Adherence to the dietary guidelines for Americans and endometrial cancer risk

The Healthy Eating Index (HEI) was developed by the US Department of Agriculture with the goal of quantifying adherence to the Dietary Guidelines for Americans. The purpose of this study was to evaluate the impact of the HEI-2005 score and each of its components on endometrial cancer risk in a population-based case-control study in New Jersey. A total of 424 cases and 398 controls completed a Food Frequency Questionnaire, which was used to derive the HEI-2005 score. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression while adjusting for potential covariates, which included all major endometrial cancer risk factors. The adjusted OR for women in the highest quartile when compared to the lowest quartile was 0.83 (95% CI: 0.52-1.34). For the meat and beans component comprising meat, eggs, poultry, fish, and beans, the OR was 0.70 (95% CI: 0.45-1.11; p for trend: 0.07), with little evidence of an association with any of the individual foods. There was no indication of an association for any of the other components of the HEI or of effect modification by body mass index. This study suggested limited value for the HEI-2005 in predicting endometrial cancer risk.

Abstract A111: Race is a predictor for endometrioid endometrial cancer cause-specific survival, but not all-cause survival

Endometrial cancer is the most common gynecologic cancer, with an estimated 42,000 new cases in 2010. The reported difference in overall five year survival between white women and African American (AA) women represents significant survival disparity in cancer. Histologic types of endometrial cancer and stage at diagnosis differ substantially between AAs and whites, but AA women experience poorer survival even after adjusting for these factors.

After IRB approval, we performed a case-only retrospective analysis of 362 patients with surgically treated endometrioid endometrial cancer. Data from 120 AA and 242 white women, diagnosed from 1990-2005 at a single institution were analyzed to examine risk factors associated with survival. Age at diagnosis, co-morbid conditions in the 5 years prior to diagnosis, BMI, and smoking history were obtained from medical record review. Tumor histologic type, 1988 FIGO stage, grade, vital status and number of months surviving were obtained from the Metropolitan Detroit Cancer Surveillance System, part of the SEER program. Differences in stage, co-morbid conditions (using a modified Charlson Comorbidity Index, CCI), and BMI were examined by race. Chisquare tests were used to assess differences in distribution of clinical and demographic variables. Log-rank tests and Cox proportional hazards models were used to assess the risk of all-cause and endometrial cancer-related deaths.

AA women were more likely than white women to have high grade tumors (p=0.009), hypertension (p=0.0005) and higher mean BMI (p=0.009). No differences by race were identified among the total group for age (p=0.98), stage at diagnosis (p=0.78), categorical modified CCI (p=0.51) or smoking history (p=0.96). When data were stratified by grade, hypertension (p=0.0009) and high BMI (p=0.002) were more frequent among AAs compared to whites with low grade tumors, but not high grade tumors. Among women with high grade tumors, AAs had a greater number of co-morbid conditions (p=0.005) and were more likely to be current or former smokers compared to whites (p=0.003). In univariate survival analysis, age at diagnosis, CCI, stage, and grade were all significantly associated with any cause survival, whereas race was not. When examining deaths due to endometrial cancer, only stage (HR=3.37,95% CI: 2.52-4.51), grade (HR=4.32,95% CI: 2.89-6.47) and race (HR=2.12,95% CI: 1.13-3.97) were predictors of survival. Analysis of endometrial cancer-related deaths by grade suggest this difference in survival by race is seen for high grade (p=0.03) but not low grade (p=0.87) tumors.

In this single institution study, race was not a predictor of overall survival, but was associated with endometrial cancer-related survival. Excess of co-morbid conditions was associated with AA race, and overall survival, but not endometrial cancer-related survival in this population. A larger, more comprehensive study, including information regarding socio-economic factors, molecular tumor markers, and treatment modality is necessary to elucidate the causes underlying the large disparity in endometrial cancer survival between AA and white women.

Citation Information: Cancer Epidemiol Biomarkers Prev 2010;19(10 Suppl):A111.

Coffee and tea consumption and endometrial cancer risk in a population-based study in New Jersey

We evaluated the role of tea and coffee and substances added (sugar/honey, creamers, and milk) on endometrial cancer risk in a population-based case-control study in six counties in New Jersey, including 417 cases and 395 controls. Multivariate odds ratios (OR) and 95% confidence intervals (CI) were computed using unconditional logistic regression. There was a moderate inverse association with coffee consumption, with an adjusted OR of 0.65 (95% CI: 0.36-1.17) for women who reported more than two cups/day of coffee compared to none. Tea consumption appeared to increase risk (OR: 1.93; 95% CI: 1.08-3.45), but after including the variables sugar/honey and cream/milk added to tea in the model, the risk estimate was attenuated and no longer statistically significant (OR: 1.77; 95% CI: 0.96-3.28 for those consuming more than one cup/day of tea compared to nonusers). There was a suggestion of a decreased risk associated with green tea, but the confidence interval included one (adjusted OR for one or more cups/week vs. none: 0.75; 95% CI: 0.48-1.18). We found an association with adding sugar/honey to tea, with those adding two or more teaspoons/cup having an OR of 2.66 (95% CI: 1.42-4.98; p for trend <0.01) after adjusting for relevant confounders. For sugar/honey added to coffee the corresponding OR was 1.43 (95% CI: 0.81-2.55). Our results indicate that sugars and milk/cream added to coffee and tea should be considered in future studies evaluating coffee and tea and endometrial cancer risk.

Genome-wide association study identifies variants in the ABO locus associated with susceptibility to pancreatic cancer

We conducted a two-stage genome-wide association study of pancreatic cancer, a cancer with one of the lowest survival rates worldwide. We genotyped 558,542 SNPs in 1,896 individuals with pancreatic cancer and 1,939 controls drawn from 12 prospective cohorts plus one hospital-based case-control study. We conducted a combined analysis of these groups plus an additional 2,457 affected individuals and 2,654 controls from eight case-control studies, adjusting for study, sex, ancestry and five principal components. We identified an association between a locus on 9q34 and pancreatic cancer marked by the SNP rs505922 (combined P = 5.37 x 10(-8); multiplicative per-allele odds ratio 1.20; 95% confidence interval 1.12-1.28). This SNP maps to the first intron of the ABO blood group gene. Our results are consistent with earlier epidemiologic evidence suggesting that people with blood group O may have a lower risk of pancreatic cancer than those with groups A or B.

Pancreatic adenocarcinoma in a young patient population--12-year experience at Memorial Sloan Kettering Cancer Center

BACKGROUND

There is a dearth of data in a younger population of patients with pancreatic ductal adenocarcinoma (PAC) regarding epidemiology, genetics, prognosis, and outcome. This report examines a large cohort of patients with PAC <or=45 years of age evaluated at MSKCC over a 12-year period.

METHODS

A retrospective analysis of patients referred to MSKCC with PAC identified from the institutional tumor registry, who were <or=45 years on the date of the diagnostic biopsy, between January 1995 and February 2008, was performed. Information reviewed included demographics, clinical and pathological staging, surgical management, therapy, date of relapse, death or last follow-up. Survival curves were estimated using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

One hundred thirty-six cases of PAC, age <or=45 years at diagnosis, were identified. Seventy-four (54%) females, 62 (46%) males. Age range: 24-45; 4, 38, and 94 patients in age groups 20-29, 30-39, 40-45 years, respectively. Fifty (37%) had a smoking history. Fourteen (10.3%) had a positive family history of PAC. Thirty-five (25.7%) underwent a curative resection for localized disease. Twenty-eight (20.1%) presented with locally advanced, inoperable disease. Sixty-eight (50%) presented as AJCC Stage IV. Twenty-three (37%) of those resected underwent adjuvant chemoradiation. Thirteen received adjuvant gemcitabine. The median overall survival for the entire cohort was 12.3 months (95% CI 10.2-14.0 months). The median overall survival for the patients with locally resectable disease was 41.8 months (95% CI 20.3-47 months). The median overall survival for the patients who presented with locally advanced, unresectable disease was 15.3 months (95% CI 12-19.3 months). The median overall survival for those who presented with metastatic disease was 7.2 months (95% CI 5.2-9.5 months).

CONCLUSIONS

This is the largest reported cohort of young patients with PAC <or=45 years of age. The data suggest that patients with stages I-II disease may have an improved prognosis, however the prognosis for stages III-IV patients appears to be similar to the typical (older) patient population with PAC.

Risk of endometrial cancer in relation to medical conditions and medication use

We studied the relation of medical conditions related to obesity and medications used for these conditions with endometrial cancer. We also investigated the association of other medical conditions and medications with risk. This U.S. population-based case-control study included 469 endometrial cancer cases and 467 controls. Information on putative risk factors for endometrial cancer was collected through personal interviews. We asked women about their medical history and medications used for six months or longer and the number of years each medication was taken. Risk was strongly associated with increasing obesity (P for trend < 0.001). Among the conditions related to obesity, and after adjustment for age, body mass index, and other risk factors and conditions, uterine fibroids were independently related to an increased cancer risk [adjusted odds ratio (OR), 1.8; 95% confidence interval (95% CI), 1.2-2.5]. Although hypertension was not significantly related to endometrial cancer after adjustment for age and body mass index, the use of thiazide diuretics was independently associated with increased risk (OR, 1.8; 95% CI, 1.1-3.0). Anemia was associated with decreased risk (OR, 0.6; 95% CI, 0.5-0.9). Use of nonsteroidal anti-inflammatory drugs was related to a decreased risk (OR, 0.7; 95% CI, 0.5-0.97). To our knowledge, the observation about thiazide diuretics is novel and requires confirmation in other studies and populations.

Two estrogen-related variants in CYP19A1 and endometrial cancer risk: a pooled analysis in the Epidemiology of Endometrial Cancer Consortium

Common variants in CYP19A1 (the A alleles of rs749292 and rs727479) have been associated with a 10% to 20% increase in circulating estrogen levels in postmenopausal women. We hypothesized that the presence of one or both A alleles in these single nucleotide polymorphisms (SNP) is associated with increased endometrial cancer risk. We tested this hypothesis in a large pooled analysis of 4,998 endometrial cancer cases and 8,285 controls from 10 studies in the Epidemiology of Endometrial Cancer Consortium. The majority of women (>66%) were whites, with smaller proportions of other races and ethnic groups (blacks, Asians, and Latinas) also included in this pooled analysis. Unconditional logistic regression was used to model the association between SNPs/haplotypes and endometrial cancer risk. Carrying the A allele of either of these SNPs was associated with an increased risk of endometrial cancer, with pooled odds ratios per allele of 1.14, 95% confidence interval of 1.09-1.21, and P = 7.1 x 10(-7) for rs749292, and odds ratio per allele of 1.08, 95% confidence interval of 1.02-1.14, and P = 0.009 for rs727479. For rs749292, these associations were generally stronger among women age >or=55 years. For both SNPs, risk increased with increasing body mass index, and for rs727479, this pattern seemed stronger among women age >or=55 years (P interaction = 0.007). The combination of A alleles in the two SNPs, either by direct count or by haplotype analysis, did not increase risk above that observed for the individual SNPs. Our study provides evidence that CYP19A1 genetic variation influences susceptibility to endometrial cancer, particularly among older and obese women.

Attenuating pregnane X receptor (PXR) activation: A molecular modelling approach

Recent studies have demonstrated that the pregnane X receptor (PXR) is a key regulator of cytochromes P450 3A (e.g. CYP3A4 in human) gene expression. As a result, activation of PXR may lead to CYP3A4 protein over-expression. Because induction of CYP3A4 could result in clinically important drug drug interactions, there has been a great interest in reducing the possibility of PXR activation by drug candidates in drug-discovery programmes. In order to provide structural insight for attenuating drug candidate-mediated PXR activation, we used a docking approach to study the structure activity relationship for PXR activators. Based on our docking models, it is proposed that introducing polar groups to the end of an activator should reduce its human PXR (hPXR) activity via destabilizing interactions in the hydrophobic areas of the PXR ligand-binding pocket. A number of analogues that incorporate these structural features then were designed and synthesized, and they exhibited significantly lower hPXR activation in a transactivation assay and decreased CYP3A4 induction in a human hepatocytes-based assay. In addition, an example in which attenuating hPXR activation was achieved by sterically destabilizing the helices 11 and 12 of the receptor is presented.

Preoperative predictors for complications after pancreaticoduodenectomy: impact of BMI and body fat distribution

BACKGROUND

The purpose of this study was to examine the preoperative patient and radiographic factors that are associated with operative morbidity after pancreaticoduodenectomy.

MATERIAL AND METHODS

Patient characteristics and preoperative radiographic findings and their association with postoperative complications after pancreaticoduodenectomy were analyzed for 356 patients with pancreatic adenocarcinoma who underwent resection between 2000 and 2005.

RESULTS

Postoperative complications developed in 135 patients (38%). The most common complications were pancreatic fistula/abscess (15%), wound infection (14%), and delayed gastric emptying (4%). On multivariate analysis, the only preoperative radiographic factors associated with having any postoperative complication were the absence of pancreatic atrophy and the extent of central obesity determined by the thickness of retrorenal visceral fat (VF). Complications occurred in 51% of patients with VF > or = 2 cm, compared to 31% of patients with VF < 2 cm, p < 0.001. Postoperatively, pancreatic fistula developed in 24% of patients with VF > or = 2 cm and in only 10% of patients with VF < 2 cm, p = 0.01. Wound infections occurred in 21% of the patients with body mass index greater than or equal to 30 kg/m(2) compared to 12% of the nonobese patients, p = 0.03.

CONCLUSIONS

Generalized obesity is associated with postoperative wound infections after pancreaticoduodenectomy. The degree of visceral fat on preoperative cross-sectional imaging is associated with significantly higher rates of overall complications and pancreatic fistula.

GLIOGENE an International Consortium to Understand Familial Glioma

Evidence for familial aggregation of glioma has been documented in both case-control and cohort studies and occurs apart from the well-described rare inherited genetic syndromes involving glioma: neurofibromatosis type 1 and 2, tuberous sclerosis, Turcot's syndrome, and Li-Fraumeni syndrome. Nonsyndromic glioma families have been studied but no genes have been identified in the two published linkage studies of familial glioma probably due to the small number of families. Because glioma is a rare but devastating cancer, and a family history of glioma has been observed in approximately 5% of the cases, we initiated an international consortium to identify glioma families not affected by syndromes to better understand the inherited factors related to this disease. The international consortium GLIOGENE is an acronym for "glioma gene" and includes 15 research groups in North America, Europe, and Israel to study familial glioma. The overarching goal is to characterize genes in glioma families using a genome-wide single-nucleotide polymorphism approach and conducting linkage analysis to identify new genomic regions or loci that could harbor genes important for gliomagenesis. Here, we review the rationale for studying familial glioma and our proposed strategy for the GLIOGENE study.

Allergies, variants in IL-4 and IL-4R alpha genes, and risk of pancreatic cancer

BACKGROUND

Several studies in epidemiology indicate that risk of pancreatic cancer is reduced in individuals with allergies. Although genes have been identified that are critical in allergic response, polymorphisms in these genes have not been studied in relation to risk of pancreatic cancer. We hypothesized that variants in these genes are related to risk.

METHODS

We investigated the association of allergies and pancreatic cancer in a hospital-based case-control study with 405 cases and 212 controls. In a subgroup of 149 cases and 135 controls, we studied the association of variants in IL-4 (C-589T, G3017T) and IL-4R alpha (Gln576Arg) with allergies and with risk of pancreatic cancer.

RESULTS

We found reduced risk of pancreatic cancer associated with allergies, with adjusted odds ratios of 0.58 (95% CI 0.40-0.84) for any allergies, 0.45 (95% CI 0.29-0.70) for hay fever, and 0.43 (95% CI 0.23-0.80) for animals. The minor allele at each locus studied was associated with reduced risk of allergies in controls, leading us to hypothesize that they would be associated with increased risk of pancreatic cancer. Overall, there was no association between the genotypes studied and risk of pancreatic cancer. In analyses within strata defined by presence or absence of allergies, there were differences in risk associated with genotype for IL-4 G3017T: there was slightly increased risk among those with allergies and reduced risk among those without allergies.

CONCLUSIONS

The consistent association of allergies with risk of pancreatic cancer and these results suggest that associations between variants in genes related to allergic response and pancreatic cancer warrant further study.

Climate change and health: global to local influences on disease risk

The World Health Organization has concluded that the climatic changes that have occurred since the mid 1970s could already be causing annually over 150,000 deaths and five million disability-adjusted life-years (DALY), mainly in developing countries. The less developed countries are, ironically, those least responsible for causing global warming. Many health outcomes and diseases are sensitive to climate, including: heat-related mortality or morbidity; air pollution-related illnesses; infectious diseases, particularly those transmitted, indirectly, via water or by insect or rodent vectors; and refugee health issues linked to forced population migration. Yet, changing landscapes can significantly affect local weather more acutely than long-term climate change. Land-cover change can influence micro-climatic conditions, including temperature, evapo-transpiration and surface run-off, that are key determinants in the emergence of many infectious diseases. To improve risk assessment and risk management of these synergistic processes (climate and land-use change), more collaborative efforts in research, training and policy-decision support, across the fields of health, environment, sociology and economics, are required.

Variants in estrogen biosynthesis genes, sex steroid hormone levels, and endometrial cancer: a HuGE review

Variants in genes involved in estrogen biosynthesis are likely to be important in the etiology of endometrial cancer. This review summarizes data on variants in seven genes in the estrogen biosynthesis pathway and their relation to circulating levels of sex steroid hormones in women and to risk of endometrial cancer. Little or no association was found between genotypes of the cytochrome P-450 genes CYP11A1 (-528[TTTTA]n) or CYP17A1 (-34T/C) or the 17beta-hydroxysteroid dehydrogenase 1 gene HSD17B1 (Ser312Gly) and levels of progesterone, androgens, or estrogens. The position -34T/C variant in CYP17A1 appears to be associated with reduced risk of endometrial cancer, with those homozygous for the variant allele having about half the risk of those homozygous for the wild type. Linked variants in CYP19A1 (intron 4 [TTTA]n, intron 4 [TCT] insertion/deletion, exon 10 C/T) are related to some hormone levels and, based on two studies, to risk of endometrial cancer. For other genes (HSD3B1, HSD3B2, HSD17B2), no information is available on these associations. Results indicate the need to study other variants and haplotypes in these genes, particularly CYP17A1 and CYP19A1, as well as variants in other genes involved in hormone biosynthesis and metabolism pathways. Larger studies or combined studies that allow for investigation of gene-gene and gene-environment interactions are warranted.

Intraepithelial CD8+ tumor-infiltrating lymphocytes and a high CD8+/regulatory T cell ratio are associated with favorable prognosis in ovarian cancer

In a recent report, [Zhang et al. (2003) N. Engl. J. Med. 348, 203-213], the presence of CD3+ tumor-infiltrating lymphocytes (TILs) was found to correlate with improved survival in epithelial ovarian cancer. We performed immunohistochemical analysis for TILs and cancer testis antigens in 117 cases of epithelial ovarian cancer. The interrelationship between subpopulations of TILs and expression of cancer testis antigens was investigated, as well as between TILs and overall survival. The median follow-up of the patients was 31 months. Patients with higher frequencies of intraepithelial CD8+ T cells demonstrated improved survival compared with patients with lower frequencies [median = 55 versus 26 months; hazard ratio = 0.33; confidence interval (C.I.) = 0.18-0.60; P = 0.0003]. No association was found for CD3+ TILs or other subtypes of intraepithelial or stromal TILs. However, the subgroups with high versus low intraepithelial CD8+/CD4+ TIL ratios had median survival of 74 and 25 months, respectively (hazard ratio = 0.30; C.I. = 0.16-0.55; P = 0.0001). These results indicate that CD4+ TILs influence the beneficial effects of CD8+ TIL. This unfavorable effect of CD4+ T cells on prognosis was found to be due to CD25+ forkhead box P3 (FOXP3)+ regulatory T cells (Treg; suppressor T cells), as indicated by survival of patients with high versus low CD8+/Treg ratios (median = 58 versus 23 months; hazard ratio = 0.31; C.I. = 0.17-0.58; P = 0.0002). The favorable prognostic effect of intraepithelial CD8+ TILs did not correlate with concurrent expression of NY-ESO-1 or MAGE antigens. We conclude that intraepithelial CD8+ TILs and a high CD8+/Treg ratio are associated with favorable prognosis in epithelial ovarian cancer.

Cancer history and other personal factors affect quality of life in patients with hepatitis C

Background

Although patients with chronic hepatitis C (CHC) have been found to have reduced quality of life, little is known about how other characteristics affect their quality of life. The purpose of this study was to investigate the effect of other characteristics, including history of cancer, on quality of life in patients with CHC.

Methods

One hundred forty patients from clinics at three hospitals in New York City completed a detailed epidemiologic interview about demographic and lifestyle characteristics and the SF-36 measuring health-related quality of life. We compared results from our patients to normative data using t-tests of differences between means. We used multivariate analyses to determine other personal and health-related factors associated with quality of life outcomes.

Results

Compared to normative data, these patients had reduced quality of life, particularly on physical functioning. The summary Physical Component Score (PCS) was 45.4 ± 10.6 and the Mental Component Score (MCS) was 48.2 ± 11.1, vs norms of 50 ± 10.0; p-values were <0.0001 and <0.05, respectively. In multivariate analyses, the PCS was significantly lower among those with cancer history, ≥ 2 other chronic conditions, less education, low physical activity, and higher alanine aminotransferase (ALT) levels. Cancer was more important for men, while other chronic conditions were more important for women. On the MCS, history of depression, low physical activity, alcohol use, and female gender were independently associated with poorer scores.

Conclusion

Several health and lifestyle factors independently influence quality of life in CHC patients. Different factors are important for men and women.

Influence of Type of Cigarette on Peripheral versus Central Lung Cancer

OBJECTIVES

Adenocarcinoma has replaced squamous cell carcinoma as the most common cell type of lung cancer in the United States. It has been proposed that this shift is due to the increased use of filter and lower-tar cigarettes, resulting in increased delivery of smoke to peripheral regions of the lungs, where adenocarcinoma usually occurs. We reviewed radiologic data to evaluate the hypothesis that tumors in smokers of cigarettes with lower-tar yield are more likely to occur peripherally than tumors in smokers of higher-yield cigarettes.

METHODS

At two urban academic medical centers, we reviewed computed tomographic scans, chest radiographs, and medical records to assign tumor location (peripheral or central) for 330 smokers diagnosed with carcinoma of the lung between 1993 and 1999. We compared the proportion of tumors in a peripheral versus central location by lifetime filter use and average lifetime tar rating (< 21 and > or = 21 mg).

RESULTS

Tumor location (69% peripheral and 31% central) was unrelated to cigarette filter use. Smokers of cigarettes with lower-tar ratings were more likely than those with higher ratings to have peripheral rather than central tumors (odds ratio, 1.76; 95% confidence interval, 0.89-3.47). When restricted to subjects with adenocarcinoma or squamous cell carcinoma, the odds ratio (95% confidence interval) was 2.31 (1.05-5.08).

CONCLUSIONS

Among cigarette smokers with lung cancer, use of cigarettes with lower-tar yield was associated with preferential occurrence of tumors in peripheral sites. Our findings support the hypothesis that changes in smoking associated with lower-tar cigarettes have led to a shift in the location of smoking-related lung cancer.

Genetic variants in SOD2, MPO, and NQO1, and risk of ovarian cancer

OBJECTIVE

One way in which parity and use of oral contraceptives may protect against ovarian cancer is by preventing inflammation and oxidative stress associated with ovulation. Since the genes superoxide dismutase (SOD2), myeloperoxidase (MPO), and NAD(P)H:quinone oxidoreductase 1 (NQO1) are involved in inflammation and oxidative stress, we investigated whether variants of these genes are associated with risk of ovarian cancer.

METHODS

In a hospital-based case-control study, we compared 125 cases and 193 controls with respect to prevalence of (1) the T-->C (val-->ala) substitution at the -9 position in the signal sequence of SOD2; (2) the G-->A substitution at the -463 position in the promoter region of MPO; and (3) the C-->T (pro-->ser) change in exon 6 of NQO1. Genotyping was done using PCR and gel electrophoresis for MPO and NQO1 and using MALDI-TOF mass spectrometry for SOD2.

RESULTS

For SOD2, women with the TC (val/ala) or CC (ala/ala) genotypes were at increased risk [odds ratio (OR) 2.1, 95% confidence interval (CI) 1.1-4.0]. Results for MPO and NQO1 were in the hypothesized directions but were not statistically significant. For MPO, there was a small inverse association among women with GA or AA genotypes (OR = 0.72, 95% CI 0.43-1.2). For NQO1, the TT (ser/ser) genotype was associated with somewhat increased risk (OR = 2.3, 95% CI 0.69-7.6).

CONCLUSIONS

While these results need to be confirmed in other studies, they point to a possible role for genes involved in oxidative stress in the development of ovarian cancer.

Alcohol consumption and endometrial cancer: some unresolved issues

The role of hormonal factors, in particular unopposed estrogens, on endometrial cancer occurrence is well established. Progesterone deficiency has also been suggested as a possible risk factor. Alcohol use has been shown to be associated with elevated estrogen levels and reduced progesterone. Epidemiologic studies, however, have not offered much support for a positive association between alcohol intake and endometrial cancer, with results generally indicating no association or suggesting an inverse relationship with endometrial cancer. However, certain methodologic limitations, such as small sample size, limited range of alcohol intake, and confounding may have explained those findings. Moreover, there are some unexplored aspects of the possible effect of alcohol, such as the possible interaction with use of exogenous estrogens, and other factors, that need clarification.

Dietary antioxidants, supplements, and risk of epithelial ovarian cancer

Several studies of dietary and serum antioxidant micronutrients (vitamins A, C, and E and beta-carotene) suggest that higher levels may be protective for ovarian cancer. None of these has examined supplements. We used a food frequency questionnaire and additional questions on supplements to study 168 histologically confirmed epithelial ovarian cancer cases, 159 community controls, and 92 hospital-based controls. Antioxidant consumption from diet or supplements was calculated in milligrams or international units per day. In multivariate analyses using only community controls, the highest levels of intake of vitamins C and E from supplements were protective: odds ratio (OR) = 0.40 [95% confidence interval (CI) = 0.21-0.78] and OR = 0.33 (95% CI = 0.18-0.60), respectively. Consumption of antioxidants from diet was unrelated to risk. In analyses combining antioxidant intake from diet and supplements, vitamins C (> 363 mg/day) and E (> 75 mg/day) were associated with reduced risks: OR = 0.45 (95% CI = 0.22-0.91) and OR = 0.44 (95% CI = 0.21-0.94), respectively. Results were similar, with some attenuation toward the null, in analyses combining both control groups. The levels of vitamins C and E associated with the protective effect were well above the current US Recommended Dietary Allowances. These findings support the hypothesis that antioxidant vitamins C and E from supplements are related to a reduced risk of ovarian cancer.

Diagnostic x-rays and risk of epithelial ovarian carcinoma in Jews

PURPOSE

To test the hypothesis that there would be ethnic differences in susceptibility to ionizing radiation from diagnostic x-rays.

METHODS

In a hospital-based study we compared reports of diagnostic x-rays to the lower abdomen and pelvis in incident cases of epithelial ovarian carcinoma (N = 161), community controls (N = 156) and convenience controls (N = 87).

RESULTS

Thirty-nine per cent of cases and 31% of controls recalled x-rays more than 10 years before; 27% of cases and 14% of controls reported four Jewish grandparents. Comparing the cases with community controls, the odds ratio (95% confidence interval) for Jews versus non-Jews among women reporting no x-rays was 1.02 (0.37-2.79); among women reporting x-rays the estimate for Jews was 8.91 (2.00-39.6). Consistent results were seen with inclusion of convenience controls. Jewish cases reported an excess of pelvic diagnostic x-rays from age 20 onward and an excess of barium enemas and pyelograms.

CONCLUSIONS

These preliminary findings require confirmation in other studies. They suggest that the known excess risk of this carcinoma in Jews might be associated with exposure to x-rays and add to a previous observation of an altered susceptibility to ionizing radiation in Jews. If confirmed, they would suggest a need for continued vigilance to evaluate the risks and benefits of diagnostic x-rays in individuals, regardless of ethnic origin, who might carry mutations in DNA repair genes.

Reporting participation in case-control studies

Although low participation in case-control studies may threaten their validity, it is difficult to evaluate the potential problem of nonresponse across studies because the level of participation among subjects is not reported in a consistent manner. This commentary presents a proposal for standard reporting of the process by which control subjects are recruited to a study and the outcomes of recruitment attempts. We encourage authors to provide a description of the sampling frame, the method of selecting units from the frame, and the number of units selected. For each unit selected, an outcome should be classified into four broad categories: ineligible sampling unit, unable to determine eligibility, respondent not eligible, and respondent screened and eligible. Details should be provided in each category; these details would differ according to the method used to contact potential respondents (by random-digit dialing, by telephone from a list, in person, or by mail). The proportion who participated can be reported as the investigator sees fit, as long as reporting of the components is complete. The sampling frame and outcomes should be reported separately for various parts of the study, such as controls from different sources or those who gave biological specimens. Standardized reporting will allow an evaluation of the success of various methods in recruiting potential participants, and will contribute important information for assessing the validity of individual studies.

Epithelial ovarian carcinoma and fertility of parents

We studied the fertility of the parents of 163 women with epithelial ovarian carcinoma in two hospitals in New York City, compared with the parents of 159 controls from similar neighborhoods. We used unconditional logistic regression to control for covariates, including parity, oral contraceptive use, age at menarche, and Jewish ancestry. Compared with women with zero or one sibling, those with two, three or four or more siblings had adjusted odds ratios (95% confidence intervals) of 0.91 (0.47-1.77), 0.61 (0.28-1.37), and 0.50 (0.26-0.98). On average, each additional sibling was associated with a risk reduction to 0.80 (0.66-0.98). These findings support the hypothesis that heritable conditions associated with reduced fertility of the subjects' parents may contribute to risk and may explain some of the effects of parity on the risk of this carcinoma. Alternatively, they may reflect some unidentified aspect of the environment experienced by girls growing up in small families. If confirmed in other data sets, these findings imply that sibship size might have confounded previous estimates of risk associated with a family history of cancer or with Jewish ethnicity.

Reported participation in case-control studies: changes over time

There is concern that participation in case-control studies has declined. To address this question, the author and colleagues reviewed data from 82 US and Canadian case-control studies published in epidemiologic journals during two periods: 1988-1990 and 1997-January 1999. The median year of data collection, which ranged from 1972 to 1996, was the primary independent variable. Reported response among both cases and controls remained constant over this time period. The regression coefficients (beta) were small: For each year, there was a change of 0.15 percentage points for cases (p = 0.56) and -0.16 percentage points for controls (p = 0.54). Possible confounders included the location where the study had been conducted and, for cases, the disease under study (cancer vs. others). After adjustment for these factors in case groups, there was still no association between year of data collection and response: For each year, there was a change of -0.20 percentage points (p = 0.43). After adjustment of results for study location among controls, there was a moderate decline over time: For each year, there was a change of -0.44 percentage points (p = 0.12). Overall, reported response in more recent studies was similar to that in earlier studies; for control groups, this may reflect changes in locations where the studies were conducted.

Succinic acids as potent inhibitors of plasmid-borne IMP-1 metallo-beta-lactamase

IMP-1 metallo-beta-lactamase (class B) is a plasmid-borne zinc metalloenzyme that efficiently hydrolyzes beta-lactam antibiotics, including carbapenems, rendering them ineffective. Because IMP-1 has been found in several clinically important carbapenem-resistant pathogens, there is a need for inhibitors of this enzyme that could protect broad spectrum antibiotics such as imipenem from hydrolysis and thus extend their utility. We have identified a series of 2,3-(S,S)-disubstituted succinic acids that are potent inhibitors of IMP-1. Determination of high resolution crystal structures and molecular modeling of succinic acid inhibitor complexes with IMP-1 has allowed an understanding of the potency, stereochemistry, and structure-activity relationships of these inhibitors.

Symptoms of ovarian cancer

OBJECTIVE

To examine the symptoms of ovarian cancer in patients compared with symptoms experienced by healthy women using a case-control design.

METHODS

Cases (n = 168) were women with ovarian cancer diagnosed at two hospitals in New York between 1994 and 1997 who were interviewed shortly after diagnosis. They were compared with healthy women (n = 251 controls) from the community. Women were asked about the prevalence, duration, and constancy of eight symptoms and about use of three types of medications in the 6 to 12 months before diagnosis (cases) or interview (controls).

RESULTS

Nearly all the cases (93%) reported at least one symptom, compared with 42% of controls. The most common symptoms among cases were: unusual bloating, fullness, and pressure in the abdomen (71%); unusual abdominal pain or lower back pain (52%); and lack of energy (43%). The proportions of controls reporting these symptoms were 9, 15, and 16%, respectively, resulting in odds ratios and 95% confidence intervals of 25.3 (15.6, 40.9), 6.2 (4.0, 9.6), and 3.9 (2.5, 6.1), respectively, for these symptoms. Bloating, fullness, and pressure was of more recent onset among cases than controls (4.9 months compared with 7.6 months, P =.01). There were only minor differences in reported symptoms between cases with early and later stage disease.

CONCLUSION

Unusual bloating, fullness, and pressure, abdominal or back pain, and lack of energy are prominent symptoms in women with ovarian cancer and distinguish them from controls. Information on symptoms may make women and physicians more aware of changes associated with ovarian cancer.

Selection of control groups by using a commercial database and random digit dialing

Identifying a control group when cases come from a specialized hospital is a challenge for epidemiologists. The authors compared controls recruited by using a commercial database with those recruited by random digit dialing in the context of a hospital-based case-control study of ovarian cancer. This part of the study was conducted in 1997-1998 among women aged 18 years or older who resided in the New York metropolitan area. A mailing list owner grouped cases into "lifestyle" clusters based on US zip+4 postal code microneighborhoods and generated a random sample of potential controls with the same distribution across the clusters. Controls recruited from the commercial database (n = 82) and from random digit dialing (n = 90) were similar in age and race. Women from the commercial database had somewhat more education and higher incomes and were more similar to the cases on these measures. The control groups resembled each other closely in terms of oral contraceptive use, nulliparity, and religion and differed from the cases on these measures. Response rates were similar for the two groups. Only 28% of the cases were included on the mailing list, indicating that it did not reflect the source population of the cases. Use of a commercial database provided a control group whose socioeconomic factors were similar to those of cases at a lower cost than when random digit dialing was used but did not result in a higher response rate.

Relation of time since last birth and parity to survival of young women with breast cancer

We investigated whether survival was related to recent childbirth or parity in a cohort of 540 women diagnosed with breast cancer before the age of 45 years who were followed for up to 14 years. Women who had given birth within 2 years before their diagnosis of breast cancer were at increased risk of dying, compared with nulliparous women, with an adjusted relative risk of 3.1 (95% confidence interval = 1.8-5.4). There was a moderate association of parity with mortality, with an adjusted relative risk of 1.8 (95% confidence interval = 1.2-2.9) for women with three or more births, compared with nulliparous women.

Antibiotic sensitization using biphenyl tetrazoles as potent inhibitors of Bacteroides fragilis metallo-beta-lactamase

BACKGROUND

High level resistance to carbapenem antibiotics in gram negative bacteria such as Bacteroides fragilis is caused, in part, by expression of a wide-spectrum metallo-beta-lactamase that hydrolyzes the drug to an inactive form. Co-administration of metallo-beta-lactamase inhibitors to resistant bacteria is expected to restore the antibacterial activity of carbapenems.

RESULTS

Biphenyl tetrazoles (BPTs) are a structural class of potent competitive inhibitors of metallo-beta-lactamase identified through screening and predicted using molecular modeling of the enzyme structure. The X-ray crystal structure of the enzyme bound to the BPT L-159,061 shows that the tetrazole moiety of the inhibitor interacts directly with one of the two zinc atoms in the active site, replacing a metal-bound water molecule. Inhibition of metallo-beta-lactamase by BPTs in vitro correlates well with antibiotic sensitization of resistant B. fragilis.

CONCLUSIONS

BPT inhibitors can sensitize a resistant B. fragilis clinical isolate expressing metallo-beta-lactamase to the antibiotics imipenem or penicillin G but not to rifampicin.

A case-case analysis of factors related to overexpression of p53 in endometrial cancer following breast cancer

We studied 54 patients diagnosed with endometrial cancer between 1981 and 1994 following a diagnosis of breast cancer. We used a case-case analysis, comparing tumors with and without overexpression of the p53 gene product to evaluate the association of putative p53 mutations with tamoxifen use and other risk factors for endometrial cancer. Twenty-four % of the tumors showed strong positive staining for the p53 gene product. Tumors in a more advanced stage (stage 2, 3, or 4, compared to stage 1) were more likely to overexpress p53 [odds ratio (OR) = 4.2; 95% confidence interval (CI), 1.1-16.2], as were tumors with serous or clear cell, compared to endometrioid, histology (OR = 5.8; 95% CI, 1.3-26.5). There was a small association between p53 overexpression and treatment with tamoxifen for breast cancer (OR = 2.6; 95% CI, 0.69-9.8). There was a strong relationship between overexpression of p53 and having a first-degree relative with breast cancer (OR = 12.3; 95% CI, 2.6-57.4) and between overexpression of p53 and having an additional cancer, i.e., at sites other than breast or endometrium (OR = 7.9; 95% CI, 1.6-40.1). In this group of women, genetic predisposition to cancer, as reflected in family history of breast cancer and personal history of an additional primary cancer, was strongly associated with overexpression of p53 in endometrial tumors. The results suggest that use of tamoxifen may be associated with an increase in tumors that overexpress p53, although the results could be due to chance.

Exercise, occupational activity, and risk of endometrial cancer

We conducted a case-control study in western New York state among 232 women with newly-diagnosed endometrial cancer and 631 controls selected from the community. Physical activity was measured by participation in vigorous exercise and walking at four time periods: at age 16, and at 20, 10, and 2 years before the interview and by occupational activity based on a detailed lifetime history. Women who did a moderate amount of vigorous exercise at age 16 and at 20 years before the interview were at reduced risk as compared with those who reported no activity, with odds ratios (OR) (95% confidence intervals) of 0.51 (0.31-0.83) and 0.50 (0.29-0.89), respectively. However, there was no evidence of declining risk with greater amount of activity. At later times, 10 years and 2 years before the interview, being in the highest group with regard to vigorous activity was associated with a slightly but nor significant lower risk as compared with women who reported no activity; the adjusted OR were 0.72 (0.43-1.19) and 0.67 (0.42-1.09), respectively. Being in the highest category of miles walked at age 16 (i.e., > or = 15 miles per week) was associated with a slightly reduced risk as compared with not walking at all (OR 0.64 (0.26-1.16)), whereas the number of miles walked at other times was not related to reduced risk. Occupational physical activity was not related to the risk of endometrial cancer. Overall, these results indicate that physical activity at levels prevalent in this population has at most a modest relationship to reduced risk of endometrial cancer.

Body mass index, weight gain, and risk of endometrial cancer

Excess weight near the time of diagnosis is a well-established risk factor for endometrial cancer; less is known about the influence of weight at earlier periods of a woman's life or weight gain in adulthood. In a case-control study in western New York State, interviews were conducted with 232 incident endometrial cancer cases, diagnosed between 1986 and 1991, and 631 community controls. Body mass index at 16 years of age and 20, 10, and 2 years before interview and changes in body mass index between these time periods were examined. While being relatively heavy at 16 years of age was associated with slightly increased risk [adjusted odds ratio (OR) = 1.28, 95% confidence interval (CI) = 0.84-1.96], large gains over the entire period from 16 years of age to 2 years ago (OR = 3.45, CI = 2.13-5.57) and high body mass index close to the time of diagnosis (OR = 3.21, CI = 2.01-5.15) were associated with greater risk. Differences in mean body mass index between cases and controls increased over time.

Characteristics of a hypothetical group of hospital controls for a case-control study

In case-control studies in which cases are ascertained from hospitals, controls are frequently chosen from among patients with other diseases at the same hospitals. This study was undertaken to examine the extent to which a hospital control group is representative of the population to which inferences are made. A hypothetical hospital control group was assembled consisting of 233 men and women aged 40-74 years who were surgical inpatients at the two hospitals in Otsego County, New York, in 1990. The characteristics of this group were compared with the characteristics of 15,563 men and women aged 40-74 years who participated in a privately conducted health census in the same county in 1989 with the use of health-related data collected in the census. In this rural setting, only small differences were found between the hospital control group and the census population on most of the measures considered, including demographic characteristics, certain health behaviors, and the prevalence of common conditions. However, the female hospital controls were more likely to be overweight than the females enumerated in the census, and the men were more likely to have ever smoked cigarettes. These differences were large enough to lead to different interpretations about the strength of the associations between these variables and case-control status.

Evaluation of random digit dialing as a method of control selection in case-control studies

Control groups selected by random digit dialing are frequently used in case-control studies. Concern about the potential for bias in these control groups has been expressed, primarily because of low response rates. This study compares the characteristics of a hypothetical control group consisting of 341 men and women aged 40-74 years, selected by random digit dialing and participating in an interview in 1990, with the characteristics of 15,563 men and women aged 40-74 years who participated in a privately conducted census in the same upstate New York county in 1989. For most measures, no differences were seen between the random digit dialing sample and the census population. However, the hypothetical control group was more likely to have had their cholesterol checked in the past 2 years and was somewhat more likely to have had other screening tests as well. In addition, the hypothetical control group was somewhat better educated. The results suggest that, at least in this setting, control groups selected by random digit dialing are representative of the general population in most respects; however, caution should be used when studying the relation between screening tests and disease occurrence by means of case-control studies using controls selected by random digit dialing.

Responses to questions frequently asked by medical students about family practice

During their medical school years medical students are frequently exposed to misinformation about family practice from faculty members in other specialties. Responses to 26 questions frequently asked by medical students about family practice are presented with a review of recent literature. These responses may assist medical students and their advisors when considering careers in family practice.