Serum concentrations of DDE, PCBs, and other persistent organic pollutants and mammographic breast density in Triana, Alabama, a highly exposed population

INTRODUCTION

Although some persistent organic pollutants (POPs) are considered human carcinogens, results from studies evaluating exposures and breast cancer risk have been inconsistent, potentially related to varying ages at exposure. Additionally, few studies evaluated the association between POPs exposure and mammographic breast density (MBD), an intermediate biomarker of breast cancer risk. We carried out a cross-sectional study to investigate associations between serum POPs concentrations and MBD measured in 1998 in female residents of Triana, Alabama, in a predominately African American population with high POPs exposures, particularly to p,p'-DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane).

METHODS

We measured lipid-adjusted serum concentrations (ng/g lipid) of p,p'-DDT and its main metabolite p,p'-DDE (1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene), polychlorinated biphenyls (PCBs), β-hexachlorocyclohexane (β-HCCH), heptachlor epoxide, oxychlordane, trans-nonachlor, mirex, and aldrin for each woman in our study (n = 210). We also measured two MBD metrics, percent MBD (%MBD) and area of MBD (aMBD). Using adjusted Spearman correlation coefficients (rs) we evaluated correlations between %MBD and aMBD with individual POPs in the overall population and by age group (19-40, 41-54, and 55-91 years) and also estimated adjusted mean measures of MBD with 95% confidence intervals across tertiles of analytes using generalized linear models (GLM). We calculated p-values for multiplicative interaction by age group using GLM. Additional analyses excluded women with current hormone replacement therapy (HRT) use and evaluated early-life exposure (prior to age 18) during the heaviest contamination period in Triana (1947-90).

RESULTS

Among all women, we found no correlation between p,p'-DDE and %MBD, but after age stratification and exclusion of HRT users, there was a suggestion of a difference by age group, with younger women having a weak positive correlation (rs = 0.12, p = 0.37) and older women having a weak negative correlation (rs = -0.12, p = 0.43); pinteraction = 0.06. In contrast, PCBs were weakly positively correlated with %MBD among all women, with the correlation magnitudes increasing after excluding current HRT users (rs-total PCBs = 0.17, p = 0.03). After age stratification and exclusion of HRT users, correlations for PCBs were higher among younger and middle-age women, with only a handful of these correlations being statistically significant. For β-HCCH, the strongest finding was a negative correlation among older women (rs = -0.26, p = 0.07). Correlations were positive predominantly in the younger age group for heptachlor epoxide (rs = 0.27, p = 0.04), oxychlordane (rs = 0.35, p = 0.006), and trans-nonachlor (rs = 0.37, p = 0.003), and largely null for the middle and older age groups; pinteraction range: 0.03-0.05. Similar patterns were found in GLM analyses using tertiles of exposure and aMBD as the metric for MBD. Women exposed during the heaviest chemical contamination period in Triana prior to age 18 had positive correlations between %MBD and PCBs, heptachlor epoxide, mirex, oxychlordane, and trans-nonachlor.

CONCLUSIONS

In this population, despite high exposures to p,p'-DDT and thus high serum concentrations of its main metabolite, p,p'-DDE, we did not find strong evidence of a positive association with MBD. In fact, there was some evidence of a negative association among older women for p,p'-DDE; a similar pattern was found for β-HCCH. However, younger women with higher serum levels of PCBs, heptachlor epoxide, oxychlordane, and trans-nonachlor, who were likely exposed in early life, had higher MBD. These findings should be replicated in larger studies.

Diabetes and Overall Survival among Breast Cancer Patients in the U.S. Military Health System

Background: Although research suggests that type II diabetes mellitus (DM-2) is associated with overall and breast cancer-specific decreased survival, most prior studies of breast cancer survival investigated the effect of preexisting DM-2 without assessing the effect of DM-2 diagnosed at or after breast cancer diagnosis. This study examined the relationship between DM-2 diagnosed before and after breast cancer diagnosis and overall survival.Methods: This study uses linked Department of Defense cancer registry and medical claims data from 9,398 women diagnosed with breast cancer between 1998 and 2007. Cox proportional hazards models were used to assess the association between DM-2 and overall survival.Results: Our analyses showed that women with DM-2 diagnosed before breast cancer diagnosis tended to have a higher risk of mortality compared with women without diabetes [HR = 1.17; 95% confidence interval (CI), 0.95-1.44] after adjustment for potential confounders. Similarly, patients diagnosed with DM-2 at or after breast cancer diagnosis had increased mortality compared with women without DM-2 (HR = 1.39; 95% CI, 1.16-1.66). The similar tendency was also observed among most subgroups when results were stratified by race, menopausal status, obesity, tumor hormone receptor status, and stage.Conclusions: Using data from a health system that provides universal health care to its beneficiaries, this study showed an increased risk of death associated with DM-2, regardless of whether it was diagnosed before or at/after breast cancer diagnosis.Impact: These results suggest the potential effects of factors independent of the timing of DM-2 clinical diagnosis on the association of DM-2 with overall survival. Cancer Epidemiol Biomarkers Prev; 27(1); 50-57. ©2017 AACR.

Metformin use and survival after non-small cell lung cancer: A cohort study in the US Military health system

Research suggests that metformin may be associated with improved survival in cancer patients with type II diabetes. This study assessed whether metformin use after non-small cell lung cancer (NSCLC) diagnosis is associated with overall survival among type II diabetic patients with NSCLC in the U.S. military health system (MHS). The study included 636 diabetic patients with histologically confirmed NSCLC diagnosed between 2002 and 2007, identified from the linked database from the Department of Defense's Central Cancer Registry (CCR) and the Military Health System Data Repository (MDR). Time-dependent multivariate Cox proportional hazards models were used to assess the association between metformin use and overall survival during follow-up. Among the 636 patients, 411 died during the follow-up. The median follow-up time was 14.6 months. Increased post-diagnosis cumulative use (per 1 year of use) conferred a significant reduction in mortality (adjusted hazard ratio (HR) = 0.76; 95% CI = 0.65-0.88). Further analysis by duration of use revealed that compared to non-users, the lowest risk reduction occurred among patients with the longest duration of use (i.e. use for more than 2 years) (HR = 0.19; 95% CI = 0.09-0.40). Finally, the reduced mortality was particularly observed only among patients who also used metformin before lung cancer diagnosis and among patients at early stage of diagnosis. Prolonged duration of metformin use in the study population was associated with improved survival, especially among early stage patients. Future research with a larger number of patients is warranted.

Exposure-response relationships for select cancer and non-cancer health outcomes in a cohort of U.S. firefighters from San Francisco, Chicago and Philadelphia (1950-2009)

OBJECTIVES

To examine exposure-response relationships between surrogates of firefighting exposure and select outcomes among previously studied US career firefighters.

METHODS

Eight cancer and four non-cancer outcomes were examined using conditional logistic regression. Incidence density sampling was used to match each case to 200 controls on attained age. Days accrued in firefighting assignments (exposed-days), run totals (fire-runs) and run times (fire-hours) were used as exposure surrogates. HRs comparing 75th and 25th centiles of lagged cumulative exposures were calculated using loglinear, linear, log-quadratic, power and restricted cubic spline general relative risk models. Piecewise constant models were used to examine risk differences by time since exposure, age at exposure and calendar period.

RESULTS

Among 19,309 male firefighters eligible for the study, there were 1333 cancer deaths and 2609 cancer incidence cases. Significant positive associations between fire-hours and lung cancer mortality and incidence were evident. A similar relation between leukaemia mortality and fire-runs was also found. The lung cancer associations were nearly linear in cumulative exposure, while the association with leukaemia mortality was attenuated at higher exposure levels and greater for recent exposures. Significant negative associations were evident for the exposure surrogates and colorectal and prostate cancers, suggesting a healthy worker survivor effect possibly enhanced by medical screening.

CONCLUSIONS

Lung cancer and leukaemia mortality risks were modestly increasing with firefighter exposures. These findings add to evidence of a causal association between firefighting and cancer. Nevertheless, small effects merit cautious interpretation. We plan to continue to follow the occurrence of disease and injury in this cohort.

Adjuvant radioactive iodine use among differentiated thyroid cancer patients in the military health system

OBJECTIVE

Adjuvant radioactive iodine (RAI) for the treatment of differentiated thyroid cancer has been associated with better prognosis, but no consensus has been reached on the best practices for RAI. Limited data on RAI use and factors associated with the receipt of postoperative RAI in the general population are available and, to our knowledge, no data on RAI use among the U.S. Department of Defense (DoD) beneficiaries.

METHODS

Among 3,002 beneficiaries with differentiated thyroid cancer, who underwent total/near-total thyroidectomy between 1998 and 2007, logistic regression identified factors associated with RAI and examined effect modification by age and tumor size.

RESULTS

Fifty-two percent of patients received RAI. Receipt of RAI was more likely among beneficiaries who were diagnosed between 2004 and 2007, active duty members, had indirect care, and more advanced disease, and less likely among those affiliated with the Air Force or had unknown medical coverage. In addition, receipt of RAI significantly varied by tumor size among patients with regional lymph node metastasis.

CONCLUSION

Among DoD beneficiaries, adjuvant RAI use was associated with clinical and nonclinical factors. Although evidence of effect modification between the recipient of RAI by tumor size was apparent, future research with a larger sample size is warranted to confirm results of this study.

Colon cancer lymph node evaluation among military health system beneficiaries: an analysis by race/ethnicity

BACKGROUND

The number of lymph nodes examined during colon cancer surgery falls below nationally recommended guidelines in the general population, with Blacks and Hispanics less likely to have adequate nodal evaluation in comparison to Whites. The Department of Defense's (DoD) Military Health System (MHS) provides equal access to medical care for its beneficiaries, regardless of racial/ethnic background. This study aimed to investigate whether racial/ethnic treatment differences exist in the MHS, an equal-access medical care system.

METHODS

Linked data from the DoD cancer registry and administrative claims databases were used and included 2,155 colon cancer cases. Multivariate logistic regression assessed the association between race/ethnicity and the number of lymph nodes examined (<12 and ≥12) overall and for stratified analyses.

RESULTS

No overall racial/ethnic differences in the number of lymph nodes examined was identified. Further stratified analyses yielded similar results, except potential racial/ethnic differences were found among persons with poorly differentiated tumors, where non-Hispanic Blacks tended to be less likely to have ≥12 lymph nodes dissected (odds ratio 0.34; 95 % confidence interval 0.14-0.80; p = 0.01) compared with non-Hispanic Whites.

CONCLUSION

Racial/ethnic disparities in the number of lymph nodes evaluated among patients with colon cancer were not apparent in an equal-access healthcare system. However, among poorly differentiated tumors there might be racial/ethnic differences in nodal yield, suggesting the possible effects of factors other than access to healthcare.

Breast reconstruction after mastectomy among Department of Defense beneficiaries by race

BACKGROUND

Postmastectomy breast reconstruction increased approximately 20% between 1998 and 2008 in the United States and has been found to improve body image, self-esteem, and quality of life. These procedures, however, tend to be less common among minority women, which may be due to variations in health care access. The Department of Defense provides equal health care access, thereby affording an exceptional environment in which to assess whether racial variations persist when access to care is equal.

METHODS

Linked Department of Defense cancer registry and medical claims data were used. The receipt of reconstruction was compared between white women (n = 2974) and black women (n = 708) who underwent mastectomies to treat incident histologically confirmed breast cancer diagnosed from 1998 through 2007.

RESULTS

During the study period, postmastectomy reconstruction increased among both black (27.3% to 40.0%) and white (21.8% to 40.6%) female patients with breast cancer. Receipt of reconstruction did not vary significantly by race (odds ratio, 0.93; 95% confidence interval, 0.76-1.15). Reconstruction decreased significantly with increasing age, tumor stage, and receipt of radiotherapy and was significantly more common in more recent years and among active service women, TRICARE Prime (health maintenance organization) beneficiaries, and women whose sponsor was an officer.

CONCLUSIONS

The receipt of breast reconstruction did not vary by race within this equal-access health system, indicating that the racial disparities reported in previous studies may have been due in part to variations in access to health care. Additional research to determine why a large percentage of patients with breast cancer do not undergo reconstruction might be beneficial, particularly because these procedures have been associated with noncosmetic benefits.

Abstract A64: Colon cancer lymph node evaluation among Military Health System beneficiaries: An analysis by race/ethnicity

Introduction: The number of lymph nodes examined during colon cancer surgery falls below nationally recommended guidelines in the general population, with blacks and Hispanics less likely to have adequate nodal evaluation in comparison to whites. The Department of Defense's (DoD's) Military Health System (MHS) provides equal access to medical care for its beneficiaries, regardless of racial/ethnic background. Thus, the MHS provided an excellent opportunity to investigate whether racial/ethnic differences exist in an equal access medical care system.

Methods: Linked data from the DoD cancer registry and administrative claims databases were used and included 2,155 colon cancer cases. Multivariate logistic regression assessed the association between race/ethnicity and the number of lymph nodes examined (&lt;12 and ≥ 12) overall and for stratified analyses.

Results: No overall racial/ethnic difference in the number of lymph nodes examined was identified. Further stratified analyses yielded similar, except potential racial/ethnic differences were found among persons with poorly differentiated tumors, where non-Hispanic blacks (NHBs) tended to be less likely to have ≥12 lymph nodes dissected (OR = 0.31, 95% CI, 0.13-0.74) compared to non-Hispanic whites.

Conclusion: Racial/ethnic disparities in the number of lymph nodes evaluated among patients with colon cancer were not apparent in an equal-access healthcare system. However, among poorly differentiated tumors, there might be racial/ethnic differences in nodal yield, suggesting the possible effects of factors other than access to healthcare.

Citation Format: Abegail A. Gill, Lindsey Enewold, Shelia H. Zahm, Craig D. Shriver, Alexander Stojadinovic, Katherine A. McGlynn, Kangmin Zhu. Colon cancer lymph node evaluation among Military Health System beneficiaries: An analysis by race/ethnicity. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr A64.

Mortality and cancer incidence in a pooled cohort of US firefighters from San Francisco, Chicago and Philadelphia (1950-2009)

OBJECTIVES

To examine mortality patterns and cancer incidence in a pooled cohort of 29 993 US career firefighters employed since 1950 and followed through 2009.

METHODS

Mortality and cancer incidence were evaluated by life table methods with the US population referent. Standardised mortality (SMR) and incidence (SIR) ratios were determined for 92 causes of death and 41 cancer incidence groupings. Analyses focused on 15 outcomes of a priori interest. Sensitivity analyses were conducted to examine the potential for significant bias.

RESULTS

Person-years at risk totalled 858 938 and 403 152 for mortality and incidence analyses, respectively. All-cause mortality was at expectation (SMR=0.99, 95% CI 0.97 to 1.01, n=12 028). There was excess cancer mortality (SMR=1.14, 95% CI 1.10 to 1.18, n=3285) and incidence (SIR=1.09, 95% CI 1.06 to 1.12, n=4461) comprised mainly of digestive (SMR=1.26, 95% CI 1.18 to 1.34, n=928; SIR=1.17, 95% CI 1.10 to 1.25, n=930) and respiratory (SMR=1.10, 95% CI 1.04 to 1.17, n=1096; SIR=1.16, 95% CI 1.08 to 1.24, n=813) cancers. Consistent with previous reports, modest elevations were observed in several solid cancers; however, evidence of excess lymphatic or haematopoietic cancers was lacking. This study is the first to report excess malignant mesothelioma (SMR=2.00, 95% CI 1.03 to 3.49, n=12; SIR=2.29, 95% CI 1.60 to 3.19, n=35) among US firefighters. Results appeared robust under differing assumptions and analytic techniques.

CONCLUSIONS

Our results provide evidence of a relation between firefighting and cancer. The new finding of excess malignant mesothelioma is noteworthy, given that asbestos exposure is a known hazard of firefighting.

Surveillance mammography among female Department of Defense beneficiaries: a study by race and ethnicity

BACKGROUND

Annual surveillance mammography is recommended after a diagnosis of breast cancer. Previous studies have suggested that surveillance mammography varies by demographics and initial tumor characteristics, which are related to an individual's access to health care. The Military Health System of the Department of Defense provides beneficiaries with equal access health care and thus offers an excellent opportunity to assess whether racial differences in surveillance mammography persist when access to care is equal.

METHODS

Among female beneficiaries with a history of breast cancer, logistic regression was used to assess racial/ethnic variations in the use of surveillance mammography during 3 periods of 12 months each, beginning 1 year after diagnosis adjusting for demographic, tumor, and health characteristics.

RESULTS

The rate of overall surveillance mammography decreased from 70% during the first year to 59% during the third year (P < .01). Although there was an overall tendency for surveillance mammography to be higher among minority women compared with non-Hispanic white women, after adjusting for covariates, the difference was found to be significant only during the first year among black women (odds ratio [OR], 1.46; 95% confidence interval [95% CI], 1.10-1.95) and the second year among Asian/Pacific Islander (OR, 2.29; 95%CI, 1.52-3.44) and Hispanic (OR, 1.92; 95%CI, 1.17-3.18) women. When stratified by age at diagnosis and type of breast cancer surgery performed, significant racial differences tended to be observed among younger women (aged < 50 years) and only among women who had undergone mastectomies.

CONCLUSIONS

Minority women were equally or more likely than non-Hispanic white women to receive surveillance mammography within the Military Health System. The racial disparities in surveillance mammography reported in other studies were not observed in a system with equal access to health care.

Breast conserving surgery versus mastectomy: the influence of comorbidities on choice of surgical operation in the Department of Defense health care system

BACKGROUND

Studies on the effect of comorbidities on breast cancer operation have been limited and inconsistent. This study investigated whether pre-existing comorbidities influenced breast cancer surgical operation in an equal access health care system.

METHODS

This study was based on linked Department of Defense cancer registry and medical claims data. The study subjects were patients diagnosed with stage I to III breast cancer during 2001 to 2007. Logistic regression was used to determine if comorbidity was associated with operation type and time between diagnosis and operation.

RESULTS

Breast cancer patients with comorbidities were more likely to receive mastectomy (odds ratio [OR] = 1.27; 95% confidence interval [CI], 1.14 to 1.42) than breast conserving surgery plus radiation. Patients with comorbidities were also more likely to delay having operation than those without comorbidities (OR = 1.27; 95% CI, 1.14 to 1.41).

CONCLUSIONS

In an equal access health care system, comorbidity was associated with having a mastectomy and with a delay in undergoing operation.

Cigarette smoking and risk of Hodgkin lymphoma and its subtypes: a pooled analysis from the International Lymphoma Epidemiology Consortium (InterLymph)

BACKGROUND

The etiology of Hodgkin lymphoma (HL) remains incompletely characterized. Studies of the association between smoking and HL have yielded ambiguous results, possibly due to differences between HL subtypes.

PATIENTS AND METHODS

Through the InterLymph Consortium, 12 case-control studies regarding cigarette smoking and HL were identified. Pooled analyses on the association between smoking and HL stratified by tumor histology and Epstein-Barr virus (EBV) status were conducted using random effects models adjusted for confounders. Analyses included 3335 HL cases and 14 278 controls.

RESULTS

Overall, 54.5% of cases and 57.4% of controls were ever cigarette smokers. Compared with never smokers, ever smokers had an odds ratio (OR) of HL of 1.10 [95% confidence interval (CI) 1.01-1.21]. This increased risk reflected associations with mixed cellularity cHL (OR = 1.60, 95% CI 1.29-1.99) and EBV-positive cHL (OR = 1.81, 95% CI 1.27-2.56) among current smokers, whereas risk of nodular sclerosis (OR = 1.09, 95% CI 0.90-1.32) and EBV-negative HL (OR = 1.02, 95% CI 0.72-1.44) was not increased.

CONCLUSION

These results support the notion of etiologic heterogeneity between HL subtypes, highlighting the need for HL stratification in future studies. Even if not relevant to all subtypes, our study emphasizes that cigarette smoking should be added to the few modifiable HL risk factors identified.

Race and colon cancer survival in an equal-access health care system

Studies have shown that Whites have a higher colorectal cancer survival rate than Blacks. However, it is unclear whether racial disparities result from unequal access to medical care or factors other than health care access or both. This study assessed whether non-Hispanic Whites (NHW) and non-Hispanic Blacks (NHB) differ in colon cancer survival in an equal-access health care system and examined whether racial differences varied by demographic and tumor characteristics. The study included 2,537 Military Health System patients diagnosed with colon cancer between 1998 and 2007. Median follow-up time was 31.4 months. Cox models estimated HRs and 95% confidence intervals (CI) for race, overall and stratified by age at diagnosis, sex, and tumor stage. No difference in overall survival (OS) between NHWs and NHBs was observed in general. However, among patients younger than 50 years old, NHBs experienced significantly worse OS than NHWs (HR: 2.03, 95% CI: 1.30-3.19). Furthermore, stratification by sex and tumor stage showed that this racial disparity was confined to women (HR: 2.87; 95% CI: 1.35-6.11) and patients with distant stage disease (HR: 2.45; 95% CI: 1.15-5.22) in this age group. When medical care is equally available to NHWs and NHBs, similar overall colon cancer survival was observed; however, evidence of racial differences in survival was apparent for patients younger than 50 years old. This study suggests that factors other than access to care may be related to racial disparities in colon cancer survival among younger, but not older, patients.

Abstract B99: Colon cancer treatment: Are there racial disparities in an equal-access healthcare system?

Purpose: Accessibility to medical care may be the most important factor influencing differences in colon cancer treatment among whites and blacks. This study assessed whether racial disparities in colon cancer surgery and chemotherapy existed in an equal access healthcare system. Additionally, we sought to examine whether racial differences varied by tumor stage.

Methods: Patients included 2,570 non-Hispanic whites and non-Hispanic blacks with colon cancer diagnosed from 1998 to 2007. Logistic regression was used to assess the associations between race and the receipt of colon cancer surgery or chemotherapy, while controlling for available potential confounders, both overall and stratified by tumor stage.

Results: Univariate analysis revealed that there were no racial differences in surgery but that non-Hispanic blacks were more likely to receive chemotherapy than non-Hispanic whites. However, after multivariate adjustment, the odds of receiving colon cancer surgery and chemotherapy were similar between the two racial groups and did not vary by tumor stage.

Conclusion: When access to medical care is equal, racial disparities in the receipt of colon cancer surgery and chemotherapy were not apparent. Thus, it is possible that equal access to care is the driving force behind racial disparities in cancer treatment in the general population.

Citation Format: Abegail Andaya, Lindsey Enewold, Shelia H. Zahm, Craig D. Shriver, Joan Warren, Alexander Stojadinovic, Katherine McGlynn, Kangmin Zhu. Colon cancer treatment: Are there racial disparities in an equal-access healthcare system? [abstract]. In: Proceedings of the Eleventh Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2012 Oct 16-19; Anaheim, CA. Philadelphia (PA): AACR; Cancer Prev Res 2012;5(11 Suppl):Abstract nr B99.

Lung cancer survival among black and white patients in an equal access health system

BACKGROUND

Racial disparities in lung cancer outcomes have been observed in the general population. However, it is unclear whether survival differences persist when patients have equal access to health care. Our objective was to determine if lung cancer survival differed among black and white patients in the U.S. Military Health System (MHS), an equal access health care system.

METHODS

The study subjects were 10,181 black and white patients identified through the Department of Defense's Automated Central Tumor Registry, who were 20 years old or more and diagnosed with lung cancer between 1990 and 2003. Racial differences in all-cause survival were examined using the Kaplan-Meier method and Cox proportional hazards regression models stratified by histology. For comparison, survival rates in the general population were calculated using Surveillance Epidemiology and End Results-9 data.

RESULTS

Analyses included 9,154 white and 1,027 black patients: 1,834 small cell lung cancers, 3,876 adenocarcinomas, 2,741 squamous cell carcinomas, and 1,730 large cell carcinomas. Although more favorable crude survival was observed among black patients than white patients with small cell lung cancer (P = 0.04), survival was similar between the two groups after covariate adjustment. Racial differences in survival were nonsignificant for adenocarcinomas, squamous cell carcinomas, and large cell carcinomas. Survival rates appeared to be better in the MHS than in the general population.

CONCLUSIONS AND IMPACT

All-cause survival was similar among black and white lung cancer patients in the MHS. Providing equal access to health care may eliminate racial disparities in lung cancer survival while improving the outcome of all cases.

Oral contraceptive use among women in the military and the general U.S. population

OBJECTIVE

To compare oral contraceptive (OC) use during a 12-month period among women aged 18-39 years in the U.S. military and the general U.S. population using data from the Military Health System Management Analysis and Reporting Tool (M2) and the National Health and Nutrition Examination Survey (NHANES), respectively.

METHODS

OC use was age adjusted to the 2000 U.S. Census population. Comparisons between the military (n = 83,181) and the general population (unweighted n = 360), as well as between the military branches, were conducted overall and stratified by age, race/ethnicity, and marital status.

RESULTS

OC use was higher in the military (34%) than in the general population (29%, p < 0.05). This difference increased with age and was most pronounced among Hispanics (military, 32.2%; general population, 19.8%). Within the military, OC use was highest in the Air Force (39%) and lowest in the Army (30%, p < 0.05).

CONCLUSIONS

These findings suggest that OC use differs between the military and the general population and within the military by service branch. Further studies that assess whether OC use is related to variations in health outcomes between these two populations and within the military are warranted.

Thyroid cancer incidence among active duty U.S. military personnel, 1990-2004

BACKGROUND

Increases in thyroid papillary carcinoma incidence rates have largely been attributed to heightened medical surveillance and improved diagnostics. We examined papillary carcinoma incidence in an equal-access health care system by demographics that are related to incidence.

METHODS

Incidence rates during 1990-2004 among white and black individuals aged 20 to 49 years in the military, and the general U.S. population were compared using data from the Department of Defense's Automated Central Tumor Registry and the National Cancer Institute's Surveillance Epidemiology and End Results (SEER-9) program.

RESULTS

Incidence was significantly higher in the military than in the general population among white women [incidence rate ratio (IRR) = 1.42; 95% confidence interval (CI), 1.25-1.61], black women (IRR = 2.31; 95% CI, 1.70-2.99), and black men (IRR = 1.69, 95% CI, 1.10-2.50). Among whites, differences between the two populations were confined to rates of localized tumors (women: IRR = 1.73, 95% CI, 1.47-2.00; men: IRR = 1.51, 95% CI, 1.30-1.75), which may partially be due to variation in staging classification. Among white women, rates were significantly higher in the military regardless of tumor size and rates rose significantly over time both for tumors ≤ 2 cm (military: IRR = 1.64, 95% CI, 1.18-2.28; general population: IRR = 1.55, 95% CI, 1.45-1.66) and > 2 cm (military: IRR = 1.74, 95% CI, 1.07-2.81; general population: IRR = 1.48, 95% CI, 1.27-1.72). Among white men, rates increased significantly only in the general population. Incidence also varied by military service branch.

CONCLUSIONS

Heightened medical surveillance does not appear to fully explain the differences between the two populations or the temporal increases in either population.

IMPACT

These findings suggest the importance of future research into thyroid cancer etiology.

Racial variation in tumor stage at diagnosis among Department of Defense beneficiaries

BACKGROUND

Tumor stage at diagnosis often varies by racial/ethnic group, possibly because of inequitable health care access. Within the Department of Defense (DoD) Military Health System, beneficiaries have equal health care access. The objective of this study was to determine whether tumor stage differed between whites and blacks with breast, cervical, colorectal, and prostate cancers, which have effective screening regimens, based on data from the DoD Automated Cancer Tumor Registry from 1990 to 2003.

METHODS

Distributions of tumor stage (localized vs nonlocalized) between whites and blacks in the military were compared stratified by sex, active duty status, and age at diagnosis. Logistic regression was used to further adjust for age, marital status, year of diagnosis, geographic region, military service branch, and tumor grade. Distributions of tumor stage were then compared between the military and general populations.

RESULTS

Racial differences in the distribution of stage were significant only among nonactive duty beneficiaries. After adjusting for covariates, earlier stages of breast cancer after age 49 years and prostate cancer after age 64 years were significantly more common among white than black nonactive duty beneficiaries (P < .05), although the absolute difference was minimal for prostate cancer. Racial differences in stage for cervical and colorectal cancers were not significant after adjustment. Compared with the general population, racial differences in the military were similar or were slightly attenuated.

CONCLUSIONS

Racial disparities in stage at diagnosis were apparent in the DoD equal-access health care system among older nonactive duty beneficiaries. Socioeconomic status, supplemental insurance, cultural beliefs, and biologic factors may be related to these results.

Racial variation in breast cancer treatment among Department of Defense beneficiaries

BACKGROUND

Although the overall age-adjusted incidence rates for female breast cancer are higher among whites than blacks, mortality rates are higher among blacks. Many attribute this discrepancy to disparities in health care access and to blacks presenting with later stage disease. Within the Department of Defense (DoD) Military Health System, all beneficiaries have equal access to health care. The aim of this study was to determine whether female breast cancer treatment varied between white and black patients in the DoD system.

METHODS

The study data were drawn from the DoD cancer registry and medical claims databases. Study subjects included 2308 white and 391 black women diagnosed with breast cancer between 1998 and 2000. Multivariate logistic regression analyses that controlled for demographic factors, tumor characteristics, and comorbidities were used to assess racial differences in the receipt of surgery, chemotherapy, and hormonal therapy.

RESULTS

There was no significant difference in surgery type, particularly when mastectomy was compared with breast-conserving surgery plus radiation (blacks vs whites: odds ratio [OR], 1.1; 95% confidence interval [CI], 0.8-1.5). Among those with local stage tumors, blacks were as likely as whites to receive chemotherapy (OR, 1.2; 95% CI, 0.9-1.7) and hormonal therapy (OR, 1.0; 95% CI, 0.6-1.4). Among those with regional stage tumors, blacks were significantly less likely than whites to receive chemotherapy (OR, 0.4; 95% CI, 0.2-0.7) and hormonal therapy (OR, 0.5; 95% CI, 0.3-0.8).

CONCLUSIONS

Even within an equal access health care system, stage-related racial variations in breast cancer treatment are evident. Studies that identify driving factors behind these within-stage racial disparities are warranted.

Polymorphisms in integrin genes and lymphoma risk

Immune deficiency is one of the best characterized and strongest known risk factors for non-Hodgkin lymphoma (NHL). We studied the association between single nucleotide polymorphisms (SNPs) in integrin genes that are important components in human innate immunity and the risk of NHL in a population-based case-control study of women in Connecticut, USA. A total of 373 tag SNPs in 33 gene regions were included in the analysis of 448 cases and 525 controls. The ADAM19 rs11466782 SNP was associated with an increased risk of lymphoma (OR, 1.73; 95% CI, 1.28-2.35; Padditive=0.0004), and the ICAM3 rs2304240 (OR, 0.67; 95% CI, 0.52-0.86; Padditive=0.002) and the PTGDR rs708486 SNPs (OR, 0.75; 95% CI, 0.63-0.90; Padditive=0.002) were associated with reduced risk of lymphoma. Two gene regions (ADAM19 (P=0.009) and ICAM3 (P=0.009)) displayed global associations with lymphoma risk at the P<0.01 level. While our results suggest that genetic polymorphisms in integrin genes may play a role in the genesis of lymphoma in women, they should be viewed as exploratory until they are replicated in additional populations.

Variation in innate immunity genes and risk of multiple myeloma

Multiple myeloma (MM) is a B-cell lymphoid malignancy suspected to be associated with immunologic factors. Given recent findings associating single-nucleotide polymorphisms (SNPs) in innate immunity genes with non-Hodgkin lymphoma, we conducted an investigation of innate immune gene variants using specimens from a population-based case-control study of MM conducted in Connecticut women. Tag SNPs (N = 1461) summarizing common variation in 149 gene regions were genotyped in non-Hispanic Caucasian subjects (103 cases, 475 controls). Odds ratios (OR) and 95% confidence intervals (CI) relating SNP associations with MM were computed using unconditional logistic regression, while the MinP test was used to investigate associations with MM at the gene level. We calculated permutation-adjusted P-values and false discovery rates (FDR) to account for the number of comparisons performed in SNP-level and gene-level tests, respectively. Three genes were associated with MM when controlling for a FDR of ≤10%: SERPINE1 (P(MinP)  < 0.0001; FDR = 0.02), CCR7 (P(MinP)  = 0.0006; FDR = 0.06) and HGF (P(MinP)  = 0.001; FDR = 0.08). Two SNPs demonstrated robust associations: SERPINE1 rs2227667 (P = 2.1 × 10(-5) , P(permutation)  = 0.03) and HGF rs17501108 (P = 5.0 × 10(-5) , P(permutation)  = 0.07). Our findings suggest that genetic variants in SERPINE1 and HGF, and possibly CCR7, are associated with MM risk, and warrant further investigation in other studies.

Genetic variation in Th1/Th2 pathway genes and risk of non-Hodgkin lymphoma: a pooled analysis of three population-based case-control studies

The balance between T-helper 1 (Th1) and T-helper 2 (Th2) activity is critical in lymphoid cell development and differentiation. Immune dysfunction underlies lymphomagenesis, so an alteration in the regulation of key Th1/Th2 cytokines may lead to the development of non-Hodgkin lymphoma (NHL). To study the impact of polymorphisms in Th1/Th2 cytokines on NHL risk, we analyzed 145 tag single nucleotide polymorphisms (SNPs) in 17 Th1/Th2 cytokine and related genes in three population-based case-control studies (1946 cases and 1808 controls). Logistic regression was used to compute odds ratios (OR) for NHL and four major NHL subtypes in relation to tag SNP genotypes and haplotypes. A gene-based analysis adjusting for the number of tag SNPs genotyped in each gene showed significant associations with risk of NHL combined and one or more NHL subtypes for Th1 (IL12A and IL12RB1) and Th2 (IL4, IL10RB, and IL18) genes. The strongest association was for rs485497 in IL12A, which plays a central role in bridging the cellular and humoral pathways of innate resistance and antigen-specific adaptive immune responses (allele risk OR= 1·17; P(trend)= 0·00099). This SNP was also associated specifically with risk of follicular lymphoma (allele risk OR= 1·26; P(trend)= 0·0012). These findings suggest that genetic variation in Th1/Th2 cytokine genes may contribute to lymphomagenesis.

GWAS of follicular lymphoma reveals allelic heterogeneity at 6p21.32 and suggests shared genetic susceptibility with diffuse large B-cell lymphoma

Non-Hodgkin lymphoma (NHL) represents a diverse group of hematological malignancies, of which follicular lymphoma (FL) is a prevalent subtype. A previous genome-wide association study has established a marker, rs10484561 in the human leukocyte antigen (HLA) class II region on 6p21.32 associated with increased FL risk. Here, in a three-stage genome-wide association study, starting with a genome-wide scan of 379 FL cases and 791 controls followed by validation in 1,049 cases and 5,790 controls, we identified a second independent FL-associated locus on 6p21.32, rs2647012 (OR(combined)  = 0.64, P(combined)  = 2 × 10(-21)) located 962 bp away from rs10484561 (r(2)<0.1 in controls). After mutual adjustment, the associations at the two SNPs remained genome-wide significant (rs2647012:OR(adjusted)  = 0.70, P(adjusted)  =  4 × 10(-12); rs10484561:OR(adjusted)  = 1.64, P(adjusted)  = 5 × 10(-15)). Haplotype and coalescence analyses indicated that rs2647012 arose on an evolutionarily distinct haplotype from that of rs10484561 and tags a novel allele with an opposite (protective) effect on FL risk. Moreover, in a follow-up analysis of the top 6 FL-associated SNPs in 4,449 cases of other NHL subtypes, rs10484561 was associated with risk of diffuse large B-cell lymphoma (OR(combined)  = 1.36, P(combined)  =  1.4 × 10(-7)). Our results reveal the presence of allelic heterogeneity within the HLA class II region influencing FL susceptibility and indicate a possible shared genetic etiology with diffuse large B-cell lymphoma. These findings suggest that the HLA class II region plays a complex yet important role in NHL.

Genetic variation in Th1/Th2 pathway genes and risk of non-Hodgkin lymphoma: a pooled analysis of three population-based case-control studies

The balance between T-helper 1 (Th1) and T-helper 2 (Th2) activity is critical in lymphoid cell development and differentiation. Immune dysfunction underlies lymphomagenesis, so an alteration in the regulation of key Th1/Th2 cytokines may lead to the development of non-Hodgkin lymphoma (NHL). To study the impact of polymorphisms in Th1/Th2 cytokines on NHL risk, we analyzed 145 tag single nucleotide polymorphisms (SNPs) in 17 Th1/Th2 cytokine and related genes in three population-based case-control studies (1946 cases and 1808 controls). Logistic regression was used to compute odds ratios (OR) for NHL and four major NHL subtypes in relation to tag SNP genotypes and haplotypes. A gene-based analysis adjusting for the number of tag SNPs genotyped in each gene showed significant associations with risk of NHL combined and one or more NHL subtypes for Th1 (IL12A and IL12RB1) and Th2 (IL4, IL10RB, and IL18) genes. The strongest association was for rs485497 in IL12A, which plays a central role in bridging the cellular and humoral pathways of innate resistance and antigen-specific adaptive immune responses (allele risk OR= 1·17; P(trend)= 0·00099). This SNP was also associated specifically with risk of follicular lymphoma (allele risk OR= 1·26; P(trend)= 0·0012). These findings suggest that genetic variation in Th1/Th2 cytokine genes may contribute to lymphomagenesis.