Surgery-related factors and local recurrence of Wilms tumor in National Wilms Tumor Study 4.
OBJECTIVE: To assess the prognostic factors for local recurrence in Wilms tumor. SUMMARY BACKGROUND DATA: Current therapy for Wilms tumor has evolved through four studies of the National Wilms Tumor Study Group. As adverse prognostic factors were identified, treatment of children with Wilms tumor has been tailored based on these factors. Two-year relapse-free survival of children in the fourth study (NWTS-4) exceeded 91%. Factors once of prognostic import for local recurrence may lose their significance as more effective therapeutic regimens are devised. METHODS: Children evaluated were drawn from the records of NWTS-4. A total of 2482 randomized or followed patients were identified. Local recurrence, defined as recurrence in the original tumor bed, retroperitoneum, or within the abdominal cavity or pelvis, occurred in 100 children. Using a nested case-control study design, 182 matched controls were selected. Factors were analyzed for their association with local failure. Relative risks and 95% confidence intervals were calculated, taking into account the matching. RESULTS: The largest relative risks for local recurrence were observed in patients with stage III disease, those with unfavorable histology (especially diffuse anaplasia), and those reported to have tumor spillage during surgery. Multiple regression analysis adjusting for the combined effects of histology, lymph node involvement, and age revealed that tumor spillage remained significant. The relative risk of local recurrence from spill was largest in children with stage II disease. The absence of lymph node biopsy was also associated with an increased relative risk of recurrence, which was largest in children with stage I disease. The survival of children after local recurrence is poor, with an average survival rate at 2 years after relapse of 43%. Survival was dependent on initial stage: those who received more therapy before relapse had a worse prognosis. CONCLUSIONS: This study has demonstrated that surgical rupture of the tumor must be prevented by the surgeon, because spills produce an increased risk of local relapse. Both local and diffuse spills produce this risk. Stage II children with local spill appear to require more aggressive therapy than that used in NWTS-4. The continued critical importance of lymph node sampling in conjunction with nephrectomy for Wilms tumor is also established. Absence of lymph node biopsy may result in understaging and inadequate treatment of the child and may produce an increased risk of local recurrence. (+info)
Role of schools in the transmission of measles in rural Senegal: implications for measles control in developing countries.
Patterns of measles transmission at school and at home were studied in 1995 in a rural area of Senegal with a high level of vaccination coverage. Among 209 case children with a median age of 8 years, there were no deaths, although the case fatality ratio has previously been 6-7% in this area. Forty percent of the case children had been vaccinated against measles; the proportion of vaccinated children was higher among secondary cases (47%) than among index cases (33%) (prevalence ratio = 1.36, 95% confidence interval (CI) 1.04-1.76). Vaccinated index cases may have been less infectious than unvaccinated index cases, since they produced fewer clinical cases among exposed children (relative risk = 0.55, 95% CI 0.29-1.04). The secondary attack rate was lower in the schools than in the homes (relative risk = 0.31, 95% CI 0.20-0.49). The school outbreaks were protracted, with 4-5 generations of cases being seen in the two larger schools. Vaccine efficacy was found to be 57% (95% CI -23 to 85) in the schools and 74% (95% CI 62-82) in the residential compounds. Measles infection resulted in a mean of 3.8 days of absenteeism per case, though this did not appear to have an impact on the children's grades. Among the index cases, 56% of children were probably infected by neighbors in the community, and 7% were probably infected at health centers, 13% outside the community, and 24% in one of the three schools which had outbreaks during the epidemic. However, most of the school-related cases occurred at the beginning and therefore contributed to the general propagation of the epidemic. To prevent school outbreaks, it may be necessary to require vaccination prior to school entry and to revaccinate children in individual schools upon detection of cases of measles. Multidose measles vaccination schedules will be necessary to control measles in developing countries. (+info)
Asthma visits to emergency rooms and soybean unloading in the harbors of Valencia and A Coruna, Spain.
Soybean unloading in the harbor of Barcelona, Spain, has been associated with large increases in the numbers of asthma patients treated in emergency departments between 1981 and 1987. In this study, the association between asthma and soybean unloading in two other Spanish cities, Valencia and A Coruna, was assessed. Asthma admissions were retrospectively identified for the period 1993-1995, and harbor activities were investigated in each location. Two approaches were used to assess the association between asthma and soybean unloading: One used unusual asthma days (days with an unusually high number of emergency room asthma visits) as an effect measure, and the other estimated the relative increase in the daily number of emergency room visits by autoregressive Poisson regression, adjusted for meteorologic variables, seasonality, and influenza incidence. No association between unusual asthma days and soya unloading was observed in either Valencia or A Coruna, except for one particular dock in Valencia. When the association between unloaded products and the daily number of emergency asthma visits was studied, a statistically significant association was observed for unloading of soya husk (relative risk = 1.50, 95% confidence interval 1.16-1.94) and soybeans (relative risk = 1.31, 95% confidence interval 1.08-1.59) in A Coruna. In Valencia, a statistical association was found only for the unloading of soybeans at two particular docks. Although these findings support the notion that asthma outbreaks are not a common hidden condition in most harbors where soybeans are unloaded, the weak associations reported are likely to be causal. Therefore, appropriate control measures should be implemented to avoid soybean dust emissions, particularly in harbors with populations living in the vicinity. (+info)
Maternal second trimester serum tumor necrosis factor-alpha-soluble receptor p55 (sTNFp55) and subsequent risk of preeclampsia.
Preeclampsia is characterized by diffuse vascular endothelial dysfunction. Tumor necrosis factor-alpha (TNF-alpha), which plays a key role in the cytokine network responsible for immunoregulation, is also known to contribute to endothelial dysfunction and other metabolic disturbances noted in preeclampsia. Results from cross-sectional studies and one longitudinal study indicate that TNF-alpha (or its soluble receptor, sTNFp55) is increased in the peripheral circulation and amniotic fluid of women with preeclampsia as compared with normotensive women. Between December 1993 and August 1994, prediagnostic sTNFp55 concentrations (a marker of excessive TNF-alpha release) were measured in 35 women with preeclampsia and 222 normotensive women to determine whether elevations precede the clinical manifestation of the disorder. Logistic regression procedures were used to calculate maximum likelihood estimates of odds ratios and 95% confidence intervals. Mean second trimester (15-22 weeks' gestation) serum sTNFp55 concentrations, measured by enzyme-linked immunosorbent assay, were 14.4% higher in preeclamptic women than in normotensive controls (716.6 pg/ml (standard deviation 193.6) vs. 626.4 pg/ml (standard deviation 158.0); p = 0.003). The relative risk of preeclampsia increased across successively higher quintiles of sTNFp55 (odds ratios were 1.0, 1.3, 2.1, and 3.7, with the lowest quintile used as the referent; p for trend = 0.007). After adjustment for maternal age, adiposity, and parity, the relative risk between extreme quintiles was 3.3 (95% confidence interval 0.8-13.4). These findings indicate that the level of TNF-alpha in maternal circulation is increased prior to the clinical manifestation of the disorder, and they are consistent with the hypothesized role of cytokines in mediating endothelial dysfunction and the pathogenesis of preeclampsia. Further work is needed to identify modifiable risk factors for the excessive synthesis and release of TNF-alpha in pregnancy, and to assess whether lowering of TNF-alpha concentrations in pregnancy alters the incidence and severity of preeclampsia. (+info)
Relation between obesity and breast cancer in young women.
This study was conducted to assess the relation between body size and risk of breast cancer among young women. A case-control study was conducted among women aged 21-45 years living in three counties in Washington State. Cases were women born after 1944 with invasive or in situ breast cancer that was diagnosed between January 1, 1983, and April 30, 1990. Controls were selected using random digit dialing and were frequency-matched to cases on the basis of age and county of residence. Interviews took place between 1986 and 1992. Body size was evaluated using indices from several different time periods. After adjustment for confounders, a decreased risk of breast cancer was found for women in the highest quintile of body mass index (weight (kg)/height (m)2) as compared with the lowest quintile (for maximum lifetime body mass index, odds ratio = 0.69, 95% confidence interval (CI) 0.51-0.94). Age modified the relation between body size and risk of breast cancer. The odds ratio for women in the highest quintile of maximum body mass index who were aged 21-35 years was 0.29 (95% CI 0.16-0.55), as compared with an odds ratio of 1.5 for women aged 36-45 years (95% CI 0.9-2.5) (p for interaction = 0.003). This study supports prior research showing a decreased risk of breast cancer associated with increased body size among premenopausal or young women. More detailed analysis in this study found a strong effect that was limited to the youngest age group (< or = 35 years). (+info)
Why do short term workers have high mortality?
Increased mortality is often reported among workers in short term employment. This may indicate either a health-related selection process or the presence of different lifestyle or social conditions among short term workers. The authors studied these two aspects of short term employment among 16,404 Danish workers in the reinforced plastics industry who were hired between 1978 and 1985 and were followed to the end of 1988. Preemployment hospitalization histories for 1977-1984 were ascertained and were related to length of employment between 1978 and 1988. Workers who had been hospitalized prior to employment showed a 20% higher risk of early termination of employment than those never hospitalized (rate ratio (RR) = 1.20, 95% confidence interval (CI) 1.16-1.29), and the risk increased with number of hospitalizations. For workers with two or more preemployment hospitalizations related to alcohol abuse or violence, the rate ratios for short term employment were 2.30 (95% CI 1.74-3.06) and 1.86 (95% CI 1.35-2.56), respectively. An unhealthy lifestyle may also be a determinant of short term employment. While it is possible in principle to adjust for lifestyle factors if proper data are collected, the health-related selection of workers requires careful consideration when choosing a reference group for comparative studies of cumulative occupational exposure. (+info)
Epidemiology of drug-resistant tuberculosis in Texas.
During 1987-1996, over 22,000 tuberculosis cases were reported in Texas, at an average annual incidence rate of 12.5 cases per 100,000 population. Counties with the highest rates were located along the Mexico-Texas border and in northwestern Texas. Nine percent of cases were resistant to at least one of the five first-line antituberculosis drugs used for treatment. Almost 5 percent (4.6%) were resistant to isoniazid, either alone or in combination with other antibiotics; 2.3% were resistant to rifampin; and only 1.3% were resistant to both isoniazid and rifampin. Being a recurrent case, being foreign-born, being 20-39 years of age, and residing in a Mexico-Texas border county were independent risk factors for isoniazid resistance and rifampin resistance. Tuberculosis patients with human immunodeficiency virus (HIV) infection were more likely to have rifampin resistance and less likely to have isoniazid resistance than patients without HIV infection. Factors associated with multi-drug-resistant tuberculosis included a history of previous tuberculosis (relative risk (RR) = 4.91, 95% confidence interval (CI) 3.5-6.8), non-US birth (RR = 2.69, 95% CI 2.1-3.5), age younger than 20 years (RR = 1.97, 95% CI 1.1-3.5), age 20-39 years (RR = 1.82, 95% CI 1.3-2.6), and residence in a Mexico-Texas border county (RR = 2.33, 95% CI 1.8-3.1). (+info)
Outcome of pregnancy in women with congenital shunt lesions.
OBJECTIVE: To evaluate the outcome of pregnancy in women with congenital shunt lesions. SETTING: Retrospective study in a tertiary care centre. METHODS: Pregnancy history was obtained by a standardised questionnaire and medical records were reviewed. PATIENTS: 175 women were identified, at a mean (SD) age of 42 (14) years. Pregnancies occurred in 126 women: 50 with an atrial septal defect, 22 with a ventricular septal defect, 22 with an atrioventricular septal defect, 19 with tetralogy of Fallot, and 13 with other complex shunt lesions. RESULTS: 309 pregnancies were reported by 126 woman (2.5 (1.6) pregnancies per woman). The shortening fraction of the systemic ventricle was 40 (8)%, and 98% were in New York Heart Association class I-II at last follow up. Spontaneous abortions occurred in 17% of pregnancies (abortion rate, 0.4 (0.9) per woman). Gestational age of the 241 newborn infants was 8.8 (0.8) months. There were no maternal deaths related to pregnancy. Pre-eclampsia and embolic events were observed in 1.3% and 0.6%, respectively of all pregnancies. Women with complex shunt lesions more often underwent caesarean section (70% v 15-30%, p = 0.005) and gave birth to smaller babies for equivalent gestation (2577 (671) g v 3016 (572) to 3207 (610) g, p < 0.05). The recurrence risk of congenital heart disease was 2.5%. CONCLUSIONS: The outcome of pregnancy is favourable in women with congenital shunt lesions if their functional class and their systolic ventricular function are good. Such patients can be reassured. (+info)