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A M Michalek

Publications and source records attributed to A M Michalek.

At least 37 records · Page 2Linked to original sources
PubMed1996

The relationship between smoking exposure and p53 overexpression in colorectal cancer.

Although epidemiological studies of the relationship between cigarette smoking and colorectal cancer risk have been equivocal, a positive association is consistently found for colorectal adenoma development. We performed an epidemiological study to determine whether p53 protein overexpression, in tumours obtained at the time of resection, is associated with cigarette exposure in colorectal cancer. A total of 163 colorectal cancer cases and 326 healthy controls responded to a standardised questionnaire on colorectal cancer risk factors including detailed information on their history of cigarette smoking. All patients' tumours were analysed immunohistochemically for p53 overexpression using an avidin-biotin immunoperoxidase procedure and polyclonal anti-p53 antibody CM1. Comparison of colorectal cases with controls revealed an elevated risk for ex-smokers (OR = 1.34, 95% CI 0.85-2.12) and current smokers (OR = 1.13, 95% CI 0.63-2.02) when compared with non-smokers. No dose-response relationship was found for total pack-years of smoking (trend test: P = 0.19). However, a trend for total pack-years of smoking was found when p53-positive cases were compared with p53-negative cases suggesting aetiological, heterogeneity (trend test: P = 0.06). Estimating the individual relative risk of developing a p53-positive tumour relative to controls showed no associations for smoking status or total pack-years of smoking. However, when p53-negative cases were compared with controls, an elevated risk was found for ex-smokers (OR = 1.84, 95% CI 1.00-3.37) and current years of smoking (trend test: P = 0.03). Colorectal tumours developing through p53-positive dependent pathways were not associated with smoking exposure. A significant increase in risk was observed for the p53-negative independent pathway with smoking. p53 overexpression appears to be associated with smoking exposure in colorectal cancer.

Adult↗
PubMed1996

Urban-based Native American cancer-control activities: services and perceptions.

BACKGROUND: Cancer has become a significant health concern in American Indian communities. Over the past several decades Native peoples have experienced significant increases in life expectancy and, with these gains, significant increases in cancer incidence and mortality. Limited data are available concerning cancer-control activities accessible to American Indian communities. Even less is known about control programs in place for American Indians resident in urban areas, where more that half of all Native peoples reside. METHODS: To ascertain the extent of available services and perceptions of health directors, a survey of all Indian-Health-Service-recognized urban clinics was undertaken. RESULTS: Results indicate that the cancer needs of American Indians resident in urban areas are not being adequately addressed. Only one-third of urban health directors reported perceived increases in cancer incidence and mortality rates. The directors ranked cancer fifth among seven health problems in terms of their clinics' commitment to addressing them. Findings from this study are juxtaposed with whose obtained in a separate survey of reservation-based health directors. CONCLUSIONS: Results indicate a need to develop more responsive cancer-control programs in Indian country and to sensitize researchers to other health needs of these communities.

Cancer Care Facilities↗
PubMed1996

Familial and nutritional risk factors for p53 overexpression in colorectal cancer.

Although familial and dietary factors are recognized as important risk determinants for colorectal tumorigenesis, the specific causes of colorectal cancer remain unclear. Studies of p53 genetic alterations have provided clues concerning the etiology of many cancers. This study was designed to determine whether overexpression of the p53 protein is associated with familial and dietary risk factors. Epidemiological data were obtained from 163 colorectal cancer cases and 326 healthy controls. Tumors of all patients were analyzed immunohistochemically for p53 overexpression using an avidin-biotin immunoperoxidase procedure and polyclonal anti-p53 antibody CM1. Of patient tumors, 44.8% showed p53 nuclear reactivity. Colorectal cases versus controls were three times more likely to report a family history of colorectal cancer [odds ratio (OR), 3.12; 95% confidence interval (CI), 1.77-5.52]. Only cruciferous vegetables exhibited a significant inverse association (OR, 0.59; 95% CI, 0.34-1.02; trend test, P = 0.03) for the highest versus lowest quartiles. Both meat and beef displayed an elevated increase in risk. When cases with p53 overexpression (p53 positive) were compared with cases without p53 overexpression (p53 negative), etiological heterogeneity was suggested for family history of colorectal cancer (OR, 0.39; 95% CI, 0.16-0.93), cruciferous vegetables (trend test, P = 0.12), and beef consumption (trend test, P = 0.08). To estimate the individual relative risks for p53-dependent and p53-independent pathways, each p53 subtype was compared with controls. Cruciferous vegetables exhibited a significant association (OR, 0.37; 95% CI, 0.17-0.82; trend test, P = 0.03) when p53 positive cases were compared with controls. When p53 negative cases were compared with controls, a significant increase in risk was observed for family history of cancer (OR, 4.46; 95% CI, 2.36-8.43) and beef (OR, 3.17; 95% CI, 1.83-11.28; trend test, P = 0.006). The p53 (positive) dependent pathway was characterized by an inverse association with cruciferous vegetables, and p53-independent tumors were characterized by family history and beef consumption. These data may indicate the significance of linking epidemiology and molecular biology in assessing specific etiological pathways.

Adenocarcinoma↗
PubMed1995

Cytochrome P4501A1 and glutathione S-transferase (M1) genetic polymorphisms and postmenopausal breast cancer risk.

Polycyclic aromatic hydrocarbons, possible human breast carcinogens, are metabolized by cytochrome P4501A1 (CYP1A1) and glutathione S-transferase (GSTM1). A CYP1A1 polymorphism (isoleucine to valine substitution in exon 7) or the null allele for GSTM1 may affect the mutagenic potential of polycyclic aromatic hydrocarbons. We examined polymorphisms in GSTM1 and CYP1A1 in relation to breast cancer risk. Included were 216 postmenopausal Caucasian women with incident breast cancer and 282 community controls. DNA analyses suggested no increased breast cancer risk with the null GSTM1 genotype [odds ratio (OR) = 1.10; CI, 0.73-1.64], although there was some indication that the null genotype was associated with risk among the youngest postmenopausal women (OR = 2.44; CI, 0.89-6.64). Slightly elevated risk was associated with the CYP1A1 polymorphism (OR = 1.61; CI, 0.94-2.75) and was highest for those who smoked up to 29 pack-years (OR = 5.22; CI, 1.16-23.56). Statistical power to detect an effect may be limited by small numbers, and larger sample sizes would be required to corroborate these suggestive findings.

Age Factors↗
PubMed1994

Occupational exposures associated with male breast cancer.

The role of occupational exposure to heat and electromagnetic fields was investigated in a case-control study of male breast cancer. Seventy-one cases reported to the New York State Tumor Registry between 1979 and 1988 were compared with 256 healthy male controls. Controls were frequency matched to cases by race, year of diagnosis, and age in 5-year intervals. Unconditional logistic regression modeling indicated that males with occupations that involved heat exposure had an elevated risk for the disease. The age- and county-adjusted odds ratio was 2.3 (95% confidence interval (CI) 0.95-5.3). Exposure to heat on the job could influence testicular function. No increase in disease risk was observed for males believed to have occupational exposure to electromagnetic fields (odds ratio = 0.7, 95% CI 0.3-1.9).

Adult↗
PubMed1994

Second malignant tumors following treatment during childhood and adolescence for cancer.

Many pediatric and adolescent cancer patients are treated with carcinogenic chemotherapeutic agents and radiation therapy to achieve permanent control of their malignancy. These modalities may induce a new cancer in the successfully treated patient. To identify disease and treatment factors which increased the risk of occurrence of a second malignant tumor following modern treatment for cancer during childhood or adolescence, we reviewed the courses of 1,406 previously untreated patients who were less than 20 years of age at diagnosis and were treated at Roswell Park Cancer Institute between January 1, 1960 and December 31, 1989. Eighteen patients developed a second malignant tumor, including two meningiomas, 2.65-25.65 years after diagnosis of the first cancer. The actuarial risk of a second malignant tumor was 5.6% at 25 years after diagnosis. Using Cox proportional hazards modelling, we identified prior therapy with BCNU (P = 0.0055) and doxorubicin (P = 0.0254) as the only factors that were significantly associated with the risk of a second malignant tumor. Three second malignant tumors of the central nervous system occurred following treatment with a nitrosourea. Successfully treated patients must be carefully followed to identify treatment related malignant tumors at an early stage.

Adolescent↗
PubMed1994

Factors that influence the further survival of patients who survive for five years after the diagnosis of cancer in childhood or adolescence.

To evaluate the further survival, and to identify disease and treatment factors which influence the further survival, of five-year survivors of cancer diagnosed during childhood or adolescence, we reviewed the courses of 591 previously untreated patients who were less than 20 years of age at diagnosis and survived for five years after diagnosis. Fifty-three of 143 patients who experienced disease recurrence during the first five years after diagnosis died during the period of observation, compared to 18 of 448 patients who did not experience disease recurrence during the first five years after diagnosis. The sex-specific standardized mortality ratios for the group of patients who never relapsed or relapsed more than five years after diagnosis were not significantly different from those of the New York State population. Cox proportional hazards modelling of the subgroup of patients who relapsed during the first five years after diagnosis demonstrated that disease which was treated surgically, a diagnosis of Hodgkin's disease or acute lymphoblastic leukemia, and older age at diagnosis were significantly associated with further survival in this group, whereas similar modelling of the patients who did not experience disease recurrence during the first five years after diagnosis failed to identify any variables which were associated with continued survival. The results of this study suggest that childhood and adolescent cancer patients who survive for five years without disease recurrence have a survival rate similar to that of the general population. Continued follow-up of this cohort is required to determine if the present findings can still be demonstrated as the majority of the cohort ages beyond 35 years of age.

Actuarial Analysis↗
PubMed1994

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.

Adenomatous Polyps↗
PubMed1994

Provision of cancer control services to Native Americans by state health departments.

To examine the extent of cancer prevention and control programs for American Indian and Alaska Native (AI/AN) tribal groups directly supported by state public health agencies, a cross-sectional survey was completed by chronic disease directors in 50 states. Descriptive statistics were used to summarize responses. Sixteen states (32%) reported having sponsored/directly supported cancer prevention and cancer control services specifically targeted to AI/AN populations. Few state public health agencies had developed culturally-relevant cancer education materials for AI/ANs. Although the respondents directed chronic disease or cancer prevention/control programs in their states, many were unfamiliar with cancer patterns or general health problems among AI/ANs. Survey results indicate that cancer prevention and control services are available to AI/AN populations through most state public health agencies. It is hoped that dissemination of survey results will increase awareness of cancer as a health problem among AI/ANs and lead to an expansion of the services available to this "invisible minority" to levels accessible by the majority population.

Cross-Sectional Studies↗
PubMed1994

Historical and contemporary correlates of syphilis and cancer.

BACKGROUND: This study examined the relationship between antecedent syphilis infection and cancer incidence in an attempt to identify specific cancer patterns. METHODS: The study cohort consisted of 16,420 people diagnosed with syphilis between 1972 and 1987 and who were residents of New York State, exclusive of New York City, at time of diagnosis. Incident cancers among cohort members were identified through linkage with files maintained by the New York State Cancer Registry. RESULTS: A total of 350 cancer cases were diagnosed among cohort members. For males and females combined, incidence was significantly elevated for cancers of the oral cavity standardized incidence ratio (SIR = 169, 95% confidence interval [CI]: 109-249), and specifically for cancer of the tongue (SIR = 251, 95% CI: 108-494). Significantly elevated incidence was observed among males for Kaposi's sarcoma (SIR = 2000, 95% CI: 1290-2950). CONCLUSION: While no conclusions may be reached concerning causality, the data do argue for increased cancer surveillance among people with syphilis. Moreover, findings are discussed in light of historical considerations.

Adolescent↗
PubMed1993

Lung cancer histologic types and family history of cancer. Analysis of histologic subtypes of 872 patients with primary lung cancer.

BACKGROUND: Previous research has demonstrated that there is clustering of cancer among relatives of patients with lung cancer and that women may be at a greater risk than men, regardless of their smoking histories. METHODS: The authors conducted a study to test the hypotheses that this predisposition varies by the histologic type of tumor and that women with particular histologic types will report more first-degree relatives with cancer than will men with the same cell type. The analyses were based on 872 patients with histologically confirmed lung cancer who had been admitted to Roswell Park Cancer Institute, Buffalo, New York, between 1982 and 1987. RESULTS: More patients with squamous and large cell carcinomas reported two or more relatives with cancer, and overall, women reported more family history of cancer. Among patients with squamous cell carcinoma, this difference between men and women was significant (P < 0.05). Among patients younger than 57 years, those with squamous cell were the most likely to report a family history of cancer (P < 0.01). A similar trend was observed for smoking. Persons with small cell and squamous cell carcinomas who were nonsmokers or had smoked 1-20 years had three times the risk of a family history of cancer than did those with large cell and adenocarcinomas (odds ratio [OR] = 3.01; confidence interval [ci] = 1.38-6.63), in contrast to those who had smoked more than 20 years (OR = 0.85; ci = 0.62-1.62). CONCLUSIONS: Squamous cell carcinoma is most associated with familial clustering of cancer, particularly among women, persons younger than 57 years, and individuals who smoked for fewer than 20 years.

Adenocarcinoma↗
PubMed1993

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 endometriosis 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 > or = 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 > or = 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 > or = 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.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Labor and delivery events and risk of sudden infant death syndrome (SIDS)

The purpose of this study was to assess whether labor and delivery events were risk factors for sudden infant death syndrome (SIDS). A nested case-control design was used. From the 1974 cohort of live births for Upstate New York (exclusive of New York City), resident mothers (n = 132,948), SIDS cases, and living controls were selected. Data were abstracted from hospital delivery and vital records for 148 autopsied cases and 355 frequency-matched controls. With the use of unconditional logistic regression, no increase in SIDS risk was observed for artificial rupture of membranes, medication use during labor, induction/augmentation of labor, or anesthesia for delivery. An increased risk of SIDS was observed for labor 16 hours or more (odds ratio (OR) = 2.6, 95% confidence interval (CI) 1.1-6.5) and vaginal breech delivery (OR = 7.2, 95% CI 0.7-72.2). Significant inverse trends were observed for Apgar scores and risk of SIDS.

Anesthesia, Obstetrical↗
PubMed1991

A meta-analysis of cancer incidence in United States and Canadian native populations.

A meta-analytic approach was used to summarize studies of cancer incidence among Native populations in the United States and Canada. Native males and females were found to have a significantly lower incidence of cancer for all sites combined. Among Native males, kidney cancer was found to exhibit significantly elevated incidence, while significantly lower incidence was found for cancers of the colon, lung, and prostate, and for lymphomas and leukaemias. Native females were found to have significantly elevated incidence for cancers of the gallbladder, cervix, and kidney, while significantly decreased incidence was found for cancers of the colon, breast and uterus, and for lymphomas. The use of meta-analysis to integrate the findings from these studies allowed the identification of subtle differences in cancer incidence. Although these findings are not definitive, they overcome the limited numbers of site-specific cancers reported in many previous studies and are suggestive of general patterns of cancer incidence among Native populations. In addition, these results may be useful in indicating directions for future research involving specific cancer sites with elevated incidence.

Canada↗
PubMed1990

Cancer in native populations--lessons to be learned.

Cancer incidence rates among Native Americans have, for the most part, been observed to be significantly lower than the general population. There has been, however, some indication that this is changing. The identification of emerging and changing patterns of cancer incidence in Natives is important in the establishment of cancer education, prevention, and screening programs. The present report attempts to put the Native cancer question into focus through a meta-analytic literature review; the presentation of a separate investigation of cancer mortality patterns in a single tribal group covering a 30-year period; and a brief review of cancer survival statistics for Natives. Meta-analytic results indicate that Native males and females experience a significantly lower incidence of cancer than expected. Females were found to experience an elevated risk of cervical cancer. Similar trends were observed in the separate mortality study. Moreover, mortality data indicate that there has been a trend towards increases in mortality from cancer, especially cancers of the lung, colon/rectum, and cervix. Natives experience significantly poorer relative survival rates for most cancer sites. Secular changes in cancer occurrence and mortality coupled with bleak survival statistics argue for the immediate establishment of effective cancer education and screening programs in these populations.

Cause of Death↗
PubMed1990

Timing of prenatal care and risk of sudden infant death syndrome.

Sudden infant death syndrome (SIDS) is the leading cause of death during post-neonatal life. Mothers whose infants succumb to SIDS are reported to initiate prenatal care later than control mothers. Previous studies have not always controlled for socioeconomic status (SES) of mothers or other potential confounders such as gestational age or birthweight of infants. The purpose of this study was to assess whether timing of prenatal care adjusted for these potential confounders was an independent risk factor for SIDS. SIDS cases (N = 148) were identified from the Upstate New York livebirth cohort for 1974 (N = 132,948) and compared to randomly selected controls (N = 355) who were frequency-matched on maternal age, race, parity and residence and infant's birth date. Data were abstracted from matched vital certificates (97% response), hospital delivery records (89% response) and selected sample of autopsy reports (100% response). Odds ratios (OR) and 95% confidence intervals (CI) were obtained using unconditional logistic regression. A significant inverse relationship was observed for number of prenatal visits and risk of SIDS; a significant direct relationship was observed between trimester prenatal care initiated and risk of SIDS. The results suggest that timing of prenatal care is important in assessing SIDS risk even after adjusting for potential confounders of early prenatal care utilization.

Case-Control Studies↗
PubMed1989

Cancer mortality in a northeastern native American population.

This study compared cancer mortality among the Seneca Nation of Indians (SNI) between 1955 and 1984 with cancer patterns exhibited by the general population of New York State (NYS), exclusive of New York City. Cancer mortality among the SNI was compared with cancer mortality in NYS using age and sex standardized mortality ratios (SMR). Deficits in overall cancer mortality were noted among both SNI males (SMR = 78) and females (SMR = 73). Results from this investigation will contribute to the understanding of patterns of malignant disease mortality among native peoples and may be of benefit for monitoring the impact of cancer mortality among the SNI and other Native American groups.

Adolescent↗