Body size, recreational physical activity, and B-cell non-Hodgkin lymphoma risk among women in the California teachers study

Nutritional status and physical activity are known to alter immune function, which may be relevant to lymphomagenesis. The authors examined body size measurements and recreational physical activity in relation to risk of B-cell non-Hodgkin lymphoma (NHL) in the prospective California Teachers Study. Between 1995 and 2007, 574 women were diagnosed with incident B-cell NHL among 121,216 eligible women aged 22-84 years at cohort entry. Multivariable-adjusted relative risks and 95% confidence intervals were estimated by fitting Cox proportional hazards models for all B-cell NHL combined and for the 3 most common subtypes: diffuse large B-cell lymphoma, follicular lymphoma, and B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma. Height was positively associated with risk of all B-cell NHLs (for >1.70 vs. 1.61-1.65 m, relative risk = 1.50, 95% confidence interval: 1.16, 1.96) and chronic lymphocytic leukemia/small lymphocytic lymphoma (relative risk = 1.93, 95% confidence interval: 1.09, 3.41). Weight and body mass index at age 18 years were positive predictors of B-cell NHL risk overall. These findings indicate that greater height, which may reflect genetics, early life immune function, infectious exposures, nutrition, or growth hormone levels, may play a role in NHL etiology. Adiposity at age 18 years may be more relevant to NHL etiology than that in later life.

Prediagnosis reproductive factors and all-cause mortality for women with breast cancer in the breast cancer family registry

Studies have examined the prognostic relevance of reproductive factors before breast cancer diagnosis, but most have been small and their overall findings inconclusive. Associations between reproductive risk factors and all-cause mortality after breast cancer diagnosis were assessed with the use of a population-based cohort of 3,107 women of White European ancestry with invasive breast cancer (1,130 from Melbourne and Sydney, Australia; 1,441 from Ontario, Canada; and 536 from Northern California, United States). During follow-up with a median of 8.5 years, 567 deaths occurred. At recruitment, questionnaire data were collected on oral contraceptive use, number of full-term pregnancies, age at first full-term pregnancy, time from last full-term pregnancy to breast cancer diagnosis, breastfeeding, age at menarche, and menopause and menopausal status at breast cancer diagnosis. Hazard ratios for all-cause mortality were estimated with the use of Cox proportional hazards models with and without adjustment for age at diagnosis, study center, education, and body mass index. Compared with nulliparous women, those who had a child up to 2 years, or between 2 and 5 years, before their breast cancer diagnosis were more likely to die. The unadjusted hazard ratio estimates were 2.75 [95% confidence interval (95% CI), 1.98-3.83; P < 0.001] and 2.20 (95% CI, 1.65-2.94; P < 0.001), respectively, and the adjusted estimates were 2.25 (95% CI, 1.59-3.18; P < 0.001) and 1.82 (95% CI, 1.35-2.46; P < 0.001), respectively. When evaluating the prognosis of women recently diagnosed with breast cancer, the time since last full-term pregnancy should be routinely considered along with other established host and tumor prognostic factors, but consideration of other reproductive factors may not be warranted.

Uncovering disparities in survival after non-small-cell lung cancer among Asian/Pacific Islander ethnic populations in California

Asians may have better survival after non-small-cell lung cancer (NSCLC) than non-Asians. However, it is unknown whether survival varies among the heterogeneous U.S. Asian/Pacific Islander (API) populations. Therefore, this study aimed to quantify survival differences among APIs with NSCLC. Differences in overall and disease-specific survival were analyzed in the California Cancer Registry among 16,577 API patients diagnosed with incident NSCLC between 1988 and 2007. Adjusted hazard ratios (HR) with 95% confidence intervals (95% CI) were estimated using Cox proportional hazards regression models with separate baseline hazards by disease stage. Despite better overall and disease-specific survival among APIs compared with non-Hispanic Whites, differences were evident across API populations. Among women, Japanese (overall survival HR, 1.16; 95% CI, 1.06-1.27) and APIs other than those in the six largest ethnic groups (other APIs; HR, 1.19; 95% CI, 1.07-1.33) had significantly poorer overall and disease-specific survival than Chinese. By contrast, South Asian women had significantly better survival than Chinese (HR, 0.79; 95% CI, 0.63-0.97). Among men, Japanese (HR, 1.15; 95% CI, 1.07-1.24), Vietnamese (HR, 1.07; 95% CI, 1.00-1.16), and other APIs (HR, 1.18; 95% CI, 1.08-1.28) had significantly poorer overall and disease-specific survival than Chinese. Other factors independently associated with poorer survival were lower neighborhood socioeconomic status, involvement with a non-university hospital, unmarried status, older age, and earlier year of diagnosis. APIs have significant ethnic differences in NSCLC survival that may be related to disparate lifestyles, biology, and especially health care access or use. To reduce the nationwide burden of lung cancer mortality, it is critical to identify and ameliorate hidden survival disparities such as those among APIs.

Stopping a silent killer in the underserved asian and pacific islander community: a chronic hepatitis B and liver cancer prevention clinic by medical students

OBJECTIVES

To assess and alleviate the burden of chronic hepatitis B virus (HBV) infection among low-income, uninsured Asian and Pacific Islanders (APIs) in San Jose, California.

METHODS

From 2007 to 2008, we provided free HBV testing and follow-up to 510 patients, 74% of whom were foreign-born Vietnamese. Patients were tested for hepatitis B surface antigen and surface antibody. Chronically infected patients who elected to undergo follow-up monitoring were evaluated for liver damage (ALT), liver cancer (AFP), and HBV replication (HBV DNA).

RESULTS

Overall, 17% were chronically infected; 33% of these were unaware that they were infected. Of those who underwent follow-up monitoring, 100% had elevated ALT, 9% had elevated AFP, and 24% had HBV DNA levels that exceeded the threshold for treatment. Patients who were candidates for antiviral therapy were enrolled in drug assistance programs, and those with elevated AFP levels were referred for CT scans. Uninfected patients lacking protective antibodies were provided free HBV vaccinations.

CONCLUSIONS

More liver cancer prevention in the medically underserved API community is needed, including universal screening for HBV and follow-up for those chronically infected.

Understanding the validity of self-reported positive family history of lymphoma in extended families to facilitate genetic epidemiology and clinical practice

The validity of self-reported information about familial Hodgkin lymphoma (HL), important for epidemiologic research and clinical practice, is undetermined. We attempted to validate 55 familial lymphomas previously reported by 48 subjects in a population-based case-control study of HL in women. Of 44 diagnoses (80%) reported by 40 (83%) recontacted subjects, we obtained medical documentation for 36 (82%). Twenty-nine (81%) were validated as lymphoma, with accuracy better for first-degree relatives and subjects with larger nuclear families and other family illness. Fourteen reports of familial HL were validated as lymphoma for 13 (93%) and as HL for nine (64%). Fifteen reports of familial NHL were validated as lymphoma for 10 (67%) and as NHL for 10 (67%). Thus, familial HL reported by HL patients and controls is highly likely to be lymphoma even in extended family members but less likely to be HL per se. Validity may vary with the subject's family size and medical history.

Eliminating the threat of chronic hepatitis B in the Asian and Pacific Islander community: a call to action

Chronic hepatitis B in the Asian and Pacific Islander (API) population is among our nation's greatest ethnic and racial health disparities. Despite comprising 4.3% of the population, API make up a disproportionate half of the 1.2-2 million Americans living with chronic hepatitis B. As many as two-thirds of API are not aware of their infection because they have not been tested. This lack of knowledge prevents them from undergoing life-saving liver cancer screening and potential treatment. Likewise, those not protected are unaware that they should be vaccinated. Instead, there is a pervasive lack of awareness among API and healthcare providers. New concerted public health actions are needed to eliminate this major health disparity.

Recent trends in breast cancer incidence in US white women by county-level urban/rural and poverty status

BACKGROUND

Unprecedented declines in invasive breast cancer rates occurred in the United States between 2001 and 2004, particularly for estrogen receptor-positive tumors among non-Hispanic white women over 50 years. To understand the broader public health import of these reductions among previously unstudied populations, we utilized the largest available US cancer registry resource to describe age-adjusted invasive and in situ breast cancer incidence trends for non-Hispanic white women aged 50 to 74 years overall and by county-level rural/urban and poverty status.

METHODS

We obtained invasive and in situ breast cancer incidence data for the years 1997 to 2004 from 29 population-based cancer registries participating in the North American Association of Central Cancer Registries resource. Annual age-adjusted rates were examined overall and by rural/urban and poverty of patients' counties of residence at diagnosis. Joinpoint regression was used to assess trends by annual quarter of diagnosis.

RESULTS

Between 2001 and 2004, overall invasive breast cancer incidence fell 13.2%, with greater reductions among women living in urban (-13.8%) versus rural (-7.5%) and low- (-13.0%) or middle- (-13.8%) versus high- (-9.6%) poverty counties. Most incidence rates peaked around 1999 then declined after second quarter 2002, although in rural counties, rates decreased monotonically after 1999. Similar but more attenuated patterns were seen for in situ cancers.

CONCLUSION

Breast cancer rates fell more substantially in urban and low-poverty, affluent counties than in rural or high-poverty counties. These patterns likely reflect a major influence of reductions in hormone therapy use after July 2002 but cannot exclude possible effects due to screening patterns, particularly among rural populations where hormone therapy use was probably less prevalent.

3 For Life: a model pilot program to prevent hepatitis B virus infection and liver cancer in Asian and Pacific Islander Americans

PURPOSE

3 For Life aims to increase hepatitis B virus (HBV) awareness and reduce the high prevalence of undiagnosed chronic HBV infection and susceptibility among Asian/Pacific Islander (API) adults.

DESIGN

This pilot program offered low-cost HBV vaccination with free HBV testing targeted primarily at foreign-born Chinese adults.

SETTING

Semimonthly screening and vaccination clinics were held in San Francisco, California, for 1 year.

SUBJECTS

A total of 1206 adults accessed the program.

INTERVENTION

Participants paid a discounted fee for a full vaccine series against HBV, hepatitis A virus (HAV), or both. Participants also provided blood samples for HBV serologic testing. Test results, recommendations, and appointment reminders were provided by mail.

MEASURES

We compared the probability of completing a recommended vaccine series by HBV serologic status and sociodemographic characteristics.

ANALYSIS

Proportions were compared using multivariate logistic regression models.

RESULTS

Nine percent of adults were chronically infected with HBV, and 53% were unprotected. In the latter group, 85% completed the HBV vaccine series. The probability of completing a recommended hepatitis vaccine series was similar across most sociodemographic groups, with slightly higher completion rates among middle-aged and Chinese participants.

CONCLUSIONS

Lessons learned from this pilot program have been used toward successful replication in other cities, demonstrating that 3 For Life is an accessible, affordable, reproducible, and sustainable model to increase HBV awareness, testing, and prevention among API adults.

Polymorphic variation in NFKB1 and other aspirin-related genes and risk of Hodgkin lymphoma

We found that regular use of aspirin may reduce the risk of Hodgkin lymphoma (HL), a common cancer of adolescents and young adults in the United States. To explore possible biological mechanisms underlying this association, we investigated whether polymorphic variation in genes involved in nuclear factor-kappaB (NF-kappaB) activation and inhibition, other inflammatory pathways, and aspirin metabolism influences HL risk. Twenty single nucleotide polymorphisms (SNP) in seven genes were genotyped in DNA from 473 classical HL cases and 373 controls enrolled between 1997 and 2000 in a population-based case-control study in the Boston, Massachusetts, metropolitan area and the state of Connecticut. We selected target genes and SNPs primarily using a candidate-SNP approach and estimated haplotypes using the expectation-maximization algorithm. We used multivariable logistic regression to estimate odds ratios (OR) for associations with HL risk. HL risk was significantly associated with rs1585215 in NFKB1 (AG versus AA: OR, 2.1; 95% confidence interval, 1.5-2.9; GG versus AA: OR, 3.5; 95% confidence interval, 2.2-5.7, Ptrend=1.7x10(-8)) and with NFKB1 haplotypes (Pglobal=6.0x10(-21)). Similar associations were apparent across categories of age, sex, tumor EBV status, tumor histology, and regular aspirin use, although statistical power was limited for stratified analyses. Nominally significant associations with HL risk were detected for SNPs in NFKBIA and CYP2C9. HL risk was not associated with SNPs in IKKA/CHUK, PTGS2/COX2, UDP1A6, or LTC4S. In conclusion, genetic variation in the NF-kappaB pathway seems to influence risk of HL. Pooled studies are needed to detect any heterogeneity in the association with NF-kappaB across HL subgroups, including aspirin users and nonusers.

Family history of haematopoietic malignancies and non-Hodgkin's lymphoma risk in the California Teachers Study

Family history of haematopoietic malignancies appears to be a risk factor for non-Hodgkin's lymphoma (NHL), but whether risk varies by family member's gender is unclear. Among 121 216 women participating in the prospective California Teachers Study, NHL risk varied by type of haematopoietic malignancy and gender of the relative.

Differences in breast cancer subtype distribution exist among ethnic subgroups of Asian women in California

Abstract #2088

Background: Distinct breast cancer subtypes have been identified by gene expression analysis. Little is known about the distribution of these subtypes among Asian women. We previously reported an increased frequency of HER2-positive breast cancers among certain ethnic subgroups of Asian women in California. To follow up on that finding in detail, we undertook the current analysis to explore factors associated with differences in breast cancer subtype distribution among Asian women in California.&#x2028; Methods: We defined immunohistochemical surrogates for each breast cancer subtype among Chinese, Japanese, Filipina, Korean, Vietnamese and South Asian patients in the population-based California Cancer Registry diagnosed in the period 1999-2005. Subtypes were defined using combinations of immunohistochemical markers: luminal A (ER+ and/or PR+, HER2-), luminal B (ER+ and/or PR+, HER2+), basal-like (ER-, PR-, HER2-) and HER2+/ER- (ER-, PR-, HER2+). Polytomous logistic regression was used to evaluate associations between breast cancer subtype and age, race, AJCC stage, tumor grade, tumor histology, socioeconomic status, nativity and hospital ownership (private vs. public). Models were used to compare differences in these characteristics simultaneously across the four breast cancer subtypes.&#x2028; Results: Of 12,245 Asian women diagnosed with invasive breast cancer, 7,217 (59%) women had data for all three immunohistochemical markers. The majority of breast cancers among Japanese women were of the luminal A subtype (67%), with a low frequency of basal-like (10%) and HER2+ (22%) cancers. Korean, Filipina and Vietnamese women had a high frequency of HER2+ cancers (35%, 31% and 31%, respectively) compared to Non-Hispanic White women diagnosed during this period (n=12,996, 21%). In regression analyses among Asian women, the four subtypes varied significantly in their associations with age group (p=0.01), detailed Asian ethnicity (p&lt;0.0001), stage (p&lt;0.0001), grade (p&lt;0.0001), histology (p&lt;0.0001), year of diagnosis (continuous; p=0.03) and hospital ownership (p&lt;0.0001). However, there was no significant variation among the subtypes in their relationships with socioeconomic status (p=0.94) or nativity (p=0.29).&#x2028; Conclusions: Differences in the distribution of breast cancer subtypes exist among Asian women according to ethnicity, as well as other demographic and disease characteristics. These differences were not associated with place of birth or socioeconomic status. Breast cancers among Japanese women had the most favorable subtype distribution, while Korean women had the least favorable distribution. Further study may identify genetic and environmental risk factors responsible for these differences, with implications for prevention and treatment.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2088.

Serum YKL-40 and interleukin 6 levels in Hodgkin lymphoma

PURPOSE

Serum levels of the inflammatory markers YKL-40 and interleukin 6 (IL-6) are increased in many conditions, including cancers. We examined serum YKL-40 and IL-6 levels in patients with Hodgkin lymphoma, a tumor with strong immunologic reaction to relatively few tumor cells, especially in nodular sclerosis Hodgkin lymphoma.

EXPERIMENTAL DESIGN

We analyzed Danish and Swedish patients with incident Hodgkin lymphoma (N=470) and population controls from Denmark (n=245 for YKL-40; n=348 for IL-6). Serum YKL-40 and IL-6 levels were determined by ELISA, and log-transformed data were analyzed by linear regression, adjusting for age and sex.

RESULTS

Serum levels of YKL-40 and IL-6 increased in Hodgkin lymphoma patients compared with controls (YKL-40, 3.6-fold; IL-6, 8.3-fold; both, P<0.0001). In pretreatment samples from pretreatment Hodgkin lymphoma patients (n=176), levels were correlated with more advanced stages (P(trend), 0.0001 for YKL-40 and 0.013 for IL-6) and in those with B symptoms; however, levels were similar in nodular sclerosis and mixed cellularity subtypes, by EBV status, and in younger (<45 years old) and older patients. Patients tested soon after treatment onset had significantly lower levels than pretreatment patients; however, even >or=6 months after treatment onset, serum YKL-40 and IL-6 levels remained significantly increased compared with controls. In patients who died (n=12), pretreatment levels for YKL-40 and IL-6 were higher than in survivors, although not statistically significantly.

CONCLUSIONS

Serum YKL-40 and IL-6 levels were increased in untreated Hodgkin lymphoma patients and those with more advanced stages but did not differ significantly by Hodgkin lymphoma histology. Following treatment, serum levels were significantly lower.

Family history of breast cancer and all-cause mortality after breast cancer diagnosis in the Breast Cancer Family Registry

Although having a family history of breast cancer is a well established breast cancer risk factor, it is not known whether it influences mortality after breast cancer diagnosis. We studied 4,153 women with first primary incident invasive breast cancer diagnosed between 1991 and 2000, and enrolled in the Breast Cancer Family Registry through population-based sampling in Northern California, USA; Ontario, Canada; and Melbourne and Sydney, Australia. Cases were oversampled for younger age at diagnosis and/or family history of breast cancer. Carriers of germline mutations in BRCA1 or BRCA2 were excluded. Cases and their relatives completed structured questionnaires assessing breast cancer risk factors and family history of cancer. Cases were followed for a median of 6.5 years, during which 725 deaths occurred. Cox proportional hazards regression was used to evaluate associations between family history of breast cancer at the time of diagnosis and risk of all-cause mortality after breast cancer diagnosis, adjusting for established prognostic factors. The hazard ratios for all-cause mortality were 0.98 (95% confidence interval [CI] = 0.84-1.15) for having at least one first- or second-degree relative with breast cancer, and 0.85 (95% CI = 0.70-1.02) for having at least one first-degree relative with breast cancer, compared with having no such family history. Estimates did not vary appreciably when stratified by case or tumor characteristics. In conclusion, family history of breast cancer is not associated with all-cause mortality after breast cancer diagnosis for women without a known germline mutation in BRCA1 or BRCA2. Therefore, clinical management should not depend on family history of breast cancer.

Dietary patterns and risk of ovarian cancer in the California Teachers Study cohort

Previous studies have examined the association between individual foods or nutrients, but not overall diet, and ovarian cancer risk. To account for the clustering of foods in the diet, we investigated the association between dietary patterns and risk of ovarian cancer in the prospective California Teachers Study cohort. Of 97,292 eligible women who completed the baseline dietary assessment in 1995-1996, 311 women developed epithelial ovarian cancer on or before December 31, 2004. Based on principal components analysis, 5 major dietary patterns were identified and termed plant-based, high-protein/high-fat, high-carbohydrate, ethnic, and salad-and-wine. Multivariable Cox proportional hazards regression analysis was used to estimate associations between these dietary patterns and risk of incident ovarian cancer. Most of the dietary patterns were not significantly associated with ovarian cancer risk. However, women who followed a plant-based diet had higher risk; comparing those in the top quintile of plant-based food intake with those in the lowest quintile, the relative risk of ovarian cancer was 1.65 (95% confidence interval = 1.07-2.54; P(trend) = 0.03). Associations with the 5 dietary patterns did not vary by known ovarian cancer risk factors or other behavioral or sociodemographic characteristics. Overall, our results show no convincing associations between dietary patterns and ovarian cancer risk.

Attitudes toward hepatitis B and liver cancer prevention among Chinese Americans in the San Francisco Bay Area, California

BACKGROUND

Chronic hepatitis B and associated liver cancer constitute important health threats with disparity among Asian/Pacific Islander Americans (APIs). However, many APIs are unaware of and unprotected against these diseases.

METHODS

To inform the development of community-based programs to increase hepatitis B and liver cancer awareness and prevention among APIs, we conducted a series of qualitative focus groups in 2007 to identify motivations and deterrents related to hepatitis B education, testing, and vaccination among San Francisco Bay Area Chinese Americans. Six focus groups were held in Cantonese, English, or Mandarin for women or men, respectively. Recorded transcripts were transcribed, translated, and then coded by consensus.

RESULTS

Factors that motivated individuals to be tested for hepatitis B included peace of mind, prevention of transmission to others, informed decision-making ability, convenience, and pre-vaccination screening. Primary motivations for hepatitis B vaccination were protection of future health and avoidance of hepatitis B. However, factors that discouraged people from testing or vaccination included costs, lack of health insurance, fear of side effects, worries about reliability or efficacy, poor patient-doctor communication, reliance on professional opinion, apparent good health, inconvenience, and personal preference. Individuals were generally in favor of informing relatives and friends about hepatitis B testing and vaccination, and offered several reasons for and against educating others about these activities.

CONCLUSIONS

In summary, our study identifies common attitudes and influences regarding the decision to take preventive action against hepatitis B and liver cancer. These findings can be applied toward the design of more effective educational and outreach materials and programs for Chinese Americans and possibly other APIs.

Racial/ethnic variation in EBV-positive classical Hodgkin lymphoma in California populations

Epstein-Barr virus (EBV) is detected in the tumor cells of some but not all Hodgkin lymphoma (HL) patients, and evidence indicates that EBV-positive and -negative HL are distinct entities. Racial/ethnic variation in EBV-positive HL in international comparisons suggests etiologic roles for environmental and genetic factors, but these studies used clinical series and evaluated EBV presence by differing protocols. Therefore, we evaluated EBV presence in the tumors of a large (n = 1,032), racially and sociodemographically diverse series of California incident classical HL cases with uniform pathology re-review and EBV detection methods. Tumor EBV-positivity was associated with Hispanic and Asian/Pacific Islander (API) but not black race/ethnicity, irrespective of demographic and clinical factors. Complex race-specific associations were observed between EBV-positive HL and age, sex, histology, stage, neighborhood socioeconomic status (SES), and birth place. In Hispanics, EBV-positive HL was associated not only with young and older age, male sex, and mixed cellularity histology, but also with foreign birth and lower SES in females, suggesting immune function responses to correlates of early childhood experience and later environmental exposures, respectively, as well as of pregnancy. For APIs, a lack of association with birth place may reflect the higher SES of API than Hispanic immigrants. In blacks, EBV-positive HL was associated with later-stage disease, consistent with racial/ethnic variation in certain cytokine polymorphisms. The racial/ethnic variation in our findings suggests that EBV-positive HL results from an intricate interplay of early- and later-life environmental, hormonal, and genetic factors leading to depressed immune function and poorly controlled EBV infection.

Incomplete pregnancy is not associated with breast cancer risk: the California Teachers Study

BACKGROUND

Early studies of incomplete pregnancy and development of breast cancer suggested that induced abortion might increase risk. Several large prospective studies, which eliminate recall bias, did not detect associations, but this relationship continues to be debated.

STUDY DESIGN

To further inform this important question, we examined invasive breast cancer as it relates to incomplete pregnancy, including total number of induced abortions, age at first induced abortion and total number of miscarriages among women participating in the ongoing California Teachers Study (CTS) cohort. Incomplete pregnancy was self-reported on the CTS baseline questionnaire in 1995-1996. Incident breast cancers were ascertained in 3324 women through 2004 via linkage with the California Cancer Registry.

RESULTS

Using Cox multivariable regression, we found no statistically significant association between any measure of incomplete pregnancy and breast cancer risk among nulliparous or parous women.

CONCLUSION

These results provide strong evidence that there is no relationship between incomplete pregnancy and breast cancer risk.

Building partnerships with traditional chinese medicine practitioners to increase hepatitis B awareness and prevention

OBJECTIVES

The annual Hepatitis B Prevention and Education Symposium aims to develop partnerships between non-Western and Western health care providers to prevent chronic hepatitis B virus (HBV) infection and death from liver cancer among Asians and Pacific Islanders (APIs).

DESIGN

Each year from 2004 through 2007, we partnered with professional, academic, and community-based organizations to organize an educational symposium for Traditional Chinese Medicine practitioners and acupuncturists in California. Participants completed pre- and postsymposium surveys assessing knowledge about HBV and liver cancer.

SETTING

The symposia were held in San Francisco, Los Angeles, and Stanford, California.

SUBJECTS

Over 1000 participants attended the four symposia combined; most were born in Asia.

INTERVENTION

Symposium activities included educational lectures and games, presentation of a physician's guide to HBV management, and case studies.

OUTCOME MEASURES

Chi-square tests were used to compare the proportion of correct responses to each knowledge-based question, as well as the total number of correct responses, before and after the symposium.

RESULTS

Knowledge about HBV and liver cancer was low prior to the symposium. The proportion of correct responses to the most commonly mistaken questions increased significantly at the conclusion of each symposium. The total number of correct responses rose from below 60% to above 75% each year.

CONCLUSIONS

Similar educational symposia targeting health care providers who serve API patients can improve HBV and liver cancer awareness and prevention throughout the API community.

Recent breast cancer trends among Asian/Pacific Islander, Hispanic, and African-American women in the US: changes by tumor subtype

BACKGROUND

Recently, unprecedented drops in breast cancer incidence have been reported for populations of mostly White European descent. Incidence patterns in non-White racial/ethnic groups are less described. Therefore, we examined population-based breast cancer incidence trends separately for US Asian/Pacific Islander, Hispanic, African-American, and non-Hispanic White women by etiologically relevant tumor subtype characteristics, including hormone receptor status, histology, size, and in situ behavior.

METHODS

We obtained breast cancer data from 13 Surveillance, Epidemiology, and End Results (SEER) cancer registries to calculate age-adjusted incidence rates and trends, stratified by race/ethnicity and tumor subtype for the period 1992-2004. Detailed analyses were limited to women 50 years old or older. Joinpoint regression was used to assess incidence trends by annual quarter of diagnosis.

RESULTS

Between 2001 and 2004, incidence rates of invasive breast cancer in women 50 years old or older declined appreciably among Asians/Pacific Islanders (-8.5%) and Hispanics (-2.9%) and were stable in African-Americans (+0.5%), reductions substantially lower than those observed among non-Hispanic Whites (-14.3%). In Asian/Pacific Islander women, perceptible but statistically nonsignificant decreases were observed for hormone receptor-positive, lobular, and small tumors only. Rates of hormone receptor-negative tumors increased among African-Americans (26.1%) and Hispanics (26.9%) during 2001-2004. Incidence trends in most groups, except African-American women, peaked between 1999 and mid-2002. Rates of in situ cancer remained stable in all groups.

CONCLUSION

Recently reported reductions in breast cancer incidence varied considerably by race/ethnicity. These patterns are consistent with documented racial/ethnic differences in the prevalence and discontinuation of hormone therapy (HT) after July 2002 but do not correspond as well to patterns of mammography use in these groups. The data presented in this analysis provide further evidence that population-level HT use is a major influence on population-level rates of particular breast cancer subtypes, especially receptor-positive tumors.

Hepatitis C infection and risk of malignant lymphoma

The association between hepatitis C virus (HCV) infection and risk of malignant lymphoma remains controversial, perhaps due to small-sized studies and low prevalence of HCV in the general population. On the basis of a large Danish-Swedish population-based case-control study, 2,819 lymphoma patients and 1,856 controls of second-generation Danish-Swedish origin were screened for HCV infection using an enzyme-linked immunosorbent assay and a confirming recombinant immunoblot assay (RIBA) test. Positive samples were tested with real-time PCR for the presence of HCV RNA. The association between HCV infection and risk of malignant lymphoma was assessed by logistic regression. When intermediate RIBA test results were interpreted as positive, anti-HCV antibody positivity was associated with a nonsignificant increased risk of non-Hodgkin lymphoma (NHL) overall (odds ratio (OR) = 2.2; 95% confidence interval (CI) 0.9-5.3; n = 20 cases), of B-cell lymphomas combined (OR = 2.4 [1.0-5.8]; n = 20) and of lymphoplasmacytic lymphoma (OR = 5.2 [1.0-26.4]; n = 2). No patients with T-cell or Hodgkin lymphoma were HCV-positive. A more conservative definition of HCV positivity (disregarding intermediate RIBA results) resulted in an OR = 1.6 (0.3-8.5; n = 5) for NHL overall. When the definition was further restricted to require HCV RNA positivity, OR was 1.7 (0.2-16.2; n = 3) for NHL overall. Our findings from a population with a low prevalence of HCV suggest a positive association between HCV and risk of NHL, in particular of B-cell origin.

Childhood social environment and risk of non-Hodgkin lymphoma in adults

Better hygiene and sanitation and decreasing family size parallel the increasing incidence of non-Hodgkin lymphoma (NHL) in many populations around the world. However, whether sibship size, birth order, and crowding are related to adult NHL risk is not clear. We investigated how family structure and childhood social environment were related to the risk of NHL and NHL subtypes in a large Scandinavian population-based case control study with 6,242 participants aged 18 to 74 years. Detailed exposure information was obtained through telephone interviews. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using logistic regression, and all statistical tests were two-sided. Having four or more siblings was associated with a moderately increased risk of NHL, compared with having no siblings (OR 1.34, 95% CI 1.11-1.62, P(trend) < 0.001). Having four or more older siblings was associated with a similar risk increase (OR 1.33, 95% CI 1.12-1.59, P(trend) = 0.003) compared with being the oldest, whereas number of younger siblings was unrelated overall. The associations were independent of other environmental exposures and did not vary by country, age, or sex. High household crowding was also positively associated with risk of NHL. Results were slightly stronger for diffuse large B-cell and T-cell lymphomas than for other major NHL subtypes. Our findings add to the evidence that large sibship size, late birth order, and childhood crowding are associated with an elevated risk of NHL. Effect mechanisms may be related to early age at onset and high frequency of specific infections or total microbial exposure in childhood.

Cigarette smoking and risk of Hodgkin lymphoma: a population-based case-control study

BACKGROUND

Studies have inconsistently reported an association between tobacco smoking and Hodgkin lymphoma (HL) risk. The conflicting finding may reflect etiologic heterogeneity between HL subtypes, warranting further characterization of the relationship.

METHODS

We collected information on tobacco-smoking habits in 586 classic HL cases and 3,187 population controls in a Danish-Swedish case-control study. HL EBV status was established for 499 cases by standard techniques. Odds ratios (OR) for an association with cigarette smoking were calculated by logistic regression for HL overall and stratified by age, sex, major histology subtypes, and tumor EBV status, adjusting for known confounders.

RESULTS

Compared with never smokers, current cigarette smokers were at an increased overall HL risk [adjusted OR, 1.57; 95% confidence interval (95% CI), 1.22-2.03]. The association was strongest for EBV-positive HL (adjusted OR, 2.36; 95% CI, 1.51-3.71), but also applied to EBV-negative HL (adjusted OR, 1.43; 95% CI, 1.05-1.97; P(homogeneity EBV-pos) versus P(homogeneity EBV-neg) = 0.04). The association did not vary appreciably by age, sex, or histologic subtype, the apparent EBV-related difference present in all strata. There was no evidence of a dose-response pattern, whether by age at smoking initiation, daily cigarette consumption, number of years smoking, or cumulative number of cigarettes smoked. Similar results were obtained in analyses using non-HL patients (n = 3,055) participating in the founding study as comparison group.

CONCLUSION

The observed association between cigarette smoking and HL risk is consistent with previous findings and biologically credible. Although not easily dismissed as an artifact, the limited evidence of a dose-response pattern renders the overall evidence of causality weak.

Why we should routinely screen Asian American adults for hepatitis B: a cross-sectional study of Asians in California

Chronic hepatitis B virus (HBV) infection is a serious liver disease that, if left undiagnosed or without appropriate medical management, is associated with a 25% chance of death from cirrhosis or liver cancer. To study the demographics and prevalence of chronic HBV infection and HBV vaccination in the Asian American population, we provided free HBV serological screening and administered a survey to 3163 Asian American adult volunteers in the San Francisco Bay Area between 2001 and 2006. Of those screened, 8.9% were chronically infected with HBV. Notably, one-half to two-thirds (65.4%) of the chronically infected adults were unaware that they were infected. Of those who were not chronically infected, 44.8% lacked protective antibodies against HBV and were likely susceptible to future infection. Men were twice as likely as women to be chronically infected (12.1% versus 6.4%). Asian Americans born in East Asia, Southeast Asia, or the Pacific Islands were 19.4 times more likely to be chronically infected than those born in the United States. Self-reporting of prior vaccination was unreliable to assess protection against HBV. Among the 12% who reported having been vaccinated, 5.2% were chronically infected, and 20.3% lacked protective antibodies.

CONCLUSION

Given the high prevalence of unrecognized chronic HBV infection in the Asian American population, we call for healthcare providers to routinely screen Asian adults for HBV, regardless of their vaccination status. Those who test positive should be provided with culturally appropriate information to prevent disease transmission and proper medical management to reduce their risk of liver disease.

Recent changes in breast cancer incidence and risk factor prevalence in San Francisco Bay area and California women: 1988 to 2004

Introduction

Historically, the incidence rate of breast cancer among non-Hispanic white women living in the San Francisco Bay area (SFBA) of California has been among the highest in the world. Substantial declines in breast cancer incidence rates have been documented in the United States and elsewhere during recent years. In light of these reports, we examined recent changes in breast cancer incidence and risk factor prevalence among non-Hispanic white women in the SFBA and other regions of California.

Methods

Annual age-adjusted breast cancer incidence and mortality rates (1988 to 2004) were obtained from the California Cancer Registry and analyzed using Joinpoint regression. Population-based risk factor prevalences were calculated using two data sources: control subjects from four case-control studies (1989 to 1999) and the 2001 and 2003 California Health Interview Surveys.

Results

In the SFBA, incidence rates of invasive breast cancer increased 1.3% per year (95% confidence interval [CI], 0.7% to 2.0%) in 1988–1999 and decreased 3.6% per year (95% CI, 1.6% to 5.6%) in 1999–2004. In other regions of California, incidence rates of invasive breast cancer increased 0.8% per year (95% CI, 0.4% to 1.1%) in 1988–2001 and decreased 4.4% per year (95% CI, 1.4% to 7.3%) in 2001–2004. In both regions, recent (2000–2001 to 2003–2004) decreases in invasive breast cancer occurred only in women 40 years old or older and in women with all histologic subtypes and tumor sizes, hormone receptor-defined types, and all stages except distant disease. Mortality rates declined 2.2% per year (95% CI, 1.8% to 2.6%) from 1988 to 2004 in the SFBA and the rest of California. Use of estrogen-progestin hormone therapy decreased significantly from 2001 to 2003 in both regions. In 2003–2004, invasive breast cancer incidence remained higher (4.2%) in the SFBA than in the rest of California, consistent with the higher distributions of many established risk factors, including advanced education, nulliparity, late age at first birth, and alcohol consumption.

Conclusion

Ongoing surveillance of breast cancer occurrence patterns in this high-risk population informs breast cancer etiology through comparison of trends with lower-risk populations and by highlighting the importance of examining how broad migration patterns influence the geographic distribution of risk factors.

The non-Hodgkin lymphomas: a review of the epidemiologic literature

The non-Hodgkin lymphomas (NHL) are a heterogeneous group of B-cell and T-cell neoplasms that arise primarily in the lymph nodes. NHL incidence rates in the US doubled between about 1970 and 1990, and stabilized during the 1990s. NHL accounts for approximately 3.4% of cancer deaths in the US. Although some of the observed patterns in NHL have been related to HIV/AIDS, these conditions cannot fully explain the magnitude of the changes; neither do changes in classification systems nor improved diagnostic capabilities. Studies of occupational and environmental exposures (e.g., pesticides, solvents) have produced no consistent pattern of significant positive associations. Inverse associations with ultraviolet radiation exposure and alcohol and fish intake, and positive associations with meat and saturated fat intake have been reported in several studies; additional studies are needed to confirm or refute these associations. Family history of NHL or other hematolympho-proliferative cancers and personal history of several autoimmune disorders are associated with increased risk of NHL, but are not likely to account for a large proportion of cases. HIV and other infectious agents, such as human herpesvirus 8 and Epstein-Barr, appear to be associated with differing types of NHL, such as some B-cell lymphomas. Future epidemiologic studies should evaluate associations by NHL type, enhance exposure information collected, and elucidate factors that may identify susceptible (or resistant) subpopulations because of genetic, immunologic or other characteristics. The extent to which the etiology of NHL types may differ is important to resolve in ongoing and future studies.

The burden of liver cancer in Asians and Pacific Islanders in the Greater San Francisco Bay Area, 1990 through 2004

BACKGROUND

To the authors' knowledge, no previous U.S. study has examined time trends in the incidence rate of liver cancer in the high-risk Asian/Pacific Islander population. In this study, liver cancer incidence trends were evaluated in Chinese, Filipino, Japanese, Korean, and Vietnamese men and women in the Greater San Francisco Bay Area of California between 1990 and 2004.

METHODS

Populations at risk were estimated by using the cohort-component demographic method. Annual percentage changes (APCs) in age-adjusted incidence rates of primary liver cancer among Asians/Pacific Islanders in the Greater Bay Area Cancer Registry were calculated by using joinpoint regression analysis.

RESULTS

The incidence rate of liver cancer between 1990 and 2004 did not change significantly in Asian/Pacific Islander men or women overall. However, the incidence rate declined, although the decline was not statistically significant, among Chinese men (APC, -1.6%; 95% confidence interval [95% CI], -3.4-0.3%), Japanese men (APC, -4.9%; 95% CI, -10.7-1.2%), and Japanese women (APC, -3.6%; 95% CI, -8.9-2%). Incidence rates remained consistently high for Vietnamese, Korean, and Filipino men and women. Trends in the incidence rate of hepatocellular carcinoma were comparable to those for liver cancer. Although disparities in liver cancer incidence between Asians/Pacific Islanders and other racial/ethnic groups diminished between the period from 1990 through 1994 and the period from 2000 through 2004, the disparities among Asian subgroups increased.

CONCLUSIONS

Liver cancer continues to affect Asian/Pacific Islander Americans disproportionately, with consistently high incidence rates in most subgroups. Culturally targeted prevention methods are needed to reduce the high rates of liver cancer in this growing population in the U.S.

Infectious mononucleosis, childhood social environment, and risk of Hodgkin lymphoma

Infectious mononucleosis (IM) has been associated with an increased risk of Hodgkin lymphoma (HL), implicating a role for Epstein-Barr virus (EBV) in HL development. Although essential to the understanding of the association, it has remained uncertain if the relationship is restricted to the EBV-positive subset of HL. We collected information on mononucleosis history and childhood socioenvironmental characteristics in a population-based study of 586 patients with classic HL and 3,187 controls in Denmark and Sweden. Tumor EBV status was established for 499 cases by immunohistochemistry and in situ hybridization techniques. Odds ratios (OR) for the relationship between HL risk and mononucleosis and other risk factors were estimated by logistic regression for HL in younger (18-44 years) and older (45-74 years) adults, overall and by tumor EBV status. All analyses were adjusted for country-specific measures of maternal education and mononucleosis history. IM was associated with an increased risk of EBV-positive [OR, 3.23; 95% confidence interval (95% CI) 1.89-5.55] but not EBV-negative HL (OR, 1.35; 95% CI, 0.86-2.14). Risk of EBV-positive HL varied with time since IM and was particularly pronounced in younger adults (OR, 3.96; 95% CI, 2.19-7.18). IM-associated lymphomas occurred with a median of 2.9 years (1.8-4.9 years) after infection. The EBV specificity of the IM association was corroborated by a case-case comparison of IM history between younger adult EBV-positive and EBV-negative HL patients (OR(IM EBV+ HL versus EBV- HL), 2.68; 95% CI, 1.40-5.12). We found further evidence that IM is associated only with EBV-positive HL. This finding is compatible with the notion that EBV-positive and EBV-negative HL may have different etiologies.

Wine and other alcohol consumption and risk of ovarian cancer in the California Teachers Study cohort

Objective

Whether alcohol consumption influences ovarian cancer risk is unclear. Therefore, we investigated the association between alcohol intake at various ages and risk of ovarian cancer.

Methods

Among 90,371 eligible members of the California Teachers Study cohort who completed a baseline alcohol assessment in 1995–1996, 253 women were diagnosed with epithelial ovarian cancer by the end of 2003. Multivariate Cox proportional hazards regression analysis was performed to estimate relative risks (RRs) and 95% confidence intervals (CIs).

Results

Consumption of total alcohol, beer, or liquor in the year prior to baseline, at ages 30–35 years, or at ages 18–22 years was not associated with risk of ovarian cancer. Consumption of at least one glass per day of wine, compared to no wine, in the year before baseline was associated with increased risk of developing ovarian cancer: RR = 1.57 (95% CI 1.11–2.22), P_trend = 0.01. The association with wine intake at baseline was particularly strong among peri-/post-menopausal women who used estrogen-only hormone therapy and women of high socioeconomic status.

Conclusions

Alcohol intake does not appear to affect ovarian cancer risk. Constituents of wine other than alcohol or, more likely, unmeasured determinants of wine drinking were associated with increased risk of ovarian cancer.

Diet and risk of ovarian cancer in the California Teachers Study cohort

Dietary phytochemical compounds, including isoflavones and isothiocyanates, may inhibit cancer development but have not yet been examined in prospective epidemiologic studies of ovarian cancer. The authors have investigated the association between consumption of these and other nutrients and ovarian cancer risk in a prospective cohort study. Among 97,275 eligible women in the California Teachers Study cohort who completed the baseline dietary assessment in 1995-1996, 280 women developed invasive or borderline ovarian cancer by December 31, 2003. Multivariable Cox proportional hazards regression, with age as the timescale, was used to estimate relative risks and 95% confidence intervals; all statistical tests were two sided. Intake of isoflavones was associated with lower risk of ovarian cancer. Compared with the risk for women who consumed less than 1 mg of total isoflavones per day, the relative risk of ovarian cancer associated with consumption of more than 3 mg/day was 0.56 (95% confidence interval: 0.33, 0.96). Intake of isothiocyanates or foods high in isothiocyanates was not associated with ovarian cancer risk, nor was intake of macronutrients, antioxidant vitamins, or other micronutrients. Although dietary consumption of isoflavones may be associated with decreased ovarian cancer risk, most dietary factors are unlikely to play a major role in ovarian cancer development.

Lung cancer incidence in never smokers

PURPOSE

Lung cancer is a leading cause of cancer death worldwide. Although smoking remains the predominant cause of lung cancer, lung cancer in never smokers is an increasingly prominent public health issue. However, data on this topic, particularly lung cancer incidence rates in never smokers, are limited.

METHODS

We reviewed the existing literature on lung cancer incidence and mortality rates among never smokers and present new data regarding rates in never smokers from the following large, prospective cohorts: Nurses' Health Study; Health Professionals Follow-Up Study; California Teachers Study; Multiethnic Cohort Study; Swedish Lung Cancer Register in the Uppsala/Orebro region; and First National Health and Nutrition Examination Survey Epidemiologic Follow-Up Study.

RESULTS

Truncated age-adjusted incidence rates of lung cancer among never smokers age 40 to 79 years in these six cohorts ranged from 14.4 to 20.8 per 100,000 person-years in women and 4.8 to 13.7 per 100,000 person-years in men, supporting earlier observations that women are more likely than men to have non-smoking-associated lung cancer. The distinct biology of lung cancer in never smokers is apparent in differential responses to epidermal growth factor receptor inhibitors and an increased prevalence of adenocarcinoma histology in never smokers.

CONCLUSION

Lung cancer in never smokers is an important public health issue, and further exploration of its incidence patterns, etiology, and biology is needed.

Atopy and Risk of Non-Hodgkin Lymphoma

BACKGROUND

A possible connection between allergy and cancer has been suspected, but allergy-related conditions or atopy have been inconsistently associated with reduced risks of non-Hodgkin lymphoma. We investigated this association in a population-based case-control study and in a prospective study with prediagnostic blood specimens.

METHODS

We carried out a population-based study of 3055 case patients with non-Hodgkin lymphoma and 3187 control subjects in Denmark and Sweden, including questionnaire information on allergy and blood specimens, and a nested case-control study within a prospective cohort of more than 400,000 Finnish women. In the second study, serum specimens from the 198 case patients who developed non-Hodgkin lymphoma within a median of 8.9 years after the blood was drawn were matched with serum specimens from 594 control subjects. In both studies, laboratory-based evidence of allergy (atopy) was determined in serum on the basis of specific IgE reactivity to common inhalant allergens. Dissemination of disease was classified by the Ann Arbor system. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by logistic regression.

RESULTS

In the first study, ever having hay fever, but not other allergic conditions, was associated with a reduced risk of non-Hodgkin lymphoma. In particular, subjects with specific IgE reactivity in serum had a 32% (95% CI = 20% to 42%) lower risk of overall non-Hodgkin lymphoma than those without such reactivity. However, among case patients, dissemination of the disease was strongly inversely associated with specific IgE reactivity. In the second (i.e., prospective) study, no association was found between non-Hodgkin lymphoma and specific IgE reactivity, except possibly immediately before a diagnosis of non-Hodgkin lymphoma (> or = 10 years before diagnosis, OR = 1.00, 95% CI = 0.48 to 2.09; 5-9 years before, OR = 0.95, 95% CI = 0.50 to 1.84; 1-4 years before, OR = 0.33, 95% CI = 0.11 to 1.02; and < 1 year before, OR = 0.27, 95% CI = 0.03 to 2.31).

CONCLUSION

Allergy may not be causally associated with the risk of non-Hodgkin lymphoma. The inverse association observed in some case-control studies may arise because non-Hodgkin lymphoma suppresses the immunologic response to allergens.

Hepatitis B and liver cancer knowledge and preventive practices among Asian Americans in the San Francisco Bay Area, California

Chronic hepatitis B virus (HBV) infection causes liver cancer and disproportionately affects the Asian community in the U.S. In order to advance HBV and liver cancer awareness and prevention, it is important to identify existing gaps in knowledge and preventive practices among Asian Americans. Therefore, the authors administered a written questionnaire to 199 adults in the Asian-American community of the San Francisco Bay Area, California. Although the majority of adults had at least a college education, knowledge regarding HBV transmission, prevention, symptoms, risks, and occurrence was low. Fewer than 60% reported having been tested for HBV, only 31% reported having been vaccinated against HBV, and only 44% reported having had their children vaccinated. Asians, especially those born in China or Southeast Asia, had significantly poorer knowledge regarding HBV and liver cancer than non-Asians. Those with higher knowledge levels were significantly more likely to have been tested for HBV and to have had their children vaccinated. Younger adults, women, Caucasians, more highly educated individuals, those not born in China or Hong Kong, and those with a personal or family history of liver disease were more likely to have taken preventive action against HBV. Our results suggest that HBV and liver cancer knowledge among Asian Americans, especially Chinese Americans, is poor, and that better knowledge is associated with increased preventive practices. Thus, there is a need for increased HBV education and improved community-based interventions to prevent HBV-related liver disease in the high-risk Asian-American community.

Nutrient intake and risk of non-Hodgkin's lymphoma

The mechanisms through which diet may influence the development of non-Hodgkin's lymphoma (NHL) are unclear but can be better understood by examining associations between nutrient consumption and NHL risk. Between 2000 and 2002, 591 NHL cases and 460 population-based controls in Sweden completed a semiquantitative food frequency questionnaire. Unconditional logistic regression was performed to estimate odds ratios and 95% confidence intervals for associations with nutrient intake; all statistical tests were two sided. Dietary intake of most macronutrients was not associated with risk of NHL or its common subtypes. Consumption of omega-3 or marine fatty acids was associated with decreased risk of NHL and chronic lymphocytic lymphoma, and dietary fiber was associated with lower risk of all subtypes examined. When the highest and the lowest quartiles of marine fat intake were compared, the odds ratio for NHL risk was 0.6 (95% confidence interval: 0.4, 0.9), ptrend=0.03; for dietary fiber intake, the corresponding odds ratio was 0.5 (95% confidence interval: 0.3, 0.7), ptrend<0.001. Dietary consumption of beta-carotene or alpha-tocopherol was associated with lower NHL risk, whereas intake of calcium or retinol was associated with increased NHL risk. Nutrients that affect inflammation, vitamin D activity, oxidative DNA damage, or DNA methylation may be associated with risk of NHL.

Body size, physical activity, and risk of Hodgkin's lymphoma in women

Few studies have examined the associations of body size and physical activity with the development of Hodgkin's lymphoma (HL) in women. In data from a population-based case-control study in women ages 19 to 79 years, we assessed the relation of self-report height, weight, body mass index (BMI), and strenuous physical activity to HL risk in 312 cases with diagnostic re-review and 325 random-digit dialed controls using logistic regression. Analyses were stratified by age group and tumor cell presence of EBV. After adjustment for social class measures, taller childhood and adult height were associated with higher HL risk. In women ages 19 to 44 years, HL risk was elevated for higher, but healthy, BMI values, whereas in women ages 45 to 79 years, associations with BMI were inverse. The odds of developing HL were lower with participation (versus nonparticipation) in strenuous physical activity in the past year [odds ratio (OR), 0.58; 95% confidence interval (95% CI), 0.39-0.87 in women 19-44 years; OR, 0.45; 95% CI, 0.19-1.06 in women 45-79 years] and throughout adult life, and with sports team membership (versus nonmembership) in high school and/or at ages 18 to 22 years. Results were similar in cases (n = 269) with and without tumor-cell EBV compared with controls, although the inverse association with physical activity was somewhat stronger for women with EBV-positive disease. These findings show that in women, body size and strenuous physical activity, both modifiable characteristics, are associated with HL risk in adult life possibly through immunologic, infectious, or genetic mechanisms.

The enigmatic epidemiology of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) has a unique and complex etiology that is not completely understood. Although NPC is rare in most populations, it is a leading form of cancer in a few well-defined populations, including natives of southern China, Southeast Asia, the Arctic, and the Middle East/North Africa. The distinctive racial/ethnic and geographic distribution of NPC worldwide suggests that both environmental factors and genetic traits contribute to its development. This review aims to summarize the current knowledge regarding the epidemiology of NPC and to propose new avenues of research that could help illuminate the causes and ultimately the prevention of this remarkable disease. Well-established risk factors for NPC include elevated antibody titers against the Epstein-Barr virus, consumption of salt-preserved fish, a family history of NPC, and certain human leukocyte antigen class I genotypes. Consumption of other preserved foods, tobacco smoking, and a history of chronic respiratory tract conditions may be associated with elevated NPC risk, whereas consumption of fresh fruits and vegetables and other human leukocyte antigen genotypes may be associated with decreased risk. Evidence for a causal role of various inhalants, herbal medicines, and occupational exposures is inconsistent. Other than dietary modification, no concrete preventive measures for NPC exist. Given the unresolved gaps in understanding of NPC, there is a clear need for large-scale, population-based molecular epidemiologic studies to elucidate how environmental, viral, and genetic factors interact in both the development and the prevention of this disease.

Dietary intake of phytoestrogens, estrogen receptor-beta polymorphisms and the risk of prostate cancer

BACKGROUND

The causes of prostate cancer are poorly understood, but genetic factors may be more important than for many other malignancies, and dietary phytoestrogens may be protective. Because phytoestrogens bind tightly to the estrogen receptor-beta, we conducted an epidemiologic investigation of synergistic effects between phytoestrogen intake and estrogen receptor-beta gene polymorphisms.

METHODS

We performed a population-based case-control study in Sweden. All participants reported their phytoestrogen intake and donated a blood sample. We identified four haplotype-tagging single nucleotide polymorphisms (htSNPs) and genotyped these htSNPs in 1314 prostate cancer patients and 782 controls. Odds ratios were estimated by multivariate logistic regression. Interactions between phytoestrogen intake and estrogen receptor-beta SNPs on prostate cancer risk were evaluated considering both multiplicative and additive effect scales.

RESULTS

We found a significant multiplicative interaction (P = 0.04) between dietary intake of phytoestrogens and a promoter SNP in the estrogen receptor-beta gene (rs 2987983-13950), but not with any of the three other htSNPs (P = 0.11, 0.69, 0.85). Among carriers of the variant promoter alleles, we found strong inverse associations with increasing intake of total phytoestrogens (odds ratio for highest vs. lowest quartile = 0.43; P for trend <0.001), isoflavonoids (odds ratio = 0.63; P for trend = 0.05), and coumestrol (odds ratio = 0.57; P for trend = 0.003). We found no association between phytoestrogens and prostate cancer among carriers homozygous for the wild-type allele (TT).

CONCLUSIONS

Our study provides strong evidence that high intake of phytoestrogens substantially reduce prostate cancer risk among men with specific polymorphic variation in the promoter region of the estrogen receptor-beta gene.

Variation in DNA repair genes ERCC2, XRCC1, and XRCC3 and risk of follicular lymphoma

The reasons for the positive association between skin cancer and non-Hodgkin's lymphoma are not known but may be due to common susceptibility involving suboptimal DNA repair. Therefore, we investigated selected polymorphisms and haplotypes in three DNA repair genes, previously associated with skin cancer and DNA repair capacity, in risk of follicular lymphoma, including possible gene interaction with cigarette smoking and sun exposure. We genotyped 19 single nucleotide polymorphisms (SNP) in the ERCC2, XRCC1, and XRCC3 genes in 430 follicular lymphoma patients and 605 controls within a population-based case-control study in Denmark and Sweden. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using unconditional logistic regression and haplotype associations were assessed with a global score test. We observed no associations between variation in the ERCC2 and XRCC1 genes and follicular lymphoma risk. In XRCC3, increased risk of follicular lymphoma was suggested for rare homozygotes of three SNPs [Rs3212024: OR, 1.8 (95% CI, 1.1-2.8); Rs3212038: OR, 1.5 (95% CI, 1.0-2.4); Rs3212090: OR, 1.5 (95% CI, 1.0-2.5)]. These results were strengthened in current cigarette smokers. However, evidence of differences in XRCC3 haplotype distributions between follicular lymphoma cases and controls was weak, both overall and in current smokers. We conclude that polymorphic variation in the XRCC3 gene, but not in ERCC2 or XRCC1, may be of importance for susceptibility to follicular lymphoma, perhaps primarily in current smokers. The link between skin cancer and follicular lymphoma is unlikely to be mediated through common variation in the studied DNA repair gene polymorphisms.

Dietary phytoestrogen, serum enterolactone and risk of prostate cancer: the cancer prostate Sweden study (Sweden)

OBJECTIVE

Based on evidence that phytoestrogens may protect against prostate cancer, we evaluated the associations between serum enterolactone concentration or dietary phytoestrogen intake and risk of prostate cancer.

METHODS

In our Swedish population-based case-control study, questionnaire-data were available for 1,499 prostate cancer cases and 1,130 controls, with serum enterolactone levels in a sub-group of 209 cases and 214 controls. Unconditional logistic regression was performed to estimate multivariate odds ratios (ORs) and 95% confidence intervals (CIs) for associations with risk of prostate cancer.

RESULTS

High intake of food items rich in phytoestrogens was associated with a decreased risk of prostate cancer. The OR comparing the highest to the lowest quartile of intake was 0.74 (95% CI: 0.57-0.95; p-value for trend: 0.01). In contrast, we found no association between dietary intake of total or individual lignans or isoflavonoids and risk of prostate cancer. Intermediate serum levels of enterolactone were associated with a decreased risk of prostate cancer. The ORs comparing increasing quartiles of serum enterolactone concentration to the lowest quartile were, respectively, 0.28 (95% CI: 0.15-0.55), 0.63 (95% CI: 0.35-1.14) and 0.74 (95% CI: 0.41-1.32).

CONCLUSIONS

Our results support the hypothesis that certain foods high in phytoestrogens are associated with a lower risk of prostate cancer.

Autoimmune and chronic inflammatory disorders and risk of non-Hodgkin lymphoma by subtype

BACKGROUND

Some autoimmune and chronic inflammatory disorders are associated with increased risks of non-Hodgkin lymphoma (NHL). Because different NHL subtypes develop at different stages of lymphocyte differentiation, associations of autoimmune and inflammatory disorders with specific NHL subtypes could lead to a better understanding of lymphomagenic mechanisms.

METHODS

In a population-based case-control study in Denmark and Sweden, 3055 NHL patients and 3187 matched control subjects were asked about their history of autoimmune and chronic inflammatory disorders, markers of severity, and treatment. Logistic regression with adjustment for study matching factors was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for NHL overall and for NHL subtypes.

RESULTS

Risks of all NHL were increased in association with rheumatoid arthritis (OR = 1.5, 95% CI = 1.1 to 1.9), primary Sjögren syndrome (OR = 6.1, 95% CI = 1.4 to 27), systemic lupus erythematosus (OR = 4.6, 95% CI = 1.0 to 22), and celiac disease (OR = 2.1, 95% CI = 1.0 to 4.8). All of these conditions were also associated with diffuse large B-cell lymphoma, and some were associated with marginal zone, lymphoplasmacytic, or T-cell lymphoma. Ever use of nonsteroidal anti-inflammatory drugs, systemic corticosteroids, and selected immunosuppressants was associated with risk of NHL in rheumatoid arthritis patients but not in subjects without rheumatoid arthritis. Also, multivariable adjustment for treatment had little impact on risk estimates. Psoriasis, sarcoidosis, and inflammatory bowel disorders were not associated with increased risk of NHL overall or of any NHL subtype.

CONCLUSIONS

Our results confirm the associations between certain autoimmune disorders and risk of NHL and suggest that the associations may not be general but rather mediated through specific NHL subtypes. These NHL subtypes develop during postantigen exposure stages of lymphocyte differentiation, consistent with a role of antigenic drive in autoimmunity-related lymphomagenesis.

Reliability of Self-Reported Family History of Cancer in a Large Case–Control Study of Lymphoma

BACKGROUND

Case-control studies of familial cancer risk traditionally rely on self-reported family history of cancer, which may bias results due to differential recall between case patients and control subjects. To evaluate the reliability of self-reported data, we analyzed questionnaire and registry-based data on familial cancer from a population-based case-control study of malignant lymphoma.

METHODS

All 1508 lymphoma case patients and 1229 control subjects completed a telephone interview assessing cancer in family members. Participants were linked to the Swedish Multi-Generation Register and Cancer Register to identify confirmed cancer diagnoses in first-degree relatives. The sensitivity and specificity of self-reported familial cancer were calculated among case patients and control subjects and were compared using logistic regression. All statistical tests were two-sided.

RESULTS

Lymphoma case patients reported a family history of any cancer with statistically significantly higher sensitivity than control subjects (0.85, 95% confidence interval [CI] = 0.83 to 0.87 and 0.80, 95% CI = 0.77 to 0.82, respectively) but with marginally lower specificity (0.89, 95% CI = 0.87 to 0.91 and 0.92, 95% CI = 0.90 to 0.94, respectively). The sensitivity of self-reporting familial cancers by site ranged from less than 0.20 for rare malignancies to nearly 0.75 for more common types, whereas specificity was generally 0.98 or greater. For most sites, the reliability of self-report was similar in patients and control subjects. However, patients reported familial hematopoietic cancer with statistically significantly higher sensitivity (0.60, 95% CI = 0.57 to 0.62) than control subjects (0.38, 95% CI = 0.35 to 0.40). Odds ratios for the association between familial cancer and risk of non-Hodgkin lymphoma were consistently higher when based on self-reported, compared with registry data-based, family history of any cancer or of hematopoietic cancer.

CONCLUSIONS

Reliability of self-reported family history of cancer varies between case patients and control subjects. Recall bias may thus produce biased results in case-control studies of familial cancer risk.

Cancer risk among patients with condylomata acuminata

Condylomata acuminata have been shown to increase the risk of anogenital cancers. However, previous studies have been of limited sample size and/or short follow-up duration, which prevent precise estimates of long-term excess risk, especially for specific cancer sites. We estimated the risk of specific cancers in a large cohort of hospitalized patients with condylomata acuminata, as recorded in the Swedish Inpatient Register between 1965 and 1999. Altogether, 10,971 patients (1,685 men and 9,286 women) were followed through 1999 for a median of 13 years. The standardized incidence ratio (SIR)--the ratio of the observed number of cancers to the number expected on the basis of the incidence in the Swedish population at large--was used as a measure of relative risk. After excluding the first-year of follow-up, we observed 43 cases of anogenital cancer in women, and 7 cases in men. Risks were elevated for cancers of the vulva (N = 13, SIR = 10.2, 95% confidence interval (CI) = 5.4-17.4), vagina (N = 4, SIR = 12.0, 95% CI = 3.3-30.7) and penis (N = 5, SIR = 21.9, 95% CI = 7.1-51.2). There was a moderate excess risk of cervical cancer in situ (N = 259, SIR = 1.9, 95% CI = 1.7-2.1), but not invasive cervical cancer. Excess risks of esophageal, buccal cavity, nonmelanoma skin, lung and bladder cancers, and Hodgkin and non-Hodgkin lymphoma, were also observed in both men and women. In conclusion, condylomata acuminata are strongly associated with increased risk of cancers of the vulva, vagina, penis and anus, as well as some nonanogenital malignancies, but not invasive cervical cancer.

Association of frequent consumption of fatty fish with prostate cancer risk is modified by COX-2 polymorphism

Dietary intake of marine fatty acids from fish may protect against prostate cancer development. We studied this association and whether it is modified by genetic variation in cyclooxygenase (COX)-2, a key enzyme in fatty acid metabolism and inflammation. We assessed dietary intake of fish among 1,499 incident prostate cancer cases and 1,130 population controls in Sweden. Five single nucleotide polymorphisms (SNPs) were identified and genotyped in available blood samples for 1,378 cases and 782 controls. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by multivariate logistic regression. Multiplicative and additive interactions between fish intake and COX-2 SNPs on prostate cancer risk were evaluated. Eating fatty fish (e.g., salmon-type fish) once or more per week, compared to never, was associated with reduced risk of prostate cancer (OR: 0.57, 95% CI: 0.43-0.76). The OR comparing the highest to the lowest quartile of marine fatty acids intake was 0.70 (95% CI: 0.51-0.97). We found a significant interaction (p < 0.001) between salmon-type fish intake and a SNP in the COX-2 gene (rs5275: +6365 T/C), but not with the 4 other SNPs examined. We found strong inverse associations with increasing intake of salmon-type fish among carriers of the variant allele (OR for once per week or more vs. never = 0.28, 95% CI: 0.18-0.45; p(trend) < 0.01), but no association among carriers of the more common allele. Frequent consumption of fatty fish and marine fatty acids appears to reduce the risk of prostate cancer, and this association is modified by genetic variation in the COX-2 gene.

Medication use and risk of non-Hodgkin's lymphoma

Conflicting results from previous epidemiologic studies shed little light on whether medication use is associated with risk of non-Hodgkin's lymphoma (NHL). To investigate this question, the authors conducted a population-based case-control study in Denmark and Sweden from 1999 to 2002, including 3,055 incident NHL cases and 3,187 controls. Participants reported their past use of medications and history of particular medical conditions. Unconditional logistic regression was used to estimate multivariate odds ratios and 95% confidence intervals for the associations between medication use and risk of NHL; all statistical tests were two sided. Use of antibiotics more than 10 times during adulthood was positively associated with risk of NHL and most major NHL subtypes; when users were compared with nonusers, the odds ratio for NHL was 1.8 (95% confidence interval: 1.4, 2.3); p(trend) for total antibiotic use <0.001. In addition, high cumulative use of nonsteroidal anti-inflammatory drugs was marginally associated with elevated NHL risk. Other medications evaluated were not associated with risk of NHL or its most common subtypes. Findings suggest that inflammation, infections, susceptibility to infections, and/or use of antibiotics or nonsteroidal anti-inflammatory drugs to treat these conditions may increase the risk of NHL. However, most of the medications examined were not associated with NHL risk.

Family history of hematopoietic malignancy and risk of lymphoma

BACKGROUND

A family history of hematopoietic malignancy is associated with an increased risk of non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL), although the magnitude of the relative risk is unclear. We estimated the association between familial hematopoietic cancer and risk of lymphoma using validated, registry-based family data, and we also investigated whether associations between some environmental exposures and risk of lymphoma vary between individuals with and without such a family history.

METHODS

In a population-based case-control study of malignant lymphoma, 1506 case patients and 1229 control subjects were linked to the Swedish Multi-Generation Register and then to the Swedish Cancer Register to ascertain history of cancer in first-degree relatives of patients with malignant lymphoma. Multiple logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations with the risk of lymphoma.

RESULTS

A history of hematopoietic malignancy in any first-degree relative was associated with an increased risk of all NHL (OR = 1.8, 95% CI = 1.2 to 2.5), common B-cell NHL subtypes, and HL. Relative risks were generally stronger in association with sibling hematopoietic cancer (OR for all NHL = 3.2, 95% CI = 1.3 to 7.6) than with parental hematopoietic cancer (OR = 1.6, 95% CI = 1.1 to 2.3). A family history of NHL or chronic lymphocytic leukemia (CLL) was associated with an increased risk of several NHL subtypes and HL, whereas familial multiple myeloma was associated with a higher risk of follicular lymphoma. There was no statistically significant heterogeneity in NHL risk associations with environmental factors between individuals with and without familial hematopoietic malignancy.

CONCLUSIONS

The increased risk of NHL and HL among individuals with a family history of hematopoietic malignancy was approximately twofold for both lymphoma types. There was no evidence that etiologic associations varied between familial NHL and nonfamilial NHL.