Temporal trends and predictors of phthalate, phthalate replacement, and phenol biomarkers in the LIFECODES Fetal Growth Study

BACKGROUND

Exposure to many phthalates and phenols is declining as replacements are introduced. There is little information on temporal trends or predictors of exposure to these newer compounds, such as phthalate replacements, especially among pregnant populations.

OBJECTIVE

Examine temporal trends and predictors of exposure to phthalates, phthalate replacements, and phenols using single- and multi-pollutant approaches.

METHODS

We analyzed data from 900 singleton pregnancies in the LIFECODES Fetal Growth Study, a nested case-cohort with recruitment from 2007 to 2018. We measured and averaged concentrations of 12 phthalate metabolites, four phthalate replacement metabolites, and 12 phenols in urine at three timepoints during pregnancy. We visualized and analyzed temporal trends and predictors of biomarker concentrations. To examine chemical mixtures, we derived clusters of individuals with shared exposure profiles using a finite mixture model and examined temporal trends and predictors of cluster assignment.

RESULTS

Exposure to phthalates and most phenols declined across the study period, while exposure to phthalate replacements (i.e., di(isononyl) cyclohexane-1,2-dicarboxylic acid, diisononyl ester [DINCH] and di-2-ethylhexyl terephthalate [DEHTP]) and bisphenol S (BPS) increased. For example, the sum of DEHTP biomarkers increased multiple orders of magnitude, with an average concentration of 0.92 ng/mL from 2007 to 2008 and 61.9 ng/mL in 2017-2018. Biomarkers of most chemical exposures varied across sociodemographic characteristics, with the highest concentrations observed in non-Hispanic Black or Hispanic participants relative to non-Hispanic White participants. We identified five clusters with shared exposure profiles and observed temporal trends in cluster membership. For example, at the end of the study period, a cluster characterized by high exposure to phthalate replacements was the most prevalent.

SIGNIFICANCE

In a large and well-characterized pregnancy cohort, we observed exposure to phthalate replacements and BPS increased over time while exposure to phthalates and other phenols decreased. Our results highlight the changing nature of exposure to consumer product chemical mixtures.

A scoping review of risk-stratified bowel screening: current evidence, future directions

PURPOSE

In this scoping review, we examined the international literature on risk-stratified bowel screening to develop recommendations for future research, practice and policy.

METHODS

Six electronic databases were searched from inception to 18 October 2021: Medline, Embase, PsycINFO, CINAHL, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials. Forward and backwards citation searches were also undertaken. All relevant literature were included.

RESULTS

After de-deduplication, 3,629 records remained. 3,416 were excluded at the title/abstract screening stage. A further 111 were excluded at full-text screening stage. In total, 102 unique studies were included. Results showed that risk-stratified bowel screening programmes can potentially improve diagnostic performance, but there is a lack of information on longer-term outcomes. Risk models do appear to show promise in refining existing risk stratification guidelines but most were not externally validated and less than half achieved good discriminatory power. Risk assessment tools in primary care have the potential for high levels of acceptability and uptake, and therefore, could form an important component of future risk-stratified bowel screening programmes, but sometimes the screening recommendations were not adhered to by the patient or healthcare provider. The review identified important knowledge gaps, most notably in the area of organisation of screening services due to few pilots, and what risk stratification might mean for inequalities.

CONCLUSION

We recommend that future research focuses on what organisational challenges risk-stratified bowel screening may face and a consideration of inequalities in any changes to organised bowel screening programmes.

The burden of COVID-19 infection in a rural Tamil Nadu community

Background

There have been over 30 million cases of COVID-19 in India and over 430,000 deaths. Transmission rates vary from region to region, and are influenced by many factors including population susceptibility, travel and uptake of preventive measures. To date there have been relatively few studies examining the impact of the pandemic in lower income, rural regions of India. We report on a study examining COVID-19 burden in a rural community in Tamil Nadu.

Methods

The study was undertaken in a population of approximately 130,000 people, served by the Rural Unit of Health and Social Affairs (RUHSA), a community health center of CMC, Vellore. We established and evaluated a COVID-19 PCR-testing programme for symptomatic patients—testing was offered to 350 individuals, and household members of test-positive cases were offered antibody testing. We also undertook two COVID-19 seroprevalence surveys in the same community, amongst 701 randomly-selected individuals.

Results

There were 182 positive tests in the symptomatic population (52.0%). Factors associated with test-positivity were older age, male gender, higher socioeconomic status (SES, as determined by occupation, education and housing), a history of diabetes, contact with a confirmed/suspected case and attending a gathering (such as a religious ceremony, festival or extended family gathering). Amongst test-positive cases, 3 (1.6%) died and 16 (8.8%) suffered a severe illness. Amongst 129 household contacts 40 (31.0%) tested positive. The two seroprevalence surveys showed positivity rates of 2.2% (July/Aug 2020) and 22.0% (Nov 2020). 40 tested positive (31.0%, 95% CI: 23.02 − 38.98). Our estimated infection-to-case ratio was 31.7.

Conclusions

A simple approach using community health workers and a community-based testing clinic can readily identify significant numbers of COVID-19 infections in Indian rural population. There appear, however, to be low rates of death and severe illness, although vulnerable groups may be under-represented in our sample. It’s vital these lower income, rural populations aren’t overlooked in ongoing pandemic monitoring and vaccine roll-out in India.

Risk of missing colorectal cancer with a COVID-adapted diagnostic pathway using quantitative faecal immunochemical testing

BACKGROUND

COVID-19 has brought an unprecedented challenge to healthcare services. The authors' COVID-adapted pathway for suspected bowel cancer combines two quantitative faecal immunochemical tests (qFITs) with a standard CT scan with oral preparation (CT mini-prep). The aim of this study was to estimate the degree of risk mitigation and residual risk of undiagnosed colorectal cancer.

METHOD

Decision-tree models were developed using a combination of data from the COVID-adapted pathway (April-May 2020), a local audit of qFIT for symptomatic patients performed since 2018, relevant data (prevalence of colorectal cancer and sensitivity and specificity of diagnostic tools) obtained from literature and a local cancer data set, and expert opinion for any missing data. The considered diagnostic scenarios included: single qFIT; two qFITs; single qFIT and CT mini-prep; two qFITs and CT mini-prep (enriched pathway). These were compared to the standard diagnostic pathway (colonoscopy or CT virtual colonoscopy (CTVC)).

RESULTS

The COVID-adapted pathway included 422 patients, whereas the audit of qFIT included more than 5000 patients. The risk of missing a colorectal cancer, if present, was estimated as high as 20.2 per cent with use of a single qFIT as a triage test. Using both a second qFIT and a CT mini-prep as add-on tests reduced the risk of missed cancer to 6.49 per cent. The trade-off was an increased rate of colonoscopy or CTVC, from 287 for a single qFIT to 418 for the double qFIT and CT mini-prep combination, per 1000 patients.

CONCLUSION

Triage using qFIT alone could lead to a high rate of missed cancers. This may be reduced using CT mini-prep as an add-on test for triage to colonoscopy or CTVC.

Attitudes of Dutch intensive care unit clinicians towards oxygen therapy

BACKGROUND

Over the last decade, there has been an increasing awareness for the potential harm of the administration of too much oxygen. We aimed to describe self-reported attitudes towards oxygen therapy by clinicians from a large representative sample of intensive care units (ICUs) in the Netherlands.

METHODS

In April 2019, 36 ICUs in the Netherlands were approached and asked to send out a questionnaire (59 questions) to their nursing and medical staff (ICU clinicians) eliciting self-reported behaviour and attitudes towards oxygen therapy in general and in specific ICU case scenarios.

RESULTS

In total, 1361 ICU clinicians (71% nurses, 24% physicians) from 28 ICUs returned the questionnaire. Of responding ICU clinicians, 64% considered oxygen-induced lung injury to be a major concern. The majority of respondents considered a partial pressure of oxygen (PaO2) of 6-10 kPa (45-75 mmHg) and an arterial saturation (SaO2) of 85-90% as acceptable for 15 minutes, and a PaO2 7-10 kPa (53-75 mmHg) and SaO2 90-95% as acceptable for 24-48 hours in an acute respiratory distress syndrome (ARDS) patient. In most case scenarios, respondents reported not to change the fraction of inspired oxygen (FiO2) if SaO2 was 90-95% or PaO2 was 12 kPa (90 mmHg).

CONCLUSION

A representative sample of ICU clinicians from the Netherlands were concerned about oxygen-induced lung injury, and reported that they preferred PaO2 and SaO2 targets in the lower physiological range and would adjust ventilation settings accordingly.

Fampridine-induced changes in walking kinetics are associated with clinical improvements in patients with multiple sclerosis

Gait dysfunction is common in patients with multiple sclerosis (PwMS). Treatment with prolonged-release fampridine (PR-fampridine) improves walking ability in some PwMS. Associated fampridine-induced changes in the walking pattern are still poorly understood but may provide a better understanding of the mechanisms underlying the beneficial drug effects. 61 PwMS were treated with PR-fampridine in a randomized, monocentric, double-blind and placebo-controlled clinical trial with crossover design (FAMPKIN). Drug-induced improvements in walking speed (Timed-25-Foot Walk; T25FW) and endurance (6-Minute Walk Test; 6MWT) were quantified. In this sub-study of the FAMPKIN trial, fampridine-induced changes in kinetic gait patterns were analyzed by pressure-based foot print analysis during treadmill walking. Vertical ground reaction forces were analyzed during different gait phases. Kinetic data of 44 PwMS was eligible for analysis. During double-blind treatment with PR-fampridine, patients performed significantly better in the T25FW and 6MWT than during placebo treatment (p < 0.0001 for both). At the group level (n = 44), there were no significant changes of gait kinetics under PR-fampridine vs. placebo. However, we found relevant changes of walking kinetics regarding forces during loading, single limb and pre-swing phase in a patient sub-group (n = 8). Interestingly, this sub-group demonstrated superior responsiveness to PR-fampridine in the clinical walking tests compared to those patients without any fampridine-induced changes in kinetics (n = 36). Our results demonstrate fampridine-induced changes in gait kinetics in a sub-group of PwMS. These gait pattern changes were accompanied by improved clinical walking performance under PR-fampridine. These results shed some light on the biomechanical changes in walking patterns underlying enhanced fampridine-induced gait performance.

A Systematic Review of Health System Level Initiatives Promoting the Earlier Diagnosis of Cancer Among the Adult Population in High-Income Countries

Background: The increased burden of cancer has driven the development of health system level initiatives worldwide promoting early diagnosis. Although it is challenging to synthesize results of such complex, diverse initiatives, it is crucial to review the evidence to inform future programs and enhance transparency and accountability. Aim: We aimed to systematically review the literature on health system level initiatives promoting early diagnosis among the adult population, describing and categorizing their components, stakeholders, target populations, and outcomes. Methods: We have searched databases (including Embase, PsycInfo, Medline and ASSIA), Web sites (including charities, governmental and nongovernmental agencies) and reference lists of included studies and relevant systematic reviews for peer-reviewed publications and gray literature. We included quantitative, qualitative, mixed-methods studies and reviews/overviews about a single initiative in high-income countries as defined by the World Bank. We included initiatives: 1) targeting adults aged 18 or older; 2) aiming to promote early diagnosis; 3) addressing the patient/public and at least two more levels of contextual influence (according to a model of multilevel influences on cancer care); 4) implemented at a national level or equivalent. Study selection, quality assessment and data extraction were carried out independently by two reviewers. Narrative synthesis was used to analyze the findings. The review protocol has been published by BMJ Open and registered at PROSPERO (CRD42016047233). Results: Twenty initiatives from 10 countries were identified in 263 publications. Data were extracted from 104 core publications about 19 initiatives. It was possible to assess the quality of 35 core publications. Initiatives focused on fast-track for patients with alarm symptoms or other referral pathways for those with other symptoms or abnormal test results (n=11), national awareness campaigns for the public (n=4), and strategies with multiple components (n=4). Tools developed for professionals included referral guidelines and online referral systems. Initiatives focusing on referral pathways showed some improvements in diagnostic intervals, and limited evidence on the impact on staging. Performance targets were often not met. Results from awareness campaigns indicated improvement in awareness, but evidence about changes in health-seeking behavior was limited. Barriers and facilitators were described, including availability of specialist staff. Conclusion: Robustness of methods/outcomes could not always be assessed as several publications were reports or government documents. Evidence on the impact of initiatives regarding longer-term outcomes is limited. Described barriers and facilitators may help to inform future initiatives. Findings may be useful to researchers, policy makers, and governments developing early diagnosis programs and assessing cancer outcomes.

Rural-Urban Variation in Time to Diagnosis and Treatment of Colorectal or Breast Cancer in Victoria, Australia

Background: Rural-urban disparities in cancer outcomes are found in many countries, though these vary by cancer type. In Victoria, Australia, survival is poorer for rural patients with colorectal cancer, but not breast cancer. Delayed diagnosis and treatment may contribute to disparities, but previous studies have not compared the timeliness of rural and urban pathways to treatment of these common cancers. Aim: We investigated whether time to diagnosis and treatment differed for rural and urban patients with colorectal or breast cancer in Victoria, Australia. Methods: Population-based, cross-sectional surveys examining events and dates on the pathway to treatment completed by patients aged ≥ 40 and approached within six months of diagnosis, their general practitioner (GP) and specialist. Data were collected from 2013 to 2014 as part of the International Cancer Benchmarking Partnership, Module 4. Six intervals were explored: patient (symptom to presentation), primary care (presentation to referral), diagnostic (presentation/screening to diagnosis), treatment (diagnosis to treatment), health system (presentation to treatment) and total intervals (symptom/screening to treatment). Rural-urban differences were examined for each cancer using quantile regression (50th, 75th and 90th percentiles) models including age, gender, health insurance and socioeconomic status. Results: 433 colorectal (48% rural) and 489 breast (42% rural) patients, 621 GPs and 370 specialists completed surveys. Compared with urban patients, symptomatic colorectal cancer patients from rural areas had a significantly longer total interval at all percentiles: 50th (18 days longer, 95% confidence interval (CI): 9-27), 75th (53, 95% CI: 47-59) 90th (44, 95% CI: 40-48). These patients also had longer health system intervals, ranging 7-85 days longer. This appeared mostly due to longer diagnostic intervals (range: 6-54 days longer). Results were similar when including screen-detected cases. In contrast, breast cancer intervals were similar for rural and urban patients, except the patient interval, which was shorter for rural patients. Conclusion: Consistent with variation in survival, we found longer total and diagnostic intervals for rural compared with urban patients with colorectal cancer, but not breast cancer. The lack of rural-urban differences observed for breast cancer suggest that inequities in the timeliness of colorectal cancer pathways can be ameliorated, and may improve clinical outcomes. Indeed, based on previous research, delays observed in this study could result in stage progression and hence reduced survival. From our results, interventions targeting the time from presentation to colorectal cancer diagnosis in rural populations should be pursued. Countries seeking to understand cancer disparities in their local context may also consider using a pathways approach to identify possible targets for policy intervention.

Second Primary Cancers (SPC): A Mixed-Methods Systematic Review of Pathways to Diagnosis and a National Linkage Study in Scotland to Understand Survival Outcomes Following an SPC Diagnosis

Background: As an increasing proportion of patients survive an initial cancer, the number who develop a second primary cancer (SPC) is also increasing. Aim: To examine the pathways to diagnosis of an SPC and the associated patients' and health practitioners' experiences, and survival outcomes following an SPC diagnosis. Methods: We conducted a systematic review to examine the pathways to diagnosis and associated patient and healthcare practitioners' experiences. Ten electronic databases were searched with no date or language restrictions. Two reviewers independently screened titles, abstracts and full-texts, and did the data extraction and quality assessment of the included studies. Secondary data analysis examined the survival outcomes following an SPC diagnosis. This involved three linked databases: the Scottish Cancer Registry, episode level data on hospital inpatient and day case discharges, and the National Register of Scotland death records. We included patients aged 18+, diagnosed with a first primary cancer (FPC) between 01.01.1980 and 31.12.2010 and subsequently diagnosed with an SPC (> 60 days following a FPC). The cases were matched for age, gender and cancer type to controls (individuals diagnosed with an FPC only within the same 5-year period). Descriptive statistics, survival analysis and Cox proportional hazard model were done. Results: Forty-nine articles were included in the review. The most commonly reported SPCs were breast, lung, colorectal, and melanoma. All included studies reported on the mode of detection of the SPC (30 symptomatic presentation, 18 screen detected, 34 other modes). The routes to detection (whether the SPC was diagnosed during routine follow-up/surveillance, or self-referral) varied by cancer type. Only two studies described provider experiences of diagnosis of an SPC; no study reported on the patients' experiences. The secondary data analysis included 37,193 people diagnosed with an SPC (51.6% females and 48.3% male). The proportion of SPC among people diagnosed with a FPC within a 5-year period ranged between 2.3% (1980-1985) and 31.2% (2006-2010). Trachea, bronchus and lung cancer (21.3%), colorectal cancer (13.9%), breast (12.9%) and prostate (7.3%) were the most frequently diagnosed SPCs in this population. These four cancers also accounted for the highest number of deaths in both sexes. Compared with people diagnosed with FPC (390 days: IQR 14-1825 days), those diagnosed with SPC had shorter median survival days (379 days: IQR 17-1825 days), which was statistically significant ( P = 0.001, X24df=163.2). Conclusion: The review provides early insights into diagnosis of an SPC. While it has identified that there is a dearth of quantitative and qualitative evidence on the pathways to diagnosis of an SPC, the secondary data analysis partly fills the gap, and has important implications for surveillance in both primary and secondary care, and secondary prevention and early detection.

Concerns, perceived need and competing priorities: a qualitative exploration of decision-making and non-participation in a population-based flexible sigmoidoscopy screening programme to prevent colorectal cancer

OBJECTIVE

Optimising uptake of colorectal cancer (CRC) screening is important to achieve projected health outcomes. Population-based screening by flexible sigmoidoscopy (FS) was introduced in England in 2013 (NHS Bowel scope screening). Little is known about reactions to the invitation to participate in FS screening, as offered within the context of the Bowel scope programme. We aimed to investigate responses to the screening invitation to inform understanding of decision-making, particularly in relation to non-participation in screening.

DESIGN

Qualitative analysis of semistructured in-depth interviews and written accounts.

PARTICIPANTS AND SETTING

People from 31 general practices in the North East and East of England invited to attend FS screening as part of NHS Bowel scope screening programme were sent invitations to take part in the study. We purposively sampled interviewees to ensure a range of accounts in terms of beliefs, screening attendance, sex and geographical location.

RESULTS

20 screeners and 25 non-screeners were interviewed. Written responses describing reasons for, and circumstances surrounding, non-participation from a further 28 non-screeners were included in the analysis. Thematic analysis identified a range of reactions to the screening invitation, decision-making processes and barriers to participation. These include a perceived or actual lack of need; inability to attend; anxiety and fear about bowel preparation, procedures or hospital; inability or reluctance to self-administer an enema; beliefs about low susceptibility to bowel cancer or treatment and understanding of harm and benefits. The strength, rather than presence, of concerns about the test and perceived need for reassurance were important in the decision to participate for screeners and non-screeners. Decision-making occurs within the context of previous experiences and day-to-day life.

CONCLUSIONS

Understanding the reasons for non-participation in FS screening can help inform strategies to improve uptake and may be transferable to other screening programmes.

UK Lung Cancer RCT Pilot Screening Trial: baseline findings from the screening arm provide evidence for the potential implementation of lung cancer screening

Background

Lung cancer screening using low-dose CT (LDCT) was shown to reduce lung cancer mortality by 20% in the National Lung Screening Trial.

Methods

The pilot UK Lung Cancer Screening (UKLS) is a randomised controlled trial of LDCT screening for lung cancer versus usual care. A population-based questionnaire was used to identify high-risk individuals. CT screen-detected nodules were managed by a pre-specified protocol. Cost effectiveness was modelled with reference to the National Lung Cancer Screening Trial mortality reduction.

Results

247 354 individuals aged 50–75 years were approached; 30.7% expressed an interest, 8729 (11.5%) were eligible and 4055 were randomised, 2028 into the CT arm (1994 underwent a CT). Forty-two participants (2.1%) had confirmed lung cancer, 34 (1.7%) at baseline and 8 (0.4%) at the 12-month scan. 28/42 (66.7%) had stage I disease, 36/42 (85.7%) had stage I or II disease. 35/42 (83.3%) had surgical resection. 536 subjects had nodules greater than 50 mm³ or 5 mm diameter and 41/536 were found to have lung cancer. One further cancer was detected by follow-up of nodules between 15 and 50 mm³ at 12 months. The baseline estimate for the incremental cost-effectiveness ratio of once-only CT screening, under the UKLS protocol, was £8466 per quality adjusted life year gained (CI £5542 to £12 569).

Conclusions

The UKLS pilot trial demonstrated that it is possible to detect lung cancer at an early stage and deliver potentially curative treatment in over 80% of cases. Health economic analysis suggests that the intervention would be cost effective—this needs to be confirmed using data on observed lung cancer mortality reduction.

Trial registration

ISRCTN 78513845.

Communication about colorectal cancer screening in Britain: public preferences for an expert recommendation

BACKGROUND

Informed decision-making approaches to cancer screening emphasise the importance of decisions being determined by individuals' own values and preferences. However, advice from a trusted source may also contribute to autonomous decision-making. This study examined preferences regarding a recommendation from the NHS and information provision in the context of colorectal cancer (CRC) screening.

METHODS

In face-to-face interviews, a population-based sample of adults across Britain (n=1964; age 50-80 years) indicated their preference between: (1) a strong recommendation to participate in CRC screening, (2) a recommendation alongside advice to make an individual decision, and (3) no recommendation but advice to make an individual decision. Other measures included trust in the NHS and preferences for information on benefits and risks.

RESULTS

Most respondents (84%) preferred a recommendation (47% strong recommendation, 37% recommendation plus individual decision-making advice), but the majority also wanted full information on risks (77%) and benefits (78%). Men were more in favour of a recommendation than women (86% vs 81%). Trust in the NHS was high overall, but the minority who expressed low trust were less likely to want a recommendation.

CONCLUSION

Most British adults want full information on risks and benefits of screening but they also want a recommendation from an authoritative source. An 'expert' view may be an important part of autonomous health decision-making.

Structural and Magnetic Properties of e-Beam Prepared CoxPt1-x Alloy Films

We have investigated structural and magnetic properties of CoPt alloy films with strong perpendicular magnetic anisotropy in the thickness range between 100Å and 400A. From a detailed x-ray analysis we find highly (111) -textured CoPt Microcrystal-lites in all samples. STM studies reveal a granular topography with grain diameters of up to 250Å. Measurements of hysteresis loops yield a saturation field which increases with thickness, and which is consistent with a freely mobile domain Model. Brillouin light scattering measurements of the frequencies of the surface and standing spin wave modes yield a bulk exchange constant, which is strongly dependent on the Pt content.

Negative screening colonoscopy after a positive guaiac faecal occult blood test: not a contraindication to continued screening

AIM

In guaiac faecal occult blood test (gFOBT) screening at least 50% of positive individuals will have a colonoscopy negative for colorectal neoplasia. The question of continuing screening in this group has not been addressed.

METHOD

Data on participants aged 50-69 years with a positive gFOBT result and a negative colonoscopy were followed through the biennial screening pilot conducted between 2000 and 2007 in Scotland.

RESULTS

In the first screening round, 1527 colonoscopies were negative for neoplasia. 1300 were re-invited in the second round, 905 accepted, and 157 had a positive gFOBT result, giving a positivity rate of 17.4%. Colonoscopy revealed 20 subjects with adenoma and six with invasive cancer. In the third screening round 1031 were invited for a third time and 730 accepted: 55 had a positive gFOBT test, giving a positivity rate of 7.5%. In this group, six colonoscopies revealed adenomas but there were no cancers diagnosed. In the third screening round, 108 individuals had had two positive gFOBT results and two subsequent negative colonoscopies. Eighty-four were invited for a third gFOBT, 66 accepted and 19 (25.6%) had a positive result none of whom had an adenoma or carcinoma.

CONCLUSION

These data indicate that a negative colonoscopy following a positive gFOBT is not a contraindication for further screening, although this is likely to have a low yield of neoplastic pathology after two negative colonoscopies.

Interval cancers in a FOBT-based colorectal cancer population screening programme: implications for stage, gender and tumour site

BACKGROUND

Between 2000 and 2007, a demonstration pilot of biennial guaiac faecal occult blood test (GFOBT) screening was carried out in Scotland.

METHODS

Interval cancers were defined as cancers diagnosed within 2 years (ie, a complete screening round) of a negative GFOBT. The stage and outcome of the interval cancers were compared with those arising contemporaneously in the non-screened Scottish population. In addition, the gender and site distributions of the interval cancers were compared with those in the screen-detected group and the non-screened population.

RESULTS

Of the cancers diagnosed in the screened population, interval cancers comprised 31.2% in the first round, 47.7% in the second, and 58.9% in the third, although this was due to a decline in the numbers of screen-detected cancers rather than an increase in interval cancers. There were no consistent differences in the stage distribution of interval cancers and cancers from the non-screened population, and, in all three rounds, both overall and cancer-specific survival were significantly better for patients diagnosed with interval cancers (p<0.01). The percentage of cancers arising in women was significantly higher in the interval cancer group (50.2%) than in either the screen-detected group (35.3%, p<0.001) or the non-screened group (40.6%, p<0.001). In addition, the proportion of both right-sided and rectal cancers was significantly higher in the interval cancer group than in either the screen-detected (p<0.001) or non-screened (p<0.004) groups.

CONCLUSIONS

Although GFOBT screening is associated with substantial interval cancer rates that increase with screening round, the absolute numbers do not. Interval cancers are associated with a better prognosis than cancers arising in a non-screened population, and GFOBT appears to preferentially detect cancers in men and the left side of the colon at the expense of cancers in women and in the right colon and rectum.

The Aarhus statement: improving design and reporting of studies on early cancer diagnosis

Early diagnosis is a key factor in improving the outcomes of cancer patients. A greater understanding of the pre-diagnostic patient pathways is vital yet, at present, research in this field lacks consistent definitions and methods. As a consequence much early diagnosis research is difficult to interpret. A consensus group was formed with the aim of producing guidance and a checklist for early cancer-diagnosis researchers. A consensus conference approach combined with nominal group techniques was used. The work was supported by a systematic review of early diagnosis literature, focussing on existing instruments used to measure time points and intervals in early cancer-diagnosis research. A series of recommendations for definitions and methodological approaches is presented. This is complemented by a checklist that early diagnosis researchers can use when designing and conducting studies in this field. The Aarhus checklist is a resource for early cancer-diagnosis research that should promote greater precision and transparency in both definitions and methods. Further work will examine whether the checklist can be readily adopted by researchers, and feedback on the guidance will be used in future updates.

The value of FDG positron emission tomography/computerised tomography (PET/CT) in pre-operative staging of colorectal cancer: a systematic review and economic evaluation

OBJECTIVES

In the UK, colorectal cancer (CRC) is the third most common malignancy (behind lung and breast cancer) with 37,514 cases registered in 2006: around two-thirds (23,384) in the colon and one-third (14,130) in the rectum. Treatment of cancers of the colon can vary considerably, but surgical resection is the mainstay of treatment for curative intent. Following surgical resection, there is a comprehensive assessment of the tumour, it's invasion characteristics and spread (tumour staging). A number of imaging modalities are used in the pre-operative staging of CRCs including; computerised tomography (CT), magnetic resonance imaging, ultrasound imaging and positron emission tomography (PET). This report examines the role of CT in combination with PET scanning (PET/CT 'hybrid' scan). The research objectives are: to evaluate the diagnostic accuracy and therapeutic impact of fluorine-18-deoxyglucose (FDG) PET/CT for the pre-operative staging of primary, recurrent and metastatic cancer using systematic review methods; undertake probabilistic decision-analytic modelling (using Monte Carlo simulation); and conduct a value of information analysis to help inform whether or not there is potential worth in undertaking further research.

DATA SOURCES

For each aspect of the research - the systematic review, the handsearch study and the economic evaluation - a database was assembled from a comprehensive search for published and unpublished studies, which included database searches, reference lists search and contact with experts. In the systematic review prospective and retrospective patient series (diagnostic cohort) and randomised controlled trials (RCTs) were eligible for inclusion. Both consecutive series and series that are not explicitly reported as consecutive were included.

REVIEW METHODS

Two reviewers extracted all data and applied the criteria independently and resolved disagreements by discussion. Data to populate 2 × 2 contingency tables consisting of the number of true positives, true negatives, false positives and false negatives using the studies' own definitions were extracted, as were data relating to changes in management. Fourteen items from the Quality Assessment of Diagnostic Accuracy Studies checklist were used to assess the methodological quality of the included studies. Patient-level data were used to calculate sensitivity and specificity with confidence intervals (CIs). Data were plotted graphically in forest plots. For the economic evaluation, economic models were designed for each of the disease states: primary, recurrent and metastatic. These were developed and populated based on a variety of information sources (in particular from published data sources) and literature, and in consultation with clinical experts.

RESULTS

The review found 30 studies that met the eligibility criteria. Only two small studies evaluated the use of FDG PET/CT in primary CRC, and there is insufficient evidence to support its routine use at this time. The use of FDG PET/CT for the detection of recurrent disease identified data from five retrospective studies from which a pooled sensitivity of 91% (95% CI 0.87% to 0.95%) and specificity of 91% (95% CI 0.85% to 0.95%) were observed. Pooled accuracy data from patients undergoing staging for suspected metastatic disease showed FDG PET/CT to have a pooled sensitivity of 91% (95% CI 87% to 94%) and a specificity of 76% (95% CI 58% to 88%), but the poor quality of the studies means the validity of the data may be compromised by several biases. The separate handsearch study did not yield any additional unique studies relevant to FDG PET/CT. Models for recurrent disease demonstrated an incremental cost-effectiveness ratio of £ 21,409 per quality-adjusted life-year (QALY) for rectal cancer, £ 6189 per QALY for colon cancer and £ 21,434 per QALY for metastatic disease. The value of handsearching to identify studies of less clearly defined or reported diagnostic tests is still to be investigated.

CONCLUSIONS

The systematic review found insufficient evidence to support the routine use of FDG PET/CT in primary CRC and only a small amount of evidence supporting its use in the pre-operative staging of recurrent and metastatic CRC, and, although FDG PET/CT was shown to change patient management, the data are divergent and the quality of research is generally poor. The handsearch to identify studies of less clearly defined or reported diagnostic tests did not find additional studies. The primary limitations in the economic evaluations were due to uncertainty and lack of available evidence from the systematic reviews for key parameters in each of the five models. In order to address this, a conservative approach was adopted in choosing DTA estimates for the model parameters. Probabilistic analyses were undertaken for each of the models, incorporating wide levels of uncertainty particularly for the DTA estimates. None of the economic models reported cost-savings, but the approach adopted was conservative in order to determine more reliable results given the lack of current information. The economic evaluations conclude that FDG PET/CT as an add-on imaging device is cost-effective in the pre-operative staging of recurrent colon, recurrent rectal and metastatic disease but not in primary colon or rectal cancers. There would be value in undertaking an RCT with a concurrent economic evaluation to evaluate the therapeutic impact and cost-effectiveness of FDG PET/CT compared with conventional imaging (without PET) for the pre-operative staging of recurrent and metastatic CRC.

Modifiable and fixed factors predicting quality of life in people with colorectal cancer

Background:

People with colorectal cancer have impaired quality of life (QoL). We investigated what factors were most highly associated with it.

Methods:

Four hundred and ninety-six people with colorectal cancer completed questionnaires about QoL, functioning, symptoms, co-morbidity, cognitions and personal and social factors. Disease, treatment and co-morbidity data were abstracted from case notes. Multiple linear regression identified modifiable and unmodifiable factors independently predictive of global quality of life (EORTC-QLQ-C30).

Results:

Of unmodifiable factors, female sex (P<0.001), more self-reported co-morbidities (P=0.006) and metastases at diagnosis (P=0.036) significantly predicted poorer QoL, but explained little of the variability in the model (R²=0.064). Adding modifiable factors, poorer role (P<0.001) and social functioning (P=0.003), fatigue (P=0.001), dyspnoea (P=0.001), anorexia (P<0.001), depression (P<0.001) and worse perceived consequences (P=0.013) improved the model fit considerably (R²=0.574). Omitting functioning subscales resulted in recent diagnosis (P=0.002), lower perceived personal control (P=0.020) and travel difficulties (P<0.001) becoming significant predictors.

Conclusion:

Most factors affecting QoL are modifiable, especially symptoms (fatigue, anorexia, dyspnoea) and depression. Beliefs about illness are also important. Unmodifiable factors, including metastatic (or unstaged) disease at diagnosis, have less impact. There appears to be potential for interventions to improve QoL in patients with colorectal cancer.

Depression and anxiety in patients repeatedly referred to secondary care with medically unexplained symptoms: a case-control study

BACKGROUND

One third of referrals from primary to secondary care are for medically unexplained symptoms (MUS). We aimed to determine the association of depression and anxiety disorders with high use of specialist services by patients with MUS. We did this by comparing their prevalence in patients who had been repeatedly referred with symptoms for which they had received repeated specialist diagnoses of MUS with that in two control groups. We also determined the adequacy of treatment received.

METHOD

A case-control study in five general practices in Edinburgh, UK. Data collection was by case note review and questionnaire. Cases were 193 adults with three or more referrals over 5 years, at least two of which resulted in a diagnosis of MUS. Controls were: (a) patients referred only once over 5 years (n=152); (b) patients with three or more referrals for symptoms always diagnosed as medically explained (n=162).

RESULTS

In total, 93 (48%) of the cases met our criteria for current depression, anxiety or panic disorders. This compared with 38 (25%) and 52 (35.2%) of the control groups; odds ratios (95% confidence intervals) of 2.6 (1.6-4.1) and 1.6 (1.01-2.4), respectively. Almost half (44%) of the cases with current depression or anxiety had not received recent minimum effective therapy.

CONCLUSIONS

Depression, anxiety and panic disorders are common in patients repeatedly referred to hospital with MUS. Improving the recognition and treatment of these disorders in these patients has the potential to provide better, more appropriate and more cost-effective medical care.

Magneto-Optical Spectroscopy of RE/TM Alloys and TM/CO Multilayers

This paper reviews on magneto-optical spectroscopy of alloys, metallic multilayers and interference enhancement structures for magneto-optic (MO) recording. Mainly rare earth transition metal (RE-TM) alloys and Co/transition metal (Co/X) multilayers will be discussed. The read out performance in MO write/read tests is given by tile reflectivity and Kerr rotation strongly depends on the wavelength. While the magneto-optical transitions in the near infrared (IR:≈820nm) are dominated by tile 3d magnetic transition metals Fe and Co, the properties in the ultraviolet (UV: <400nm) can be dominated by either rare earths like Nd or Pr in RE-TM alloys or by exchange polarized Pt or Pd in Co/X multilayers and their respective alloys.

In an attempt to correlate the magneto-optic Kerr effect to electronic properties we have systematically investigated alloys and multilayers with x-ray photoemission (XPS) and polar magneto-optical Kerr spectroscopy (0.5–5.3eV range). It is found that electronic 4f levels in Nd or Pr contribute to the Kerr elffct via Γ→, d transitions in the order of 0.3°. Exchange polarized Pd and Pt in Co/X multilayers give rise to a room temperature Kerr rotation in the same order of magnitude via excitations of the 4d and 5d bands, respectively. These effects clearly depend on film compositions and thickness ratios.,

Microstructure and Chemical Ordering in UHV-Deposited, Polycrystalline Coxpt1−x Alloy Films for Magneto-Optical Recording

We report magneto-optical recording with 62 dB CNR (carrier-to-noise ratio) at 488 nm for quadrilayer structures comprising polycrystalline CoxPt1-x (x = 0.28) alloy films deposited on ungrooved, silicon nitride -coated glass discs, held at 300°C, by UHV evaporation. The key parameter controlling magnetic anisotropy of the films is substrate temperature during deposition. Polycrystalline films grown on amorphous silicon nitride have a large coercivity and full perpendicular remanance when grown at 300°C. Synchrotron X-ray diffraction data for polycrystalline films grown at 300 and 600°C confirm the presence of short-range compositional order, to the CoPt3-L12 phase in both cases. Such ordering can introduce an anisotropy in the distribution of Co-Co pairs in the alloy and is a possible source of the magnetic anisotropy.

Effect of gender, age and deprivation on key performance indicators in a FOBT-based colorectal screening programme

OBJECTIVES

To assess the effect of gender, age and deprivation on key performance indicators in a colorectal cancer screening programme.

SETTING

Between March 2000 and May 2006 a demonstration pilot of biennial guaiac faecal occult blood test (gFOBT) colorectal screening was carried out in North-East Scotland for all individuals aged 50-69 years.

METHODS

The relevant populations were subdivided, by gender, into four age groups and into five deprivation categories according to the Scottish Index of Multiple Deprivation (SIMD), and key performance indicators analysed within these groups.

RESULTS

In all rounds, uptake of the gFOBT increased with age (P < 0.001), decreased with increasing deprivation in both genders (P < 0.001), and was consistently higher in women than in men in all age and all SIMD groups. In addition, increasing deprivation was negatively associated with uptake of colonoscopy in men with a positive gFOBT (P < 0.001) although this effect was not observed in women. Positivity rates increased with age (P < 0.001) and increasing deprivation (P < 0.001) in both genders in all rounds, although they were higher in men than in women for all age and SIMD categories. Cancer detection rates increased with age (P < 0.001), were higher in men than in women in all age and SIMD categories, but were not consistently related to deprivation. In both genders, the positive predictive value (PPV) for cancer increased with age (P < 0.001) and decreased with increasing deprivation (P < 0.001) in all rounds and was consistently higher in men than in women in all age and SIMD categories.

CONCLUSIONS

In this population-based colorectal screening programme gender, age, and deprivation had marked effects on key performance indicators, and this has implications both for the evaluation of screening programmes and for strategies designed to reduce inequalities.