Pain alleviation and functional improvement: ultra-early patient-reported outcome measures after full endoscopic spine surgery

OBJECTIVE

Questions regarding anticipated pain improvement and functional recovery postsurgery are frequently posed in preoperative consultations. However, a lack of data characterizing outcomes for the first postoperative days only allows for anecdotal answers. Hence, the assessment of ultra-early patient-reported outcome measures (PROMs) is essential for patient-provider communication and patient satisfaction. The aim of this study was to elucidate this research gap by assessing and characterizing PROMs for the first days after full endoscopic spine surgery (FESS).

METHODS

This multicenter study included patients undergoing lumbar FESS from March 2021 to July 2023. After informed consent was provided, data were collected prospectively through a smartphone application. Patients underwent either discectomy or decompression. Analyzed parameters included demographics, surgical details, visual analog scale scores for both back and leg pain, and the Oswestry Disability Index (ODI) score. Data were acquired daily for the 1st postoperative week, as well as after 2 weeks, 3 months, and 6 months.

RESULTS

A total of 182 patients were included, of whom 102 underwent FESS discectomy and 80 underwent FESS decompression. Significant differences between the discectomy and decompression groups were found for age (mean 50.45 ± 15.28 years and 63.85 ± 13.25 years, p < 0.001; respectively), sex (p = 0.007), and surgery duration (73.45 ± 45.23 minutes vs 98.05 ± 46.47 minutes, p < 0.001; respectively). Patients in both groups reported a significant amelioration of leg pain on the 1st postoperative day (discectomy group VAS score: 6.2 ± 2.6 vs 2.4 ± 2.9, p < 0.001; decompression group: 5.3 ± 2.8 vs 1.9 ± 2.2, p < 0.001) and of back pain within the 1st postoperative week (discectomy group VAS score: 5.5 ± 2.8 vs 2.8 ± 2.2, p < 0.001; decompression group: 5.2 ± 2.7 vs 3.1 ± 2.4, p < 0.001). ODI score improvement was most pronounced at the 3-month time point (discectomy group: 21.7 ± 9.1 vs 9.3 ± 9.1, p < 0.001; decompression group: 19.3 ± 7.8 vs 9.9 ± 8.3, p < 0.001). For both groups, pain improvement within the 1st week after surgery was highly predictive of later benefits.

CONCLUSIONS

Ultra-early PROMs reveal an immediate pain improvement after FESS. While the benefits in pain reduction plateaued within the 1st postoperative week for both groups, functional improvements developed over a more extended period. These results illustrate a biphasic rehabilitation process wherein initial pain alleviation transitions into functional improvement over time.

People, places and the climate emergency – the Scottish Place Standard Tool with a climate lens

Since the launch of the Place Standard tool (PST) in Scotland in 2015 awareness has increased of the critical impact of the climate emergency on health and equity. A 2019 review of the PST, informed by emerging evidence and community and stakeholder feedback, confirmed the need to strengthen its contribution towards place-based climate action. This was partly achieved by integrating enhanced prompts within the PST itself, however with the increased focus of policy and action around climate adaptation and mitigation a knowledge and resource gap remained. So in 2020 PST partners* began work with experts from environmental organisations (Sniffer, Sustainable Scotland Network) and other partners to develop a “Place Standard with a climate lens” (PST CL). The PST CL toolkit was created through an iterative process integrating feedback from 10 pilot projects chosen to represent the varied communities, scales, landscapes and placemaking projects being undertaken across Scotland. It provides a suite of materials to use alongside existing PST resources to help placemaking conversations consider how climate change might play out in a local area. This ensures that local responses to climate change are designed holistically, delivered collaboratively, and helps achieve on other local priorities such as health, wellbeing and equity. This presentation will provide a brief overview of the project background, describe the Scottish PST with a climate lens, share case study examples from the piloting phases, and enable exploration of the learning from Scotland around the value of integrating health and climate in place-based approaches. While the Place Standard tool was not originally designed as a climate change tool, it is an effective method to support the design of local responses to the climate emergency. A “climate lens” can help us to plan the future of our places to maximise the health benefits and minimise the negative consequences of a changing climate.

636 Impact of the COVID-19 Pandemic on Emergency Admissions with Colorectal Cancer

Aim

Method

Results

Conclusions

1580 Introduction of Dedicated Boarder’s Bleep and Registrar for Improved Clinical Communication, Management, And Care of Boarder Surgical Patients

Aim

Surgical patients are often placed within non-surgical wards due to shortage of beds, however the care of these patients remains under the parent surgical team. Unfortunately, patients outwith surgical areas can frequently feel neglected, with staff often unsure who to contact for reviews. This project aims to improve communication between boarding wards and the surgical team, as well as improving patient care and management.

Method

This prospective study was based on the Model for Improvement Framework approach to quality improvement. Data was gathered using questionnaires from various staff members on non-surgical wards. Outcomes were measured on a qualitative basis.

Results

Qualitative data was collected from 45 nursing staff (NS). Prior to introduction of a designated boarder’s bleep, 25% of NS felt they knew who to contact for queries and reviews, whereas 46% contacted the parent ward and 29% contacted the on-call surgical registrar. Only 46% of boarded patients received daily reviews. Following introduction of a dedicated surgical registrar for boarders, 62% of NS felt they knew who to contact with 48% aware of surgical boarder’s bleep. Daily reviews of patients increased to 65% over the course of the cycles of this project.

Conclusions

Bed shortages can play a vast role in patient care and treatment. This study has effectively demonstrated an improvement in provision of patient care, demonstrating an increase in NS knowing who to contact, as well as a 19% increase in daily patient reviews. Introduction of a dedicated boarder’s bleep-holder has shown improvement in clinical communication and management.

Structural development of cortical lobes during the first 6 months of life in infant macaques

This study mapped the developmental trajectories of cortical regions in comparison to overall brain growth in typically developing, socially-housed infant macaques. Volumetric changes of cortical brain regions were examined longitudinally between 2-24 weeks of age (equivalent to the first 2 years in humans) in 21 male rhesus macaques. Growth of the prefrontal, frontal, parietal, occipital, and temporal cortices (visual and auditory) was examined using MRI and age-specific infant macaque brain atlases developed by our group. Results indicate that cortical volumetric development follows a cubic growth curve, but maturational timelines and growth rates are region-specific. Total intracranial volume (ICV) increased significantly during the first 5 months of life, leveling off thereafter. Prefrontal and temporal visual cortices showed fast volume increases during the first 16 weeks, followed by a plateau, and significant growth again between 20-24 weeks. Volume of the frontal and temporal auditory cortices increased substantially between 2-24 weeks. The parietal cortex showed a significant volume increase during the first 4 months, whereas the volume of the occipital lobe increased between 2-12 weeks and plateaued thereafter. These developmental trajectories show similarities to cortical growth in human infants, providing foundational information necessary to build nonhuman primate (NHP) models of human neurodevelopmental disorders.

Malignant transformation of tailgut cysts is significantly higher than previously reported: systematic review of cases in the literature

AIM

The best treatment for tailgut cysts has not been firmly established. We report a systematic review of the cases in the available literature in order to provide an evidence base for treatment.

METHOD

A systematic search of articles wholly or partly in English was made of PubMed, Embase and Google Scholar; additional studies were discovered by searching reference lists and contacting authors directly. Search terms 'tailgut cyst', 'tail gut cyst', 'retrorectal hamartoma' and 'retrorectal tumour' were used for case reports or case series; no publication date restrictions were imposed. Only studies with histological confirmation of diagnosis and reporting the age and gender of patients were included. Papers were excluded by consensus between the first two authors.

RESULTS

A total of 196 individual cases were analysed in detail including 51 cases of neoplasia. The overall rate of neoplastic transformation was 26.6%. Although the male:female cyst incidence ratio was 1:4, men over 18 had a significantly greater relative risk of neoplasm at 1.94 (P = 0.0055). Radiological evidence of nodular thickening of the cyst wall significantly increased the relative risk of the presence of cancer (P = 0.0023).

CONCLUSIONS

Current orthodoxy that these are not dangerous embryological remnants is unfounded and may be false. The available data suggest the risk of malignant transformation is high and will apply to any residual tissue after excision. The same rationale behind total mesorectal excision in rectal cancer applies to tailgut cysts. Consequently they should be resected with similar oncological margins.

Read Codes Version 3: A User Led Terminology

Version 3 of the Read Codes was designed in response to a new set of requirements generated by three new terming initiatives in the UK, the Clinical Terms Project, the Professions Allied to Medicine Terms Project and the Nursing Terms Project. The challenge was to cope with the detail required by clinical specialists for maintaining a computerised record, to capture the natural language used by clinicians in their everyday work, and to support efficient analysis across medical records required to extract information from clinicians’ individual patient data. The structure of Version 3 allows a directed acyclic graph to replace the traditional hierarchy; permits multiple such graphs if necessary; introduces qualifiers, embedding these in an information model to support analysis; introduces one-to-many mapping to external classifications where this is necessary; and maintains the tradition of a dynamic terminology that stresses the inclusion of natural clinical terms.

Hydrogels from amphiphilic star block copolypeptides

Star-shaped amphiphilic block copolymers form hydrogels as opposed to their linear counterparts.

Translation research: 'Back on Track', a multiprofessional rehabilitation service for cancer-related fatigue

Objectives

To assess the effectiveness and acceptability of an individually tailored rehabilitation intervention for patients with cancer-related fatigue (CRF).

Methods

Eighteen individuals, (16 female, two male, aged 40–83 years), who self-reported CRF (above four on a 10-point Likert scale) took part in an 8 week physical activity intervention weekly review and optional gym-based support. Fifteen participants had a primary diagnosis of breast cancer and along with the other participants had multiple myeloma, colorectal or prostate cancer. All participants took part in a goal-oriented walking and muscle strengthening programme with dietary advice and psychological support based on the Transtheoretical Model (TTM) of behaviour change. Effectiveness was assessed by physical and psychological outcomes. Focus groups with participants and individual interviews with the professionals delivering the intervention explored the feasibility and acceptability of the intervention.

Results

Statistically significant improvements were seen in the primary outcome of fatigue and on the secondary outcomes of physical function, depression and in triceps skin fold thickness reduction. Participants endorsed the intervention as being highly acceptable, holistic and as important as medical treatments for cancer. The importance of team working was highlighted as key to service delivery and success.

Conclusions

A multidisciplinary home-based tailored intervention with optional weekly gym attendance is acceptable to people with CRF, improving physical and psychosocial outcomes. Study limitations and suggestions for further research are discussed.

Physiotherapists’ use and perspectives on the importance of patient-reported outcome measures for shoulder dysfunction

Background:

Many patient-reported outcome measures (PROs) for shoulder dysfunctions have acceptable psychometric properties. However, the large number of measures that are available present clinicians and researchers with dilemmas in PRO selection. This study set out to determine the perceived importance of PROs, the measures currently used by physiotherapists in clinical practice and research, and the psychometric criteria that are considered important in PRO selection.

Methods:

Delegates at the 2010 International Congress of Shoulder and Elbow Therapists were invited to participate in this cross-sectional observational study. Research Electronic Data Capture (REDCap) web-based tools were used to design an online questionnaire. IRB approval was gained prior to commencement of the study. Anonymised numerical survey data were tallied and frequency counts reported descriptively.

Results:

Participants submitted 101 completed questionnaires, which was an 84% response rate. One or more validated shoulder or upper extremity PROs were used by 91% of clinicians, and 94% of researchers. The use of PROs was considered to be ‘extremely’ or ‘very’ important by the majority of clinicians (76%), and researchers (98%). Most commonly used as a primary outcome by clinicians and researchers respectively were: the Disabilities of the Arm Shoulder Hand Questionnaire (DASH) (40%, 44%) and the Oxford Shoulder Scale (OSS) (36%, 22%); and as secondary outcomes: the DASH (33%, 28%); OSS (17%, 8%), the Shoulder Pain and Disability Index (SPADI) (8%, 18%); and the American Shoulder and Elbow Surgeons standardized assessment form (ASES) (8%, 13%). Psychometric properties and practicality aspects were deemed extremely or very important by 86–96% of participants.

Conclusion:

The majority of clinicians and researchers use a shoulder or upper extremity function or disability questionnaire. This indicates that PROs are considered important in clinical practice and research, and psychometric properties are critical in PRO selection. The DASH, OSS, SPADI and ASES are most commonly used by shoulder therapists in clinical practice and research studies.

Implications:

These findings can be used to aid the development of a consensus on a core set of PROs for shoulder dysfunctions for use by clinicians and researchers.

Exercise and nutrition interventions in advanced lung cancer: a systematic review

In this systematic review, we sought to evaluate the effect of physical activity or nutrition interventions (or both) in adults with advanced non-small-cell lung cancer (nsclc).

METHODS

A systematic search for relevant clinical trials was conducted in 6 electronic databases, by hand searching, and by contacting key investigators. No limits were placed on study language. Information about recruitment rates, protocol adherence, patient-reported and clinical outcome measures, and study conclusions was extracted. Methodologic quality and risk of bias in each study was assessed using validated tools.

MAIN RESULTS

Six papers detailing five studies involving 203 participants met the inclusion criteria. Two of the studies were single-cohort physical activity studies (54 participants), and three were controlled nutrition studies (149 participants). All were conducted in an outpatient setting. None of the included studies combined physical activity with nutrition interventions.

CONCLUSIONS

Our systematic review suggests that exercise and nutrition interventions are not harmful and may have beneficial effects on unintentional weight loss, physical strength, and functional performance in patients with advanced nsclc. However, the observed improvements must be interpreted with caution, because findings were not consistent across the included studies. Moreover, the included studies were small and at significant risk of bias. More research is required to ascertain the optimal physical activity and nutrition interventions in advanced inoperable nsclc. Specifically, the potential benefits of combining physical activity with nutrition counselling have yet to be adequately explored in this population.

Randomised controlled trial adapting US school obesity prevention to England

OBJECTIVES

To determine whether a school obesity prevention project developed in the United States can be adapted for use in England.

METHODS

A pilot cluster randomised controlled trial and interviews with teachers were carried out in 19 primary schools in South West England. Participants included 679 children in year 5 (age 9-10). Baseline and follow-up assessments were completed for 323 children (screen viewing) and 472 children (body mass index). Sixteen lessons on healthy eating, physical activity and reducing TV viewing were taught over 5 months by teachers. Main outcome measures were hours of screen activities, body mass index, mode of transport to school and teachers' views of the intervention.

RESULTS

Children from intervention schools spent less time on screen-viewing activities after the intervention but these differences were imprecisely estimated: mean difference in minutes spent on screen viewing at the end of the intervention (intervention schools minus control schools) adjusted for baseline levels and clustering within schools was -11.6 (95% CI -42.7 to 19.4) for a week day and was -15.4 (95% CI -57.5 to 26.8) for a Saturday. There was no difference in mean body mass index or the odds of obesity.

CONCLUSIONS

It is feasible to transfer this US school-based intervention to UK schools, and it may be effective in reducing the time children spend on screen-based activities. The study has provided information for a full-scale trial, which would require 50 schools ( approximately 1250 pupils) to detect effects on screen viewing and body mass index over 2 years of follow-up.

The impact of published recommendations on the management of penetrating abdominal injury

Background

In patients with penetrating abdominal injury (PAI), haemodynamic instability and peritonitis are indications for laparotomy, but it remains uncertain whether laparotomy is indicated for evisceration, retained foreign body and pneumoperitoneum. In 1989, a review of 107 patients with PAI revealed a 78·5 per cent laparotomy rate, with 35 per cent considered unnecessary. The aim of this study was to review current practice in the same hospitals.

Methods

A retrospective review included case notes from 224 patients with PAI presenting to three hospitals between 2001 and 2005.

Results

Some 206 patients (92·0 per cent) were male and the mean age was 30·5 years. Aetiologies were stabbing (96·4 per cent), impalement (2·7 per cent) and gunshot wound (0·9 per cent). Laparotomy was performed in 48 patients (21·4 per cent), and was positive in 33 and unnecessary or negative in 15. Haemodynamic instability and peritonitis were strong indicators of positive laparotomy; seven of 13 laparotomies for evisceration alone were negative, as were two of four for retained foreign bodies.

Conclusion

The laparotomy rate fell from 78·5 to 21·4 per cent over 25 years. The rate of unnecessary or negative laparotomy did not change. Isolated evisceration and retained foreign body remain relative indications.

Skin-cancer awareness in Scottish cardiac transplant recipients

BACKGROUND

Cardiac transplant recipients have a greatly increased risk of nonmelanoma skin cancer, with a relative risk of up to 108. Skin cancer is more aggressive in transplant patients and results in substantial morbidity and mortality. It is therefore important that these patients understand this risk and take adequate sun-protection measures.

AIM

To assess awareness of skin cancer risk and sun protection measures used by cardiac transplant recipients and determine the impact of patient education.

METHODS

Using a detailed questionnaire, we surveyed 118 patients attending the cardiac transplant clinic at our centre to quantify knowledge of skin cancer risk (maximum total score 10) and behaviour in the sun (maximum total score 15). Of these patients, 50 were then seen by a dermatologist for education about skin cancer risk, sun protection measures and skin cancer screening. Six months later, we asked them to complete the same questionnaire again.

RESULTS

The mean knowledge score was 7.3/10 and the mean behaviour score was 11.2/15. In the group that received education, the mean knowledge score improved from 7.2/10 before the dermatology consultation to 7.8/10 after the consultation (P < 0.03). The mean score for the behaviour questions improved even more, from 11.2/15 before to 13.5/15 after the consultation (P < 0.0001). CONCLUSIONS. This study demonstrates that specialist advice can improve self-reported knowledge of skin cancer risk and sun protective behaviour in cardiac transplant recipients. It is hoped that this may reduce the risk of nonmelanoma skin cancer in these patients.

Should Pre-operative Troponin be a Standard Requirement in Patients Undergoing Major Lower Extremity Amputation?

OBJECTIVES

The objective of this study was to ascertain the benefit of routine pre-operative cardiac troponin I (cTnI) measurement in patients undergoing major lower extremity amputation for critical limb ischaemia.

DESIGN

This was a prospective, blinded observational study.

METHODS

All patients scheduled for lower extremity amputation, without evidence of unstable coronary artery disease were recruited prospectively over a period of 1 year. In addition to routine pre-operative evaluation, a blood sample was taken for measurement of serum cTnI. Post-operative screening was conducted for cardiac events with patients followed up to 6 weeks.

RESULTS

Ten of the 44 patients included suffered a non-fatal myocardial infarction or died from a cardiac cause post-operatively. A rise in pre-operative cTnI was associated with a very poor outcome (two cardiac deaths and one post-operative myocardial infarction) and was the only significant predictor of post-operative cardiac events.

CONCLUSION

Routine pre-operative cTnI measurement may be of use to identify patients at high risk of cardiac complication who would benefit from optimization of cardiac status or in whom surgery could be deferred.

A new once-daily formulation of tolterodine provides superior efficacy and is well tolerated in women with overactive bladder

This study evaluated the efficacy and tolerability of new extended-release (ER) tolterodine for the treatment of overactive bladder in women. In this subpopulation analysis of a double-blind multicenter trial, 1235 female patients were randomized to oral therapy with tolterodine ER 4 mg once daily (n=417), tolterodine IR 2 mg twice daily (n=408) or placebo (n=410) for 12 weeks. Both formulations reduced the mean number of urge incontinence episodes per week (both P=0.001 vs placebo); tolterodine ER was more effective than tolterodine IR (P=0.036). Both formulations significantly improved all other micturition chart variables compared to placebo. Dry mouth was the most common adverse event. There were no safety concerns. Toltrodine ER 4 mg once daily is effective and well tolerated in the treatment of women with overactive bladder, and reduces urge incontinence episodes more than the existing IR twice-daily formulation.

The clash between theory and science on the kinematic effectiveness of foot orthoses

Foot orthoses have been shown to be effective in the management of lower extremity pathologic conditions, but the mechanism by which orthoses achieve this effect is unclear. Kinematic studies that investigate changes in skeletal alignment from the use of foot orthoses have shown mixed results with generally small changes which may not be sufficient to account for the outcomes achieved with foot orthoses. A number of theoretic constructs have not been taken into account in the design and reporting of kinematic studies, and these omissions may account for mixed results. Kinematic studies need to report information about participants, (e.g., the subtalar joint axis position) so readers can judge the appropriateness of the orthoses prescriptions and the kinematic variable measured. The high prevalence of forefoot varus reported in some studies and the variability in orthoses prescriptions and in casting for these devices used in studies also needs to be addressed. In light of some of the theoretic explanations offered here, the recent suggestions that foot orthoses may work by methods other than aligning the skeleton may need to be re-evaluated.

Limited joint mobility and plantar fascia function in Charcot's neuroarthropathy

AIM

The aim of this study was to investigate the prevalence of limited joint mobility at the first metatarsophalangeal joint (MPJ) and dysfunction of the plantar fascia in people with diabetes mellitus and Charcot's neuroarthropathy and a control group.

METHODS

Fifteen subjects with a history of mid-foot Charcot's neuroarthropathy and 26 controls with sensory neuropathy but no Charcot's neuro arthropathy were recruited. Ranges of ankle and first MPJ dorsiflexion were measured for each participant. Plantar fascia function was assessed using Jack's test.

RESULTS

The range of dorsiflexion at the first MPJ was significantly reduced in the subject group compared with the control group (51.2 vs. 64.8; P < 0.001). Jack's test demonstrated the plantar fascia to be ruptured or dysfunctional in all feet in the subject group and to be functioning in all feet in the control group.

CONCLUSIONS

It is not possible to determine from this study if the limited joint mobility at the first MPJ and dysfunction of the plantar fascia preceded or followed the development of Charcot's neuroarthropathy; however, these results are a previously unreported finding in Charcot's neuroarthropathy. Diabet. Med. 18, 558-561 (2001)

Function of the windlass mechanism in excessively pronated feet

The foot postures of 39 subjects were evaluated for excessive pronation by means of six static weightbearing and five nonweightbearing measurements, and two types of footprint indexes. Visual evidence of windlass function was recorded by video. Chi-square analysis revealed that excessive pronation does not affect the establishment of the windlass mechanism. The position of the forefoot relative to the rearfoot, subtalar joint axis position, and navicular drift/foot length ratio were significantly associated with dynamic windlass function. These results suggest that selected static measurements may have value in predicting some aspects of dynamic foot function during the propulsive phase of the gait cycle.

The human preprotachykinin-A gene promoter has been highly conserved and can drive human-like marker gene expression in the adult mouse CNS

Toward an understanding of the mechanisms controlling Preprotachykinin-A (PPTA) transcription, we introduced a 380-kb human yeast artificial chromosome containing the PPTA gene tagged with the beta-galactosidase gene into transgenic mice. This resulted in a pattern of LacZ expression in the central nervous system (CNS) remarkably similar to that reported for PPTA mRNA in the rat. However, the human gene drove expression in areas of the mouse CNS not associated with strong PPTA expression in rodents but which have been shown to express PPTA in the human. This study clearly demonstrates the high degree of conservation of the mechanisms involved in PPTA transcription that has occurred throughout 100 million of divergent human and rodent evolution. This study also defines the maximum linear extent of the human PPT-A promoter. We believe these findings constitute the removal of a significant obstacle in studying the transcriptional regulation of the human PPTA gene in vivo.

Biparental inheritance of gamma-tubulin during human fertilization: molecular reconstitution of functional zygotic centrosomes in inseminated human oocytes and in cell-free extracts nucleated by human sperm

Human sperm centrosome reconstitution and the parental contributions to the zygotic centrosome are examined in mammalian zygotes and after exposure of spermatozoa to Xenopus laevis cell-free extracts. The presence and inheritance of the conserved centrosomal constituents gamma-tubulin, centrin, and MPM-2 (which detects phosphorylated epitopes) are traced, as is the sperm microtubule-nucleating capability on reconstituted centrosomes. gamma-Tubulin is biparentally inherited in humans (maternal >> than paternal): Western blots detect the presence of paternal gamma-tubulin. Recruitment of maternal gamma-tubulin to the sperm centrosome occurs after sperm incorporation in vivo or exposure to cell-free extract, especially after sperm "priming" induced by disulfide bond reduction. Centrin is found in the proximal sperm centrosomal region, demonstrates expected calcium sensitivity, but appears absent from the zygotic centrosome after sperm incorporation or exposure to extracts. Sperm centrosome phosphorylation is detected after exposure of primed sperm to egg extracts as well as during the early stages of sperm incorporation after fertilization. Finally, centrosome reconstitution in cell-free extracts permits sperm aster microtubule assembly in vitro. Collectively, these results support a model of a blended zygotic centrosome composed of maternal constituents attracted to an introduced paternal template after insemination.

A bile acid-induced apoptosis assay for colon cancer risk and associated quality control studies

Bile acids are important in the etiology of colorectal cancer. Bile acids induce apoptosis in colonic goblet cells at concentrations comparable to those found in fecal water after high-fat meals. Preliminary evidence indicated that cells of the normal-appearing (nontumorous) portion of the colon epithelium of colon cancer patients are more resistant to bile salt-induced apoptosis than are cells from normal individuals. In the present study, 68 patients were examined, and biopsies were taken at 20 cm from the anal verge, cecum, and descending colon. The patients included 17 individuals with a history of colorectal cancer, 37 individuals with adenomas, and 14 individuals who were neoplasia free. The mean bile salt-induced apoptotic index among normal individuals was 57.6 +/- 3.47 (SE), which differed significantly (P < 0.05) from the mean value of 36.41 +/- 3.12 in individuals with a history of colon cancer. The correlation between independent observers was 0.89 (P < 0.001), indicating good interobserver reliability. Components of variance comparing interindividual versus intraindividual sources of variation suggested that site-to-site variability, both between regions of the colon and for adjacent biopsies, was larger than the interpatient variability for individuals with a history of neoplasia. Therefore, there was "patchiness" of the susceptibility of regions of the colon to bile acid-induced apoptosis in individuals with a history of neoplasia (a patchy field effect). There was no obvious correlation of low-apoptotic index regions with regions in which previous neoplasias had been found and removed. On the other hand, for normal, i.e., neoplasia-free, individuals, there was relatively less intraindividual variation compared to interindividual variation. Our assay shows an association between resistance to bile acid-induced apoptosis, measured at 20 cm from the anal verge, and colon cancer risk. Thus, this assay may prove useful as a biomarker of colon cancer risk.