Defining Benchmarks for Pelvic Exenteration Surgery: A Multicentre Analysis of Patients with Locally Advanced and Recurrent Rectal Cancer.

OBJECTIVE: To establish globally applicable benchmark outcomes for pelvic exenteration (PE) in patients with locally advanced primary (LARC) and recurrent rectal cancer (LRRC), using outcomes achieved at highly specialised centres. BACKGROUND DATA: PE is established as the standard of care for selected patients with LARC and LRRC. There are currently no available benchmarks against which surgical performance in PE can be compared for audit and quality improvement. METHODS: This international multicentre retrospective cohort study included patients undergoing PE for LARC or LRRC at 16 highly experienced centres between 2018 and 2023. Ten outcome benchmarks were established in a lower-risk subgroup. Benchmarks were defined by the 75th percentile of the results achieved at the individual centres. RESULTS: 763 patients underwent PE, of which 464 patients (61%) had LARC and 299 (39%) had LRRC. 544 patients (71%) who met predefined lower risk criteria formed the benchmark cohort. For LARC patients, the calculated benchmark threshold for major complication rate was ≤44%; comprehensive complication index (CCI): ≤30.2; 30-day mortality rate: 0%; 90-day mortality rate: ≤4.3%; R0 resection rate: ≥79%. For LRRC patients, the calculated benchmark threshold for major complication rate was ≤53%; CCI: ≤34.1; 30-day mortality rate: 0%; 90-day mortality rate: ≤6%; R0 resection rate: ≥77%. CONCLUSIONS: The reported benchmarks for PE in patients with LARC and LRRC represent the best available care for this patient group globally and can be used for rigorous assessment of surgical quality and to facilitate quality improvement initiatives at international exenteration centres.

Variation in outcome measurement and reporting in studies of pelvic exenteration for locally advanced and recurrent rectal cancer: a systematic review.

AIM: There is increasing research interest in pelvic exenteration for locally advanced and recurrent rectal cancer. Heterogeneity in outcome reporting can prevent meaningful interpretation and valid synthesis of pooled data and meta-analyses. The aim of this study was to assess homogeneity in outcome measures in the current pelvic exenteration literature. METHOD: MEDLINE, Embase, CENTRAL, CINAHL and Scopus databases were searched from 1990 to 25 April 2023 to identify studies reporting outcomes of pelvic exenteration for locally advanced or recurrent rectal cancer. All reported outcomes were extracted, merged with those of similar meaning and assigned a domain. RESULTS: Of 4137 abstracts screened, 156 studies met the inclusion criteria. A total of 2765 outcomes were reported, of which 17% were accompanied by a definition. There were 1157 unique outcomes, merged into 84 standardized outcomes and assigned one of seven domains. The most reported domains were complications (147 studies, 94%), survival (127, 81%) and surgical outcomes (123, 79%). Resection margins were reported in 122 studies (78%): the definition of a clear resection margin was not provided in 45 studies (37%), it was unclear in 11 studies (9%) and not specified beyond microscopically 'clear' or 'negative' in 31 (28%). Measurements of 2, 1, 0.5 mm and any healthy tissue were all used to define R0 margins. CONCLUSION: There is significant heterogeneity in outcome measurement and reporting in the current pelvic exenteration literature, raising concerns about the validity of comparative or collaborative studies between centres and meta-analyses. Coordinated international collaboration is required to define core outcome sets and benchmarks.

Long-term surgical complications following pelvic exenteration: Operative management of the empty pelvis syndrome.

AIM: Pelvic exenteration (PE) has become the standard of care for locally advanced and recurrent rectal cancer. The high short-term morbidity reported from this procedure is well established; however, longer term complications of such radical surgery and their management have not been fully addressed. This study aimed to investigate the incidence, indications and outcomes of long-term (more than 90-day) reoperative surgery in this group of patients, with a focus on the empty pelvis syndrome (EPS). METHODS: Clinical data were extracted from a prospectively maintained database, with additional data pertaining to indications, operative details and outcomes of reoperative surgery obtained from electronic medical records. Patients were excluded if reoperative surgery was endoscopic or radiologically guided, was for the investigation or treatment of recurrent disease, or was clearly unrelated to previous surgery. RESULTS: Of 716 patients who underwent PE, 75 (11%) required 101 reoperative abdominal or perineal procedures, 52 (51%) of which were in 40 (6%) patients for complications of EPS. This group were more likely to have undergone a total PE (65% vs. 43%; P < 0.01) with either major bony (70% vs. 50%; P < 0.01) and/or nerve (40% vs. 25%; P = 0.03) resections at index exenteration. The patho-anatomy, surgical management and outcomes of these patients are described herein, considering separately complications of entero-cutaneous fistula, entero-perineal fistula, small bowel obstruction and local management of perineal wound complications. CONCLUSION: Six per cent of PE patients will require re-intervention for the management of EPS. Reliable strategies for preventing EPS remain elusive; however, surgical management is feasible with acceptable short-term outcomes with the optimum strategy to be selected on an individual patient basis.

Specific mutations in KRAS codon 12 are associated with worse overall survival in patients with advanced and recurrent colorectal cancer.

BACKGROUND: Activating mutations in KRAS have been suggested as potential predictive and prognostic biomarkers. However, the prognostic impact of specific point mutations remains less clear. This study assessed the prognostic impact of specific KRAS mutations on survival for patients with colorectal cancer. METHODS: Retrospective review of patients KRAS typed for advanced and recurrent colorectal cancer between 2010 and 2015 in a UK Cancer Network. RESULTS: We evaluated the impact of KRAS genotype in 392 patients. Mutated KRAS was detected in 42.9% of tumours. KRAS mutations were more common in moderate vs well-differentiated tumours. On multivariate analysis, primary tumour T stage (HR 2.77 (1.54-4.98), P=0.001), N stage (HR 1.51 (1.01-2.26), P=0.04), curative intent surgery (HR 0.51 (0.34-0.76), P=0.001), tumour grade (HR 0.44 (0.30-0.65), P=0.001) and KRAS mutation (1.54 (1.23-2.12), P=0.005) were all predictive of overall survival. Patients with KRAS codon 12 mutations had worse overall survival (HR 1.76 (95% CI 1.27-2.43), P=0.001). Among the five most common codon 12 mutations, only p.G12C (HR 2.21 (1.15-4.25), P=0.01) and p.G12V (HR 1.69 (1.08-2.62), P=0.02) were predictive of overall survival. CONCLUSIONS: For patients with colorectal cancer, p.G12C and p.G12V mutations in codon 12 were independently associated with worse overall survival after diagnosis.

Class Type Separation of the Polar and Apolar Components of Petroleum.

Identification of the heteroatom (nitrogen, sulfur, and oxygen)-containing compounds of petroleum is of key importance when considering industrial and environmental issues associated with crude oil production. The more commonly performed methods of crude oil fractionation are often insufficient in the extent to which they separate oils, not allowing defined "molecular" fractions to be obtained. Methods capable of performing a class type separation are uncommon and are often extensive and resource and time intensive. Here we report a method for the separation of crude oils into discrete compound classes. The method utilizes both ion exchange and normal phase chromatography to generate fractions of saturated hydrocarbons, aromatic hydrocarbons, basic compounds, naphthenic acids, and other oxygen-containing species, carbazoles, sulfones, and thiophenes from small crude oil samples (∼0.5 g). Assessment of method selectivity with a suite of model compounds has shown the fractions to be well-defined, with classes of model compounds isolated within discrete fractions. Application of the method to five crude oils of varying API gravity (12.1-38.3°) demonstrates a potential for wide-ranging use. Sample recoveries were high (77-98%) with simple evaporative losses correlating closely with total sample loss. Repeatability was also high, demonstrated by triplicate analyses of model compound mixtures, oils spiked with model compounds and oils alone. Separation selectivity was further demonstrated by application of the scheme to the Alaska North Slope (ANS) crude oil and analysis of fractions by comprehensive two-dimensional gas-chromatography mass-spectrometry (GC × GC/MS) and/or liquid-chromatography high-resolution accurate-mass mass-spectrometry methods (LC-HRAM-MS). Isolation of discrete fractions then allowed excellent separation (by LC and GC methods) of carbazole, dibenzothiophene, fluorenones, xanthones, and quinoline fractions. Individual parent and C1-5 alkyl homologues were easily separated (GC × GC/MS), allowing high-quality mass spectra (EI) to be obtained for the individual compounds in many cases. Analysis of fractions by GC × GC/MS also allowed a series of thioxanones to be identified.

If speed is of the essence: rapid analysis of ambergris by APCI compact mass spectrometry.

The use of atmospheric pressure chemical ionisation (APCI) compact mass spectrometry (CMS) was investigated for the analysis of jetsam and museum-archived ambergris and of ambergris components in perfumes. The data were compared with those from existing methods. Authentic samples of some individual ambergris constituents (ambrein, coprostanol, epicoprostanol and coprostanone), were also examined. Rapid APCI CMS was achieved using either a solids probe or a probe with solutions held in capillary melting point tubes. Interpretation is made of the spectra of the principal natural product components, the relative ion responses were measured and the elemental composition of key ions in the spectra confirmed using high resolution accurate mass APCI MS. Rapid analysis of ambergris by APCI CMS may prove to be a further convenient method of identifying ambrein, of measuring the relative ratios of ambrein and steroids in ambergris and even of quantifying the latter, with minimal sample preparation.

Chemical analysis of flotsam ambergris.

The natural product ambergris is only found rarely on beaches, as jetsam. Even more scarce, or even absent, are accounts of flotsam ambergris. Here, we report the chemical analysis of a rare, large piece (>100kg) of flotsam found in the Atlantic in 2019. About 95% of subsamples from the outside of the coprolith was soluble in dichloromethane. Of this, FTIR spectroscopy, APCI-MS and GC-MS indicated the presence of ambrein. Radiocarbon dating indicated that the sample was post 1950s in age. The 13C/12C isotope ratio (-22.5 ‰) was typical of those reported to date for whale 'body' ambergris. Metals of ambergris have hardly been reported previously. The distribution found here for the flotsam, was dominated by copper and zinc, which is similar to that of several squid species. This is also consistent with the presence of squid beaks in the coprolith. Squid are a major prey species of sperm whales.

Myoferlin: a potential marker of response to radiotherapy and survival in locally advanced rectal cancer.

PURPOSE: Patients with locally advanced rectal cancer often require neo-adjuvant chemoradiotherapy to downstage the disease, but the response is variable with no predictive biomarkers. We have previously revealed through proteomic profiling that myoferlin is associated with response to radiotherapy. The aims of this study were to further validate this finding and explore the potential for myoferlin to act as a prognostic and/or therapeutic target. MATERIALS AND METHODS: Immunohistochemical analysis of a tissue microarray for 111 patients was used to validate the initial proteomic findings. Manipulation of myoferlin was achieved using siRNA, a small molecular inhibitor (wj460) and a CRISPR-Cas9 knockout cell line. Radiosensitisation following treatment was assessed using 2D clonogenic assays, 3D spheroid models and patient derived organoids. Underlying mechanisms were investigated using electrophoresis, immunofluorescence and immunoblotting. RESULTS: Analysis of both the diagnostic biopsy and tumour resection samples confirmed that low myoferlin expression correlated with a good response to neoadjuvant LCRT. High myoferlin expression was associated with spread to local lymph nodes and worse 5-year survival (p = 0.01, HR 3.5, 95%CI [1.27, 10.04]). This was externally validated using the S:CORT database. Quantification of myoferlin using immunoblotting in immortalised colorectal cancer cell lines and organoids demonstrated that high myoferlin expression was associated with increased radioresistance. Biological and pharmacological manipulation of myoferlin resulted in significantly increased radiosensitivity across all cell lines in 2D and 3D models. Following irradiation, myoferlin knockdown cells had a significantly impaired ability to repair DNA double strand breaks. This appeared to be mediated via non-homologous end-joining. CONCLUSIONS: We have confirmed that high expression of myoferlin in rectal cancer is associated with poor response to neoadjuvant therapy and worse long-term survival. Furthermore, the manipulation of myoferlin led to increased radiosensitivity in vitro. This suggests that myoferlin could be targeted to enhance the sensitivity of rectal cancer patients to radiotherapy and further work is required.

Patients Undergoing Systemic Anti-Cancer Therapy Who Require Surgical Intervention: What Surgeons Need to Know.

As part of routine cancer care, patients may undergo elective surgery with the aim of long-term cure. Some of these patients will receive systemic anti-cancer therapy (SACT) in the neoadjuvant and adjuvant settings. The majority of patients, usually with locally advanced or metastatic disease, will receive SACT with palliative intent. These treatment options are expanding beyond traditional chemotherapy to include targeted therapies, immunotherapy, hormone therapy, radionuclide therapy and gene therapy. During treatment, some patients will require surgical intervention on an urgent or emergency basis. This narrative review examined the evidence base for SACT-associated surgical risk and the precautions that a surgical team should consider in patients undergoing SACT.

Fluorescence-guided surgery: comprehensive review.

BACKGROUND: Despite significant improvements in preoperative workup and surgical planning, surgeons often rely on their eyes and hands during surgery. Although this can be sufficient in some patients, intraoperative guidance is highly desirable. Near-infrared fluorescence has been advocated as a potential technique to guide surgeons during surgery. METHODS: A literature search was conducted to identify relevant articles for fluorescence-guided surgery. The literature search was performed using Medical Subject Headings on PubMed for articles in English until November 2022 and a narrative review undertaken. RESULTS: The use of invisible light, enabling real-time imaging, superior penetration depth, and the possibility to use targeted imaging agents, makes this optical imaging technique increasingly popular. Four main indications are described in this review: tissue perfusion, lymph node assessment, anatomy of vital structures, and tumour tissue imaging. Furthermore, this review provides an overview of future opportunities in the field of fluorescence-guided surgery. CONCLUSION: Fluorescence-guided surgery has proven to be a widely innovative technique applicable in many fields of surgery. The potential indications for its use are diverse and can be combined. The big challenge for the future will be in bringing experimental fluorophores and conjugates through trials and into clinical practice, as well as validation of computer visualization with large data sets. This will require collaborative surgical groups focusing on utility, efficacy, and outcomes for these techniques.

Characterizations and comparison of low sulfur fuel oils compliant with 2020 global sulfur cap regulation for international shipping.

The International Marine Organization 2020 Global Sulfur Cap requires ships to burn fuels with <0.50% S and some countries require <0.10% S in certain Sulfur Emission Control Areas but little is known about these new types of fuels. Using both traditional GC-MS and more advanced chromatographic and mass spectrometry techniques, plus stable isotopic, δ13C and δ2H, analyses of pristane, phytane and n-alkanes, the organic components of a suite of three 0.50% S and three 0.10% S compliant fuels were characterized. Two oils were found to be near identical but all of the remaining oils could be forensically distinguished by comparison of their molecular biomarkers and by the profiles of the heterocyclic parent and alkylated homologues. Oils could also be differentiated by their δ13C and δ2H of n-alkanes and isoprenoids. This study provides important forensic data that may prove invaluable in the event of future oil spills.

Biosynthesis of ambrein in ambergris: evidence from isotopic data and identification of possible intermediates.

Ambrein is found in ambergris, a coprolith occurring in the rectum of the sperm whale. In vitro, ambrein is produced by enzymatic cyclisation of squalene, via a monocyclic intermediate. However, little is known of the in vivo process. In order to find evidence for the reaction in vivo, a comparison was made of the δ13C relative isotopic ratios of ambrein in ambergris with those of co-occurring sterols. A statistically significant difference was noted. This suggests that ambrein originates via a different biosynthetic mechanism from that of the sterols. Examination of the minor constituents of a hydrogenolysed extract of ambergris revealed compounds with a bicyclic polypodane nucleus, rather than those with monocyclic structures. It is hypothesised that in vivo biosynthesis of ambrein proceeds, at least in some cases, via bacterial production of bicyclic polypodenols. The latter are known products of non-concerted squalene (or squalene oxide) cyclisations in other organisms.

MV Wakashio grounding incident in Mauritius 2020: The world's first major spillage of Very Low Sulfur Fuel Oil.

Very Low Sulfur Fuel Oils (VSLFO, <0.5% S) are a new class of marine fuel oils, introduced to meet recent International Maritime Organization regulations. The MV Wakashio was reported to have released 1000 t of VLSFO when it grounded on a reef in Mauritius on 25th July 2020. A field sample of oily residue contaminating the Mauritian coast was collected on 16th August 2020 and compared with the Wakashio fuel oil. Both oils were analyzed for organic and elemental content, and stable isotope ratios δ13C and δ2H measured. Comprehensive two-dimensional gas chromatography with high-resolution mass spectrometry was used to identify and compare biomarkers resistant to weathering. The aromatic content in the VLSFO was relatively low suggesting that the potential for ecosystem harm arising from exposure to toxic components may be less than with traditional fuel oil spills. The Wakashio oil spill is, to our knowledge, the first documented spill involving VLSFO.

Ambrein: a minor, but common constituent of mammalian faeces?

For nearly 200 years, the only natural source of the alcohol ambrein has been coproliths produced in about 1% of sperm whales and in related jetsam. However, the finding of ambrein in adipocere/faeces of human corpses, led us to hypothesise that ambrein might occur in the faeces of other mammals. Herein, we used a recently developed gas chromatography-mass spectrometry method, with suitable derivatisation of the hindered hydroxy group of ambrein, to screen a number of extracts of mammalian faeces. Minor proportions of ambrein were detected in digested human sewage sludge and in the dung of elephant, domestic cattle, giraffe and buffalo. Whether ambrein formation in the terrestrial species is associated with coprolith formation, is unknown, but solid deposits known as enteroliths and fecaliths occur in humans and some domestic animals.

Mass spectrometry of polycyclic tetracarboxylic ('ARN') acids and tetramethyl esters.

Polycyclic C(80) tetracarboxylic (so-called 'ARN') acids are found as calcium salts in deposits which form in certain oilfield pipelines and equipment. Characterisation of these acids is important for improving the prediction and hence avoidance or minimisation of oilfield deposition problems. Although several of the acids have been isolated and characterised (as regioisomeric mixtures) by nuclear magnetic resonance spectroscopy, mass spectrometric methods are likely to be much more useful for the routine analysis of oils and deposits containing the acids. A publication summarising the mass spectra of the purified acids and major derivatives might thus be a very useful source of reference for scientists and technologists studying these unusual compounds. We now report the characterisation of several of the purified acids and of the tetramethyl esters by electrospray ionisation mass spectrometry (ESI-MS) in both positive ion and negative ion modes, by multistage ESI-MS with a suggested rationalisation of the ions produced, by positive ion atmospheric solids analysis probe (ASAP) atmospheric pressure chemical ionisation (APCI), and by positive ion electron ionisation (EI)-MS. Tentative identifications of C(80) acyclic, mono-, bi- and tricylic tetraacids and the δ(13)C isotope values of a mixture of the semi-pure acids determined by MS are also reported for the first time.

Volatile and semi-volatile components of jetsam ambergris.

Volatile and semi-volatile compounds account for the odors, long valued in the perfumery industry, of the natural product, ambergris. Here we demonstrate application of solid phase micro extraction (SPME) and gas chromatography-mass spectrometry (GC-MS) to headspace analysis of the volatiles and semi-volatiles of jetsam ambergris. The samples collected in 2017/2018, ranged from a black, sticky material from New Zealand, likely recently ejected from a sperm whale, to a white solid found on a beach in Chile and radiocarbon-dated previously to be about 1000 years old. The traces of volatile/semi-volatile compounds extracted included, odorous γ-dihydroionone and odor-free pristane (2,6,10,14-tetramethylpentadecane), as the major constituents. The ratios of these to one another and to many other minor constituents, varied, depending on sample color and age.