Biomedical subjects

P Silcocks

Publications and source records attributed to P Silcocks.

At least 19 recordsLinked to original sources

PubMed2006

Survival of death certificate initiated registrations: Selection bias, incomplete trace-back or higher mortality?

Cases first notified to a Registry and successfully followed back have an apparently worse prognosis than cases registered in life. A simple approach can be used to assess whether this is due to selection bias, incomplete follow-back or intrinsically higher mortality. For the colorectal, breast and stomach cancers studied and for comparable registries, the main explanations are likely to be selection bias and higher mortality.

Breast Neoplasms↗

PubMed2006

An exploratory prospective observational study of environmental factors exacerbating atopic eczema in children.

BACKGROUND: Possible exacerbating factors are a major concern of parents of children with atopic eczema (AE). However, there is minimal evidence for their direct role in leading to disease flares. OBJECTIVES: To assess the association between 'trigger factors' and disease flares in AE. METHODS: Twenty-five children with AE were recruited. Participants completed diaries, recording severity and exposure to potential exacerbating factors (18 variables) over 28 days. Severity was assessed at baseline and study completion. The relationship between severity and exposures was assessed. RESULTS: At episode level, on the day of exposure (lag 0), hot weather correlated to increased scratch scores (P=0.043). At a lag of 2 days after exposure, damp weather was associated with raised scratch scores (P=0.027). At lag 3 days, elevated scratch scores were associated with sweating and stress (P=0.029 and 0.019, respectively). Outside damp was associated with elevated scores (P=0.001) at lag 4. Multivariate analysis of all significant variables showed that only damp at lag 4 was significantly associated with flares (P=0.039). CONCLUSIONS: This study suggests association between stress, damp and heat and disease flares. These findings need to be studied over a longer period, using objective exposure measures.

Adolescent↗

PubMed2004

The role of repeat uterine evacuation in the management of persistent gestational trophoblastic disease.

OBJECTIVE: To evaluate the role of second (and third) uterine evacuation in the management of persistent gestational trophoblastic disease (GTD). METHODS: This was an observational study of all cases registered over a 10-year period at the Trophoblastic Disease Centre at Weston Park Hospital, Sheffield. Five hundred and forty-four of 4050 women registered during 1991-2000 underwent a second uterine evacuation following a presumptive diagnosis of persistent GTD. The reason for evacuation, hCG level prior to the procedure, histological appearances of evacuated products and the clinical outcome (in terms of the need for chemotherapy) were determined. RESULTS: After a second uterine evacuation 368 patients (68%) completed the follow-up programme without further evidence of persistent disease or need for chemotherapy. If the diagnosis of persistent GTD was confirmed solely on the basis of elevated hCG levels then 171 of 282 (60%) patients did not require chemotherapy. Chemotherapy was more likely where there was histological evidence of persistent trophoblastic disease and where the urinary hCG was >1500 IU/L at the time of the repeat evacuation. Twenty-eight of 60 patients (46%) undergoing a third evacuation required chemotherapy. CONCLUSION: Second uterine evacuation can be a useful therapeutic option for patients with presumed persistent trophoblastic disease not mandating immediate chemotherapy, particularly where the hCG level is <1500 IU/L. Patients with documented persistent trophoblastic disease on histological examination of the second evacuation sample are more likely to require chemotherapy. Third evacuation is not now recommended.

Adolescent↗

PubMed2002

Changing the diagnostic criteria for myocardial infarction in patients with a suspected heart attack affects the measurement of 30 day mortality but not long term survival.

OBJECTIVES: To explore the effects of alternative methods of defining myocardial infarction on the numbers and survival patterns of patients identified as having sustained a confirmed myocardial infarct. DESIGN: An inclusive historical cohort of patients admitted with a suspected heart attack. Patients were recoded from raw clinical data (collected at the index admission) to the epidemiological definitions of myocardial infarction used by the Nottingham heart attack register (NHAR), the World Health Organization (MONICA), and the UK heart attack study. SETTING: Single health district. PATIENTS: The NHAR identified all patients admitted in 1992 with suspected myocardial infarction. OUTCOME MEASURES: Survival at 30 days and four year postdischarge. RESULTS: 2739 patients were identified, of whom 90% survived to discharge. Recoding increased the numbers of patients defined as having confirmed myocardial infarction from 26% under the original NHAR classification to 69%, depending on the classification system used. In confirmed myocardial infarction, subsequent 30 day survival from admission varied from 77-86% depending on the classification system; four year survival after discharge was not affected. The distribution of important prognostic variables differed significantly between groups of patients with confirmed myocardial infarction defined by different systems. Patients with suspected but unconfirmed myocardial infarction under all classification systems had a worse postdischarge mortality. CONCLUSIONS: The classification system used had a substantial effect on the numbers of patients identified as having had a myocardial infarct, and on the 30 day survival. There were significant numbers of patients with more atypical presentations, not labelled as myocardial infarction, who did badly following discharge. More research is needed on these patients.

Age Factors↗

PubMed2001

Childhood cancer in the south Asian population of England (1990-1992).

Cancer incidence in 1990-92 among English south Asian (residents with ethnic origins in India, Pakistan or Bangladesh) and non-south Asian children is compared. Standardized incidence ratios show significant overall excesses in south Asians (131), largely due to higher rates in south Asian boys, and specific excesses for leukaemia (141), lymphoid leukaemia (141), lymphoma (172) and hepatic tumours (375). Aetiological investigation is required.

Adolescent↗

PubMed2001

Diet, smoking and lung cancer: a case-control study of 1000 cases and 1500 controls in South-West England.

We have examined the relationship between diet and lung cancer in a case-control study of 982 cases of lung cancer and 1486 population controls in south-west England in which subjects were interviewed personally about their smoking habits and their consumption of foods and supplements rich in retinol or carotene. Analyses were performed for 15 dietary variables, including intake of pre-formed retinol and carotene. There were significant associations (P< 0.01) with lung cancer risk for 13 of the variables, eight of which remained after adjustment for smoking. When the 15 variables were considered simultaneously, independent significant associations remained for 5: pre-formed retinol (increased risk), and fish liver oil, vitamin pills, carrots and tomato sauce (decreased risk). It is unlikely that all five associations represent biological effects, or that they can all be explained by residual confounding by smoking, or by biases. We conclude that there is at least one as yet unidentified factor that is causally related to lung cancer risk and of considerable importance in terms of attributable risk in this population.

Carotenoids↗

PubMed2001

What constitutes a histological confirmation of cancer? A survey of terminology interpretation in two English regions.

AIMS: To compare interpretation by cancer registries and histopathologists of phrases that might confirm a diagnosis of cancer. METHODS: One hundred and thirty one consultant pathologists were sent a questionnaire containing 37 phrases used in pathology reports, including those indicating cancer and those not. Pathologists were asked to indicate whether each phrase confirmed the disease, ruled it out, or was uncertain, together with a subjective estimate of how frequently they used the phrase. RESULTS: There was a 58% response rate with similar interpretation between regions. There were some differences in frequency of use. At least 50% of respondents considered 12 terms as confirmatory (for nine the lower 95% confidence limit was greater than 66%). CONCLUSIONS: The registry should consider ignoring four of the 13 terms currently regarded as confirmatory. Terminology used in pathology reports should be standardised across registries. Registries and coding departments should use empirical evidence to assess which phrases confirm a diagnosis.

Communication↗

PubMed2000

Smoking, smoking cessation, and lung cancer in the UK since 1950: combination of national statistics with two case-control studies.

OBJECTIVE AND DESIGN: To relate UK national trends since 1950 in smoking, in smoking cessation, and in lung cancer to the contrasting results from two large case-control studies centred around 1950 and 1990. SETTING: United Kingdom. PARTICIPANTS: Hospital patients under 75 years of age with and without lung cancer in 1950 and 1990, plus, in 1990, a matched sample of the local population: 1465 case-control pairs in the 1950 study, and 982 cases plus 3185 controls in the 1990 study. MAIN OUTCOME MEASURES: Smoking prevalence and lung cancer. RESULTS: For men in early middle age in the United Kingdom the prevalence of smoking halved between 1950 and 1990 but the death rate from lung cancer at ages 35-54 fell even more rapidly, indicating some reduction in the risk among continuing smokers. In contrast, women and older men who were still current smokers in 1990 were more likely than those in 1950 to have been persistent cigarette smokers throughout adult life and so had higher lung cancer rates than current smokers in 1950. The cumulative risk of death from lung cancer by age 75 (in the absence of other causes of death) rose from 6% at 1950 rates to 16% at 1990 rates in male cigarette smokers, and from 1% to 10% in female cigarette smokers. Among both men and women in 1990, however, the former smokers had only a fraction of the lung cancer rate of continuing smokers, and this fraction fell steeply with time since stopping. By 1990 cessation had almost halved the number of lung cancers that would have been expected if the former smokers had continued. For men who stopped at ages 60, 50, 40, and 30 the cumulative risks of lung cancer by age 75 were 10%, 6%, 3%, and 2%. CONCLUSIONS: People who stop smoking, even well into middle age, avoid most of their subsequent risk of lung cancer, and stopping before middle age avoids more than 90% of the risk attributable to tobacco. Mortality in the near future and throughout the first half of the 21st century could be substantially reduced by current smokers giving up the habit. In contrast, the extent to which young people henceforth become persistent smokers will affect mortality rates chiefly in the middle or second half of the 21st century.

Adult↗

PubMed2000

Guidelines for the stratification of patients recruited to trials of therapy for low-risk gestational trophoblastic tumor.

OBJECTIVE: The aim of the study was to initiate a search for factors which might independently predict the need for salvage therapy in patients with low-risk gestational trophoblastic tumor. METHODS: The independent effect of six factors on the need for salvage chemotherapy was assessed in patients with low-risk gestational trophoblastic tumor who were treated with low-dose methotrexate and folinic acid. The accuracies of World Health Organization and Charing Cross Hospital scores were also compared. RESULTS: Age, pretreatment beta hCG, antecedent pregnancy-treatment interval, and the presence of chest metastases detected on chest X ray were not significantly predictive. The size of tumor (P = 0.001) and the presence of chest metastases on chest computerized tomography (P = 0. 00028) had independent, statistically significant predictive power, and a simple prognostic index was derived from these variables. The World Health Organization score was found to be significantly better than the Charing Cross Hospital score. The accuracy of the simple prognostic index was slightly greater than that of the World Health Organization score, although this was not statistically significant. CONCLUSIONS: These results confirm that patients entered into studies of different therapies for low-risk gestational trophoblastic tumor should be stratified and that a simple score, derived from the results of tumor size and chest computerized tomography, is potentially as good as the World Health Organization score for predicting the need for salvage therapy.

Adolescent↗

PubMed2000

Mortality of patients admitted with a suspected acute myocardial infarction in whom the diagnosis is not confirmed.

AIMS: To examine the survival of patients admitted with a suspected acute myocardial infarction in whom the diagnosis was not confirmed ('possible myocardial infarction'). METHODS AND RESULTS: A cohort study based on the Nottingham Heart Attack Register of 1716 sequential patients discharged alive from two acute teaching hospitals following admission in 1992. The main outcome was mortality following hospital discharge after 5 years of follow-up. Survival of the cohort of patients in whom myocardial infarction was suspected but not confirmed was 58% (95% C.I. 56 to 60%) after 5 years of follow-up, compared with an expected survival of 76% in an age/sex matched general population. Patients with ECG abnormalities that were not diagnostic of myocardial infarction had a 5-year survival of 56%, compared with 77% in those without such changes (P<0.00001). In the 703 patients who died in the first 5 years of follow-up, the cause of death was cardiovascular in at least 53% of cases. Survival following hospital discharge was worse than that in patients discharged alive in the same year following a confirmed myocardial infarction (63% vs 69% after 4 years of follow-up P=0.0016). CONCLUSION: Patients in this study had a substantially increased risk of death in the 5 years after discharge from hospital, compared with an age- and sex-matched population, and worse than patients discharged following a confirmed myocardial infarction. Almost half of those with ECG changes at the time of their admission died over the next 5 years. As over half of all deaths in this cohort were due to cardiovascular causes, further work is needed to identify patients at high and low risk of subsequent mortality who may warrant investigation and treatment following hospital discharge.

Aged↗

PubMed2000

Identifying the risk of death following hospital discharge in patients admitted with a suspected acute myocardial infarction in whom the diagnosis is not confirmed.

AIMS: To describe clinical factors, available at the time of discharge, that predicted survival of patients admitted with a suspected acute myocardial infarction in whom the diagnosis was not confirmed. METHODS AND RESULTS: A cohort study based on the Nottingham Heart Attack Register of 1716 sequential patients discharged alive from two acute teaching hospitals following admission in 1992. The main outcome was identification of high and low mortality risk groups over 5 years of follow-up. Overall 5-year survival was 58% (95% CI 56 to 60%). Having abnormal cardiac enzyme changes or an abnormal ECG that was insufficient to meet established diagnostic criteria of myocardial infarction, or both, identified three groups with a 5 year survival of 77%, 60% or 51%. Multivariate methods were used to develop a risk score from seven variables available at the time of discharge (age, sex, past history of myocardial infarction, ECG abnormalities, cardiac enzyme abnormalities, Killip score of 2 or 3 on admission and being discharged on a diuretic). Quartiles of this risk score then identified four groups with 5 year survival ranging from 89% to 25%. CONCLUSION: Among the study cohort, it was possible to identify subgroups with a markedly different risk of subsequent mortality from clinical indicators that were readily available at the time of hospital discharge. Risk stratification has the potential to improve targeting of subsequent secondary preventive efforts, but further work is required to ascertain whether cardiovascular risk can be modified through a more intensive approach to management.

Aged↗

PubMed1999

The significance of Erb-b2 immunostaining in cervical cancer.

OBJECTIVE: The aim of this study was to assess the relationship between survival and erb-b2 immunohistochemical staining in patients with early stage cervical carcinoma. METHODS: Archival specimens for 126 patients with stage IB/IIA cervical carcinoma treated with radical hysterectomy and bilateral pelvic node dissection (RH-BPND) were retrieved and submitted to immunohistochemistry for ERBB2 expression. The association between positive results and poor survival was assessed in a multivariate analysis. RESULTS: Erb-b2 immunostaining was significantly associated with poor survival (P = 0.0284) but less so than parametrial extension (P = 0.0014) and nodal disease (P = 0.0106). Tumor type (squamous/adenosquamous/adenocarcinoma) and the status of surgical margins were not significantly associated with survival. CONCLUSIONS: These results supported further investigations of ERBB2 expression as a marker of high-risk disease in patients treated with RH-BPND.

Adenocarcinoma↗

PubMed1999

Cancer incidence in the south Asian population of England (1990-92).

Cancer incidence among English south Asians (residents in England with ethnic origins in India, Pakistan or Bangladesh) is described and compared with non-south Asian and Indian subcontinent rates. The setting for the study was areas covered by Thames, Trent, West Midlands and Yorkshire cancer registries. The study identified 356 555 cases of incident cancer (ICD9:140-208) registered between 1990 and 1992, including 3845 classified as English south Asian. The main outcome measures were age specific and directly standardized incidence rates for all cancer sites (ICD9:140-208). English south Asian incidence rates for all sites combined were significantly lower than non-south Asian rates but higher than Indian subcontinent rates. English south Asian rates were substantially higher than Indian subcontinent rates for a number of common sites including lung cancer in males, breast cancer in females and lymphoma in both sexes. English south Asian rates for childhood and early adult cancer (0-29 years) were similar or higher than non-south Asian rates. English south Asian rates were significantly higher than non-south Asian rates for Hodgkin's disease in males, cancer of the tongue, mouth, oesophagus, thyroid gland and myeloid leukaemia in females, and cancer of the hypopharynx, liver and gall bladder in both sexes. The results are consistent with a transition from the lower cancer risk of the country of ethnic origin to that of the country of residence. They suggest that detrimental changes in lifestyle and other exposures have occurred in the migrant south Asian population.

Adolescent↗

PubMed1999

Audit of prostate cancer: validity and feasibility of registry-based staging.

The sample consisted of 251 prostate cancer patients who were newly registered during 1994 from a Regional Cancer Registry. It was possible for 96% of cases to be staged by Registry clerical staff, but none had been formally staged by clinicians. In 45% of cases tumour extent was based only on Digital Rectal Examination (DRE), and on 32% there was no assessment found. 81% had no investigation of nodal status and 16% of cases had echography other than trans-rectal ultrasound. To find metastases 18% had scintigraphy and 13% had a plain chest X Ray while 61% had no investigation. Cox regression gave age-adjusted hazard ratios relative to stage A (95% CI) of 2.94 (1.59 to 5.44) for Stage B, 6.43 (3.37 to 12.24) for Stage C, and 9.03 (5.12 to 15.95) for stage D. Key lessons were: Registry clerical staff can abstract stage-related information from a high proportion of case-notes even if stage is not explicitly recorded by clinicians; The validity of registry based staging information is supported by survival analysis; This activity has resource implications and would be more appropriately performed by a member of the clinical team.

England↗

PubMed1999

Audit of prostate cancer: lessons learnt for current clinical practice, surrogates for quality of care and standardisation and quality assurance.

Two-hundred and fifty-one prostate cancer patients first registered during 1994 were sampled from a Regional Cancer Registry. In the six months after diagnosis, 39% received drug treatment alone, while 37% had no active treatment. Eighty-one percent of cases were histologically proven. Seventy-six percent had a prostate specific antigen (PSA) test and in 3% the PSA test was the basis for diagnosis. Of histologically proven cases 29% had a Gleason grade. None were staged by clinicians. Key lessons were: The result was a snapshot of current clinical practice which suggested other possible surrogates for quality of care, such as basis of stage and timing of investigations; There is a need for standardisation and quality assurance of the content of pathology reports; Standard treatment protocols would aid recording and comparison of treatments.

Biomarkers↗

PubMed1999

An assessment of the Nam Pehchan computer program for the identification of names of south Asian ethnic origin.

BACKGROUND: An assessment was made of the usefulness and accuracy of a computer program for the identification of the south Asian population through the classification of names on a disease register. METHODS: The computer program, Nam Pehchan, was used to classify names as either south Asian or non south Asian. The results were compared with a reference standard, which combined use of the program with visual inspection. The latter was facilitated by a computer-generated dictionary of common non south Asian names. The data set consisted of 356,555 cases of incident cancer (ICD9: 140-208) registered between 1990 and 1992 by Thames, Trent, West Midlands and Yorkshire cancer registries. RESULTS: Nam Pehchan classified 5506 cases as south Asian. Visual inspection identified 2024 false positives (36.8 per cent of all cases identified as south Asian by Nam Pehchan) and 363 false negatives (9.5 per cent of those identified by the reference standard). Compared with the reference standard, Nam Pehchan had a sensitivity of 90.5 per cent and a positive predictive value of 63.2 per cent. CONCLUSION: The Nam Pehchan program quickly identified a high proportion of the names classified as south Asian by the reference standard, but the high false positive rate means that the program alone is not an adequate single strategy. The time-consuming process of inspection of program negatives for large data sets can be substantially reduced by comparison with dictionaries of common non south Asian names.

Asia↗

PubMed1999

Coinfection with influenza B virus does not affect association of Neisseria meningitidis with human nasopharyngeal mucosa in organ culture.

There is an epidemiological association between influenza virus infection and meningococcal disease. Proposed mechanisms are the destruction of the normal epithelial barrier function of the upper respiratory tract by influenza virus or the expression of human or viral surface-exposed proteins that enhance bacterial adherence and/or invasion. To test these hypotheses, human nasopharyngeal mucosa specimens from a total of 19 individual donors were successfully infected with influenza B virus and then inoculated with serogroup B Neisseria meningitidis. Subsequent bacterial association with the epithelial surface was measured in three separate series of experiments by using transmission electron microscopy (n = 6), scanning electron microscopy (n = 6), and counting of viable bacteria within homogenates of explants (n = 7). Penetration of the mucosa was estimated by measuring the count of viable bacteria recovered from explants after exposure to sodium taurocholate. Bacterial association with the surface of explants was time dependent over 24 h of superinfection. Influenza virus did not positively or negatively influence bacterial attachment to or penetration of explant mucosa compared to those of uninfected controls, even when the period of preincubation with virus was extended to 7 days. When proteins were purified from mucosal epithelium and immobilized on nitrocellulose membranes, N. meningitidis attached predominantly to bands corresponding to proteins of 210 and 130 kDa. In the presence of influenza virus infection, these proteins were gradually lost over the course of 72 h. In conclusion, influenza B virus did not increase association of serogroup B N. meningitidis with human nasopharyngeal mucosa.

Antigens, Viral↗

PubMed1998

Risk of lung cancer associated with residential radon exposure in south-west England: a case-control study.

Studies of underground miners occupationally exposed to radon have consistently demonstrated an increased risk of lung cancer in both smokers and non-smokers. Radon exposure also occurs elsewhere, especially in houses, and estimates based on the findings for miners suggest that residential radon is responsible for about one in 20 lung cancers in the UK, most being caused in combination with smoking. These calculations depend, however, on several assumptions and more direct evidence on the magnitude of the risk is needed. To obtain such evidence, a case-control study was carried out in south-west England in which 982 subjects with lung cancer and 3185 control subjects were interviewed. In addition, radon concentrations were measured at the addresses at which subjects had lived during the 30-year period ending 5 years before the interview. Lung cancer risk was examined in relation to residential radon concentration after taking into account the length of time that subjects had lived at each address and adjusting for age, sex, smoking status, county of residence and social class. The relative risk of lung cancer increased by 0.08 (95% CI -0.03, 0.20) per 100 Bq m(-3) increase in the observed time-weighted residential radon concentration. When the analysis was restricted to the 484 subjects with lung cancer and the 1637 control subjects with radon measurements available for the entire 30-year period of interest, the corresponding increase was somewhat higher at 0.14 per 100 Bq m(-3) (95% CI 0.01, 0.29), although the difference between this group and the remaining subjects was not statistically significant. When the analysis was repeated taking into account uncertainties in the assessment of radon exposure, the estimated increases in relative risk per 100 Bq m(-3) were larger, at 0.12 (95% CI -0.05, 0.33) when all subjects were included and 0.24 (95% CI -0.01, 0.56) when limited to subjects with radon measurements available for all 30 years. These results are consistent with those from studies of residential radon carried out in other countries in which data on individual subjects have been collected. The combined evidence suggests that the risk of lung cancer associated with residential radon exposure is about the size that has been postulated on the basis of the studies of miners exposed to radon.

Aged↗