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Biomedical subjects

T Bates

Publications and source records attributed to T Bates.

At least 37 records · Page 2Linked to original sources
PubMed1999

Does open-access mammography and ultrasound delay the diagnosis of breast cancer?

There is a consensus that open-access breast imaging for general practitioners is inappropriate since the process omits an expert clinical examination and fine needle aspiration cytology. However, it was decided to test this hypothesis by comparing the outcome of breast referrals in a district with both an open-access imaging and a one-stop clinic. The time from referral to definitive diagnosis in all women with breast cancer was compared over a 12 month period in 1996. Of 1049 women referred for open-access imaging 20 (2%) were found to have breast cancer compared with 91 (9%) of 995 women referred to the one-stop breast clinic. There was a longer interval before the diagnosis of breast cancer was made in cases referred for open-access imaging compared with cases referred to the one-stop breast clinic (mean 63 vs 35 days). However, if patients with advanced disease are excluded the mean interval was 63 vs 44 days. The mean tumour size of breast cancers in cases referred to open-access imaging was smaller (1.5 vs 2.3 cm), there were fewer grade 3 tumours (10% vs 39%), and there was a lower rate of axillary lymph node metastases (20% vs 32%) compared with cases referred to the one-stop breast clinic. The longer interval for the open-access patients was largely due to administrative delay and the 3 patients with a delay of more than 3 months had all had a triple assessment which was false negative. This study does not support the hypothesis that open-access mammography is unsafe and should be withdrawn.

Journal Article↗
PubMed1999

Body mass index, height and cumulative menstrual cycles at the time of diagnosis are not risk factors for poor outcome in breast cancer.

Obesity, height and age at menarche have been shown to be risk factors for the development of primary breast cancer. However, their prognostic influence on breast cancer once it has presented is uncertain. The present study analysed 448 patients with primary breast cancer to determine whether or not body mass index (BMI), height and cumulative menstrual cycles at diagnosis are independent prognostic variables. The effects of all three variables on survival time and disease free interval were estimated. Of the 448 patients after a median follow up of 6 years, 190 (42%) developed recurrence and 162 (36%) had died. Body Mass Index and height could be calculated from available data in 403 patients and cumulative menstrual cycles in 388 patients. There was no evidence of an effect of BMI on survival time (P=0.99; hazard ratio=1.000; 95% Confidence Interval 0.968-1.034) or disease free interval (P=0.92; hazard ratio=1.002; 95% Confidence Interval 0.973-1.031). Similarly, height and cumulative menstrual years did not influence outcome in patients with primary breast cancer. However, nodal status and tumour size were both significant prognostic factors (P<0.001). The present study found no association between Body Mass Index, height and cumulative menstrual years and outcome in patients with primary breast cancer.

Journal Article↗
PubMed1997

Variation in management of small invasive breast cancers detected on screening in the former south east Thames region: observational study.

OBJECTIVE: To examine the variation in surgical and adjuvant treatment of breast cancer of known histology and detected on screening in a large cohort of patients treated by the surgeons of a health region. DESIGN: Part prospective, part retrospective observational study using the databases of a region's breast screening programme and of the cancer registry. SETTING: The former South East Thames region. SUBJECTS: 600 women aged 49-79 who presented during 1991-2 with invasive breast cancer up to 20 mm in diameter that had been detected on screening. These patients were treated by 35 surgeons. MAIN OUTCOME MEASURES: Mastectomy rate by surgeon and the use of adjuvant treatment (radiotherapy, tamoxifen, and chemotherapy) were compared with risk factors, tumour grade, resection margins, and axillary node status. RESULTS: The mastectomy rate varied between nil and 80%, although the numbers at these extremes were small (0/13 v 8/10). Surgeons operating on more than 20 such cases had a lower mastectomy rate (15%) than surgeons treating fewer cases (23%), but this difference was confounded by variation in casemix. There were also wide variations in mastectomy rates and in axillary sampling rates that were independent of casemix or caseload. There was broad agreement on the use of adjuvant tamoxifen (94%), but few patients received chemotherapy (2.5%). 78 patients (19%) did not receive radiotherapy, including 51 out of 317 patients with unfavourable tumours, and 26 patients did not receive tamoxifen. Whether the patient received adjuvant treatment was more dependent on referral by the surgeon than the risk factors for local recurrence and was independent of caseload. CONCLUSION: Mastectomy rates for similar tumours vary widely by surgeon independently of casemix or caseload, but surgeons with a higher caseload tend to have a lower mastectomy rate. Omission of postoperative radiotherapy or tamoxifen after conservative treatment is not related to risk factors for local recurrence or caseload. Confidential feedback of treatment profiles to individual surgeons has been used, but when benefit has been established treatment should be guided by evidence based protocol.

Aged↗
PubMed1996

Cholecystectomy as a risk factor for colorectal cancer: a meta-analysis.

BACKGROUND: It has been suggested that there is an increased risk of colorectal cancer after cholecystectomy due to increased levels of secondary bile acids. Some studies suggest the risk is higher for women and for the development of right-sided tumours. METHODS: A review of the literature yielded 95 relevant studies, of which 35 were suitable for a meta-analysis involving age- and sex-matched controls. RESULTS: The pooled odds ratio for a positive association between cholecystectomy and colorectal cancer was 1.11 (95% confidence interval (CI), 1.02 to 1.21). For women the odds ratio was 1.14 (95 % CI, 10.01 to 1.28) and for right-sided cancer 1.86 (95% CI, 1.31 to 2.65). CONCLUSIONS: It is possible that this small observed association may be due to a publication bias for positive results or bias within the included studies. If it is indeed a real effect, the risk to an individual is very small.

Adolescent↗
PubMed1996

Impact of laparoscopic cholecystectomy on surgical training.

All cholecystectomies in a single health district were studied during a 5-year period spanning the introduction of laparoscopic cholecystectomy (LC). The number of LCs increased from 2 (1.3%) in year 3 to 86 (56%) in year 5. The number of operative cholangiograms and explorations of the common bile duct performed both fell substantially. The age distribution did not change significantly during the study period, but the percentage of females undergoing cholecystectomy increased. The percentage of trainee operations remained constant in those Firms performing only open cholecystectomy (OC), but fell from 67% to 9% in those adopting LC. An increase in annual cholecystectomy rate was seen with the laparoscopic surgeons, with a corresponding fall for those surgeons performing only OC. There was a threefold increase in the percentage of operations performed privately from years 2 to 5, with 73% being laparoscopic in year 5. The consequences for training of the introduction of LC must be addressed.

Adolescent↗
PubMed1996

Curricular training and the new deal.

There is concern that the shortened period of training to be introduced for the new Specialist Registrar Grade is incompatible with the limitation of hours of work required by the New Deal. Surgeons in training may require more experience than other specialties but the Calman proposals introduce the concept of a structured curricular training which will mean a radical change in the way that surgical training is delivered. The changes will be uncomfortable and may need to be modified in the light of experience but the end-result will be worthwhile and should be achievable within the new time constraints.

Continuity of Patient Care↗
PubMed1995

Smoking, processing speed and attention in a choice reaction time task.

Nineteen subjects performed a choice reaction time task in which two levels of choice (two and four stimuli), and two levels of spatial attention (narrow and wide) were manipulated under each of two smoking conditions: sham smoking (denicotinised cigarette) or regular smoking (0.8 mg nicotine cigarette). All three factors significantly affected reaction time, with the smallest reaction times being recorded to the two-choice narrow grouped stimuli recorded under the high nicotine condition. Nicotine appears to speed decision time for both complex and hard-to-attend tasks, which is compatible with a role for nicotinic receptors in systems jointly mediating attention, memory and processing speed.

Adolescent↗
PubMed1995

Effects of nicotine on perceptual speed.

Two experiments investigating the effects of nicotine on performance in the inspection time (IT) procedure are reported. Experiment 1 compared ITs in smoking (0.8 mg nicotine cigarette), sham-smoking, and no-smoking conditions. IT was significantly shorter in the smoking condition as compared to both the no-smoking or sham-smoking conditions, suggesting that nicotine enhances early information processing. This result is of particular interest because of the correlation between IT and IQ reported in previous experiments. The nicotine related decrease in IT raises the possibility that nicotine enhances at least a subset of the physiological processes underlying intellectual performance. Experiment 2 examined the persistence of this nicotine related enhancement in IT, and investigated the effects of nicotine across 480 IT trials. Results suggested that ITs derived from the last third of the 480 trials were significantly shorter in the 0.8 mg cigarette condition than in no-smoking condition. The results from these two experiments, taken together with recent work examining the effects of nicotine on the string length measure of AEP waveform complexity and Hick decision time (DT), and studies investigating cognitive functioning and cholinergic system dysfunction in dementia, suggest a role of the cholinergic system in intellectual performance.

Adolescent↗
PubMed1995

The relationship between cholecystectomy, unoperated gallstone disease, and colorectal cancer. A necropsy study.

BACKGROUND: There may be an increased risk of colorectal cancer after cholecystectomy, but the literature is not consistent. It is also possible that any risk might be associated with gallstones rather than cholecystectomy. METHODS: In a prospective necropsy study of 8563 cases, all 219 cases of a previous cholecystectomy were pair-matched to subjects with gallstones and to subjects with a normal gallbladder. In a second study all 192 cases of colorectal cancer were pair-matched to cancer-free subjects. RESULTS: The odds ratio (OR) for developing colorectal cancer after cholecystectomy compared with a normal gallbladder was 1.0 (95% confidence interval, 0.30-3.34) and with unoperated gallstones was 0.88 (0.27-2.76). CONCLUSIONS: This study fails to support an association between cholecystectomy or gallstones and colorectal cancer. For those cases of colorectal cancer versus controls, the OR for previous cholecystectomy was 0.70 (0.23-2.04) and for gallstone disease was 0.93 (0.58-1.48).

Cholecystectomy↗
PubMed1994

Effects of smoking on simple and choice reaction time.

Twenty-nine subjects performed a reaction time task with four levels of choice-task complexity under non-smoking, sham smoking, and low, medium and high nicotine cigarette conditions. Nicotine reduced decision time, while sham smoking increased decision time. This effect was independent of subjects' habitual levels of cigarette consumption. No effect of smoking was found on movement time.

Adolescent↗
PubMed1994

Smoking and Raven IQ.

Nicotine has recently been shown to enhance measures of information processing speed including the decision time (DT) component of simple and choice reaction time and the string length measure of evoked potential waveform complexity. Both (DT and string length) have been previously demonstrated to correlate with performance on standard intelligence tests (IQ). We therefore hypothesised that nicotine is acting to improve intellectual performance on the elementary information processing correlates of IQ. In the current experiment we tested this hypothesis using the Raven Advanced Progressive Matrices (APM) test. APM scores were significantly higher in the smoking session compared to the non-smoking session, suggesting that nicotine acts to enhance physiological processes underlying performance on intellectual tasks.

Adolescent↗
PubMed1994

Report on the clinical effects of inadvertent radiation underdosage in 1045 patients.

Between Autumn 1982 and Winter 1991, 1045 patients received lower doses of radiation than were prescribed for the treatment of their cancers because of a miscalculation of radiation doses. This occurred as a result of the introduction of a new technique of treatment planning. An error in the application of the planning system lead to an underdosage of radiation of between 5 and 35%. In patients who received radiation alone for radical treatment a dose reduction of 20% or more resulted in a lower than expected local control rate. The effects were less marked in patients who were treated by combinations of surgery and radiation and in those with a very high rate of distant metastases. In 1991, a new computer planning system was installed and a discrepancy was discovered between the new plans and those from the previous system. Further investigation revealed that the original planning system already contained within it a correction factor for the tumour to skin distance and that systematically reapplying this correction had resulted in underdoses of radiation being delivered to patients for nearly 10 years. During the 9-year period of this dose miscalculation only 6% of patients treated in the department were treated with the isocentric technique; for many of those it formed only a part of their treatment.

Adolescent↗
PubMed1994

Indirect laryngoscopic evaluation of vocal cord function in patients undergoing transhiatal esophagectomy.

Vocal cord function was assessed by indirect laryngoscopy before and after transhiatal esophagectomy for carcinoma of the middle and lower esophagus. Unilateral vocal cord palsy was found in 16 (34 percent) of 47 patients, but three of these patients were not hoarse and coughed normally. Four patients were hoarse postoperatively but had normal vocal cord function on indirect laryngoscopic examination. All vocal cord palsies but one were on the left side and the left side of the neck was used for esophageal mobilization with the only exception of the one patient who had a right cord palsy after a right-sided neck dissection. Patients with impaired vocal cord function did not have a significantly increased stay in the intensive therapy unit or in the hospital, nor was there an increase in pulmonary complications. Vocal cord palsy is a recognized complication of transhiatal esophagectomy, and although it remains unresolved whether or not the recurrent laryngeal nerve damage occurs at the level of the aortic arch or in the neck, the present evidence suggests the latter site. The clinical impression of postoperative vocal cord palsy is often incorrect.

Adenocarcinoma↗