Breast Cancer Risk Factors and Circulating Anti-Müllerian Hormone Concentration in Healthy Premenopausal Women

CONTEXT

We previously reported that anti-Müllerian hormone (AMH), a marker of ovarian reserve, is positively associated with breast cancer risk, consistent with other studies.

OBJECTIVE

This study assessed whether risk factors for breast cancer are correlates of AMH concentration.

METHODS

This cross-sectional study included 3831 healthy premenopausal women (aged 21-57, 87% aged 35-49) from 10 cohort studies among the general population.

RESULTS

Adjusting for age and cohort, AMH positively associated with age at menarche (P < 0.0001) and parity (P = 0.0008) and inversely associated with hysterectomy/partial oophorectomy (P = 0.0008). Compared with women of normal weight, AMH was lower (relative geometric mean difference 27%, P < 0.0001) among women who were obese. Current oral contraceptive (OC) use and current/former smoking were associated with lower AMH concentration than never use (40% and 12% lower, respectively, P < 0.0001). We observed higher AMH concentrations among women who had had a benign breast biopsy (15% higher, P = 0.03), a surrogate for benign breast disease, an association that has not been reported. In analyses stratified by age (<40 vs ≥40), associations of AMH with body mass index and OCs were similar in younger and older women, while associations with the other factors (menarche, parity, hysterectomy/partial oophorectomy, smoking, and benign breast biopsy) were limited to women ≥40 (P-interaction < 0.05).

CONCLUSION

This is the largest study of AMH and breast cancer risk factors among women from the general population (not presenting with infertility), and it suggests that most associations are limited to women over 40, who are approaching menopause and whose AMH concentration is declining.

All-Cause and Cardiovascular Disease Mortality Among Breast Cancer Survivors in CLUE II, a Long-Standing Community-Based Cohort

BACKGROUND

There is growing evidence that breast cancer survivors have higher cardiovascular disease (CVD) mortality relative to the general population. Information on temporal patterns for all-cause and CVD mortality among breast cancer survivors relative to cancer-free women is limited.

METHODS

All-cause and CVD-related mortality were compared in 628 women with breast cancer and 3140 age-matched cancer-free women within CLUE II, a prospective cohort. We calculated adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression for all-cause mortality, and Fine and Gray models for CVD-related mortality to account for competing risks.

RESULTS

Over 25 years of follow-up, 916 deaths occurred (249 CVD related). Breast cancer survivors had an overall higher risk of dying compared with cancer-free women (HR = 1.79, 95% CI = 1.53 to 2.09) irrespective of time since diagnosis, tumor stage, estrogen receptor status, and older age at diagnosis (≥70 years). Risk of death was greatest among older survivors at more than 15 years after diagnosis (HR = 2.69, 95% CI = 1.59 to 4.55). CVD (69.1% ischemic heart disease) was the leading cause of death among cancer-free women and the second among survivors. Survivors had an increase in CVD-related deaths compared with cancer-free women beginning at 8 years after diagnosis (HR = 1.65, 95% CI = 1.00 to 2.73), with the highest risk among older survivors (HR = 2.24, 95% CI = 1.29 to 3.88) and after estrogen receptor-positive disease (HR = 1.85, 95% CI = 1.06 to 3.20).

CONCLUSIONS

Breast cancer survivors continue to have an elevated mortality compared with the general population for many years after diagnosis. Preventing cardiac deaths, particularly among older breast cancer patients, could lead to reductions in mortality.

Survival advantage of cohort participation attenuates over time: results from three long-standing community-based studies

PURPOSE

Cohort participants usually have lower mortality rates than nonparticipants, but it is unclear if this survival advantage decreases or increases as cohort studies age.

METHODS

We used a 1975 private census of Washington County, Maryland, to compare mortality among cohort participants to nonparticipants for three cohorts, Campaign Against Cancer and Stroke (CLUE I), Campaign Against Cancer and Heart Disease (CLUE II), and Atherosclerosis Risk In Communities (ARIC) initiated in 1974, 1989, and 1986, respectively. We analyzed mortality risk using time-truncated Cox regression models.

RESULTS

Participants had lower mortality risk in the first 10 years of follow-up compared with nonparticipants (fully adjusted average hazard ratio [95% confidence intervals] were 0.72 [0.68, 0.77] in CLUE I, 0.69 [0.65, 0.73] in CLUE II, and 0.74 [0.63, 0.86] in ARIC), which persisted over 20 years of follow-up (0.81 [0.78, 0.84] in CLUE I, 0.87 [0.84, 0.91] in CLUE II, and 0.90 [0.83, 0.97] in ARIC). This lower average hazard for mortality among participants compared with nonparticipants attenuated with longer follow-up (0.99 [0.96, 1.01] after 30+ years in CLUE I, 1.02 [0.99, 1.05] after 30 years in CLUE II, and 0.95 [0.89, 1.00] after 30+ years in ARIC). In ARIC, participants who did not attend visits had higher mortality, but those who did attend visits had similar mortality to the community.

CONCLUSIONS

Our results suggest the volunteer selection for mortality in long-standing epidemiologic cohort studies often diminishes as the cohort ages.

Is high vitamin B12 status a cause of lung cancer?

Vitamin B supplementation can have side effects for human health, including cancer risk. We aimed to elucidate the role of vitamin B12 in lung cancer etiology via direct measurements of pre-diagnostic circulating vitamin B12 concentrations in a nested case-control study, complemented with a Mendelian randomization (MR) approach in an independent case-control sample. We used pre-diagnostic biomarker data from 5183 case-control pairs nested within 20 prospective cohorts, and genetic data from 29,266 cases and 56,450 controls. Exposures included directly measured circulating vitamin B12 in pre-diagnostic blood samples from the nested case-control study, and 8 single nucleotide polymorphisms associated with vitamin B12 concentrations in the MR study. Our main outcome of interest was increased risk for lung cancer, overall and by histological subtype, per increase in circulating vitamin B12 concentrations. We found circulating vitamin B12 to be positively associated with overall lung cancer risk in a dose response fashion (odds ratio for a doubling in B12 [ORlog2B12 ] = 1.15, 95% confidence interval (95%CI) = 1.06-1.25). The MR analysis based on 8 genetic variants also indicated that genetically determined higher vitamin B12 concentrations were positively associated with overall lung cancer risk (OR per 150 pmol/L standard deviation increase in B12 [ORSD ] = 1.08, 95%CI = 1.00-1.16). Considering the consistency of these two independent and complementary analyses, these findings support the hypothesis that high vitamin B12 status increases the risk of lung cancer.

Timing of HPV16-E6 antibody seroconversion before OPSCC: findings from the HPVC3 consortium

BACKGROUND

Human papillomavirus type 16 (HPV16)-E6 antibodies are detectable in peripheral blood before diagnosis in the majority of HPV16-driven oropharyngeal squamous cell carcinoma (OPSCC), but the timing of seroconversion is unknown.

PATIENTS AND METHODS

We formed the HPV Cancer Cohort Consortium which comprises nine population cohorts from Europe, North America and Australia. In total, 743 incident OPSCC cases and 5814 controls provided at least one pre-diagnostic blood sample, including 111 cases with multiple samples. Median time between first blood collection and OPSCC diagnosis was 11.4 years (IQR = 6-11 years, range = 0-40 years). Antibodies against HPV16-E6 were measured by multiplex serology (GST fusion protein based Luminex assay).

RESULTS

HPV16-E6 seropositivity was present in 0.4% of controls (22/5814; 95% CI 0.2% to 0.6%) and 26.2% (195/743; 95% CI 23.1% to 29.6%) of OPSCC cases. HPV16-E6 seropositivity increased the odds of OPSCC 98.2-fold (95% CI 62.1-155.4) in whites and 17.2-fold (95% CI 1.7-170.5) in blacks. Seropositivity in cases was more frequent in recent calendar periods, ranging from 21.9% pre-1996 to 68.4% in 2005 onwards, in those with blood collection near diagnosis (lead time <5 years). HPV16-E6 seropositivity increased with lead time: 0.0%, 13.5%, 23.7%, and 38.9% with lead times of >30 years (N = 24), 20-30 years (N = 148), 10-20 years (N = 228), and <10 years (N = 301 cases) (p-trend < 0.001). Of the 47 HPV16-E6 seropositive cases with serially-collected blood samples, 17 cases seroconverted during follow-up, with timing ranging from 6 to 28 years before diagnosis. For the remaining 30 cases, robust seropositivity was observed up to 25 years before diagnosis.

CONCLUSIONS

The immune response to HPV16-driven tumorigenesis is most often detectable several decades before OPSCC diagnosis. HPV16-E6 seropositive individuals face increased risk of OPSCC over several decades.

Ovarian cancer risk factors by tumor aggressiveness: An analysis from the Ovarian Cancer Cohort Consortium

Ovarian cancer risk factors differ by histotype; however, within subtype, there is substantial variability in outcomes. We hypothesized that risk factor profiles may influence tumor aggressiveness, defined by time between diagnosis and death, independent of histology. Among 1.3 million women from 21 prospective cohorts, 4,584 invasive epithelial ovarian cancers were identified and classified as highly aggressive (death in <1 year, n = 864), very aggressive (death in 1 to < 3 years, n = 1,390), moderately aggressive (death in 3 to < 5 years, n = 639), and less aggressive (lived 5+ years, n = 1,691). Using competing risks Cox proportional hazards regression, we assessed heterogeneity of associations by tumor aggressiveness for all cases and among serous and endometrioid/clear cell tumors. Associations between parity (p_het = 0.01), family history of ovarian cancer (p_het = 0.02), body mass index (BMI; p_het ≤ 0.04) and smoking (p_het < 0.01) and ovarian cancer risk differed by aggressiveness. A first/single pregnancy, relative to nulliparity, was inversely associated with highly aggressive disease (HR: 0.72; 95% CI [0.58-0.88]), no association was observed for subsequent pregnancies (per pregnancy, 0.97 [0.92-1.02]). In contrast, first and subsequent pregnancies were similarly associated with less aggressive disease (0.87 for both). Family history of ovarian cancer was only associated with risk of less aggressive disease (1.94 [1.47-2.55]). High BMI (≥35 vs. 20 to < 25 kg/m² , 1.93 [1.46-2.56] and current smoking (vs. never, 1.30 [1.07-1.57]) were associated with increased risk of highly aggressive disease. Results were similar within histotypes. Ovarian cancer risk factors may be directly associated with subtypes defined by tumor aggressiveness, rather than through differential effects on histology. Studies to assess biological pathways are warranted.

Ovarian cancer risk factors by tumor aggressiveness: An analysis from the Ovarian Cancer Cohort Consortium

Ovarian cancer risk factors differ by histotype; however, within subtype, there is substantial variability in outcomes. We hypothesized that risk factor profiles may influence tumor aggressiveness, defined by time between diagnosis and death, independent of histology. Among 1.3 million women from 21 prospective cohorts, 4,584 invasive epithelial ovarian cancers were identified and classified as highly aggressive (death in <1 year, n = 864), very aggressive (death in 1 to < 3 years, n = 1,390), moderately aggressive (death in 3 to < 5 years, n = 639), and less aggressive (lived 5+ years, n = 1,691). Using competing risks Cox proportional hazards regression, we assessed heterogeneity of associations by tumor aggressiveness for all cases and among serous and endometrioid/clear cell tumors. Associations between parity (phet = 0.01), family history of ovarian cancer (phet = 0.02), body mass index (BMI; phet ≤ 0.04) and smoking (phet < 0.01) and ovarian cancer risk differed by aggressiveness. A first/single pregnancy, relative to nulliparity, was inversely associated with highly aggressive disease (HR: 0.72; 95% CI [0.58-0.88]), no association was observed for subsequent pregnancies (per pregnancy, 0.97 [0.92-1.02]). In contrast, first and subsequent pregnancies were similarly associated with less aggressive disease (0.87 for both). Family history of ovarian cancer was only associated with risk of less aggressive disease (1.94 [1.47-2.55]). High BMI (≥35 vs. 20 to < 25 kg/m2 , 1.93 [1.46-2.56] and current smoking (vs. never, 1.30 [1.07-1.57]) were associated with increased risk of highly aggressive disease. Results were similar within histotypes. Ovarian cancer risk factors may be directly associated with subtypes defined by tumor aggressiveness, rather than through differential effects on histology. Studies to assess biological pathways are warranted.

Ovarian cancer risk factors by tumor aggressiveness: An analysis from the Ovarian Cancer Cohort Consortium

Ovarian cancer risk factors differ by histotype; however, within subtype, there is substantial variability in outcomes. We hypothesized that risk factor profiles may influence tumor aggressiveness, defined by time between diagnosis and death, independent of histology. Among 1.3 million women from 21 prospective cohorts, 4,584 invasive epithelial ovarian cancers were identified and classified as highly aggressive (death in <1 year, n = 864), very aggressive (death in 1 to < 3 years, n = 1,390), moderately aggressive (death in 3 to < 5 years, n = 639), and less aggressive (lived 5+ years, n = 1,691). Using competing risks Cox proportional hazards regression, we assessed heterogeneity of associations by tumor aggressiveness for all cases and among serous and endometrioid/clear cell tumors. Associations between parity (p_het = 0.01), family history of ovarian cancer (p_het = 0.02), body mass index (BMI; p_het ≤ 0.04) and smoking (p_het < 0.01) and ovarian cancer risk differed by aggressiveness. A first/single pregnancy, relative to nulliparity, was inversely associated with highly aggressive disease (HR: 0.72; 95% CI [0.58-0.88]), no association was observed for subsequent pregnancies (per pregnancy, 0.97 [0.92-1.02]). In contrast, first and subsequent pregnancies were similarly associated with less aggressive disease (0.87 for both). Family history of ovarian cancer was only associated with risk of less aggressive disease (1.94 [1.47-2.55]). High BMI (≥35 vs. 20 to < 25 kg/m² , 1.93 [1.46-2.56] and current smoking (vs. never, 1.30 [1.07-1.57]) were associated with increased risk of highly aggressive disease. Results were similar within histotypes. Ovarian cancer risk factors may be directly associated with subtypes defined by tumor aggressiveness, rather than through differential effects on histology. Studies to assess biological pathways are warranted.

Breast cancer risk prediction in women aged 35-50 years: impact of including sex hormone concentrations in the Gail model

Background

Models that accurately predict risk of breast cancer are needed to help younger women make decisions about when to begin screening. Premenopausal concentrations of circulating anti-Müllerian hormone (AMH), a biomarker of ovarian reserve, and testosterone have been positively associated with breast cancer risk in prospective studies. We assessed whether adding AMH and/or testosterone to the Gail model improves its prediction performance for women aged 35–50.

Methods

In a nested case-control study including ten prospective cohorts (1762 invasive cases/1890 matched controls) with pre-diagnostic serum/plasma samples, we estimated relative risks (RR) for the biomarkers and Gail risk factors using conditional logistic regression and random-effects meta-analysis. Absolute risk models were developed using these RR estimates, attributable risk fractions calculated using the distributions of the risk factors in the cases from the consortium, and population-based incidence and mortality rates. The area under the receiver operating characteristic curve (AUC) was used to compare the discriminatory accuracy of the models with and without biomarkers.

Results

The AUC for invasive breast cancer including only the Gail risk factor variables was 55.3 (95% CI 53.4, 57.1). The AUC increased moderately with the addition of AMH (AUC 57.6, 95% CI 55.7, 59.5), testosterone (AUC 56.2, 95% CI 54.4, 58.1), or both (AUC 58.1, 95% CI 56.2, 59.9). The largest AUC improvement (4.0) was among women without a family history of breast cancer.

Conclusions

AMH and testosterone moderately increase the discriminatory accuracy of the Gail model among women aged 35–50. We observed the largest AUC increase for women without a family history of breast cancer, the group that would benefit most from improved risk prediction because early screening is already recommended for women with a family history.

Electronic supplementary material

The online version of this article (10.1186/s13058-019-1126-z) contains supplementary material, which is available to authorized users.

Analgesic Use and Ovarian Cancer Risk: An Analysis in the Ovarian Cancer Cohort Consortium

BACKGROUND

Aspirin use is associated with reduced risk of several cancers. A pooled analysis of 12 case-control studies showed a 10% decrease in ovarian cancer risk with regular aspirin use, which was stronger for daily and low-dose users. To prospectively investigate associations of analgesic use with ovarian cancer, we analyzed data from 13 studies in the Ovarian Cancer Cohort Consortium (OC3).

METHODS

The current study included 758 829 women who at study enrollment self-reported analgesic use, among whom 3514 developed ovarian cancer. Using Cox regression, we assessed associations between frequent medication use and risk of ovarian cancer. Dose and duration were also evaluated. All statistical tests were two-sided.

RESULTS

Women who used aspirin almost daily (≥6 days/wk) vs infrequent/nonuse experienced a 10% reduction in ovarian cancer risk (rate ratio [RR] = 0.90, 95% confidence interval [CI] = 0.82 to 1.00, P = .05). Frequent use (≥4 days/wk) of aspirin (RR = 0.95, 95% CI = 0.88 to 1.03), nonaspirin nonsteroidal anti-inflammatory drugs (NSAIDs; RR = 1.00, 95% CI = 0.90 to 1.11), or acetaminophen (RR = 1.05, 95% CI = 0.88 to 1.24) was not associated with risk. Daily acetaminophen use (RR = 1.28, 95% CI = 1.00 to 1.65, P = .05) was associated with elevated ovarian cancer risk. Risk estimates for frequent, long-term (10+ years) use of aspirin (RR = 1.15, 95% CI = 0.98 to 1.34) or nonaspirin NSAIDs (RR = 1.19, 95% CI = 0.84 to 1.68) were modestly elevated, although not statistically significantly so.

CONCLUSIONS

This large, prospective analysis suggests that women who use aspirin daily have a slightly lower risk of developing ovarian cancer (∼10% lower than infrequent/nonuse)-similar to the risk reduction observed in case-control analyses. The observed potential elevated risks for 10+ years of frequent aspirin and NSAID use require further study but could be due to confounding by medical indications for use or variation in drug dosing.

Circulating sCD27 and sCD30 in pre-diagnostic samples collected fifteen years apart and future non-Hodgkin lymphoma risk

Elevated serum sCD27 and sCD30 from a single banked sample have been associated with future non-Hodgkin lymphoma risk (NHL); however, the etiologic relevance of this finding is unclear. To address this question, we conducted a case-control study (235 cases, 235 controls) nested within the CLUE-I and CLUE-II cohorts, which enrolled participants in 1974 and 1989 respectively in Washington County, Maryland. Our study features a subset of 102 cases and 102 controls with two banked pre-diagnostic samples each, collected 15 years apart. In analyses involving an individual sample per subject, both sCD27 and sCD30 were associated with NHL diagnosed up to 20 years later. In analyses involving repeated samples, cases were significantly more likely than controls to have higher analyte levels in the CLUE-II vs. CLUE-I sample for sCD27 (p = 0.006) but not sCD30 (p = 0.16). In joint analyses of dichotomized analyte levels in both samples, the strongest NHL association observed for sCD27 was for having below-median levels in CLUE-I and above-median levels in CLUE-II [odds ratio (OR) 3.6, 95% confidence interval (CI) 1.4-9.2 vs. below-median levels in both). In joint analyses for sCD30, the strongest NHL association was observed for having above-median levels in both samples (OR 1.7, 95% CI 0.8-3.7), particularly for cases diagnosed >10 years after the CLUE-II sample (OR 2.4, 95% CI 0.9-6.7). Our findings suggest that sCD27 is a disease marker for NHL and add to the weight of evidence that elevated circulating sCD30 is a marker of increased NHL susceptibility.

Abstract 3232: Circulating sCD27 and sCD30 in samples collected fifteen years apart and non-Hodgkin lymphoma risk: Findings from the CLUE-I and CLUE-II cohorts

Elevated serum levels of the immune activation markers sCD27 and sCD30 have been consistently associated with increased future risk of non-Hodgkin lymphoma (NHL). However, past studies could not clarify patterns of these markers over time preceding diagnosis, given their use of a single banked sample per participant. To address this question, we conducted a nested case-control study within the CLUE-I and CLUE-II cohorts including 102 case-control matched pairs with two banked samples per participant, collected fifteen years apart. The CLUE-II sCD27 concentrations among cases were higher than in the earlier CLUE-I samples (P&lt;0.0001), whereas no systematic difference was observed for controls (P=0.89). The sCD27 increase was greater for cases diagnosed less than 10 years vs. 10+ years after CLUE-II enrollment (P = 0.0007). For sCD30, an increase between samples was observed for both cases (P = 0.0002) and controls (P=0.02), and the magnitude of increase among cases did not significantly differ across the two follow-up periods (P = 0.12). In comparison to having low (below-median) sCD27 levels in both CLUE-I and CLUE-II samples, associations with NHL were observed for having low CLUE-I sCD27 and high CLUE-II sCD27 (“low / high”; odds ratio 2.4, 95% confidence interval 1.0-6.2) as well as having high sCD27 levels in both samples (“high / high”; 2.1, 1.0-4.4). For sCD30, only the “high-high” category was associated with NHL (2.1, 0.9-5.0). The “low-high” sCD27 association was apparent only for cases diagnosed less than 10 years after CLUE-II (4.1, 1.3-13.0), while the “high-high” associations were consistent across follow-up periods. Our findings suggest that multiple factors may underlie NHL associations with these markers; rising sCD27 closer to diagnosis is likely driven by occult disease, whereas associations with stable elevated analyte levels may reflect etiologically relevant effects.

Citation Format: Mark P. Purdue, Qing Lan, Judith Hoffman-Bolton, Allan Hildesheim, Paul Strickland, Kala Visvanathan, Nathaniel Rothman. Circulating sCD27 and sCD30 in samples collected fifteen years apart and non-Hodgkin lymphoma risk: Findings from the CLUE-I and CLUE-II cohorts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3232.

Polymorphisms in genes related to inflammation and obesity and colorectal adenoma risk

We previously investigated the association between single nucleotide polymorphisms (SNPs) in genes related to obesity and inflammation and colorectal cancer in the CLUE II cohort. However, the relationships between these SNPs and colorectal adenomas have not been well evaluated. In a nested case-control study of 135 incident adenoma cases and 269 matched controls in the CLUE II cohort (1989-2000), we genotyped 17 candidate SNPs in 12 genes (PPARG, TCF7L2, ADIPOQ, LEP, IL10, CRP, TLR4, IL6, IL1B, IL8, TNF, RNASEL) and 19 tagSNPs in three genes (IL10, CRP, and TLR4). Conditional logistic regression was used to calculate odds ratios (OR) for adenomas (overall and by size, histology, location, number). Polymorphisms in the inflammatory-related genes CRP, ADIPOQ, IL6, and TLR4 were observed to be associated with adenoma risk. At rs1205 in CRP, T (minor allele) carriers had a higher risk (OR 1.67, 95%CI 1.07-2.60; reference: CC) of adenomas overall and adenomas with aggressive characteristics. At rs1201299 in ADIPOQ, the AC genotype had a higher risk (OR 1.58, 95%CI 1.00-2.49) of adenomas, while the minor AA genotype had a borderline inverse association (OR 0.44, 95%CI 0.18-1.08; reference: CC). At rs1800797 in IL6, the AA genotype had a borderline inverse association (OR 0.53, 95%CI 0.27-1.05; reference: GG). Three TLR4 tagSNPs (rs10116253, rs1927911, rs7873784) were associated with adenomas among obese participants. None of these SNPs were associated with colorectal cancer in our prior study in CLUE II, possibly suggesting a different genetic etiology for early colorectal neoplasia.

Circulating anti-Müllerian hormone and breast cancer risk: A study in ten prospective cohorts

A strong positive association has been observed between circulating anti-Müllerian hormone (AMH), a biomarker of ovarian reserve, and breast cancer risk in three prospective studies. Confirming this association is important because of the paucity of biomarkers of breast cancer risk in premenopausal women. We conducted a consortium study including ten prospective cohorts that had collected blood from premenopausal women. A nested case-control design was implemented within each cohort. A total of 2,835 invasive (80%) and in situ (20%) breast cancer cases were individually matched to controls (n = 3,122) on age at blood donation. AMH was measured using a high sensitivity enzyme-linked immunoabsorbent assay. Conditional logistic regression was applied to the aggregated dataset. There was a statistically significant trend of increasing breast cancer risk with increasing AMH concentration (ptrend across quartiles <0.0001) after adjusting for breast cancer risk factors. The odds ratio (OR) for breast cancer in the top vs. bottom quartile of AMH was 1.60 (95% CI = 1.31-1.94). Though the test for interaction was not statistically significant (pinteraction  = 0.15), the trend was statistically significant only for tumors positive for both estrogen receptor (ER) and progesterone receptor (PR): ER+/PR+: ORQ4-Q1  = 1.96, 95% CI = 1.46-2.64, ptrend <0.0001; ER+/PR-: ORQ4-Q1  = 0.82, 95% CI = 0.40-1.68, ptrend  = 0.51; ER-/PR+: ORQ4-Q1  = 3.23, 95% CI = 0.48-21.9, ptrend  = 0.26; ER-/PR-: ORQ4-Q1  = 1.15, 95% CI = 0.63-2.09, ptrend  = 0.60. The association was observed for both pre- (ORQ4-Q1 = 1.35, 95% CI = 1.05-1.73) and post-menopausal (ORQ4-Q1  = 1.61, 95% CI = 1.03-2.53) breast cancer (pinteraction  = 0.34). In this large consortium study, we confirmed that AMH is associated with breast cancer risk, with a 60% increase in risk for women in the top vs. bottom quartile of AMH.

Ovarian Cancer Risk Factors by Histologic Subtype: An Analysis From the Ovarian Cancer Cohort Consortium

PURPOSE

An understanding of the etiologic heterogeneity of ovarian cancer is important for improving prevention, early detection, and therapeutic approaches. We evaluated 14 hormonal, reproductive, and lifestyle factors by histologic subtype in the Ovarian Cancer Cohort Consortium (OC3).

PATIENTS AND METHODS

Among 1.3 million women from 21 studies, 5,584 invasive epithelial ovarian cancers were identified (3,378 serous, 606 endometrioid, 331 mucinous, 269 clear cell, 1,000 other). By using competing-risks Cox proportional hazards regression stratified by study and birth year and adjusted for age, parity, and oral contraceptive use, we assessed associations for all invasive cancers by histology. Heterogeneity was evaluated by likelihood ratio test.

RESULTS

Most risk factors exhibited significant heterogeneity by histology. Higher parity was most strongly associated with endometrioid (relative risk [RR] per birth, 0.78; 95% CI, 0.74 to 0.83) and clear cell (RR, 0.68; 95% CI, 0.61 to 0.76) carcinomas (P value for heterogeneity [P-het] < .001). Similarly, age at menopause, endometriosis, and tubal ligation were only associated with endometrioid and clear cell tumors (P-het ≤ .01). Family history of breast cancer (P-het = .008) had modest heterogeneity. Smoking was associated with an increased risk of mucinous (RR per 20 pack-years, 1.26; 95% CI, 1.08 to 1.46) but a decreased risk of clear cell (RR, 0.72; 95% CI, 0.55 to 0.94) tumors (P-het = .004). Unsupervised clustering by risk factors separated endometrioid, clear cell, and low-grade serous carcinomas from high-grade serous and mucinous carcinomas.

CONCLUSION

The heterogeneous associations of risk factors with ovarian cancer subtypes emphasize the importance of conducting etiologic studies by ovarian cancer subtypes. Most established risk factors were more strongly associated with nonserous carcinomas, which demonstrate challenges for risk prediction of serous cancers, the most fatal subtype.

Analysis of Heritability and Shared Heritability Based on Genome-Wide Association Studies for Thirteen Cancer Types

BACKGROUND

Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites.

METHODS

Between 2007 and 2014, the US National Cancer Institute has generated data from genome-wide association studies (GWAS) for 49 492 cancer case patients and 34 131 control patients. We apply novel mixed model methodology (GCTA) to this GWAS data to estimate the heritability of individual cancers, as well as the proportion of heritability attributable to cigarette smoking in smoking-related cancers, and the genetic correlation between pairs of cancers.

RESULTS

GWAS heritability was statistically significant at nearly all sites, with the estimates of array-based heritability, hl (2), on the liability threshold (LT) scale ranging from 0.05 to 0.38. Estimating the combined heritability of multiple smoking characteristics, we calculate that at least 24% (95% confidence interval [CI] = 14% to 37%) and 7% (95% CI = 4% to 11%) of the heritability for lung and bladder cancer, respectively, can be attributed to genetic determinants of smoking. Most pairs of cancers studied did not show evidence of strong genetic correlation. We found only four pairs of cancers with marginally statistically significant correlations, specifically kidney and testes (ρ = 0.73, SE = 0.28), diffuse large B-cell lymphoma (DLBCL) and pediatric osteosarcoma (ρ = 0.53, SE = 0.21), DLBCL and chronic lymphocytic leukemia (CLL) (ρ = 0.51, SE =0.18), and bladder and lung (ρ = 0.35, SE = 0.14). Correlation analysis also indicates that the genetic architecture of lung cancer differs between a smoking population of European ancestry and a nonsmoking Asian population, allowing for the possibility that the genetic etiology for the same disease can vary by population and environmental exposures.

CONCLUSION

Our results provide important insights into the genetic architecture of cancers and suggest new avenues for investigation.

Alcohol consumption and breast cancer risk by estrogen receptor status: in a pooled analysis of 20 studies

BACKGROUND

Breast cancer aetiology may differ by estrogen receptor (ER) status. Associations of alcohol and folate intakes with risk of breast cancer defined by ER status were examined in pooled analyses of the primary data from 20 cohorts.

METHODS

During a maximum of 6-18 years of follow-up of 1 089 273 women, 21 624 ER+ and 5113 ER- breast cancers were identified. Study-specific multivariable relative risks (RRs) were calculated using Cox proportional hazards regression models and then combined using a random-effects model.

RESULTS

Alcohol consumption was positively associated with risk of ER+ and ER- breast cancer. The pooled multivariable RRs (95% confidence intervals) comparing ≥ 30 g/d with 0 g/day of alcohol consumption were 1.35 (1.23-1.48) for ER+ and 1.28 (1.10-1.49) for ER- breast cancer (Ptrend ≤ 0.001; Pcommon-effects by ER status: 0.57). Associations were similar for alcohol intake from beer, wine and liquor. The associations with alcohol intake did not vary significantly by total (from foods and supplements) folate intake (Pinteraction ≥ 0.26). Dietary (from foods only) and total folate intakes were not associated with risk of overall, ER+ and ER- breast cancer; pooled multivariable RRs ranged from 0.98 to 1.02 comparing extreme quintiles. Following-up US studies through only the period before mandatory folic acid fortification did not change the results. The alcohol and folate associations did not vary by tumour subtypes defined by progesterone receptor status.

CONCLUSIONS

Alcohol consumption was positively associated with risk of both ER+ and ER- breast cancer, even among women with high folate intake. Folate intake was not associated with breast cancer risk.

Abstract 854: Ovarian cancer risk factors by histologic subtypes: evidence for etiologic heterogeneity

Background: A subset of high grade serous carcinomas may arise from the fallopian tube, while some endometrioid and clear cell carcinomas may derive from endometrial tissue. Previous studies have suggested differences in ovarian cancer risk factors by histologic subtypes, but had limited sample sizes. In the Ovarian Cancer Cohort Consortium (OC3), we evaluated associations of reproductive, hormonal, demographic and lifestyle factors, and family history of cancer with ovarian cancer subtypes. Identification of potential differences in associations among subtypes is important for clarifying ovarian cancer etiology and for developing novel prevention and risk prediction approaches.

Methods: Among over 1.2 million women from 21 cohort studies, 4,347 ovarian cancers with histology information were identified during follow-up (3223 serous, 555 endometrioid, 316 mucinous, 253 clear cell). We used competing risks Cox proportional hazards regression to compute risk factor associations by histologic subtype. Models were stratified on study and year of birth and adjusted for age, parity and oral contraceptive use; subtype heterogeneity was evaluated by a likelihood ratio test. Unsupervised hierarchical clustering was used to evaluate patterns of risk factors by histology.

Results: Most risk factors showed significant heterogeneity across histologic subtypes. Higher parity was most strongly associated with lower risks of endometrioid (RR per child: 0.79; 95%CI: 0.74-0.85) and clear cell (RR: 0.69; 95%CI: 0.61-0.78) carcinomas (p-het&lt;0.0001). Age at menopause was positively and tubal ligation was inversely associated only with endometrioid and clear cell carcinomas (p-het = 0.02 and 0.003, respectively). Long-term menopausal hormone use (&gt;5 years) was associated with endometrioid carcinomas (RR: 2.23; 95% CI: 1.46-3.42) and serous carcinomas (RR: 1.66; 95% CI: 1.44-1.92), and inversely associated with clear cell carcinomas (RR: 0.43; 95% CI: 0.20-0.91; p-het = 0.001). Family history of breast cancer was associated with increased risk of serous carcinomas (RR:1.13; 95% CI:1.02-1.27) and endometrioid carcinomas (RR: 1.44; 95% CI: 1.12-1.87; p-het = 0.02). Smoking (per 20 pack years) showed a positive association with mucinous carcinomas (RR: 1.38; 95% CI: 1.09-1.75) and an inverse association with clear cell carcinomas (RR:0.62; 95% CI: 0.46-0.85; p-het = 0.001). In unsupervised hierarchical clustering, serous and mucinous carcinomas clustered in one group and endometrioid and clear cell carcinomas in the other.

Conclusion: Our results demonstrate heterogeneous associations of risk factors with ovarian cancer subtypes, supporting the hypothesis that the subtypes develop through different pathways. Most established risk factors were more strongly associated with non-serous carcinomas, suggesting that risk prediction may be more challenging for serous cancers, the most fatal subtype.

Citation Format: Nicolas A. Wentzensen, Elizabeth Poole, Alan A. Arslan, Alpa V. Patel, V Wendy Setiawan, Kala Visvanathan, Elisabete Weiderpass, Emily White, Hans-Olov Adami, Louise A. Brinton, Leslie Bernstein, Julie Buring, Lesley M. Butler, Saioa Chamosa, Tess V. Clendenen, Laure Dossus, Renee Fortner, Susan M. Gapstur, Mia M. Gaudet, Inger Torhild Gram, Patricia Hartge, Judith Hoffman-Bolton, Annika Idahl, Michael Jones, Rudolf Kaaks, Vivki Kirsh, Woon-Puay Koh, James V. Lacey, I-Min Lee, Eva Lundin, Melissa Merritt, Ulrike Peters, Jenny Poynter, Sabina Rinaldi, Kim Robien, Thomas Rohan, Dale P. Sandler, Leo J. Schouten, Louise Sjöholm, Sabina Sieri, Anthony Swerdlow, Anne Tjønneland, Britton Trabert, Lynne Wilkens, Alicja Wolk, Hannah P. Yang, Anne Zeleniuch-Jacquotte, Shelley S. Tworoger. Ovarian cancer risk factors by histologic subtypes: evidence for etiologic heterogeneity. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 854. doi:10.1158/1538-7445.AM2015-854

Interleukin-6 and risk of colorectal cancer: results from the CLUE II cohort and a meta-analysis of prospective studies

PURPOSE

The association between prediagnostic interleukin-6 (IL-6) concentrations and risk of colorectal cancer was evaluated in a nested case-control study and a meta-analysis of prospective studies.

METHODS

Colorectal cancer cases (n = 173) and matched controls (n = 345) were identified between 1989 and 2000 among participants in the CLUE II cohort of Washington Country, Maryland. Matched odds ratios and the corresponding 95 % confidence intervals (CIs) were estimated using conditional logistic regression models.

RESULTS

Participants in the highest third of plasma IL-6 concentration had a 2.48 times higher risk of colon cancer compared to participants in the bottom third (95 % CI 1.26-4.87; p-trend 0.02) after multivariate adjustment. This association did not differ according to the stage of disease, age, sex, or other potential modifying variables and remained statistically significant after adjustment for C-reactive protein concentrations. No statistically significant association was observed for rectal cancer risk. The meta-analysis of six prospective studies yielded an increased but borderline statistically significant risk of colon cancer per 1 U increase in naturally logarithm-transformed IL-6 (summary RR 1.22; 95 % CI 1.00-1.49; I (2) 46 %). An inverse association was noted for rectal cancer (RR 0.69; 95 % CI 0.54-0.88; I (2) 0 %), but there was evidence for small-study effects (p 0.02).

CONCLUSION

Our findings provide support for a modest positive association between IL-6 concentrations and colon cancer risk. More work is needed to determine whether IL-6 is a valid marker of colorectal inflammation and whether such inflammation contributes to colon and rectal cancer risk.

Further Confirmation of Germline Glioma Risk Variant rs78378222 in TP53 and Its Implication in Tumor Tissues via Integrative Analysis of TCGA Data

We confirmed strong association of rs78378222:A>C (per allele odds ratio [OR] = 3.14; P = 6.48 × 10(-11) ), a germline rare single-nucleotide polymorphism (SNP) in TP53, via imputation of a genome-wide association study of glioma (1,856 cases and 4,955 controls). We subsequently performed integrative analyses on the Cancer Genome Atlas (TCGA) data for GBM (glioblastoma multiforme) and LUAD (lung adenocarcinoma). Based on SNP data, we imputed genotypes for rs78378222 and selected individuals carrying rare risk allele (C). Using RNA sequencing data, we observed aberrant transcripts with ∼3 kb longer than normal for those individuals. Using exome sequencing data, we further showed that loss of haplotype carrying common protective allele (A) occurred somatically in GBM but not in LUAD. Our bioinformatic analysis suggests rare risk allele (C) disrupts mRNA termination, and an allelic loss of a genomic region harboring common protective allele (A) occurs during tumor initiation or progression for glioma.

Imputation and subset-based association analysis across different cancer types identifies multiple independent risk loci in the TERT-CLPTM1L region on chromosome 5p15.33

Genome-wide association studies (GWAS) have mapped risk alleles for at least 10 distinct cancers to a small region of 63 000 bp on chromosome 5p15.33. This region harbors the TERT and CLPTM1L genes; the former encodes the catalytic subunit of telomerase reverse transcriptase and the latter may play a role in apoptosis. To investigate further the genetic architecture of common susceptibility alleles in this region, we conducted an agnostic subset-based meta-analysis (association analysis based on subsets) across six distinct cancers in 34 248 cases and 45 036 controls. Based on sequential conditional analysis, we identified as many as six independent risk loci marked by common single-nucleotide polymorphisms: five in the TERT gene (Region 1: rs7726159, P = 2.10 × 10(-39); Region 3: rs2853677, P = 3.30 × 10(-36) and PConditional = 2.36 × 10(-8); Region 4: rs2736098, P = 3.87 × 10(-12) and PConditional = 5.19 × 10(-6), Region 5: rs13172201, P = 0.041 and PConditional = 2.04 × 10(-6); and Region 6: rs10069690, P = 7.49 × 10(-15) and PConditional = 5.35 × 10(-7)) and one in the neighboring CLPTM1L gene (Region 2: rs451360; P = 1.90 × 10(-18) and PConditional = 7.06 × 10(-16)). Between three and five cancers mapped to each independent locus with both risk-enhancing and protective effects. Allele-specific effects on DNA methylation were seen for a subset of risk loci, indicating that methylation and subsequent effects on gene expression may contribute to the biology of risk variants on 5p15.33. Our results provide strong support for extensive pleiotropy across this region of 5p15.33, to an extent not previously observed in other cancer susceptibility loci.

Adipocytokines, inflammation, and breast cancer risk in postmenopausal women: a prospective study

Obesity is a known risk factor for postmenopausal breast cancer; it has been postulated that adipocytokines may mediate this association. We explored the relationship between three markers altered by obesity: leptin, adiponectin, and soluble tumor necrosis factor receptor 2 (sTNF-R2), an inflammatory marker, with breast cancer risk in postmenopausal women. A nested case-control study of postmenopausal women was conducted within CLUE II, a prospective population-based cohort. Baseline plasma levels of leptin, adiponectin, and sTNF-R2 were assayed in 272 female breast cancer cases and 272 controls matched on age, date, and hour of blood draw. Conditional logistic regression was used to estimate matched odds ratios (OR) and 95% confidence intervals (CI). sTNF-R2 and leptin were independently positively associated with breast cancer risk in adjusted models. The OR for breast cancer comparing the highest to lowest tertile was 2.44 (95% CI: 1.30-4.58) for sTNF-R2 and 1.98 (95% CI: 1.20-3.29) for leptin. While higher levels of adiponectin were protective (OR for the lowest tertile = 1.63; 95% CI: 1.02-2.60), there was no dose response. A 20% reduction in the breast cancer risk associated with overweight/obesity was observed when sTNF-R2 alone was included in multivariable models. Including both sTNF-R2 and adiponectin in the models resulted in a 29% reduction in the OR. Adipocytokines and sTNF-R2 are important factors in the etiology of postmenopausal breast cancer due to adiposity. This study informs our understanding of the relationship between obesity, inflammation, and postmenopausal breast cancer and identifies potential biomarkers.

DNA repair gene variants in relation to overall cancer risk: a population-based study

The hypothesis that germ-line polymorphisms in DNA repair genes influence cancer risk has previously been tested primarily on a cancer site-specific basis. The purpose of this study was to test the hypothesis that DNA repair gene allelic variants contribute to globally elevated cancer risk by measuring associations with risk of all cancers that occurred within a population-based cohort. In the CLUE II cohort study established in 1989 in Washington County, MD, this study was comprised of all 3619 cancer cases ascertained through 2007 compared with a sample of 2296 with no cancer. Associations were measured between 759 DNA repair gene single nucleotide polymorphisms (SNPs) and risk of all cancers. A SNP in O(6)-methylguanine-DNA methyltransferase, MGMT, (rs2296675) was significantly associated with overall cancer risk [per minor allele odds ratio (OR) 1.30, 95% confidence interval (CI) 1.19-1.43 and P-value: 4.1 × 10(-8)]. The association between rs2296675 and cancer risk was stronger among those aged ≤54 years old than those who were ≥55 years at baseline (P-for-(interaction) = 0.021). OR were in the direction of increased risk for all 15 categories of malignancies studied (P < 0.0001), ranging from 1.22 (P = 0.42) for ovarian cancer to 2.01 (P = 0.008) for urinary tract cancers; the smallest P-value was for breast cancer (OR 1.45, P = 0.0002). The results indicate that the minor allele of MGMT SNP rs2296675, a common genetic marker with 37% carriers, was significantly associated with increased risk of cancer across multiple tissues. Replication is needed to more definitively determine the scientific and public health significance of this observed association.

Genome-wide association study of glioma and meta-analysis

Gliomas account for approximately 80 % of all primary malignant brain tumors and, despite improvements in clinical care over the last 20 years, remain among the most lethal tumors, underscoring the need for gaining new insights that could translate into clinical advances. Recent genome-wide association studies (GWAS) have identified seven new susceptibility regions. We conducted a new independent GWAS of glioma using 1,856 cases and 4,955 controls (from 14 cohort studies, 3 case-control studies, and 1 population-based case-only study) and found evidence of strong replication for three of the seven previously reported associations at 20q13.33 (RTEL), 5p15.33 (TERT), and 9p21.3 (CDKN2BAS), and consistent association signals for the remaining four at 7p11.2 (EGFR both loci), 8q24.21 (CCDC26) and 11q23.3 (PHLDB1). The direction and magnitude of the signal were consistent for samples from cohort and case-control studies, but the strength of the association was more pronounced for loci rs6010620 (20q,13.33; RTEL) and rs2736100 (5p15.33, TERT) in cohort studies despite the smaller number of cases in this group, likely due to relatively more higher grade tumors being captured in the cohort studies. We further examined the 85 most promising single nucleotide polymorphism (SNP) markers identified in our study in three replication sets (5,015 cases and 11,601 controls), but no new markers reached genome-wide significance. Our findings suggest that larger studies focusing on novel approaches as well as specific tumor subtypes or subgroups will be required to identify additional common susceptibility loci for glioma risk.

A population-based study of hedgehog pathway gene variants in relation to the dual risk of basal cell carcinoma plus another cancer

INTRODUCTION

A personal history of basal cell carcinoma (BCC) is associated with increased risk of other malignancies, but the reason is unknown. The hedgehog pathway is critical to the etiology of BCC, and is also believed to contribute to susceptibility to other cancers. This study tested the hypothesis that hedgehog pathway and pathway-related gene variants contribute to the increased risk of subsequent cancers among those with a history of BCC.

METHODS

The study was nested within the ongoing CLUE II cohort study, established in 1989 in Washington County, Maryland, USA. The study consisted of a cancer-free control group (n=2296) compared to three different groups of cancer cases ascertained through 2007, those diagnosed with: (1) Other (non-BCC) cancer only (n=2349); (2) BCC only (n=534); and (3) BCC plus other cancer (n=446). The frequencies of variant alleles were compared among these four groups for 20 single nucleotide polymorphisms (SNPs) in 6 hedgehog pathway genes (SHH, IHH, PTCH2, SMO, GLI1, SUFU), and also 22 SNPs in VDR and 8 SNPs in FAS, which have cross-talk with the hedgehog pathway.

RESULTS

Comparing those with both BCC and other cancer versus those with no cancer, no significant associations were observed for any of the hedgehog pathway SNPs, or for the FAS SNPs. One VDR SNP was nominally significantly associated with the BCC cancer-prone phenotype, rs11574085 [per minor allele odds ratio (OR) 1.38, 95% confidence interval (CI) 1.05-1.82; p-value=0.02].

CONCLUSION

The hedgehog pathway gene SNPs studied, along with the VDR and FAS SNPs studied, are not strongly associated with the BCC cancer-prone phenotype.

A population-based study of DNA repair gene variants in relation to non-melanoma skin cancer as a marker of a cancer-prone phenotype

For unknown reasons, non-melanoma skin cancer (NMSC) is associated with increased risk of other malignancies. Focusing solely on DNA repair or DNA repair-related genes, this study tested the hypothesis that DNA repair gene variants contribute to the increased cancer risk associated with a personal history of NMSC. From the parent CLUE II cohort study, established in 1989 in Washington County, MD, the study consisted of a cancer-free control group (n 5 2296) compared with three mutually exclusive groups of cancer cases ascertained through 2007: (i) Other (non-NMSC) cancer only (n 5 2349); (ii) NMSC only (n 5 694) and (iii) NMSC plus other cancer (n 5 577). The frequency of minor alleles in 759 DNA repair gene single nucleotide polymorphisms (SNPs) was compared in these four groups. Comparing those with both NMSC and other cancer versus those with no cancer, 10 SNPs had allelic trend P-values <0.01. The two top-ranked SNPs were both within the thymine DNA glycosylase gene (TDG). One was a non-synonymous coding SNP (rs2888805) [per allele odds ratio (OR) 1.40, 95% confidence interval (CI) 1.16-1.70; P-value 5 0.0006] and the other was an intronic SNP in high linkage disequilibrium with rs2888805 (rs4135150). None of the associations had a P-value <6.6310(-5), the threshold for statistical significance after correcting for multiple comparisons. The results pinpoint DNA repair genes most likely to contribute to the NMSC cancer-prone phenotype. A promising lead is genetic variants in TDG, important not only in base excision repair but also in regulating the epigenome and gene expression, which may contribute to the NMSC-associated increase in overall cancer risk.

Abstract 2639: A community-based study of nucleotide excision repair polymorphisms in relation to risk of non-melanoma skin cancer

Nucleotide excision repair (NER) is responsible for protecting DNA in skin cells against ultraviolet radiation-induced damage. Using a candidate pathway approach, a matched case-control study nested within a prospective, community-based cohort was carried out to test the hypothesis that single nucleotide polymorphisms (SNPs) in NER genes are associated with susceptibility to non-melanoma skin cancer (NMSC). Histologically-confirmed cases of NMSC (n=900) were matched to controls (n=900) on age, gender, and skin type. Associations were measured between NMSC and 221 SNPs in 26 NER genes. Using the additive model, two tightly linked functional SNPs in ERCC6 were significantly associated with increased risk of NMSC: rs2228527 (odds ratio (OR) 1.57, 95% confidence interval (CI) 1.20 - 2.05), and rs2228529 (OR 1.57, 95% CI 1.20 - 2.05). These associations were confined to basal cell carcinoma of the skin (BCC) (rs2228529, OR 1.78, 95% CI 1.30 - 2.44; rs2228527 OR 1.78, 95% CI 1.31 - 2.43). These novel, hypothesis-generating findings suggest functional variants in ERCC6 may be associated with an increased risk of NMSC that may be specific to BCC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2639. doi:1538-7445.AM2012-2639

Sun-seeking behavior to increase cutaneous vitamin D synthesis: when prevention messages conflict

OBJECTIVES

The public has long been encouraged to engage in sun-safe practices to minimize exposure to sunlight, the major cause of nonmelanoma skin cancer. More recently, some have advocated unprotected sun exposure to increase cutaneous synthesis of vitamin D as a way to promote health. We assessed the net result of these conflicting messages.

METHODS

In a cross-sectional survey in 2007, questionnaires were mailed to participants of an ongoing cohort study in Washington County, Maryland. The study population consisted of 8,027 adults (55% response rate).

RESULTS

Thirty percent of respondents were aware that unprotected sun exposure increased endogenous vitamin D levels. Among those who were aware of this benefit, 42% reported going out into the sun to increase vitamin D levels. Sun-seeking to increase vitamin D production did not significantly differ according to self-reported personal history of skin cancer, but was significantly higher among women, older age groups, those with less education, and vitamin D supplement users.

CONCLUSION

A substantial proportion of respondents reported sun-seeking behavior expressly to increase endogenous vitamin D levels. The message about sun exposure and vitamin D is reaching the general public; however, this finding poses challenges to skin cancer prevention efforts.

Body-mass index and mortality among 1.46 million white adults

BACKGROUND

A high body-mass index (BMI, the weight in kilograms divided by the square of the height in meters) is associated with increased mortality from cardiovascular disease and certain cancers, but the precise relationship between BMI and all-cause mortality remains uncertain.

METHODS

We used Cox regression to estimate hazard ratios and 95% confidence intervals for an association between BMI and all-cause mortality, adjusting for age, study, physical activity, alcohol consumption, education, and marital status in pooled data from 19 prospective studies encompassing 1.46 million white adults, 19 to 84 years of age (median, 58).

RESULTS

The median baseline BMI was 26.2. During a median follow-up period of 10 years (range, 5 to 28), 160,087 deaths were identified. Among healthy participants who never smoked, there was a J-shaped relationship between BMI and all-cause mortality. With a BMI of 22.5 to 24.9 as the reference category, hazard ratios among women were 1.47 (95 percent confidence interval [CI], 1.33 to 1.62) for a BMI of 15.0 to 18.4; 1.14 (95% CI, 1.07 to 1.22) for a BMI of 18.5 to 19.9; 1.00 (95% CI, 0.96 to 1.04) for a BMI of 20.0 to 22.4; 1.13 (95% CI, 1.09 to 1.17) for a BMI of 25.0 to 29.9; 1.44 (95% CI, 1.38 to 1.50) for a BMI of 30.0 to 34.9; 1.88 (95% CI, 1.77 to 2.00) for a BMI of 35.0 to 39.9; and 2.51 (95% CI, 2.30 to 2.73) for a BMI of 40.0 to 49.9. In general, the hazard ratios for the men were similar. Hazard ratios for a BMI below 20.0 were attenuated with longer-term follow-up.

CONCLUSIONS

In white adults, overweight and obesity (and possibly underweight) are associated with increased all-cause mortality. All-cause mortality is generally lowest with a BMI of 20.0 to 24.9.

Circulating 25-hydroxyvitamin D and risk of non-hodgkin lymphoma: Cohort Consortium Vitamin D Pooling Project of Rarer Cancers

Case-control studies generally suggesting an inverse association between sun exposure and non-Hodgkin lymphoma (NHL) have led to speculation that vitamin D may protect against lymphomagenesis. To examine this hypothesis, the authors conducted a pooled investigation of circulating 25-hydroxyvitamin D (25(OH)D) and subsequent NHL risk within 10 cohorts participating in the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers. The authors analyzed measurements from 1,353 cases and 1,778 controls using conditional logistic regression and other methods to estimate the association of 25(OH)D with NHL. No clear evidence of association between categories of 25(OH)D concentration and NHL was observed overall (P(trend) = 0.68) or by sex (men, P(trend) = 0.50; women, P(trend) = 0.16). Findings for other measures (continuous log(25(OH)D), categories of 25(OH)D using sex-/cohort-/season-specific quartiles as cutpoints, categories of season-adjusted residuals of predicted 25(OH)D using quartiles as cutpoints) were generally null, although some measures of increasing 25(OH)D were suggestive of an increased risk for women. Results from stratified analyses and investigations of histologic subtypes of NHL were also null. These findings do not support the hypothesis that elevated circulating 25(OH)D concentration is associated with a reduced risk of NHL. Future research investigating the biologic basis for the sunlight-NHL association should consider alternative mechanisms, such as immunologic effects.

Cigarette smoking and malignant melanoma: a case-control study

BACKGROUND

Several previous studies have reported inverse associations between cigarette smoking and melanoma. Often these studies have not adjusted for ultraviolet (UV) exposure history, skin type, or number of blistering sunburns, which could confound the observed associations between cigarette smoking and melanoma.

OBJECTIVE

We sought to assess whether this reported inverse association persists after adjusting for UV exposure, skin type, and number of blistering sunburns.

METHODS

We conducted a population-based case-control study (82 patients with melanoma, 164 control subjects). Two control subjects were matched to each patient by age, sex, race, and skin type. Conditional logistic regression models were fit to assess the association between cigarette smoking history and melanoma, with additional adjustments for UV exposure and sunburns.

RESULTS

Compared with never smoking, both former (odds ratio 0.43, 95% confidence interval 0.18-1.04) and current (odds ratio 0.65, 95% confidence interval 0.19-2.24) smoking were inversely associated with melanoma, but the associations were not statistically significant.

LIMITATIONS

The number of cutaneous nevi was not assessed in this study. In addition, the relatively small number of patients limits the statistical precision of the observed associations.

CONCLUSIONS

After matching for age, sex, race, and skin type, and further adjusting for UV exposure and number of sunburns, cigarette smoking was not statistically significantly associated with melanoma risk, but the results were consistent with previous observations of an inverse association.

Association of common polymorphisms in IL10, and in other genes related to inflammatory response and obesity with colorectal cancer

OBJECTIVE AND METHODS

The association of 17 candidate single nucleotide polymorphisms (SNPs) in IL10 and other immune response genes (CRP, TLR4, IL6, IL1B, IL8, TNF, RNASEL) and genes related to obesity (PPARG, TCF7L2, ADIPOQ, LEP) with colorectal cancer was investigated. Haplotype tagging SNPs were chosen for IL10, CRP, and TLR4. Incident colorectal cancer cases (n = 208) and matched controls (n = 381) were identified between baseline in 1989 and 2003 among participants in the CLUE II cohort. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using conditional logistic regression.

RESULTS

Compared with the AA genotype at the candidate IL10-1082 locus (rs1800896), carrying one (OR, 0.79; 95% CI, 0.53-1.18) or two (OR, 0.58; 95% CI, 0.35-0.95) G alleles, a known higher producer of the anti-inflammatory cytokine IL-10, was associated with lower risk of colorectal cancer (p trend = 0.03). Statistically significant associations with colorectal cancer were observed for three tagSNPs in IL10 (rs1800890, rs3024496, rs3024498) and one common haplotype, but these associations were due to high linkage disequilibrium with IL10-1082. Two CRP haplotypes (global p = 0.04) and TLR4 tagSNPs (rs7873784, rs11536891), but not TLR4 haplotypes, were associated with colorectal cancer.

CONCLUSIONS

Our study suggests that polymorphisms in IL10, and also possibly in CRP and other genes related to immune response or obesity may be associated with colorectal cancer.

The association between skin characteristics and skin cancer prevention behaviors

BACKGROUND

Behaviors such as sunscreen use and wearing sun-protective clothing are thought to prevent certain types of skin cancer and precancerous lesions, but few studies have examined differences in these prevention behaviors by skin type.

METHODS

We carried out a cross-sectional study (n = 6,858) nested within a community-based prospective cohort in Washington County, Maryland. We measured the associations between skin type, complexion, freckling, and eye color, and sunscreen and sun-protective clothing use.

RESULTS

The prevalence of regular sunscreen use was 23% and regular sun-protective clothing use was 21%. There were consistent trends indicating those with the most sun-sensitive skin type were most likely to engage in prevention behaviors. For example, compared with those who tan without burning, those who develop blistering sunburns were more likely to use sunscreen [odds ratio (OR), 6.04; 95% confidence interval (95% CI), 2.82-12.95 men; OR, 4.89; 95% CI, 3.34-7.16 women] and sun-protective clothing (OR, 2.87; 95% CI, 1.71-4.80 men; OR, 4.44; 95% CI, 2.88-6.85 women). Health-related characteristics such as body mass index and cigarette smoking were also significantly inversely associated with prevention behaviors.

CONCLUSION

The overall prevalence of prevention behaviors was low. Those with phenotypic risk factors for skin cancer were most likely to use sunscreen and sun-protective clothing. Those with high-risk skin cancer phenotypes may also be those who are most receptive to skin cancer prevention educational interventions.

Abstract A75: DNA repair genotypes associated with benign breast disease in women at high breast cancer risk

A75

Background

Benign breast disease (BBD) is a risk factor for breast cancer and may have a heritable component. Little is known about genetic factors associated with BBD risk. Deficient DNA repair has been implicated in the etiology of breast cancer. Since DNA repair occurs early in the breast carcinogenesis pathway, it is logical that polymorphic forms of DNA repair genes may alter BBD risk. No prior studies have reported on the association between DNA repair variants and BBD.

Methods

We examined the association between a panel of DNA repair genotypes and BBD in a sub-cohort of women within CLUE II, a population based cohort study in Washington County, Maryland. The women were followed from 1989 to 2003 with biennial questionnaires from 1996 onwards eliciting information on many health outcomes, including physician diagnosis of BBD and breast biopsies. 3,212 women reporting no prior diagnosis of BBD at baseline were genotyped for non-synonymous SNPs in 8 DNA repair genes (ERCC2, ERCC4, ERCC5, RAD23B, XPC, XRCC1, XRCC2, and XRCC4) that had previously been implicated in cancer risk. BBD-free survival time was fitted to age-adjusted Cox proportional hazards model and analyzed by DNA repair genotype.

Results

Carriers of the variant alleles of XRCC1 codon 194 and ERCC4 codon 415 were significantly more likely to be diagnosed with BBD than non-carriers -- hazard ratios (HR) = 1.36, 95%CI 1.06-1.74 and 1.39, 95%CI 1.09-1.76, respectively. The association between the ERCC4 variant and BBD was even greater among women with a positive family history of breast cancer. In this subgroup, the variant ERCC4 allele was associated with a 2.7 fold increase in breast cancer risk (HR = 2.63, 95% CI 1.52-4.66, p interaction = 0.02).

Conclusion

Variant ERCC4 and XRCC1 genotypes are significantly associated with a diagnosis of BBD in this population, particularly in women with a family history of breast cancer. These same genes have also been implicated in the risk of breast cancer in other studies. Taken together, these studies support the notion that these two DNA repair genes may have a common role in the etiology of both BBD and breast cancer.

Citation Information: Cancer Prev Res 2008;1(7 Suppl):A75.

Abstract B16: The association between skin characteristics and sun-protection behaviors

B16

Background

Behaviors such as sunscreen use and use of skin-protective clothing can help prevent skin cancer, but little is known about how these sun protection behaviors vary by phenotypic risk factors for skin cancer.

Objective

We carried out a cross-sectional study (n = 6898) nested within a community-based prospective cohort in Washington County, MD. We measured the associations between skin cancer risk characteristics (skin type, complexion, freckling, and eye color) and personal sun protection behaviors (sunscreen and sun-protective clothing use).

Results

The prevalence of regular use of sunscreen was 23%, and the prevalence of regular use of sun-protective clothing was 21%. There were consistent trends indicating those at highest risk of skin cancer were most likely to engage in sun protection behaviors. For example, compared to those who tan without burning, those who develop blistering sunburns were more likely to use sunscreen (OR 6.55, 95% CI 3.08 -13.92 men, OR 4.87, 95% CI 3.34 - 7.09 women) and sun-protective clothing (OR 2.90, 95% CI 1.73 - 4.85 men, OR 4.29, 95% CI 2.81 - 6.55 women). Those with fair skin were more likely than those with medium or dark brown complexion to use sunscreen or sun-protective clothing. Other factors significantly associated with sun protection behaviors were lifestyle-related factors such as lower body mass index and never smoking.

Conclusion

The overall prevalence of sun protection behaviors was low. Our results indicate individuals with the highest skin cancer susceptibility are most likely to use sunscreen and sun-protective clothing, and may also be most receptive to skin cancer prevention educational interventions.

Citation Information: Cancer Prev Res 2008;1(7 Suppl):B16.

Abstract B145: Association between physical activity, sleep duration, and cancer risk among women in Washington County, MD: A prospective cohort study

B145

Background

Physical activity is known to be protective for multiple cancers including breast. Modulation of hormonal factors such as leptin, ghrelin, and hyperinsulinemia as well as energy balance and BMI are thought to play a protective role. Short duration of sleep appears to have an opposite effect on many of these factors.

Methods

In a population based prospective cohort (CLUE II), we assessed the association between physical activity energy expenditure (PAEE), sleep duration, and incidence of first cancer (all-site) in women. 5968 adult females who answered questions on sleep and physical activity on a 1998 follow up questionnaire were included in the study population. Incident cases were identified through linkage of cohort participants with the Washington County Cancer Registry and Maryland State Cancer Registry. Adjusted hazard ratios (HR) and 95% confidence intervals were estimated from Cox proportional hazards models. All statistical tests were two sided.

Results

During 9.6 years of follow up, 604 1st incident cancer cases including 186 breast cancers were diagnosed. Overall cancer risk (HR=0.80, 95% CI 0.68, 0.95) and breast cancer risk (HR=0.75, 95% CI 0.55, 1.01) were significantly reduced among women in the upper 50% of PAEE compared to the lower. Sleep duration was not significantly associated with overall or breast cancer risk in adjusted HR models, but with an increase in colon cancer risk (HR = 1.72, 95% CI 0.99, 2.78) though the sample size was small. Excluding elderly women (&gt; 65 yrs in 1998) who may have different sleep patterns, sleep duration [≥ 7hrs/day vs. &lt; 7hrs/day] significantly modified the association between PAEE [upper vs. lower 50%] and overall cancer risk (p interaction=0.014). A 1.5 fold increase in cancer risk (HR=1.47, 95% CI 1.05, 2.06) was observed among women ≤ 65 years in the upper 50% of PAEE who did not have sufficient sleep (&lt; 7 hrs/day).

Conclusions

Increased PAEE was protective for cancer risk irrespective of age. In addition insufficient sleep may modify the observed protective effect of increased PAEE on cancer incidence among young and middle aged women.

Citation Information: Cancer Prev Res 2008;1(7 Suppl):B145.

Nonmelanoma skin cancer and risk for subsequent malignancy

BACKGROUND

Individuals with a personal history of nonmelanoma skin cancer (NMSC) may have an increased risk of subsequent noncutaneous malignancies. To test this hypothesis, we carried out a community-based, prospective cohort study.

METHODS

In the CLUE (Give Us a Clue to Cancer and Heart Disease) II cohort, which was established in Washington County, MD, in 1989, the risk of new malignancies was compared among individuals with (n = 769) and without (n = 18,405) a personal history of NMSC (total n = 19,174) during a 16-year follow-up period. Pathologically confirmed NMSC (and other malignancies) were ascertained from the Washington County Cancer Registry. Cox regression analysis with time-dependent covariates was used to determine the hazard ratios (presented as multivariable-adjusted relative risks [RRs]) and 95% confidence intervals (CIs) of second primary malignancies associated with a previously confirmed NMSC diagnosis. All statistical tests were two-sided.

RESULTS

The crude incidence rate (per 10,000 person-years) of subsequent cancers other than NMSC among participants with a positive personal history of NMSC was 293.5 and with a negative history was 77.8. Compared with persons with no personal history of NMSC, those with such a history had a statistically significantly increased risk of being diagnosed with a subsequent cancer other than NMSC (RR = 1.99, 95% CI = 1.70 to 2.33) after adjusting for age, sex, body mass index, smoking status, and educational level. The association was observed for both basal cell carcinoma (multivariable-adjusted RR = 2.03, 95% CI = 1.70 to 2.42) and squamous cell carcinoma (multivariable-adjusted RR = 1.97, 95% CI = 1.50 to 2.59) of the skin. NMSC was a statistically significantly stronger cancer risk factor in younger age groups than in older age groups (P for interaction = .022).

CONCLUSIONS

This community-based, prospective cohort study provides evidence for an association between an NMSC diagnosis and an increased risk of subsequent cancer, even after adjusting for individual-level risk factors.