Biomedical subjects

Lori C Sakoda

Publications and source records attributed to Lori C Sakoda.

17 recordsLinked to original sources

PubMed2025

Genetic risk factors modulate the association between physical activity and colorectal cancer.

BACKGROUND: Physical activity (PA) is an established protective factor for colorectal cancer (CRC), but it is unclear if genetic variants modify this effect. To investigate this possibility, we conducted a genome-wide gene-PA interaction analysis. METHODS: Using logistic regression and two-step and joint tests, we analyzed interactions between common genetic variants across the genome and PA in relation to CRC risk. Self-reported PA levels were categorized as active (≥ 8.75 MET-h/wk) vs. inactive (< 8.75 MET-h/wk) and as study- and sex-specific quartiles of activity. RESULTS: PA had an overall protective effect on CRC (OR [active vs. inactive] = 0.85; 95%CI = 0.81-0.90). The two-step GxE method identified an interaction between rs4779584, an intergenic variant near the GREM1 and SCG5 genes, and PA for CRC risk (p-interaction = 2.6×10- 8). Stratification by genotype at this locus showed a significant reduction in CRC risk by 20% in active vs. inactive participants with the CC genotype (OR = 0.80; 95%CI = 0.75-0.85), but no significant PA-CRC association among CT or TT carriers. When PA was modeled as quartiles, the 1-d.f. GxE test identified that rs56906466, an intergenic variant near the KCNG1 gene, modified the association between PA and CRC (p-interaction = 3.5×10- 8). Stratification at this locus showed that increase in PA (highest vs. lowest quartile) was associated with a lower CRC risk solely among TT carriers (OR = 0.77; 95%CI = 0.72-0.82). CONCLUSIONS: In summary, we identified two genetic variants that modified the association between PA and CRC risk. One of them, related to GREM1 and SCG5, suggests that the bone morphogenetic protein (BMP)-related, inflammatory, and/or insulin signaling pathways may be associated with the protective influence of PA on colorectal carcinogenesis.

GWAS↗

PubMed2007

Risk for breast cancer among women with endometriosis.

Although several risk factors are common to endometriosis and breast cancer, the results of observational studies of an association have so far been inconsistent. We evaluated the relationship between endometriosis and breast cancer on the basis of data on selected cancers and medical histories from the Danish nationwide cancer and hospital registries used in a large case-cohort study. A total of 114,327 women were included in the study of whom 1,978 women had received a diagnosis of endometriosis and 16,983 had had a diagnosis of breast cancer between 1978 and 1998. Of the women with endometriosis, 236 subsequently received a diagnosis of breast cancer. The crude overall rate ratio for breast cancer after endometriosis was 1.00 and after adjustment for reproductive factors, calendar-period, bilateral oophorectomy and benign breast disease, the rate ratio was 0.97 (95% confidence interval, 0.85-1.11). The risk for breast cancer increased with age at diagnosis of endometriosis, so that women in whom endometriosis was diagnosed at a young age (approximately <40 years) had a reduced risk for breast cancer and women in whom endometriosis was diagnosed at older ages (approximately > or =40 years) tended to have an increased risk for breast cancer. The reduced risks observed among young women may reflect their exposure to drugs with antiestrogenic effects. The increased risk associated with endometriosis among postmenopausal women may be due to common risk factors between postmenopausal endometriosis and breast cancer or an altered endogenous estrogen.

Adult↗

PubMed2007

Risk factors for intrahepatic cholangiocarcinoma in a low-risk population: a nationwide case-control study.

Recently, the incidence of intrahepatic cholangiocarcinoma (ICC) has been increasing in a number of developed (Western) countries. However, risk factors in these low-risk populations are poorly understood. In this nationwide population based case-control study in Denmark, we examined the relationship between selected medical conditions and subsequent ICC risk to provide additional clues to etiopathogenesis. All histologically confirmed ICC cases diagnosed in Denmark between 1978 and 1991 were identified from the Danish cancer registry. Population controls were selected from the central population registry and were matched 4:1 to cases on sex and year of birth. Cases and controls were linked to the Danish hospital discharge registry to obtain information on prior hospital diagnoses. Odds ratios (OR) and 95% confidence intervals (95% CI) were derived using conditional logistic regression. A total of 764 ICC cases and 3,056 population controls were included in the study. Chronic liver diseases were significantly related to ICC: alcoholic liver disease (OR = 19.22, 95% CI = 5.55-66.54), unspecified cirrhosis (OR = 75.9, 95% CI 10.2-565.7). Bile duct diseases were also associated with risk: cholangitis (OR = 6.3, 95% CI = 2.3-17.5), choledocholithiasis (OR = 23.97, 95% CI = 2.9-198.9), cholecystolithiasis (OR = 4.0, 95% CI = 2.0-7.99), though gallbladder removal did not change risk (OR = 1.6, 95% CI = 0.65-3.7). Among other conditions, chronic inflammatory bowel disease (OR = 4.7, 95% CI = 1.65-13.9) was significantly associated with ICC. Diabetes was associated with risk in the year prior to diagnosis of ICC (OR = 3.02, 95% CI = 1.05-8.69). Obesity was unrelated to risk. These results confirm that prior bile duct diseases increase risk of ICC and suggest that alcoholic liver disease and diabetes may also increase risk.

Aged↗

PubMed2007

A case-control investigation of immune function gene polymorphisms and risk of testicular germ cell tumors.

There is reason to suspect that testicular germ cell tumor (TGCT) development may be influenced by cytokines, secreted proteins that modulate tumor immune surveillance activity as well as a variety of processes in the testis. To address this hypothesis, we conducted a case-control analysis (508 cases, 608 controls) of 32 putatively functional single-nucleotide polymorphisms (SNP) in 16 immune function genes among non-Hispanic Caucasian participants in the U.S. Servicemen's Testicular Tumor Environmental and Endocrine Determinants Study. The TGFB1 Ex5-73C>T variant was positively associated with TGCT (CT/TT versus CC: odds ratio, 1.73; 95% confidence interval, 1.01-2.95; P(trend) = 0.05); additionally, haplotypes of the assessed TGFB1 SNPs (-509C>T, 327C>T, Ex1-282C>G, and Ex5-73C>T) differed in frequency between cases and controls (all TGCT, P 0.07; seminoma, P 0.04; nonseminoma, P 0.11). We also observed excess frequencies among TGCT cases versus controls of LTA 252G (P(trend) = 0.08) and of the TNF variants -1042C (P(trend) = 0.06), -1036T (P(trend) = 0.07), and -238G (P(trend) = 0.09). Analyses of haplotypes for LTA-TNF SNPs (LTA -91C>A, LTA 252A>G, TNF -863C>A, TNF -857C>T, TNF -308G>A, and -238G>A) were similarly suggestive of an association with TGCT (P = 0.06) and nonseminoma (P = 0.04), but not seminoma (P = 0.21). Polymorphisms in other genes were found to be associated only with seminoma (IL2) or nonseminoma (IFNGR2 and IL10). However, none of the associations remained noteworthy after applying the false discovery rate method to control for multiple testing. In conclusion, our findings suggest that polymorphisms in TGFB1 and LTA/TNF, and possibly other immune function genes, may influence susceptibility to TGCT.

Case-Control Studies↗

PubMed2006

Body size, dairy consumption, puberty, and risk of testicular germ cell tumors.

The etiology of testicular germ cell tumors (TGCTs) is poorly understood, with cryptorchidism and family history being the only well-established risk factors. Body size, age at puberty, and dairy consumption, however, have been suggested to be related to TGCTs. To clarify the relation of these variables to TGCT risk and to one another, the authors analyzed data from 767 cases and 928 controls enrolled in the Servicemen's Testicular Tumor Environmental and Endocrine Determinants Study (2002-2005). Overall, increased height was significantly related to risk (odds ratio (OR) = 1.83, 95% confidence interval (CI): 1.36, 2.45), though body mass index was not (OR = 1.06, 95% CI: 0.66, 1.69). There was no association with age at puberty, based on ages at first shaving (OR = 1.29, 95% CI: 0.96, 1.73), voice changing (OR = 0.97, 95% CI: 0.71, 1.32), and nocturnal emissions (OR = 1.00, 95% CI: 0.73, 1.37). Similarly, there was no relation with dairy consumption at any age between birth and 12th grade. These results suggest that height is a risk factor for TGCTs, but the relation is unlikely explained by childhood dairy consumption. As adult height is largely determined in the first 2 years of life, increased attention to events in this interval may help elucidate the etiology of TGCTs.

Adult↗

PubMed2006

Rising prostate cancer rates in South Korea.

BACKGROUND: Prostate cancer incidence and mortality rates in South Korea are relatively low, but rising steadily. METHODS: We examined age-standardized incidence and mortality trends of prostate cancer in South Korea to gain further insight into prostate cancer etiology. RESULTS: Although prostate cancer incidence has been low (7.9 per 100,000 man-years), it has increased up to 28.2% between 1996-1998 and 1999-2001. Prostate cancer mortality increased 12.7-fold over a 20-year period. Despite the increase in prostate cancer incidence and mortality rates, marked differences in rates remain for Koreans, Korean Americans, and Caucasian Americans. CONCLUSIONS: The rising rates of prostate cancer in South Korea cannot be attributed entirely to PSA screening due to the low PSA screening prevalence; this trend is most likely related to increased westernization among Koreans. Interdisciplinary epidemiological studies incorporating the collection of biological samples are needed to clarify the extent to which lifestyle and genetic factors contribute to the observed racial disparity.

Age Distribution↗

PubMed2006

Tea drinking and the risk of biliary tract cancers and biliary stones: a population-based case-control study in Shanghai, China.

Biliary tract cancers, encompassing tumors of the gallbladder, extrahepatic bile ducts and ampulla of Vater, are rare but highly fatal malignancies. Apart from gallstones, etiologic factors for biliary tract cancer are not clearly defined. Several epidemiologic studies have suggested that consumption of tea, especially green tea, is protective against a variety of cancers, including gastrointestinal malignancies. As part of a large population-based case-control study of biliary tract disease in Shanghai, China, we evaluated the effects of tea consumption on the risk of biliary tract cancers and biliary stones. The study included 627 incident cases with biliary tract cancer, 1,037 cases with biliary stones and 959 randomly selected controls. Study subjects were interviewed to ascertain data on demographic, medical and dietary factors, including tea consumption. Forty-one percent of the controls were ever tea drinkers, defined as those who consumed at least 1 cup of tea per day for at least 6 months. After adjustment for age, education and body mass index, among women, ever tea drinkers had significantly reduced risks of biliary stones (OR = 0.73, 95% CI = 0.54-0.98) and gallbladder cancer (OR = 0.56, 95% CI = 0.38-0.83). The inverse relationship between tea consumption and gallbladder cancer risk was independent of gallstone disease. Among men, tea drinkers were more likely to be cigarette smokers, and the risk estimates were generally below 1.0, but were not statistically significant. Further studies are needed to confirm these results in other populations and clarify the hormonal and other mechanisms that may be involved.

Adult↗

PubMed2006

CYP17 MspA1 polymorphism and risk of biliary tract cancers and gallstones: a population-based study in Shanghai, China.

Biliary tract cancers, encompassing cancers of the gallbladder, extrahepatic bile duct and ampulla of Vater, are rare but highly fatal malignancies. Other than gallstones, little is known about the risk factors for biliary tract cancers. Endogenous estrogens are thought to play a role in the etiology of gallstones and gallbladder cancer, since both conditions predominate in females and are associated with parity and obesity. In view of reports linking the CYP17 MspA1 polymorphism to high circulating levels of estrogens and a predisposition to other hormonally related cancers, we examined the relationship between CYP17 MspA1 variants and risk of biliary disease in a population-based case-control study in Shanghai. The study included 446 cancer cases (254 gallbladder, 139 extrahepatic bile duct, 53 ampullary cancers), 929 biliary stone cases (691 gallbladder, 238 bile duct) and 818 population controls. Genomic DNA from peripheral blood lymphocytes was used for genotyping. Relative to those with the A2/A2 genotype, A1 carriers (A1/A1 and A1/A2 genotypes) had an increased risk of gallbladder cancer (odds ratio (OR) = 1.5, 95% confidence interval (CI) = 1.1-2.1). In addition, women with the A1 allele and high parity (> or =3) had a 3-fold risk of gallbladder cancer (OR = 3.3, 95% CI = 1.6-6.9), compared to those with the A2/A2 genotype and lower parity, with the highest risk seen for those also having biliary stones (OR = 4.6, 95% CI = 1.8-11.7, P(interaction) = 0.04). The A1 allele was not associated with a higher risk of gallstones except among those with body mass index (BMI) greater than 25 kg/m2 (OR = 3.1, 95% CI = 2.0-4.8, P(interaction) = 0.02) and among those with a history of diabetes (OR = 2.5, 95% CI = 1.4-4.3, P interaction = 0.09). No clear relation was seen between the CYP17 polymorphism and cancers of the bile duct or ampulla of Vater. The association of the CYP17 MspA1 polymorphism with an increased risk of gallbladder cancer, as well as biliary stones among overweight and diabetic individuals, suggests an interplay between genetic and hormonal risk factors in gallbladder disease.

Adult↗

PubMed2006

Resampling-based multiple hypothesis testing procedures for genetic case-control association studies.

In case-control studies of unrelated subjects, gene-based hypothesis tests consider whether any tested feature in a candidate gene--single nucleotide polymorphisms (SNPs), haplotypes, or both--are associated with disease. Standard statistical tests are available that control the false-positive rate at the nominal level over all polymorphisms considered. However, more powerful tests can be constructed that use permutation resampling to account for correlations between polymorphisms and test statistics. A key question is whether the gain in power is large enough to justify the computational burden. We compared the computationally simple Simes Global Test to the min P test, which considers the permutation distribution of the minimum p-value from marginal tests of each SNP. In simulation studies incorporating empirical haplotype structures in 15 genes, the min P test controlled the type I error, and was modestly more powerful than the Simes test, by 2.1 percentage points on average. When disease susceptibility was conferred by a haplotype, the min P test sometimes, but not always, under-performed haplotype analysis. A resampling-based omnibus test combining the min P and haplotype frequency test controlled the type I error, and closely tracked the more powerful of the two component tests. This test achieved consistent gains in power (5.7 percentage points on average), compared to a simple Bonferroni test of Simes and haplotype analysis. Using data from the Shanghai Biliary Tract Cancer Study, the advantages of the newly proposed omnibus test were apparent in a population-based study of bile duct cancer and polymorphisms in the prostaglandin-endoperoxide synthase 2 (PTGS2) gene.

Algorithms↗

PubMed2006

Maternal smoking and testicular germ cell tumors.

Testicular germ cell tumors (TGCT) are the most common cancer among men ages 15 to 35 years in the United States. The well-established TGCT risk factors cryptorchism, prior diagnosis of TGCT, and family history of testicular cancer indicate that exposures in early life and/or in the familial setting may be critical to determining risk. Previous reports of familial clustering of lung cancer in mothers and testicular cancers in sons suggest that passive smoking in childhood may be such an exposure. To clarify the relationship of passive smoking exposure to TGCT risk, data from 754 cases and 928 controls enrolled in the Servicemen's Testicular Tumor Environmental and Endocrine Determinants study were analyzed. Data from 1,086 mothers of the cases and controls were also examined. Overall, there was no relationship between maternal [odds ratio (OR), 1.1; 95% confidence interval (95% CI), 0.9-1.3] or paternal smoking (OR, 1.0; 95% CI, 0.8-1.3) and TGCT risk. Although living with a non-parent smoker was marginally related to risk (OR, 1.4; 95% CI, 1.0-2.1), there was no relationship with number of smokers, amount smoked, or duration of smoking. Responses from both case-control participants and mothers also revealed no relationship between either maternal smoking while pregnant or while breast-feeding. Results did not differ by TGCT histology (seminoma, non-seminoma). These results do not support the hypothesis that passive smoking, either in utero or in childhood, is related to risk of TGCT. Other early life exposures, however, may explain the familial clustering of lung cancer in mothers and TGCT in sons.

Adolescent↗

PubMed2005

Prostaglandin-endoperoxide synthase 2 (PTGS2) gene polymorphisms and risk of biliary tract cancer and gallstones: a population-based study in Shanghai, China.

There is evidence that chronic inflammation predisposes to biliary tract cancer and that use of non-steroidal anti-inflammatory drugs (NSAIDs) is protective. Although the mechanisms by which NSAIDs lower cancer risk remain unclear, NSAIDs reduce prostaglandin production by blocking prostaglandin-endoperoxide synthase 2 (PTGS2, commonly known as COX-2), an enzyme induced by proinflammatory stimuli that is often overexpressed in malignant tissue. Since variants in the PTGS2 gene may modify the expression or function of its encoded enzyme to modulate the inflammatory response in the biliary tract, we examined the associations of eight PTGS2 polymorphisms (-645C-->T; Ex3 -8G-->C; IVS5 -275T-->G; IVS7 +111T-->C; Ex10 +127T-->C; Ex10 +686 --->ATTAT-->TTATA; Ex10 +837T-->C; Ex10 -90C-->T) with biliary tract cancer and stones in a population-based case-control study conducted in Shanghai, China. Genotyping was performed for 411 patients with biliary tract cancer (237 gallbladder, 127 extrahepatic bile duct and 47 ampulla of Vater), 895 patients with biliary stones (673 gallbladder, 222 bile duct), and 786 healthy individuals randomly selected from the population. Significant associations were seen only between the Ex10 +837T-->C marker and bile duct cancer risk. Relative to individuals with the TT genotype, those carrying the C allele (TC or CC genotype) had a 1.8-fold (95% confidence interval: 1.2-2.7) risk of bile duct cancer. Inferred haplotypes including this risk-conferring allele were also associated with increased bile duct cancer risk of similar magnitude. Our results suggest that a common PTGS2 variant increases bile duct cancer risk. Further investigation is needed to confirm and extend our findings in studies of biliary tract cancer that more comprehensively examine PTGS2 and other inflammation-related genes.

Age Factors↗

PubMed2005

Toenail selenium and risk of hepatocellular carcinoma mortality in Haimen City, China.

Selenium (Se) is an essential trace mineral with known anticarcinogenic properties in humans. However, few studies have examined the association between Se nutrient status and risk of liver cancer. We conducted a nested case-control study comparing the Se content in toenail clippings of 166 individuals (154 men, 12 women) with hepatocellular carcinoma (HCC) to 394 healthy controls (360 men, 34 women) in Haimen City, China, where HCC is a leading cause of mortality. Toenail Se concentration was measured by inductively coupled plasma-optical emission spectroscopy. Median toenail Se was lower for HCC cases than controls (p = 0.03). Adjusted odds ratios and 95% confidence intervals for HCC mortality by increasing quartile of toenail Se were 1.00 (reference), 0.58 (0.32-1.03), 0.83 (0.48-1.42) and 0.50 (0.28-0.90), with a marginally significant trend in risk observed (p for trend = 0.06). This inverse association appeared stronger among those who did not consume alcohol and among women. Future studies are needed to examine the interrelationship between Se, viral hepatitis infection and HCC in order to better understand the etiologic mechanisms involved and evaluate the true chemopreventive potential of Se compounds for liver diseases.

Adult↗

PubMed2005

Aspirin use and risk of biliary tract cancer: a population-based study in Shanghai, China.

The association of gallbladder and bile duct cancers with gallstones, cholecystitis, and cholangitis suggest that chronic inflammation contributes to the carcinogenic process. However, the effect of nonsteroidal anti-inflammatory drugs, such as aspirin, on biliary tract cancer has not been well studied. In a population-based case-control study conducted in Shanghai, China, we examined the relationship between aspirin use and the risk of biliary disease. A total of 627 patients with biliary tract cancer, including cancers of the gallbladder (n = 368), extrahepatic bile duct (n = 191), and ampulla of Vater (n = 68); 1,037 patients with biliary stones; and 958 healthy adults were included in the study. Self-reported data on aspirin use was collected from study participants by in-person interview. The prevalence of aspirin use was low, with 5.7% of the population controls being regular users. After controlling for age, sex, education, and biliary stone status, aspirin use was associated with a reduced risk of gallbladder cancer [odds ratio (OR), 0.37; 95% confidence interval (CI), 0.17-0.88]. An inverse relationship was also observed for frequency and duration of use and with younger age when starting use. In addition, there was a nonsignificant reduction in the risk of bile duct (OR, 0.48; 95% CI, 0.19-1.19) and ampullary cancers (OR, 0.22; 95% CI, 0.03-1.65) associated with aspirin use, whereas no clear association was seen with biliary stones (OR, 0.92; 95% CI, 0.59-1.44). Further studies of biliary tract cancer in other populations are needed to confirm these results and to elucidate the mechanisms that underlie the reduced risk associated with use of aspirin and possibly other nonsteroidal anti-inflammatory drugs.

Adult↗

PubMed2005

Relationship of benign gynecologic diseases to subsequent risk of ovarian and uterine tumors.

OBJECTIVE: Although endometriosis and uterine leiomyomas are common conditions, the extent to which either is associated with certain types of malignancies remains uncertain. METHODS: Using record linkage techniques, we assessed the relationships between hospital and outpatient admissions for endometriosis or leiomyomas and the development of ovarian and uterine cancers in Denmark between 1978 and 1998. Based on a population-based cohort exceeding 99,000 women, including 2,491 ovarian cancers, 860 borderline ovarian tumors, and 1,398 uterine cancers, we derived relative risks (RR) and 95% confidence intervals (95% CI) associated with overall and histology-specific tumor risks after adjustment for calendar time and reproductive characteristics. RESULTS: Endometriosis seemed to predispose to the development of ovarian cancer, with the association restricted to endometrioid or clear cell malignancies. Five or more years after the diagnosis of endometriosis, the RRs (95% CIs) were 2.53 (1.19-5.38) for endometrioid (7 exposed cases) and 3.37 (1.24-9.14) for clear cell (4 exposed cases) malignancies. Uterine leiomyomas were associated with increases in the risk of uterine malignancies, particularly sarcomas, where the RRs (95% CIs) were 20.80 (11.32-38.22) for women with 1 to 4 years of follow-up (11 exposed cases) and 5.70 (2.27-14.32) for those with more extended follow-up (5 exposed cases). CONCLUSION: In combination with clinical, pathologic, and molecular data, our results support that some endometriotic lesions may predispose to clear cell and endometrioid ovarian cancers. Uterine leiomyomas also showed a strong connection with subsequent uterine sarcomas, although it was difficult to decipher whether this reflected detection bias, shared risk factors, or an etiologic relationship.

Adult↗

PubMed2005

Hemochromatosis gene mutations and distal adenomatous colorectal polyps.

Iron has been suggested to be a risk factor for colorectal neoplasia. Some individuals who are heterozygous for mutations in the hemochromatosis gene (HFE) have higher than average serologic measures of iron. We therefore investigated whether heterozygosity for HFE mutations was related to risk of advanced distal adenoma and whether the relationship was affected by dietary iron intake. In the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, 679 persons with advanced distal adenoma and 697 control persons were genotyped for the two major HFE mutations (C282Y and H63D), one HFE polymorphism (IVS2+4), and one polymorphism (G142S) in the transferrin receptor gene (TFRC). HFE haplotypes were also created to examine the effect of haplotype on risk. Food frequency questionnaire data were used to estimate daily iron intake. There was no relationship between any HFE genotype or haplotype and advanced adenoma. Stratification of HFE genotype by TFRC genotype did not change the results. In addition, there was no relationship between dietary iron intake and risk of adenoma or between HFE genotype and risk of adenoma, stratified by iron intake. These results do not support a relationship between HFE heterozygosity and risk of advanced distal adenoma.

Adenomatous Polyps↗

PubMed2004

Loss of antigenicity in stored sections of breast cancer tissue microarrays.

Immunohistochemical characterization of tumor tissues in epidemiological studies is a promising approach to identify breast cancer subtypes with distinct etiology. The recent development of the tissue microarray (TMA) technique allows for standardized, rapid, and cost-effective immunohistochemical characterization of many cases, which is critical in epidemiological studies. Sectioning paraffin blocks at different times results in loss of material, which can be reduced by preparing many sections each time a block is cut. However, data suggest that staining intensity declines in whole sections prepared from conventional paraffin blocks with storage time, resulting in false-negative results. This problem would be accentuated in TMAs because of the limited tissue representation of each case. To evaluate this concern, we prepared a single TMA block from 125 invasive breast carcinomas collected in a population-based case-control study conducted in Poland and compared estrogen receptor (ER-alpha), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression in sections cut and stored for 6 months at room temperature with sections cut from the same TMA block and stained on the same day. Percentage of positive cases for stored versus fresh sections was similar for ER (59.0%) but significantly higher in fresh sections for PR (56.3% versus 64.1%, P = 0.01) and HER2 (45.5% versus 64.4%, P < 0.001). Among cases positive in both stored and fresh sections, the median percentage of immunoreactive cells was significantly reduced and the staining intensity was consistently lower in stored compared with fresh sections. We conclude that loss of immunoreactivity is an important problem in TMAs of breast cancer. Improved methods for sectioning TMAs and storing tissue sections aimed at reducing loss of immunoreactivity are critical for the use of TMAs in epidemiological studies.

Adult↗

PubMed2002

Reproductive and menstrual history and papillary thyroid cancer risk: the San Francisco Bay Area thyroid cancer study.

Thyroid cancer rates are three times higher in women than men during the period between puberty and menopause, suggesting that the etiology of thyroid cancer may be related to female sex hormones and reproductive function. However, the results from epidemiological studies have been mixed. To assess this hypothesis, data on menstrual history, pregnancy history, and exogenous hormone use were analyzed from a population-based, case-control study conducted in the San Francisco Bay Area. Of 817 incident thyroid cancer patients (cases), ages 20-74 years, who were diagnosed in 1992-1998 and 793 controls, identified by random-digit dialing and frequency matched to cases on age and race/ethnicity, 608 (74%) cases and 558 (70%) controls were interviewed. Of these cases, 544 were of papillary histology and included in the present analysis. Women who reported onset of menarche before age 12 or after age 14 were at about 50% increased risk for papillary thyroid cancer; however, this effect differed among age- and ethnic-specific subgroups. Among parous women younger than age 45, risk was elevated for several variables measuring recency of pregnancy. Risk was reduced for women who had ever used oral contraceptives [odds ratio (OR), 0.73; 95% confidence interval (CI), 0.52-0.97], but there was no trend with duration of use. Although it remains unclear how sex hormones influence thyroid carcinogenesis, these relationships warrant further investigation.

Adult↗