PubMed Health⌕ Search

Biomedical subjects

P Silcocks

Publications and source records attributed to P Silcocks.

17 recordsLinked to original sources
PubMed1994

P53 mutation in a series of epithelial ovarian cancers from the U.K., and its prognostic significance.

In an initial study of 20 fresh ovarian tumour samples, we compared the immunohistochemical positivity of staining of the p53 protein with the presence of missense mutations of the p53 gene. This revealed a prevalence of 50% with a perfect correlation between mutation and immunohistochemical staining. Detection of the p53 protein by immunohistochemistry was, therefore, used as a reliable indicator for the presence of P53 mutation, and was applied to a study of an archival series of 93 ovarian tumours. Positive immunostaining of the p53 protein was observed in 47% of this series. Cox regression was used to assess whether various clinical variables and P53 mutation were related to survival. As a result, it was found that positive staining of the p53 protein was independent of age, tumour differentiation, tumour type, though possibly not stage. There was some evidence that p53 positivity was associated with reduced survival after adjusting for other variables, but the result was not statistically significant.

Biomarkers, Tumor↗
PubMed1994

Estimating confidence limits on a standardised mortality ratio when the expected number is not error free.

OBJECTIVE: The aim was to demonstrate how the beta distribution may be used to find confidence limits on a standardised mortality ratio (SMR) when the expected number of events is subject to random variation and to compare these limits with those obtained with the standard exact approach used for SMRs and with a Fieller-based confidence interval. DESIGN: The relationship of the binomial and the beta distributions is explained. For cohort studies in which deaths are counted in exposed and unexposed groups exact confidence limits on the relative risk are found conditional on the total number of observed deaths. A similar method for the SMR is justified by analogy between the SMR and the relative risk found from such cohort studies, and the fact that the relevant (beta) distribution does not require integer parameters. SOURCE OF DATA: Illustrative examples of hypothetical data were used, together with a MINITAB macro (see appendix) to perform the calculations. MAIN RESULTS: Exact confidence intervals that include error in the expected number are much wider than those found with the standard exact method. Fieller intervals are comparable with the new exact method provided the observed and expected numbers (taken to be means of Poisson variates) are large enough to approximate normality. As the expected number is increased, the standard method gives results closer to the new method, but may still lead to different conclusions even with as many as 100 expected. CONCLUSIONS: If there is reason to suppose the expected number of deaths in an SMR is subject to sampling error (because of imprecisely estimated rates in the standard population) then exact confidence limits should be found by the methods described here, or approximate Fieller-based limits provided enough events are observed and expected to approximate normality.

Adolescent↗
PubMed1992

Suicidal hanging in Cardiff--a 15-year retrospective study.

A retrospective study of 84 cases of suicidal hanging was undertaken in which petechial haemorrhages or congestion were seen in 27%, soft tissue haemorrhage in 29% and fracture of the hyoid or laryngeal cartilages in 36%. Fractures were found to be related to increasing age and were not found when a soft ligature had been employed. Petechial haemorrhages and congestion were related to the completeness of suspension. Apart from the lack of fractures in the soft ligature group any of these findings, either singly or in combination, was found to occur without regard to age, suspension type or ligature type. No evidence was found of clustering or seasonality. The findings are compared to other series and discussed with regard to the mechanisms of causation.

Adult↗
PubMed1991

Does lithium reduce the mortality of recurrent mood disorders?

Numerous follow-up studies have shown that patients with mood disorders who do not receive prophylactic medication are at increased risk of death, particularly from suicide. After 11 years follow-up we compared the mortality of 103 patients attending a lithium clinic with that expected on the basis of age/sex/year-specific rates for England and Wales. Only 10 patients died during the study, although the expected number of deaths was 18.31 (P = 0.052, two-tailed) and no deaths from suicide were observed. After correcting for the prevalence of mood disorder in the general population, the relative risk was 0.60 (95% CI 0.29-1.12) which suggests that lithium reverses the excess mortality associated with recurrent mood disorders, including that from suicide.

Bipolar Disorder↗
PubMed1990

Survival among women with cancer of the uterine cervix: influence of marital status and social class.

STUDY OBJECTIVE: The aim was to investigate whether the survival of women with cancer of the uterine cervix is associated with their marital status and social class. DESIGN: The study was a survey of survival up to 5 years from diagnosis of women with cancer of the cervix registered in the South Thames Cancer Registry, using Cox regression to adjust for marital status, social class, age, and stage at registration. Because of deficiencies in social class data held by the Registry (social class was assigned in only 51% of cases, as opposed to 93% for marital status), the findings were compared with survival data from the OPCS Longitudinal Study. SETTING: During the period of study (1977-81) the South Thames Cancer Registry covered a female population of about 3.5 million in the south east of England. PATIENTS: Data on 1728 women were analysed. MEASUREMENTS AND AND MAIN RESULTS: Apparent differences in crude survival by marital status and social class were examined. These were found to be accounted for by adjustment for age and stage. The better survival of those whose social class was unknown was found to be an artefact of the way in which cancer registries assign social class, but this did not appear to bias registry based studies of social class survival seriously. CONCLUSIONS: (1) After adjusting for age, factors affecting survival in women with cancer of the cervix, such as stage at presentation or host resistance, appear to be similarly distributed in the different marital status and social class groups; (2) for cervical cancer, the marked social class gradient and unusual marital status distribution found in cross sectional mortality data reflect the incidence of the disease, not differences in survival; (3) explanations for these patterns in incidence and mortality data are to be found in the aetiology of the disease.

Adult↗
PubMed1988

Chemotherapy for the primary treatment of osteosarcoma: population effectiveness over 20 years.

Examination of the survival rate of 5-year cohorts with primary osteosarcoma registered by the Thames Cancer Registry between 1963 and 1982 and followed up to the end of 1984 showed a borderline significant improvement in survival (test for trend p = 0.05) for patients aged under 25 years at registration, but not for patients 25-64 years. A Cox's proportional hazards model was used to identify effects of sex, period of treatment, whether the patient received chemotherapy, and experience of the hospital. For patients aged under 25 years, a significant (p = 0.02) trend of improved survival was seen among the most recent cohort, and the greater the treatment experience of the hospital, possibly the better the results (p = 0.11), although selective referral cannot be excluded as a reason for this finding. Chemotherapy was not independently associated with survival. Period of treatment, chemotherapy, and experience of hospital were not associated with improved survival for patients aged 25-64. Recent clinical trials for primary osteosarcoma have contributed to an apparent improved survival through selection of patients with good prognosis. Claims for the efficacy of new regimens should be assessed in clinical practice by population monitoring through the analysis of cancer registers.

Adolescent↗