Arthur M. Michalek

Chernobyl-related ionising radiation exposure and cancer risk: an epidemiological review

The Chernobyl nuclear accident on 26th April, 1986, led to a massive release of radionuclides into the environment. Although vast areas of Europe were affected by Chernobyl-related ionising radiation, the accident had the greatest impact in Belarus, Ukraine, and the Russian Federation. Epidemiological studies that have investigated the link between the Chernobyl accident and cancer have largely focused on malignant diseases in children, specifically thyroid cancer and leukaemia. There is good evidence to suggest that rates of thyroid cancer in children from the countries that were formally part of the Soviet Union have risen as a consequence of the Chernobyl accident. The findings for childhood leukaemia are less conclusive. Overall rates for this disease do not seem to have been affected by the Chernobyl-related ionising radiation, but there may be a larger risk of infant leukaemia in contaminated areas of Europe. Among adult populations, there is no strong evidence to suggest that risk of thyroid cancer, leukaemia, or other malignant disease has increased as a result of the Chernobyl accident.

Menstrual cycle characteristics and the risk of endometriosis.

The present study utilized a case-control design to assess the relation between menstrual cycle factors and risk of endo-metriosis in women age 19–45 years. From a gynecologic specialty clinic in Western New York in 1987, we identified 104 laparoscopically confirmed cases of endometriosis. We used two control groups: (1) 100 friend controls (friends of cases), and (2) 98 medical controls (patients from the same medical practice with conditions other than endometriosis). Controls were frequency matched to cases by age. Because crude odds ratios (ORs), stratified by age (< 30 vs ≥ 30 years), revealed effect modification by age, we performed all analyses by age group. We used logistic regression to calculate ORs and 95% confidence intervals (CIs), controlling for pregnancy, religion, and body mass index. Among women under age 30, using friend controls, we observed elevated risks for menstrual flow ≥6 days per month (OR = 2.5, 95% CI = 1.1–5.9), heavy flow (OR = 2.5, 95% CI = 1.1–6.3), severe cramps (OR = 2.5, 95% CI = 1.2–6.0), increasing symptoms (OR = 6.6, 95% CI = 2.6–16.5), and tampon use ≥14 years (OR = 3.6, 95% CI = 1.04–13.5). Risks were also elevated for women age 30 and over, but not to the same degree as among younger women. Using medical controls, we observed elevated risks for menstrual flow ≥6 days (OR = 2.3, 95% CI = 1.1–5.1), severe cramps (OR = 2.3, 95% CI = 1.1–5.3), and increasing symptoms (OR = 8.3, 95% CI = 3.3–21.0) among women under age 30. These results support theories that associate endometriosis with increased exposure to menstruation.

Efficacy of high-efficiency particulate air filtration in preventing aspergillosis in immunocompromised patients with hematologic malignancies.

OBJECTIVES To describe and investigate the cause of an outbreak of 10 cases of nosocomial invasive infection with Aspergillus flavus in a hematologic oncology patient care unit. DESIGN A retrospective cohort study. SETTING The hematologic oncology unit of a comprehensive cancer center. PATIENTS Ninety-one patients admitted to the hematologic oncology service between January 1 and December 31, 1992, for 4 or more consecutive days were included in the study. RESULTS Ten (18%) of 55 patients admitted from July to December 1992 were diagnosed as having invasive aspergillosis compared with 0 (0%) of 36 patients admitted from January to June 1992 to the same patient care units. Patient characteristics, mortality rate, autopsy rate, and admitting location did not change significantly during the course of the year to result in a sudden increase in the number of aspergillosis cases. The source of the outbreak was the high counts of Aspergillus conidia determined from air sampling in the non-bone marrow transplant wing during the outbreak. After high-efficiency particulate air (HEPA) filters were installed as an infection control measure, there were only two additional cases of nosocomial aspergillosis in the 2 years following the outbreak. CONCLUSIONS This outbreak occurred among hematologic oncology patients with prolonged granulocytopenia housed in an environment with neither HEPA filters nor laminar air flow units. Our data demonstrate that in the setting of an outbreak of aspergillosis, HEPA filters are protective for highly immunocompromised patients with hematologic malignancies and are effective at controlling outbreaks due to air contamination with Aspergillus conidia.

Exposure to Schistosoma mansoni infection in a rural area in Brazil. II: household risk factors.

A number of studies have pointed out the potential importance of the household in the transmission of schistosomiasis. The clustering of domestic activities associated with water collection, storage, and usage can result in the sharing of transmission sites and infective water contact behaviours. In this study, we employed a variance component method to estimate effects due to individual risk factors and shared residence on the variance in faecal egg counts during Schistosoma mansoni infection. A suite of covariates, which included demographic, socioeconomic, water supply, and water contact behaviour terms, contributed 15% to the variance in faecal egg counts. Shared residence alone accounted for 28% of the variance in faecal egg excretion. When both the suite of covariates and shared residence were considered in the same model, shared residence still contributed 22% to the variance in infection intensity. These results point to the importance of shared residence as a means of capturing the complex interrelationship between shared demographic, socioeconomic, physical environmental, and behavioural factors that influence transmission of schistosomiasis at the household level.

Immunochemical versus guaiac occult blood stool tests: results of a community-based screening program

This study was designed to investigate two guaiac-based and one immunochemical faecal occult blood test in a community screening program. A total of 39,000 test kits consisting of Hemoccult II, Hemoccult Sensa and HemeSelect were distributed and of these 8933 (23%) were returned for testing. Follow-up contact with 1165 individuals who tested positive on at least one of the nine test slides was successful in 1076 cases (92.4%). Physician verification in 631 individuals revealed 25 patients (4%) diagnosed with colorectal cancer and 145 (23%) with polyps, of which 120 (82.7%) were adenomatous. The percentage of smaller adenomatous polyps detected relative to the percentage of large polyps (> 1 cm) was: Hemoccult II 31% versus 60%, Hemoccult Sensa 73% versus 80% and HemeSelect 34% versus 57%, respectively. The proportion of adenomatous polyps greater than 2 cm detected by individual tests was even more striking with Hemoccult II positive for 83%, Hemoccult Sensa for 100% and HemeSelect for 75%. Of the 25 patients diagnosed with cancer, 17 (68%) were diagnosed with early-stage disease. A statistically significant trend (P < 0.001) was observed with positive predictive values ranging from 3.3% for individuals with only one positive test to one approaching 40% for individuals with 7 or more positive tests. In this study, the most sensitive predictor of colorectal cancer was found to be the combination of Hemoccult II/HemeSelect. While there was no increase in the positive predicted value for adenomatous polyps < or = 1 cm, there was a direct linear increase for adenomatous polyps > 1 cm.

Parental occupational exposures and risk of neuroblastoma: a case–control study (United States)

AbstractBackground: A case–control study was conducted with 183 histologically confirmed neuroblastoma cases aged 0–14 years diagnosed among residents of New York State, excluding New York City, between 1976 and 1987. Three hundred seventy-two controls were selected from the New York State live birth certificate registry and were matched to cases on year of birth. Methods: Parental occupational exposures at the time of each childs birth were obtained from maternal telephone interviews, successfully completed for 85% of cases and 87% of controls. Results: Odds ratios were significantly elevated for maternal occupation in the service (OR = 2.0, 95% CI = 1.0–4.1) and retail (OR = 2.0, 95% CI = 1.1–3.7) industries and paternal occupation in materials handling (OR = 3.8, 95% CI = 1.1–14.6). Odds ratios were also significantly elevated for maternal report of occupational exposure to acetone (OR = 3.1, 95% CI = 1.7–5.6), insecticides (OR = 2.3, 95% CI = 1.4–3.7), lead (OR = 4.7, 95% CI = 1.3–18.2) and petroleum (OR = 3.0, 95% CI = 1.5–6.1) and paternal exposure to creosote (OR = 2.1, 95% CI = 1.1–4.3), dioxin (OR = 6.9, 95% CI = 1.3–68.4), lead (OR = 2.4, 95% CI = 1.2–4.8), and petroleum (OR = 1.8, 95% CI = 1.1–2.8). Conclusions: Due to the uncertainty of the biologic plausibility of these associations and the possibility of alternative explanations, these results should be interpreted cautiously.

Impact on survival by method of recurrence detection in stage I and II cutaneous melanoma

AbstractBackground: The impact on survival by components of a surveillance program (physical examination, blood tests, and chest radiograph) used to detect recurrences in patients with cutaneous melanoma was assessed. Methods: Data were collected from medical records and tumor registry information on a historical cohort of 1004 patients who presented with AJCC Stage I or II cutaneous melanoma at Roswell Park Cancer Institute from 1971 through 1995. Results: Information on method of detection was available on 154 out of 174 identified first recurrences (89%). Physical examination detected 72% of recurrences, constitutional symptoms indicated 17% of recurrences, and chest radiograph revealed 11% of recurrences. Blood tests did not predict any recurrence. Only 9 of 17 patients with recurrences detected by chest radiograph alone underwent curative surgical resection. These patients had a statistically significant prolonged survival after diagnosis of recurrence compared to those surgical candidates who did not undergo resection. There was no statistically significant difference in overall survival between patients with asymptomatic pulmonary recurrences and those whose pulmonary recurrences were detected after symptoms of metastatic disease had developed. Conclusions: Most recurrences are detected on physical examination. Blood tests have no role in surveillance programs. Chest radiographs can detect pulmonary recurrences in a small number of asymptomatic patients at a stage when surgery may prolong survival.

The costs and underappreciated consequences of research misconduct: a case study.

Arthur Michalek and colleagues explore the consequences of scientific misconduct and, using a single case as an illustration, estimate that direct costs can approach US

Breast cancer risk and lifetime occupational history: employment in professional and managerial occupations.

525,000, although total costs are likely to be higher.

Cancer surveillance in a northeastern native American population

OBJECTIVE: In this case-control study, occupational histories were used to assess the relation between risk of breast cancer and employment in professional and managerial occupations while adjusting for reproductive and other risk factors. METHODS: Incident, primary, female cases of breast cancer diagnosed between 1986 and 1991, and randomly selected controls were interviewed to obtain detailed medical, reproductive, and occupational histories. Mantel-Haenszel crude odds ratios (OR) and 95% confidence intervals (95% CIs) were used to estimate risk of breast cancer related to the job of longest duration. Unconditional logistic regression was used to estimate crude and adjusted ORs and 95% CIs associated with having ever been employed and duration of employment in a professional or managerial occupation. RESULTS: A non-significant threefold increase in risk was found among premenopausal women whose major job was in the occupational category of precision production, craft, and repair (95% CI 0.90 to 20.35). No increase in risk was found for premenopausal women whose major job was a managerial or professional occupation. However, an inverse relation between risk of premenopausal breast cancer and having ever held a professional or managerial job was observed (OR 0.53, 95% CI 0.34 to 0.82). This relation was strongest for women who worked one to 10 years (OR 0.47, 95% CI 0.29 to 0.77). Postmenopausal breast cancer was not related to professional and managerial employment. CONCLUSIONS: In this population, employment in professional and managerial occupations is not associated with postmenopausal risk of breast cancer, but seems to be related to a reduction in risk of premenopausal breast cancer. Methodological limitations of this study including response rates are discussed.