently of a.a. 4-14. Finally, CtBP1 and CtBP2 can form heterodimers, and we show that the interaction with CtBP2 is one mechanism whereby CtBP1 can be recruited to the nucleus. CONCLUSION: Together, these findings represent key distinctions in the regulation of the functions of CtBP family members that may have important implications as to their roles in development, and cell differentiation and survival.

Hdm2 recruits a hypoxia-sensitive corepressor to negatively regulate p53-dependent transcription.

The transcription factor p53 lies at the center of a protein network that controls cell cycle progression and commitment to apoptosis. p53 is inactive in proliferating cells, largely because of negative regulation by the Hdm2/Mdm2 oncoprotein, with which it physically associates. Release from this negative regulation is sufficient to activate p53 and can be triggered in cells by multiple stimuli through diverse pathways. This diversity is achieved in part because Hdm2 uses multiple mechanisms to inactivate p53; it targets p53 for ubiquitination and degradation by the proteosome, shuttles it out of the nucleus and into the cytoplasm, prevents its interaction with transcriptional coactivators, and contains an intrinsic transcriptional repressor activity. Here we show that Hdm2 can also repress p53 activity through the recruitment of a known transcriptional corepressor, hCtBP2. This interaction, and consequent repression of p53-dependent transcription, is relieved under hypoxia or hypoxia-mimicking conditions that are known to increase levels of intracellular NADH. CtBP proteins can undergo an NADH-induced conformational change, which we show here results in a loss of their Hdm2 binding ability. This pathway represents a novel mechanism whereby p53 activity can be induced by cellular stress.