Somatic symptom severity, depression and anxiety associations with pancreatitis and undifferentiated abdominal pain in surgical inpatients.

BACKGROUND: Somatic Symptom Disorder is a psychiatric diagnosis that describes the experience of physical symptoms and associated distress, that is disproportionate to recognized organic pathology. Somatic symptom severity (SSS) may be associated with some surgical diagnoses; particularly the complex pain associated with pancreatitis, or the diagnostic ambiguity of undifferentiated abdominal pain (UAP). We aimed to estimate the prevalence of SSS in different diagnostic groups in surgical inpatients with abdominal pain; and to estimate the magnitude and direction of any association of SSS, anxiety and depression. METHODS: Cross sectional analysis (n = 465) of adult admissions with non-traumatic abdominal pain, at a tertiary hospital in Australia. We estimated SSS with the Patient Health Questionnaire-15 (PHQ-15), depression with the Patient Health Questionnaire (PHQ-9) and anxiety with the General Anxiety Disorder (GAD-7), at standard cut-points ≥ 10; comparing acute pancreatitis (n = 20), chronic pancreatitis (n = 18) and UAP (n = 64) versus other causes of abdominal pain. RESULTS: Somatic symptoms were common, 52% having moderate and 19.6% severe SSS. There was an association between moderate SSS and pancreatitis (OR 2.11, 95% CI 1.05-4.25) and depressive symptoms and chronic pancreatitis (OR = 3.47, 95% CI 1.31-9.24). There was no significant association between the four mental health categories and UAP. CONCLUSIONS: SSS and psychological comorbidity were common in a surgical inpatients admitted for abdominal pain and equally represented across most diagnostic sub-groups. However, the pancreatitis sub-group had greater proportions with clinically significant SSS and depression, suggesting that they have a higher requirement for psychological assessment and intervention.

Getting back 'home' after emergency laparotomy: how many never make it?

BACKGROUND: Emergency laparotomy (EL) is performed on about 15 500 patients in Australia each year. Aside from mortality there is significant concern about the possibility that previously independent patients discharged after EL will become reliant on long-term dependent care. This study aimed to establish the proportion of patients not returning to their pre-admission residence, a proxy for dependent care, following EL. METHODS: Data were collected on all adult patients who underwent EL across four Australian hospitals over 2 years. A total of 113 data points were collected including pre-hospital residence, discharge destination, mortality and place of residence at 90 and 365 days. RESULTS: A total of 782 patients underwent EL, the mean age was 64 years. Pre-admission, 95.5% of patients were living in their own home. Inpatient mortality was 7.0% and at discharge 72.4% of patients returned directly back to their pre-hospital residence. At 90 days, mortality was 10.5%, and 87% of patients had returned to their pre-hospital residence, including all patients under 70 years of age. By 365 days, overall mortality was 16.8%, and only 1.5% of patients (all aged >70 years) had not returned to their pre-hospital residence. CONCLUSION: Patients who survive 90 and 365 days following EL nearly all return to their pre-hospital residence, with only a very small proportion of previously independent patients entering dependent care. This should help inform shared decision-making regarding emergency laparotomy in the acute setting.

Evaluation of a Multi-Gene Methylation Blood-Test for the Detection of Colorectal Cancer.

Circulating tumour DNA biomarkers are an expanding field in oncology research that offer great potential but are currently often limited in value by overall cost. The aim of this study was to evaluate the efficacy of a novel multi-gene methylation blood test for the identification of colorectal cancer and throughout the spectrum of colorectal disease. Participants were recruited either prior to resection for known CRC or prior to screening colonoscopy after a positive faecal immunochemical test. Blood was collected from participants prior to their procedure being performed. The plasma was separated, and multiplex MethylLight droplet digital PCR was used to analyse for the presence of four methylated genes: SDC2, NPY, IKZF1 and SEPT9. A total of 537 participants underwent analysis. The SDC2/NPY genes showed a sensitivity of 33-54% and a specificity of 72-96%, whilst the IKZF1/SEPT9 genes showed a sensitivity of 19-42% and a specificity of 88-96%. Combining the two tests did not significantly increase the test accuracy. The sensitivity for advanced adenoma was 2-15%. There was a significant difference in the frequency of detectable methylation between the participants with CRC and those without CRC. However, neither the sensitivity nor the specificity was superior to current diagnostic screening tests.

Increased mucosal eosinophils in colonic diverticulosis and diverticular disease.

AIMS: Eosinophils contribute to tissue homeostasis, damage, and repair. The mucosa of colonic diverticula has not been evaluated for eosinophils by quantitative histology. We aimed to investigate whether mucosal eosinophils and other immune cells are increased in colonic diverticula. METHODS: Hematoxylin and eosin stained sections from colonic surgical resections (n = 82) containing diverticula were examined. Eosinophils, neutrophils, and lymphocytes, in five high power fields in the lamina propria were counted at the base, neck, and ostia of the diverticulum and counts compared to non-diverticula mucosa. The cohort was further subgrouped by elective and emergency surgical indications. RESULTS: Following an initial review of 10 surgical resections from patients with diverticulosis, a total of 82 patients with colonic resections containing diverticula from the descending colon were evaluated (median age 71.5, 42 M/40F). Eosinophil counts for the entire cohort were increased in the base and neck (median 99 and 42, both P = <0.001) compared with the control location (median 16). Eosinophil counts remained significantly increased in the diverticula base (both P = <0.001) and neck (P = 0.01 and <0.001, respectively) in both elective and emergency cases. Lymphocytes were also significantly increased at the diverticula base compared to controls in both elective and emergency subgroups. CONCLUSION: Eosinophils are significantly and most strikingly increased within the diverticulum in resected colonic diverticula. While these observations are novel, the role of eosinophil and chronic inflammation is as yet unclear in the pathophysiology of colonic diverticulosis and diverticular disease.

Combining sarcopenia and ASA status to inform emergency laparotomy outcomes: could it be that simple?

BACKGROUND: Risk assessment for emergency laparotomy (EL) is important for guiding decision-making and anticipating the level of perioperative care in acute clinical settings. While established tools such as the American College of Surgeons National Surgical Quality Improvement Program calculator (ACS-NSQIP), the National Emergency Laparotomy Audit Risk Prediction Calculator (NELA) and the Portsmouth Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity calculation (P-POSSUM) are accurate predictors for mortality, there has been increasing recognition of the benefits from including measurements for frailty in a simple and quantifiable manner. Psoas muscle to 3rd lumbar vertebra area ratio (PM:L3) measured on CT scans was proven to have a significant inverse association with 30-, 90- and 365-day mortality in EL patients. METHODS: A retrospective analysis was conducted of 500 patients admitted to four Australian hospitals who underwent EL during 2016-2017, and had contemporaneous abdomino-pelvic CT scans. Radiological sarcopenia was measured as PM:L3 ratios. ASC-NSQIP, NELA and P-POSSUM were retrospectively calculated. Univariate and multivariate logistic regression modelling was used to assess these ratios and scores, as well as American Society of Anaesthesiologists (ASA) classification separated into ASA I-III and IV/V (simplified ASA), as potential predictors of 30-, 90- and 365-day mortality. RESULTS: PM:L3, simplified ASA, ACS-NSQIP, NELA and P-POSSUM were each statistically significant predictors of 30-day, 90-day and 365-day mortality (P < 0.001). Logistic regression models of 30-, 90- and 365-day mortality combining PM:L3 (P = 0.001) and simplified ASA (P < 0.001) exhibited AUCs of 0.838 (0.780, 0.896), 0.805 (0.751, 0.860) and 0.775 (0.729, 0.822), respectively, which were comparable to that of ACS-NSQIP and NELA. CONCLUSION: Combining the semi-physiological parameter ASA classification with PM:L3 provides a quick and simple alternative to the more complex established risk assessment scores and is superior to PM:L3 alone.

A pilot study: intraoperative 16S rRNA sequencing versus culture in predicting colorectal incisional surgical site infection.

BACKGROUND: Surgical Site Infection (SSI) of the abdominal incision is a dreaded complication following colorectal surgery. Identifying the intraoperative surgical site microbes may provide clarity in the pathogenesis of SSIs. Genomic sequencing has revolutionized the ability to identify microbes from clinical samples. Utilization of 16S rRNA amplicon sequencing to characterize the intraoperative surgical site may provide the critical information required to predict and prevent infection in colorectal surgery. METHODS: This is a pilot, prospective observational study of 50 patients undergoing elective colorectal resection. At completion of surgery, prior to skin closure, swabs were taken from the subcutaneous tissue of the abdominal incision to investigate the microbial profile. Dual swabs were taken to compare standard culture technique and 16S rRNA sequencing to establish if a microbial profile was associated with postoperative SSI. RESULTS: 8/50 patients developed an SSI, which was more likely in those undergoing open surgery (5/15 33.3% versus 3/35, 8.6%; P = 0.029). 16S rRNA amplicon sequencing was more sensitive in microbial detection compared to traditional culture. Both culture and 16S rRNA demonstrated contamination of the surgical site, predominantly with anaerobes. Culture was not statistically predictive of infection. 16S rRNA amplicon sequencing was not statistically predictive of infection, however, it demonstrated patients with an SSI had an increased biodiversity (not significant) and a greater relative abundance (not significant) of pathogens such as Bacteroidacaea and Enterobacteriaceae within the intraoperative site. CONCLUSIONS: 16S rRNA amplicon sequencing has demonstrated a potential difference in the intraoperative microbial profile of those that develop an infection. These findings require validation through powered experiments to determine the overall clinical significance.

Improving colonoscopy prioritisation and promoting the National Bowel Cancer Screening Program: keys to reducing bowel cancer burden.

Australia's National Bowel Cancer Screening Program (NBCSP) has the potential to prevent almost 84 000 bowel cancer deaths if 60% program participation rates could be reached and maintained over the next two decades. Immunochemical faecal occult blood test (iFOBT) is used as an initial screening tool. Participants who test positive are referred for colonoscopy for diagnostic assessment. Concerns about colonoscopy capacity and lengthy wait times between positive iFOBT and colonoscopy have hampered efforts to promote the program. However, a separate research paper published in this issue of PHRP shows that only an estimated 10-14% of Medicare-funded colonoscopies (almost 75% of all colonoscopies) in Australia are generated by the NBCSP. Inappropriate use of colonoscopy as a primary screening tool and failure to prioritise NBCSP participants may be the main reasons for long colonoscopy wait times associated with the program. Promoting clinical practice guidelines, and the Direct Access Colonoscopy initiative for priority patients, are key to reducing colonoscopy wait times and proactive promotion of the NBCSP.

A Systematic Review and Meta-Analysis of Intra-Operative Surgical Site Sampling: Culture versus Culture-Independent Techniques in Predicting Downstream Surgical Site Infection.

Background: Surgical site infection remains a significant cause of morbidity and mortality. Traditionally, the causation has been inferred from the organism(s) detected in the post-operative setting. However, the intra-operative surgical site and the bacteria it harbors have been scarcely studied. Compared with culture-dependent methods, the development of genomic technology provides a new sensitive tool that could aid in characterizing the bacteria within the surgical site. The purpose of this literature review is to establish if there is a predictive role of sampling the intra-operative surgical site. Methods: A systematic literature review was conducted identifying relevant literature reporting on studies that sampled the intra-operative surgical site of any specialty, using either traditional culture or a culture-independent genomic sequencing-based technique and correlation with infection was attempted. The review identified studies between 1959 and 2021 in MEDLINE, EMBASE and Cochrane. Results: The initial search identified 7,835 articles; 36 remained after screening. Thirty-one articles focused on culture-dependent techniques, five on culture-independent. Subgroup meta-analysis demonstrates that a positive intra-operative culture carries a risk of downstream infection with an odds ratio of 8.6, however limited by a high false-positive and inability to correlate the intra-operative culture with the post-operative infection. In contrast, culture-independent studies through genomic sequencing are not predictive but suggest that the surgical incision is a complex microbial community with a shift toward dysbiosis in certain patients. Conclusion: The intra-operative surgical site clearly harbors bacteria. Both techniques give rise to separate explanations underpinning the role of bacteria in surgical site infection. It is possible there is a more complex dynamic community within the incision that makes a patient susceptible to infection. Characterizing this microbial community in large scale studies, including patients with infections may enhance our ability to predict and prevent incisional surgical site infections in patients undergoing surgical procedures.

Somatic symptom severity association with healthcare utilization and costs in surgical inpatients with an episode of abdominal pain.

BACKGROUND: Somatic syndromes are present in 30 per cent of primary healthcare populations and are associated with increased health service use and health costs. Less is known about secondary care surgical inpatient populations. METHODS: This was a prospective longitudinal cohort study (n = 465) of consecutive adult admissions with an episode of non-traumatic abdominal pain, to the Acute General Surgical Unit at a tertiary hospital in New South Wales, Australia. Somatic symptom severity (SSS) was dichotomized using the Patient Health Questionnaire (PHQ)-15 with a cut-off point of 10 or higher (medium-high SSS) and compared pre-admission and during admission. Total healthcare utilization and direct costs were stratified by a PHQ-15 score of 10 or higher. Linear regression was used to examine differences in costs, and a multivariable linear regression was used to examine the relationship of PHQ-15 scores of 10 or higher to total costs, reported as mean total costs of care and percentage difference (95 per cent confidence intervals). RESULTS: Fifty-two per cent (n = 242) of participants had a medium-high SSS with greater pre-admission and admission interval health service costs. Mean total direct costs of care were 25 per cent (95 per cent c.i. 8 to 44 per cent) higher in the PHQ-15 score of 10 or higher group: mean difference €1401.93 (95 per cent c.i. €512.19 to €2273.67). The multivariable model showed a significant association of PHQ-15 scores of 10 or higher (2.1 per cent; 0.2-4.1 per cent greater for each one-point increase in score) with total hospital costs, although the strongest contributions to cost were older age, operative management, and lower socioeconomic level. There was a linear relationship between PHQ scores and total healthcare costs. CONCLUSIONS: Medium to high levels of somatic symptoms are common in surgical inpatients with abdominal pain and are independently associated with greater healthcare utilization.

Parental decision regret among Australian parents after consenting to or refusing hypospadias repair for their son: Results of a survey with controls.

INTRODUCTION: Parental decision regret in hypospadias surgery is a recognised source of long-lasting psycho-social morbidity. High parental decision regret after their child's hypospadias repair is reported. The aim of this study is to report on decision regret in Australian parents, who accepted and declined surgery for their son and explore underlying factors for decision-making, satisfaction, and regret. MATERIALS AND METHODS: An online anonymous survey was administered to three groups of parents: 1) parents who consented for hypospadias repair, 2) parents who declined repair and 3) a control group who requested circumcision for their child. Operations occurred between 2010 and 2020 in two paediatric hospitals in New South Wales, Australia. The survey included a validated decision regret assessment tool and additional questions to explore the possible basis of the opinions. RESULTS: One hundred and eighteen parents (invited - 381, completed - 116, response rate - 31%) participated in the survey. Decision regret was present in group 1 (n = 89) - 55% (moderate-to-severe 15%), in group 2 (n = 14) - 71% (moderate-to-severe 57%), and in the control group (n = 15) - 15% (moderate-to-severe 8%) of parents. There was a significant difference in the median decision regret score between all three groups. Parents who chose hypospadias repair were mostly concerned about function. CONCLUSIONS: The prevalence of decision regret among Australian parents who consented for their son's hypospadias repair was lower compared with the mean decision regret reported in the literature to date (55% vs 65%). Decision regret and its severity were highest among parents who declined hypospadias repair. New strategies are needed to reduce decision regret in parents whether they elect for surgery or not.

Lynch syndrome testing of colorectal cancer patients in a high-income country with universal healthcare: a retrospective study of current practice and gaps in seven australian hospitals.

BACKGROUND: To inform effective genomic medicine strategies, it is important to examine current approaches and gaps in well-established applications. Lynch syndrome (LS) causes 3-5% of colorectal cancers (CRCs). While guidelines commonly recommend LS tumour testing of all CRC patients, implementation in health systems is known to be highly variable. To provide insights on the heterogeneity in practice and current bottlenecks in a high-income country with universal healthcare, we characterise the approaches and gaps in LS testing and referral in seven Australian hospitals across three states. METHODS: We obtained surgery, pathology, and genetics services data for 1,624 patients who underwent CRC resections from 01/01/2017 to 31/12/2018 in the included hospitals. RESULTS: Tumour testing approaches differed between hospitals, with 0-19% of patients missing mismatch repair deficiency test results (total 211/1,624 patients). Tumour tests to exclude somatic MLH1 loss were incomplete at five hospitals (42/187 patients). Of 74 patients with tumour tests completed appropriately and indicating high risk of LS, 36 (49%) were missing a record of referral to genetics services for diagnostic testing, with higher missingness for older patients (0% of patients aged ≤ 40 years, 76% of patients aged > 70 years). Of 38 patients with high-risk tumour test results and genetics services referral, diagnostic testing was carried out for 25 (89%) and identified a LS pathogenic/likely pathogenic variant for 11 patients (44% of 25; 0.7% of 1,624 patients). CONCLUSIONS: Given the LS testing and referral gaps, further work is needed to identify strategies for successful integration of LS testing into clinical care, and provide a model for hereditary cancers and broader genomic medicine. Standardised reporting may help clinicians interpret tumour test results and initiate further actions.

Sarcopenia 'made simple' and outcomes from emergency laparotomy.

BACKGROUND: Emergency Laparotomy (EL) is recognized as high-risk surgery with high mortality. Established surgical risk assessment tools (NELA Risk Prediction Calculator, P-POSSUM, ACS-NSQIP) are accurate predictors of morbidity and mortality. However, their multicomponent complexity limits their use in practice. Sarcopenia is associated with poorer surgical outcomes. This study tests for an association between a simple measure of radiological sarcopenia and mortality in EL patients in an Australian cohort. METHODS: A retrospective analysis was conducted of 500 patients admitted to four Australian hospitals who underwent EL during 2016-2017. All patients had a contemporaneous abdomino-pelvic CT scan. Radiological sarcopenia was measured as the ratio of total psoas muscle area (PM) to L3 vertebral body cross sectional area (PM:L3). Patients were followed up to 12 months. Primary outcomes were 30-, 90- and 365-day mortality. RESULTS: The mean 30-day mortality predictions for NELA, P-POSSUM and ACS-NSQIP were 11.36%, 17.28% and 11.30% respectively. PM:L3 ratio was associated with 30-, 90- and 365-day mortality (P < 0.001) and sex (P < 0.001) and negatively correlated with age (r = -0.4612; P < 0.001). Radiological sarcopenia had a weak negative correlation with NELA (r = -0.2737; P < 0.001), P-POSSUM (r = -0.1880; P < 0.001) and ACS-NSQIP (r = -0.2351; P < 0.001). The latter three metrics were significantly correlated (r > 0.5696; P < 0.001). CONCLUSION: Radiological sarcopenia (CT-assessed PM:L3) is a significant predictor of mortality in EL patients in Australia. The results of this study suggest that radiological sarcopenia is equivalent to established risk assessment tools. The more timely and easily accessible CT-assessed PM:L3 metric is potentially automatable and may have significant utility in clinical practice.

Using the Patient Health Questionnaire to estimate prevalence and gender differences of somatic symptoms and psychological co-morbidity in a secondary inpatient population with abdominal pain.

BACKGROUND: Somatic disorders and somatic symptoms are common in primary care populations; however, little is known about the prevalence in surgical populations. Identification of inpatients with high somatic symptom burden and psychological co-morbidity could improve access to effective psychological therapies. METHODS: Cross-sectional analysis (n = 465) from a prospective longitudinal cohort study of consecutive adult admissions with non-traumatic abdominal pain, at a tertiary hospital in New South Wales, Australia. We estimated somatic symptom prevalence with the Patient Health Questionnaire-15 at three cut-points: moderate (⩾10), severe (⩾15) and 'bothered a lot' on ⩾3 symptoms; and psychological co-morbidity with the Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7 at standard (⩾10) cut-points. We also examined gender differences for somatic symptoms and psychological co-morbidity. RESULTS: Prevalence was moderate (52%), female predominance (odds ratio = 1.71; 95% confidence interval = [1.18, 2.48]), severe (20%), no gender difference (1.32; [0.83, 2.10]) and 'bothered a lot' on ⩾3 symptoms (53%), female predominance (2.07; [1.42, 3.03]). Co-morbidity of depressive, anxiety and somatic symptoms ranged from 8.2% to 15.9% with no gender differences. CONCLUSION: Somatic symptoms were common and psychological triple co-morbidity occurred in one-sixth of a clinical population admitted for abdominal pain. Co-ordinated surgical and psychological clinical intervention and changes in clinical service organisation may be warranted to provide optimal care.

Variation in Human Research Ethics Committee and governance processes throughout Australia: a need for a uniform approach.

BACKGROUND: In Australia, ethics committees across different states vary in application, requirement and process for the ethical review and approval for clinical research. This may lead to confusion and delays in the enablement of multicentre research projects. This study explores the effect of differing processes for Ethics and Governance in the establishment of the CovidSurg-Cancer study during the global COVID-19 pandemic. METHODS: An anonymous, structured web-based questionnaire was designed using the Research Electronic Data Capture application (REDCap) platform to capture consultant surgeons, fellows, and trainees experience in the ethics application process. 'CovidSurg-Cancer' was an international multicentre collaborative study to assess the impact of COVID-19 on the outcomes of patients undergoing cancer surgery. The ethics process to set up this observational study was used as to explore the differing processes applied across Australia. RESULTS: The CovidSurg-Cancer study was successfully set up in 14 hospitals. Four hospitals approved the study directly as an audit. Of the remaining sites, 10 ethics applications underwent Human Research Ethics Committee review following which two (14%) were subsequently approved as an audit activity and eight hospitals (57%) were given formal ethical approval with waiver of consent. Ethics application acceptance from another Australian Human Research Ethics Committee was provided with six applications; however, only three were reciprocated without the requirement for further agreements. A third of (30%) respondents suggested that the details of the application pathway, process and documentation were unclear. CONCLUSION: Ethics processes are varied across Australia with considerable repetition. A centralized, harmonized application process would enhance collaborative research.

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks.

A systematic scoping review on natural killer cell function in colorectal cancer.

PURPOSE: Natural Killer (NK) cells are a vital part of immune surveillance and have been implicated in colorectal cancer development and prognosis. This systematic review aims to distil the literature on NK cells as it relates to colorectal cancer. METHODS: All published studies over 10 years relating to NK cells and colorectal cancer were reviewed. All studies publishing in English, searchable via pubmed or through reference review and reporting directly on the nature or function of NK cells in colorectal cancer patients were included. Outcomes were determined as alterations or new information regarding NK cells in colorectal cancer patients. RESULTS: Natural killer cells may be implicated in the development of colorectal cancer and may play a role in prognostication of the disease. NK cells are altered by the treatment (both surgical and medical) of colorectal cancer and it seems likely that they will also be a target for manipulation to improve colorectal cancer survival. CONCLUSIONS: NK cell morphology and function are significantly affected by the development of colorectal cancer. Observation of NK cell changes may lead to earlier detection and better prognostication in colorectal cancer. Further study is needed into immunological manipulation of NK cells which may lead to improved colorectal cancer survival.