The relationship of cancer history and chronic disease status to colorectal cancer screening: A cross-sectional analysis of 2020-2021 Behavioral Risk Factor Surveillance System

PURPOSE

We examined whether having a history of cancer and chronic diseases was associated with guideline-concordant colorectal cancer (CRC) screening utilization.

METHODS

Self-reported data from the 2020 and 2021 Behavioral Risk Factor Surveillance System in Oregon and West Virginia were used. Guideline-concordant CRC screening was the outcome of interest. The exposure was having a personal history of cancer, chronic diseases, or both. Multivariable logistic regressions were applied to assess the abovementioned association.

RESULTS

Among 10,373 respondents aged 45-75 years, 75.5% of those with a history of cancer and chronic diseases had guideline-concordant CRC screening use versus 52.8% of those without any history (p-value < 0.05). In multivariable analysis, having a history of cancer (OR 1.74; 95% CI 1.11-2.71), chronic diseases (OR 1.35; 95% CI 1.14-1.59), and both cancer and chronic diseases (OR 2.14; 95% CI 1.62-2.82) were positively associated with screening uptake compared to respondents without any history. Regardless of disease history, older age was associated with greater CRC screening uptake (p-value < 0.05). Among respondents with chronic diseases only or without any condition, those with a health care provider had 1.7-fold and 2.7-fold increased odds of receiving CRC screening, respectively. However, current smokers were 28% and 34% less likely to be screened for CRC among those with chronic diseases only and without any conditions, respectively.

CONCLUSION

Having a personal history of cancer and chronic diseases appears to be positively associated with guideline-concordant CRC screening use. Effective implementation of patient-centered communication through primary care initiatives may increase adherence to CRC screening recommendations.

A framework for assessing interactions for risk stratification models: the example of ovarian cancer

Generally, risk stratification models for cancer use effect estimates from risk/protective factor analyses that have not assessed potential interactions between these exposures. We have developed a 4-criterion framework for assessing interactions that includes statistical, qualitative, biological, and practical approaches. We present the application of this framework in an ovarian cancer setting because this is an important step in developing more accurate risk stratification models. Using data from 9 case-control studies in the Ovarian Cancer Association Consortium, we conducted a comprehensive analysis of interactions among 15 unequivocal risk and protective factors for ovarian cancer (including 14 non-genetic factors and a 36-variant polygenic score) with age and menopausal status. Pairwise interactions between the risk/protective factors were also assessed. We found that menopausal status modifies the association among endometriosis, first-degree family history of ovarian cancer, breastfeeding, and depot-medroxyprogesterone acetate use and disease risk, highlighting the importance of understanding multiplicative interactions when developing risk prediction models.

Multi-Institutional Study of Stereotactic Radiosurgery for Recurrent WHO Grade 2/3 Meningiomas: An Interim Analysis

PURPOSE/OBJECTIVE(S)

Meningiomas are the most common tumors of the central nervous system (CNS). Approximately 80% are classified as World Health Organization (WHO) grade 1, while 20% correspond to grade 2 or grade 3. In those with grade 2/3 disease, local recurrence is not uncommon. Salvage treatment options vary widely and include resection, external beam radiation therapy (EBRT), stereotactic radiosurgery (SRS), and/or clinical trials. Although retrospective studies have reported on the use of upfront SRS in grade 2/3 meningiomas, large-scale outcomes with SRS in the recurrent setting are lacking. The objective of this study was to report on oncologic outcomes for patients with recurrent grade 2/3 meningioma treated with SRS.

MATERIALS/METHODS

This is an ongoing multi-institutional retrospective cohort study. Eligibility criteria include patients >18 years old with pathologically confirmed WHO grade 2 or 3 meningioma treated with SRS monotherapy at the time of first recurrence. Patients require pathologic confirmation only at time of diagnosis; those with upfront grade 1 disease must have pathologic confirmation of grade 2/3 disease at time of first recurrence. Patients with multifocal disease upfront were excluded from this study.

RESULTS

A total of 60 patients met eligibility criteria. Baseline demographics at time of initial diagnosis are shown in table 1. At the time of first recurrence, 57 (95%) were WHO grade 2, and 3 (5%) were grade 3. Median follow up time from first recurrence was 5.02 years. Median marginal SRS dose was 16 Gy (IQR 14-17) to a 2.67cc planning treatment volume (IQR 1.4-5.1). 92% of patients received single fraction SRS. Median time to second recurrence was 5.92 years. 1, 3, and 5-year progression-free survival (PFS) was 95%, 68%, and 51%, respectively. 1, 3, and 5-year overall survival (OS) was 100%, 98%, and 96%, respectively. On multivariate analysis, grade 3 disease was independently associated with worse PFS (HR 15.7, p = 0.03). Median SRS dose and treatment volume did not correlate with PFS. 1 patient (1.7%) experienced symptomatic radiation necrosis requiring steroids, 3 (5.0%) experienced new seizure activity, and 2 (3.3%) additional patients showed clinical evidence of post-treatment neurocognitive decline.

CONCLUSION

Based on this interim analysis, primary SRS for recurrent grade 2/3 meningioma appears safe and feasible, with outcomes comparable to prospective data on high-risk grade 2/3 patients treated with post-operative fractionated EBRT. We look forward to further analysis with a larger cohort which may help guide further prospective studies.

CT-Guided Online Adaptive Stereotactic Body Radiotherapy for Pancreas Ductal Adenocarcinoma: Dosimetric and Initial Clinical Experience

PURPOSE/OBJECTIVE(S)

Retrospective analysis suggests that dose escalation to a biologically effective dose of more than 70 Gy may improve overall survival in patients with pancreatic ductal adenocarcinoma (PDAC), but such treatments in practice are limited by proximity of organs at risk (OARs). We hypothesized that CT-guided online adaptive radiotherapy (OART) can account for interfraction movement of OARs, reduce dose to OARs, and improve coverage of targets.

MATERIALS/METHODS

This is a single institution retrospective analysis of patients with PDAC treated with OART on a CBCT-based OART platform. All patients were treated to 40 Gy in 5 fractions. PTV overlapping with a 5 mm planning risk volume expansion on the stomach, duodenum and bowel received 25 Gy. Initial treatment plans were created conventionally. For each fraction, PTV and OAR volumes were recontoured with AI assistance after initial cone beam CT (CBCT). The adapted plan was calculated, underwent QA, and then compared to the scheduled plan. A second CBCT was obtained prior to delivery of the selected plan. Total treatment time (first CBCT to end of radiation delivery) and active physician time (first to second CBCT) were recorded. PTV_4000 V95%, PTV_2500 V95%, and D0.03 cc to stomach, duodenum and bowel were reported for scheduled (S) and adapted (A) plans. CTCAEv5.0 toxicities were recorded. Statistical analysis was performed using a two-sided T test and α of 0.05.

RESULTS

Seven patients with unresectable or locally-recurrent PDAC were analyzed, with a total of 35 fractions. Average total time was 33:00 minutes (22:25-49:40) and average active time was 22:48 minutes (14:15-39:34). All fractions were treated with adapted plans. All adapted plans met PTV_4000 V95.0% > 95.0% coverage goal and OAR dose constraints. Dosimetric data for scheduled and adapted plans per fraction are in Table 1. Median follow up was 1.7 months. 5 (71%) patients experienced either Grade 1 or 2 toxicities. No patients experienced Grade 3+ toxicities.

CONCLUSION

Daily OART significantly reduced dose OARs while achieving superior PTV coverage. Treatment was generally well tolerated with no grade 3+ acute toxicity, and required only 22:48 minutes on average of active physician time. Our initial clinical experience demonstrates OART allows for safe dose escalation in the treatment of PDAC.

A comparative study on behavior, awareness and belief about cervical cancer among rural and urban women in Vietnam

Cervical cancer is the second most common gynecologic cancer in Vietnam but based on the literature, only ~25% of Vietnamese women reported ever being screened for cervical cancer. To inform strategies to reduce the cervical cancer burden in Southern Vietnam where disease incidence is higher than the national average, this study examined behaviors, awareness, barriers, and beliefs about cervical cancer screening among rural and urban women in this geographical region. In October-November 2021, we conducted a cross-sectional study among 196 rural and 202 urban women in Southern Vietnam; participants completed a cervical cancer screening questionnaire. Descriptive analyses and rural-urban differences in screening behavior, awareness, barriers, and beliefs are presented. About half of the rural and urban participants reported ever being screened for cervical cancer. Most participants showed high perceived severity of cervical cancer and benefits of screening. Further, they reported that they would screen if it was recommended by doctors and/or friends/family. However, most women showed low awareness and perceived susceptibility to cervical cancer. Logistical and psychosocial barriers to physician-based screening methods were reported. Based on our results, the World Health Organization 2030 goals for cervical cancer screening are not currently met in Southern Vietnam. Increasing health literacy and engaging doctors and family members/social networks emerged as important avenues to improve screening. HPV (Human papillomavirus) self-sampling is also a potential approach to increase uptake of cervical cancer screening given the identified psychosocial and logistical barriers.

Lifetime ovulatory years and risk of epithelial ovarian cancer: a multinational pooled analysis

BACKGROUND

The role of ovulation in epithelial ovarian cancer (EOC) is supported by the consistent protective effects of parity and oral contraceptive use. Whether these factors protect through anovulation alone remains unclear. We explored the association between lifetime ovulatory years (LOY) and EOC.

METHODS

LOY was calculated using 12 algorithms. Odds ratios (ORs) and 95% confidence intervals (CIs) estimated the association between LOY or LOY components and EOC among 26 204 control participants and 21 267 case patients from 25 studies. To assess whether LOY components act through ovulation suppression alone, we compared beta coefficients obtained from regression models with expected estimates assuming 1 year of ovulation suppression has the same effect regardless of source.

RESULTS

LOY was associated with increased EOC risk (OR per year increase = 1.014, 95% CI = 1.009 to 1.020 to OR per year increase = 1.044, 95% CI = 1.041 to 1.048). Individual LOY components, except age at menarche, also associated with EOC. The estimated model coefficient for oral contraceptive use and pregnancies were 4.45 times and 12- to 15-fold greater than expected, respectively. LOY was associated with high-grade serous, low-grade serous, endometrioid, and clear cell histotypes (ORs per year increase = 1.054, 1.040, 1.065, and 1.098, respectively) but not mucinous tumors. Estimated coefficients of LOY components were close to expected estimates for high-grade serous but larger than expected for low-grade serous, endometrioid, and clear cell histotypes.

CONCLUSIONS

LOY is positively associated with nonmucinous EOC. Differences between estimated and expected model coefficients for LOY components suggest factors beyond ovulation underlie the associations between LOY components and EOC in general and for non-HGSOC.

Early onset of nasopharyngeal cancer in Asian/Pacific Islander Americans revealed by age-specific analysis

PURPOSE

Incidence of nasopharyngeal cancer is substantially higher in Asian/Pacific Islanders (APIs) than other racial groups. Examining age-specific incidence patterns by racial group and histology could inform disease etiology.

METHODS

We analyzed data from 2000 through 2019 from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program to compare age-specific incidence rates of nasopharyngeal cancer in non-Hispanic (NH) Blacks, NH APIs, and Hispanics to NH Whites using incidence rate ratios with 95% confidence intervals (CIs).

RESULTS

NH APIs showed the highest incidence of nasopharyngeal cancer across all histologic subtypes and almost all age groups. The racial differences were most pronounced in the age 30-39 group; relative to NH Whites, NH APIs were 15.24 (95% CI: 11.69-20.05), 17.26 (95% CI: 12.56-24.07), and 8.91 (95% CI: 6.79-11.48) times as likely to have differentiated non-keratinizing, undifferentiated non-keratinizing, and keratinizing squamous cell tumors, respectively.

CONCLUSIONS

These findings suggest an earlier onset of nasopharyngeal cancer among NH APIs, which highlight unique early life exposure to critical nasopharyngeal cancer risk factors as well as genetic predisposition in this high-risk population.

Severe maternal morbidity associated with endometriosis: a population based retrospective cohort study

OBJECTIVE

To evaluate the association between endometriosis and risk of severe maternal morbidity as defined by the Center for Disease Control and Prevention (CDC).

DESIGN

This was a population based retrospective cohort study using The California Office of Statewide Health Planning and Development (OSHPD) Linked Birth File with hospital discharge International Classification of Diseases, 9^th Revision, Clinical Modification (ICD-9-CM) diagnoses between 2007 and 2012.

PARTICIPANTS

3,098,578 pregnancies from 2007 to 2012 EXPOSURE: Prior diagnosis of endometriosis identified by ICD-9 codes 617.0-617.9.

MAIN OUTCOME AND MEASURES

The primary outcome of interest was severe maternal morbidity, which was defined as having been diagnosed with any of the ICD-9 codes corresponding to the 25 peripartum conditions listed by the CDC. Secondary outcomes of interest were each individual condition.

RESULTS

Of the 3,098,578 pregnancies analyzed, there were 2,910 pregnancies among women with a prior diagnosis of endometriosis. There were 45,655 pregnancies complicated by at least one severe maternal morbidity; 158 (54.3 per 1,000 pregnancies) were in pregnancies with endometriosis and 45,497 (14.7 per 1,000 pregnancies) were in pregnancies without endometriosis. Pregnancies complicated by endometriosis were 2.41 times as likely to develop severe maternal morbidity when compared to women who did not have endometriosis (aOR=2.41, 95% CI 2.03-2.87). There was increased risk of disseminated intravascular coagulation (aOR=2.46, 95% CI 1.65-3.66), heart failure during procedure or surgery (aOR=2.58, 95% CI 1.69-3.94), pulmonary edema (aOR=3.02, 95% CI 1.11-8.17), blood transfusion (aOR=2.17, 95% CI 1.75-2.68), and hysterectomy (aOR=2.46, 95% CI 1.58-3.85). When the association was stratified by delivery mode, risk of severe maternal morbidity was higher for vaginal delivery (aOR=4.59, 95% CI 2.73-7.71) versus cesarean delivery (aOR=1.64, 95% CI 1.37-1.97) (p-interaction <0.0001).

CONCLUSION

This study demonstrated that endometriosis is a major risk factor for severe maternal morbidity especially among those who deliver vaginally. Furthermore, precautions should be taken prior to delivery in anticipation of potential complications.

Characterization of mortality and high-risk characteristics of thyroid cancer in Filipinos using the California Cancer Registry

Introduction

Filipinos are the third largest Asian American subgroup and have the highest incidence of thyroid cancer among all races. To better understand this racial/ethnic disparity in thyroid cancer affecting Filipinos we analyzed the California Cancer Registry (CCR) data in Filipino thyroid cancer cases from 1988 to 2018.

Methods

97,948 thyroid cancer cases in California from 1988 to 2018 (until 2015 for Asian subgroups) were evaluated. We examined the case distribution by sex, age at diagnosis, race/ethnicity including Asian ethnic subgroups, histology, TNM stage, tumor size, lymph node involvement, lymphovascular invasion, and multifocality. We also looked at treatment data including surgery and radiation including radioactive iodine therapy. We calculated age-adjusted mortality rates (AAMR) for each major racial group and each Asian ethnic subgroup. Binary logistic regression was used to determine the likelihood of high-risk characteristics and treatment when comparing Filipinos to other racial/ethnic groups. Kaplan-Meier Estimate was performed to evaluate thyroid cancer survival across all race/ethnicities. Multivariate Cox proportion hazards regression was performed to evaluate mortality risk from all causes of death by race.

Results

There were 5,243 (5.35%) Filipino thyroid cancer cases in California from 1988 to 2018. Filipinos had the highest AAMR (1.22 deaths per 100,000) in 2015. Filipinos had a higher likelihood of Stage IV thyroid cancer compared with Non-Hispanic Whites, Non-Hispanic Blacks, Hispanics and nearly all Asian subgroups. Filipinos had a worse 5-year and 10-year overall survival (OS) than the combination of all other Asian/Pacific Islanders. Filipinos compared to Non-Hispanic Whites had significant mortality risk in overall and papillary thyroid cancer cases (Overall HR: 1.10, 95% CI 1.07-1.13, p < 0.0001, Papillary HR: 1.11, 95% CI 1.07-1.14, p < 0.0001) when adjusted for race/ethnicity, age, gender, socioeconomic status, and stage. When stratified by Charlson comorbidity score, Filipinos compared to Non-Hispanic Whites still had significant mortality risk (Charlson 0 HR: 1.07, 95% CI 1.02-1.11, p = 0.0017, Charlson 1+ HR: 1.07 95% CI 1.002-1.14, p = 0.0434).

Conclusions

Filipino thyroid cancer patients have higher incidences of high-risk pathological features and greater AAMR and mortality risk. These findings warrant further investigation into better understanding the connection between the greater incidence of high-risk characteristics and increased mortality in Filipinos.

Lifestyle and personal factors associated with having macroscopic residual disease after ovarian cancer primary cytoreductive surgery

OBJECTIVE

The presence of macroscopic residual disease after primary cytoreductive surgery (PCS) is an important factor influencing survival for patients with high-grade serous ovarian cancer (HGSC). More research is needed to identify factors associated with having macroscopic residual disease. We analyzed 12 lifestyle and personal exposures known to be related to ovarian cancer risk or inflammation to identify those associated with having residual disease after surgery.

METHODS

This analysis used data on 2054 patients with advanced stage HGSC from the Ovarian Cancer Association Consortium. The exposures were body mass index, breastfeeding, oral contraceptive use, depot-medroxyprogesterone acetate use, endometriosis, first-degree family history of ovarian cancer, incomplete pregnancy, menopausal hormone therapy use, menopausal status, parity, smoking, and tubal ligation. Logistic regression models were fit to assess the association between these exposures and having residual disease following PCS.

RESULTS

Menopausal estrogen-only therapy (ET) use was associated with 33% lower odds of having macroscopic residual disease compared to never use (OR = 0.67, 95%CI 0.46-0.97, p = 0.033). Compared to nulliparous women, parous women who did not breastfeed had 36% lower odds of having residual disease (OR = 0.64, 95%CI 0.43-0.94, p = 0.022), while there was no association among parous women who breastfed (OR = 0.90, 95%CI 0.65-1.25, p = 0.53).

CONCLUSIONS

The association between ET and having no macroscopic residual disease is plausible given a strong underlying biologic hypothesis between this exposure and diagnosis with HGSC. If this or the parity finding is replicated, these factors could be included in risk stratification models to determine whether HGSC patients should receive PCS or neoadjuvant chemotherapy.

Effects of risk factors for ovarian cancer in women with and without endometriosis

OBJECTIVE

To evaluate the associations between 10 well-established ovarian cancer risk factors and risk of ovarian cancer among women with vs. without endometriosis.

DESIGN

Pooled analysis of 9 case-control studies in the Ovarian Cancer Association Consortium.

SETTING

Population-based.

PATIENT(S)

We included 8,500 women with ovarian cancer, 13,592 control women.

INTERVENTION(S)

Ten well-established ovarian cancer risk factors.

MAIN OUTCOME MEASURE(S)

Risk of ovarian cancer for women with and without endometriosis.

RESULT(S)

Most risk factor-ovarian cancer associations were similar when comparing women with and without endometriosis, and no interactions were statistically significant. However, body mass index (BMI) 25-<30 kg/m² was associated with increased ovarian cancer risk among women with endometriosis (odds ratio [OR] = 1.27, 95% confidence interval [CI] 1.00-1.60), but not associated with the risk among women without endometriosis (OR = 0.97; 95% CI, 0.91-1.05) when compared with BMI 18.5-<25 kg/m²; an increased risk was observed for a BMI ≥30 kg/m², although there was little difference comparing women with endometriosis (OR = 1.21; 95% CI, 0.94-1.57) to women without (OR = 1.13; 95% CI, 1.04-1.22) (P-interaction = .51). Genital talcum powder use and long-term menopausal estrogen-only therapy use showed increased ovarian cancer risk, but risk appeared greater for those with endometriosis vs. those without (genital talcum powder: OR = 1.38; 95% CI, 1.04-1.84 vs. OR = 1.12; 95% CI, 1.01-1.25, respectively; ≥10 years of estrogen-only therapy: OR = 1.88; 95% CI, 1.09-3.24 vs. OR = 1.42; 95% CI, 1.14-1.76, respectively); neither of these interactions were statistically significant (P-interaction = .65 and P-interaction = .96, respectively).

CONCLUSION(S)

The associations between ovarian cancer and most risk factors were similar among women with and without endometriosis. However, there was some suggestion of differences by endometriosis status for BMI, menopausal hormone therapy use, and genital talcum powder use, highlighting the complexity of ovarian cancer etiology.

Sociodemographic characteristics associated with hepatitis C virus infection in Vietnamese Americans: A cross-sectional analysis of community screening data

Background

Prevalence of hepatitis C virus (HCV) infection among Vietnamese Americans is reportedly high. Understanding the profile of those at greater risk of HCV in this ethnic population is a vital step to addressing this high prevalence. We hypothesize that certain sociodemographic characteristics increase the likelihood of having HCV in Vietnamese Americans.

Methods

Cross-sectional data from 2,497 Vietnamese Americans in Southern California who participated in a series of community hepatitis screening events organized by the Vietnamese American Cancer Foundation (VACF) were analyzed. Serological tests via immunoassays were used to determine whether the participant had hepatitis C antibodies (anti-HCV) to indicate a HCV infection. Sociodemographic characteristics as well as participants’ reasons for screening were collected from questionnaires, and logistic regression models with odds ratios (ORs) and 95% confidence intervals (CIs) were used to quantify their associations with HCV infection.

Results

Approximately 5.8% of the study population was infected with HCV. Older adults and male participants had higher odds of being infected with HCV (e.g. OR = 2.90, 95% CI 1.25–6.76 for ages 70+ versus ages <40; OR = 2.57, 95% CI 1.79–3.69 for male versus female participants) as were those with a family history of HCV infection (OR = 2.74, 95% CI 1.57–4.78). In addition, perceived self-risk as a motivation for screening was significantly associated with HCV infection (OR = 1.88, 95% CI 1.26–2.78).

Conclusions

This study identifies specific subgroups in the Vietnamese American community who would largely benefit from targeted interventions given their higher likelihood of having HCV. These interventions should emphasize improving HCV knowledge and promoting HCV self-risk assessment since awareness of one’s own risk may motivate those likely to be infected to get screened.

Abstract 736: Exploring the impact of infertility and its treatments on risk of ovarian cancer

Background: Infertility is related to both nulligravidity and endometriosis, which are both well-established risk factors for ovarian cancer. Infertility is also characterized by various underlying causes and can be treated with different types of fertility drugs. However, most studies to date have been unable to properly address these important issues when examining the infertility-ovarian cancer association due to small numbers of patients and a lack of detailed infertility and risk factor information.

Methods: We pooled self-reported data from 8,324 invasive, epithelial ovarian cancer cases and 13,325 control women in eight population-based case-control studies participating in the Ovarian Cancer Association Consortium (OCAC) to study the infertility-ovarian cancer relationship. Women classified as having a history of infertility were those who had spoken to a doctor about infertility problems or those who had regular sexual intercourse without birth control for a prolonged period (usually one year) without getting pregnant. Cause of infertility as well as use of fertility drugs was examined among those who experienced infertility issues. These associations with risk of ovarian cancer were evaluated using logistic regression models and quantified using odds ratios (ORs) and 95% confidence intervals (CIs). Gravidity and endometriosis were considered in the analyses as well as potential confounding factors.

Results: Overall, infertility was not associated with risk of ovarian cancer (OR=1.02, 95% CI 0.95-1.09). However, women who reported their infertility was due to problems with ovulation or menstruation showed a decreased risk (OR=0.72, 95% CI 0.52-1.01 and OR=0.62, 95% CI 0.43-0.91, respectively) whereas women who reported their infertility was due to endometriosis were at an increased risk (OR=1.54, 95% CI 1.19-1.98). Among women who reported infertility issues, use of fertility drugs was not associated with an increased risk of ovarian cancer regardless of their gravidity status (OR=0.89, 95% CI 0.76-1.05).

Conclusions: The relationship between infertility and risk of ovarian cancer is complex. Although infertility does not appear to be an independent risk factor for ovarian cancer, specific causes of infertility may be differentially associated with ovarian cancer risk, which may shed light on the disease’s underlying etiology. In addition, for women experiencing infertility issues, use of fertility drugs did not show an increased risk of ovarian cancer, which may have important clinical implications.

Citation Format: Alice W. Lee, Minh T. Phung, Allan Jensen, Anna H. Wu, Daniel W. Cramer, Francesmary Modugno, Holly Harris, Jennifer A. Doherty, Joellen Schildkraut, Kathryn L. Terry, Kirsten B. Moysich, Malcolm C. Pike, Marc T. Goodman, Penelope M. Webb, Susanne K. Kjaer, Celeste L. Pearce. Exploring the impact of infertility and its treatments on risk of ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 736.

Reproductive Factors Do Not Influence Survival with Ovarian Cancer

BACKGROUND

Previous studies on the association between reproductive factors and ovarian cancer survival are equivocal, possibly due to small sample sizes.

METHODS

Using data on 11,175 people diagnosed with primary invasive epithelial ovarian, fallopian tube, or primary peritoneal cancer (ovarian cancer) from 16 studies in the Ovarian Cancer Association Consortium (OCAC), we examined the associations between survival and age at menarche, combined oral contraceptive use, parity, breastfeeding, age at last pregnancy, and menopausal status using Cox proportional hazard models. The models were adjusted for age at diagnosis, race/ethnicity, education level, and OCAC study and stratified on stage and histotype.

RESULTS

During the mean follow-up of 6.34 years (SD = 4.80), 6,418 patients passed away (57.4%). There was no evidence of associations between the reproductive factors and survival among patients with ovarian cancer overall or by histotype.

CONCLUSIONS

This study found no association between reproductive factors and survival after an ovarian cancer diagnosis.

IMPACT

Reproductive factors are well-established risk factors for ovarian cancer, but they are not associated with survival after a diagnosis of ovarian cancer.

Urinary Phytoestrogen Levels Are Associated with Female Hormonal Cancers: An Analysis of NHANES Data From 1999 to 2010

Phytoestrogens are plant-derived compounds that are structurally similar to endogenous estrogens. Studies have shown phytoestrogens to have possible health benefits although they could also act as endocrine disruptors. This is particularly relevant for estrogen-dependent cancers since estrogens increase risk of breast, endometrial, and ovarian cancer. Using data from the National Health and Nutritional Examination Survey (NHANES), we assessed the associations between urinary phytoestrogens (daidzein, equol, o-Desmethylangolensin (O-DMA), genistein, enterodiol, enterolactone) and breast, endometrial, and ovarian cancer using multivariate logistic regression with odds ratios (ORs) and 95% confidence intervals (CIs). Cancer diagnosis and other characteristics were collected via in-person questionnaires. We found women in the highest tertile for daidzein and enterodiol had over twice the odds of having breast cancer (OR = 2.51, 95% CI 1.44-4.36 for daidzein, OR = 2.78, 95% CI 1.44-5.37 for enterodiol). In addition, women in the highest tertiles for daidzein and genistein had three to four times the odds of having endometrial cancer, respectively (OR = 3.09, 95% CI 1.01-9.49 for daidzein, OR = 4.00, 95% CI 1.38-11.59 for genistein). Overall, phytoestrogens were positively associated with breast and endometrial cancer although the associations varied by phytoestrogen type. Additional studies are needed to further inform phytoestrogens' role in disease etiology.Supplemental data for this article is available online at at https://doi.org/10.1080/01635581.2021.2020304.

Abstract PO-198: Disparities in nasopharyngeal cancer incidence among Asian American ethnic subgroups

Background: Although nasopharyngeal cancer is a relatively rare malignancy in the United States (U.S.), its racial disparities are striking. Incidence has been shown to be over four times higher in Asian Americans than the general U.S. population and over seven times higher when compared to Whites. However, Asian Americans constitute a heterogeneous racial group, and it is becoming increasingly evident that considering each Asian ethnicity separately is crucial when it comes to cancer research so ethnic-specific differences are not missed. These differences can inform disease etiology and improve prevention efforts, but there is limited literature that considers the diversity of the Asian American population when it comes to nasopharyngeal cancer. Methods: Using population-based cancer registry data in the Surveillance, Epidemiology, and End Results Program from 1990 to 2014, we calculated age-adjusted incidence rates of nasopharyngeal cancer for nine Asian American ethnic subgroups: Chinese, Japanese, Filipino, Korean, Asian Indian/Pakistani, Vietnamese, Laotian, Cambodian, and Native Hawaiian/Pacific Islander. We compared these rates to the rate for non-Hispanic whites using incidence rate ratios (IRRs) and 95% confidence intervals (CIs). Sex and tumor histology were considered in the analyses as well. Results: Approximately 9,700 nasopharyngeal cancer cases were included. Incidence of nasopharyngeal cancer in all Asian American ethnic subgroups with the exception of Japanese and Asian Indian/Pakistani were statistically significantly higher than non-Hispanic whites; most notably, incidence in Laotians was over 14 times higher (IRR=14.71, 95% CI 11.87-18.02) and incidence in Chinese was over 10 times higher (IRR=10.73, 95% CI 10.19-11.29). When tumor histology was considered, the disparities were most pronounced for the differentiated and undifferentiated non-keratinizing tumors. Relative to non-Hispanic whites, incidence of the differentiated non-keratinizing histology was over 30 times higher in Laotians (IRR=30.19, 95% CI 17.97-47.45), and incidence of the undifferentiated non-keratinizing histology was close to 25 times higher in both Chinese and Laotians (IRR=24.82, 95% CI 21.97-28.02 and IRR=24.95, 95% CI 15.24-38.91, respectively). Conclusions: The higher incidence of nasopharyngeal cancer previously observed in Asian Americans is largely attributable to specific ethnic subgroups. Such disparities are overlooked when Asian Americans are studied in the aggregate. Future research should explore the environmental, behavioral, and genetic factors that may contribute to the significantly higher incidence of nasopharyngeal cancer observed in Chinese and Laotians.

Citation Format: Alice W. Lee, Angela Sou, Lihua Liu. Disparities in nasopharyngeal cancer incidence among Asian American ethnic subgroups [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-198.

Thyroid cancer incidence disparities among ethnic Asian American populations, 1990-2014

PURPOSE

Asian/Pacific Islanders (APIs) are at high risk of thyroid cancer, hence we examined thyroid cancer's incidence among disaggregated API subgroups in the United States (U.S.) to identify potential ethnic-specific disparities.

METHODS

Data from 1990 to 2014 in the Surveillance, Epidemiology, and End Results Program (SEER) were used to compare age-adjusted incidence rates (AAIRs) of thyroid cancer for seven API ethnic subgroups to non-Hispanic whites (NHWs) using incidence rate ratios (IRRs) and 95% confidence intervals (CIs). Sex, age, tumor histotype, and year of diagnosis were considered. Trends were evaluated using average annual percent change (AAPC) statistics.

RESULTS

The highest AAIRs (per 100,000 person-years) were among Filipinos (female AAIR=20.49, male AAIR=7.06) and the lowest among Japanese (female AAIR=8.36, male AAIR=3.20). However, Filipinos showed significantly lower incidence of medullary tumors when compared to NHWs (female IRR=0.60, 95% CI 0.40-0.87, male IRR=0.26, 95% CI 0.26-0.51). The largest increasing trends were among Asian Indian/Pakistanis for females (AAPC=5.19, 95% CI 3.81 to 6.58) and Koreans for males (AAPC=4.57, 95% CI 3.14 to 6.03).

CONCLUSIONS

There are clear differences in thyroid cancer incidence and trends when U.S. API ethnic subgroups are examined separately. Disaggregating APIs in research can provide critical information for understanding thyroid cancer risk.

Combination atezolizumab, bevacizumab, pemetrexed and carboplatin for metastatic EGFR mutated NSCLC after TKI failure

INTRODUCTION

Acquired resistance to TKI is an important unmet need in the management of EGFR mutated lung cancer. Recent clinical trial IMPower150 suggested that combination approach with VEGF inhibitor, check point inhibitor immunotherapy and platinum-based chemotherapy was effective in oncogene driven lung cancer. The current trial examined the efficacy of a modified regimen in an EGFR mutated cohort.

METHODS

An open-labelled, single arm, phase II study was conducted in patients with EGFR mutated NSCLC who had progressed on at least one EGFR TKI. For those with T790M mutation, radiological progression on osimertinib was required for enrolment. Patients were treated with combination atezolizumab (1200 mg), bevacizumab (7.5 mg/kg), pemetrexed (500 mg/m2) and carboplatin (AUC 5) given once every 3 weeks until progression.

RESULTS

Forty patients were enrolled. Median age was 62 (range 45-76) years. More than one half (23/40, 57.5%) had progressed on osimertinib. PD-L1 expression was < 1% in 52.5%. Median follow-up time was 17.8 months. ORR was 62.5%. Median PFS was 9.4 months (95% CI: 7.6 - 12.1). One year OS was 72.5% (95% CI: 0.56-0.83). Treatment related grade 3 or above adverse events (AE) occurred in 37.5% (15/40). Immune-related AE occurred in 32.5% (13/40) patients. Quality of life measures of function and symptoms did not change significantly throughout the course of treatments. Post-trial rechallenge with EGFR TKI containing regimen resulted in PFS of 5.8 months (95% CI 3.9-10.0 months).

CONCLUSION

Combination approach of atezolizumab, bevacizumab, pemetrexed and carboplatin achieved promising efficacy in metastatic EGFR mutated NSCLC after TKI failure. The results were comparable with taxane based regimen of IMPower150 while toxicity profile was improved.

Expanding Our Understanding of Ovarian Cancer Risk: The Role of Incomplete Pregnancies

BACKGROUND

Parity is associated with decreased risk of invasive ovarian cancer; however, the relationship between incomplete pregnancies and invasive ovarian cancer risk is unclear. This relationship was examined using 15 case-control studies from the Ovarian Cancer Association Consortium (OCAC). Histotype-specific associations, which have not been examined previously with large sample sizes, were also evaluated.

METHODS

A pooled analysis of 10 470 invasive epithelial ovarian cancer cases and 16 942 controls was conducted. Odds ratios (ORs) and 95% confidence intervals (CIs) for the association between incomplete pregnancies and invasive epithelial ovarian cancer were estimated using logistic regression. All models were conditioned on OCAC study, race and ethnicity, age, and education level and adjusted for number of complete pregnancies, oral contraceptive use, and history of breastfeeding. The same approach was used for histotype-specific analyses.

RESULTS

Ever having an incomplete pregnancy was associated with a 16% reduction in ovarian cancer risk (OR = 0.84, 95% CI = 0.79 to 0.89). There was a trend of decreasing risk with increasing number of incomplete pregnancies (2-sided Ptrend < .001). An inverse association was observed for all major histotypes; it was strongest for clear cell ovarian cancer.

CONCLUSIONS

Incomplete pregnancies are associated with a reduced risk of invasive epithelial ovarian cancer. Pregnancy, including incomplete pregnancy, was associated with a greater reduction in risk of clear cell ovarian cancer, but the result was broadly consistent across histotypes. Future work should focus on understanding the mechanisms underlying this reduced risk.

Depot-Medroxyprogesterone Acetate Use Is Associated with Decreased Risk of Ovarian Cancer: The Mounting Evidence of a Protective Role of Progestins

BACKGROUND

Combined oral contraceptive use is associated with a decreased risk of invasive epithelial ovarian cancer (ovarian cancer). There is suggestive evidence of an inverse association between progestin-only contraceptive use and ovarian cancer risk, but previous studies have been underpowered.

METHODS

The current study used primary data from 7,977 women with ovarian cancer and 11,820 control women in seven case-control studies from the Ovarian Cancer Association Consortium to evaluate the association between use of depot-medroxyprogesterone acetate (DMPA), an injectable progestin-only contraceptive, and ovarian cancer risk. Logistic models were fit to determine the association between ever use of DMPA and ovarian cancer risk overall and by histotype. A systematic review of the association between DMPA use and ovarian cancer risk was conducted.

RESULTS

Ever use of DMPA was associated with a 35% decreased risk of ovarian cancer overall (OR, 0.65; 95% confidence interval, 0.50-0.85). There was a statistically significant trend of decreasing risk with increasing duration of use (P _trend < 0.001). The systematic review yielded six studies, four of which showed an inverse association and two showed increased risk.

CONCLUSIONS

DMPA use appears to be associated with a decreased risk of ovarian cancer in a duration-dependent manner based on the preponderance of evidence. Further study of the mechanism through which DMPA use is associated with ovarian cancer is warranted.

IMPACT

The results of this study are of particular interest given the rise in popularity of progestin-releasing intrauterine devices that have a substantially lower progestin dose than that in DMPA, but may have a stronger local effect.

Menopausal hormone therapy prior to the diagnosis of ovarian cancer is associated with improved survival

PURPOSE

Prior studies of menopausal hormone therapy (MHT) and ovarian cancer survival have been limited by lack of hormone regimen detail and insufficient sample sizes. To address these limitations, a comprehensive analysis of 6419 post-menopausal women with pathologically confirmed ovarian carcinoma was conducted to examine the association between MHT use prior to diagnosis and survival.

METHODS

Data from 15 studies in the Ovarian Cancer Association Consortium were included. MHT use was examined by type (estrogen-only (ET) or estrogen+progestin (EPT)), duration, and recency of use relative to diagnosis. Cox proportional hazards models were used to estimate the association between hormone therapy use and survival. Logistic regression and mediation analysis was used to explore the relationship between MHT use and residual disease following debulking surgery.

RESULTS

Use of ET or EPT for at least five years prior to diagnosis was associated with better ovarian cancer survival (hazard ratio, 0.80; 95% CI, 0.74 to 0.87). Among women with advanced stage, high-grade serous carcinoma, those who used MHT were less likely to have any macroscopic residual disease at the time of primary debulking surgery (p for trend <0.01 for duration of MHT use). Residual disease mediated some (17%) of the relationship between MHT and survival.

CONCLUSIONS

Pre-diagnosis MHT use for 5+ years was a favorable prognostic factor for women with ovarian cancer. This large study is consistent with prior smaller studies, and further work is needed to understand the underlying mechanism.

Abstract 3498: Ovarian cancer risk factors multiply to create high risk in pre-menopausal women

Background: Ovarian cancer is the eighth-most common cancer among women. Although a number of established risk factors exist for this disease, analyses of these exposures have largely not taken into account potential interactions. We present an interaction analysis of eight ovarian cancer risk factors, followed by the creation of modifiable and non-modifiable risk scores for the disease.

Methods: Data used in this analysis come from nine studies in the Ovarian Cancer Association Consortium (OCAC): one from Australia, one from Europe and seven from the US. Analyses were restricted to pre-menopausal women without first-degree family histories of ovarian cancer, leading to a final study population of 1504 cases and 3515 controls. Five potentially modifiable predictors (oral contraceptive (OC) use duration, body mass index, tubal ligation, hysterectomy and breastfeeding) and three non-modifiable predictors (parity, incomplete pregnancies and history of endometriosis) were considered. A complete analysis of interactions between the eight variables as well as with age, race/ethnicity, education level and study site was conducted. No statistically significant pairwise interactions were found with likelihood ratio statistics, thus suggesting no departure from multiplicativity in the odds ratios. The modifiable and non-modifiable risk scores were calculated as the product of the odds ratios for each group of exposures. Logistic regression was used to model the association between ovarian cancer and the risk scores. Age, race/ethnicity, education level and study site were included in the model.

Results: The associations between the second, third and fourth quartiles of the modifiable risk score compared to the lowest quartile were 1.67 (95% CI 1.35-2.09), 2.18 (95% CI 1.76-2.71) and 3.72 (95% CI 3.04-4.57), respectively. The odds ratios for the non-modifiable risk score were 1.17 (95% CI 0.95-1.44), 1.24 (95% CI 0.99-1.54) and 2.06 (95% CI 1.68-2.53), respectively for the second, third and fourth quartiles compared to the first. Women in the highest quartiles of both the modifiable and non-modifiable risk scores, representing 14.6% of the women, had a 7.67-fold increased risk of ovarian cancer (95% CI 4.68-11.39) compared to women in the lowest quartiles for both risk scores (3.6% of the women).

Conclusions: Pre-menopausal women in the highest risk quartiles have a substantially elevated risk of ovarian cancer based on these eight exposures. Modifiable factors contribute more than non-modifiable factors to ovarian cancer risk among pre-menopausal women with no family history in our study. Women in the highest risk group (fourth quartile of both risk scores) could reduce their risk by intervening on the modifiable exposures; for example, 63% of women in this group had not used oral contraceptives and 93% had not had tubal ligation. However, careful consideration of the risks and benefits of such prevention measures is needed.

Citation Format: Minh Tung Phung, Bhramar Mukherjee, Alice W. Lee, Penelope M. Webb, Harvey A. Risch, Jennifer Anne Doherty, Holly R. Harris, Marc T. Goodman, Roberta B. Ness, Francesmary Modugno, Allan Jensen, Susanne K. Kjaer, Kathryn L. Terry, Daniel W. Cramer, Argyrios Ziogas, Hoda Anton-Culver, Malcolm C. Pike, Anna H. Wu, Celeste Leigh Pearce. Ovarian cancer risk factors multiply to create high risk in pre-menopausal women [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3498.

Abstract B38: Use of progestin-only injectable contraceptive is associated with reduced risk of ovarian cancer in the Ovarian Cancer Association Consortium

Background: Combined oral contraceptive use is associated with a decreased risk of ovarian carcinoma (cancer). However, the relationship between progestin-only contraceptives and ovarian cancer risk is unclear. Two previous studies have suggested a protective effect whereas another reported a non-statistically significant increased risk of ovarian cancer. The current study examined the association between use of depot medroxyprogesterone acetate (DMPA), a progestin-only injectable contraceptive, and ovarian cancer risk, using data from seven case-control studies participating in the Ovarian Cancer Association Consortium (OCAC).

Methods: A pooled analysis examining the relationship between DMPA use and ovarian cancer risk was conducted using 7,679 invasive ovarian cancer cases and 11,136 controls from six studies from the United States and one from Australia. Combined oral contraceptive use, parity, education level, age, and race/ethnicity were considered important a priori confounders and were included in all statistical models. OCAC study site was also included in all models. The impact of additional exposures, including a personal history of endometriosis, first-degree family history of ovarian cancer, tubal ligation, breastfeeding, body mass index, and menopausal hormonal therapy use on the association between DMPA use and ovarian cancer were considered. None of these variables was found to impact the DMPA use-ovarian cancer association by &gt;10% and thus not included in the final models. Odds ratios (OR) and 95% confidence intervals (CI) were generated from logistic regression models. The association between duration of DMPA use, categorized as never use, &lt;2 years of use, and 2+ years of use, and ovarian cancer risk was examined in the two studies that had this information available.

Results: The frequency of DMPA use among controls ranged from 1.25% to 3.53% across the seven studies. DMPA use was more common in controls than in cases in all of the studies. Overall, ever use of DMPA was associated with a 26% decreased risk of ovarian cancer (95% CI 0.58-0.94), after taking into account combined oral contraceptive use, parity, education level, age, race/ethnicity, and OCAC study site. A significant trend with duration of use was observed in the two studies with these data (p=0.02).

Conclusions: DMPA use appears to be associated with a decreased risk of ovarian cancer. The finding provides additional evidence that progestins may be protective for ovarian cancer. Further evaluation of the role of DMPA as a potential primary prevention strategy for ovarian cancer, especially in women for whom combined oral contraceptive use is contraindicated due to concerns about estrogen-induced thromboembolic events, is warranted.

Citation Format: Minh Tung Phung, Penelope M. Webb, Jennifer Anne Doherty, Holly R. Harris, Pamela J. Thompson, Marc T. Goodman, Kirsten Moysich, Francesmary Modugno, Roberta B. Ness, Joellen M. Schildkraut, Andrew Berchuck, Daniel W. Cramer, Kathryn L. Terry, Linda Titus, Alice W. Lee, Malcolm C. Pike, Anna H. Wu, Celeste Leigh Pearce. Use of progestin-only injectable contraceptive is associated with reduced risk of ovarian cancer in the Ovarian Cancer Association Consortium [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr B38.

Abstract B32: Are ovarian cancer risk factors different for women with endometriosis?

Background: Endometriosis is a common gynecologic disorder that affects approximately 10% of women of reproductive age. It is also a well-established risk factor for ovarian cancer. Whether hormonal-related and other risk factors for ovarian cancer (e.g., parity, oral contraceptive use) are the same for women with and without endometriosis is currently unknown.

Methods: We pooled questionnaire information from 10 population-based case-control studies participating in the Ovarian Cancer Association Consortium (OCAC). Data from 8,172 women with invasive epithelial ovarian cancer and 12,464 controls were included in our analysis. Associations of body mass index (BMI), parity, oral contraceptive use, breastfeeding, menopausal hormone therapy use, first-degree family history of ovarian cancer, tubal ligation, and hysterectomy with risk of ovarian cancer were stratified by history of endometriosis and analyzed using logistic regression. All models were conditioned on age, race/ethnicity, education, and OCAC study site. We fit an endometriosis interaction term for each risk factor to evaluate statistical interactions.

Results: Among women with no history of endometriosis, those who had hysterectomies showed a 12% increased risk of ovarian cancer compared to those with intact uteri (OR=1.12, 95% CI 1.01-1.24); an increased risk was not observed among women with endometriosis (OR=0.74, 95% CI 0.53-1.05; p-interaction=0.009). Use of estrogen-progestin hormone therapy was associated with decreased risk ovarian cancer for women with histories of endometriosis (OR=0.69, 95% CI 0.47-1.02), but not for those without endometriosis (OR=0.96, 95% CI 0.87-1.07; p-interaction=0.02). We did not observe any significant statistical interactions for the other risk factors considered, and no interactions were significant after consideration of multiple comparisons.

Conclusions: The associations of hysterectomy and menopausal estrogen-progestin hormone therapy use with risk of ovarian cancer seemed to differ by endometriosis status, suggesting interactions that may need to be considered in ovarian cancer risk profiling strategies. Future investigations into the biology underlying these interactions would be relevant.

Citation Format: Aruna Muthukumar, Lilah Khoja, Penelope M. Webb, Harvey Risch, Jennifer Doherty, Holly Harris, Marc Goodman, Roberta Ness, Francesmary Modugno, Susanne K. Kjaer, Allan Jensen, Joellen Schildkraut, Andrew Berchuck, Kathryn L. Terry, Daniel Cramer, Linda J. Titus, Hoda Anton-Culver, Argyrios Ziogas, Anna H. Wu, Malcolm C. Pike, Celeste L. Pearce, Alice W. Lee. Are ovarian cancer risk factors different for women with endometriosis? [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr B32.

Abstract D021: Chinese E-Women Project: A community-based approach to improving breast cancer knowledge among Chinese American women

Background: Breast cancer is the most common cancer for Chinese women living in the United States (U.S.). Despite overall rates being significantly lower than other races and ethnicities, incidence has steadily increased over the last few decades. This is concerning given that Asian Americans are the fastest growing racial group in the U.S. and Chinese Americans constitute the largest Asian American ethnic population. In addition, mammography screening rates are low among Chinese American women, and this may be attributable to a lack of breast cancer knowledge and awareness. Methods: The Chinese E-Women Project (CEWP) is a breast health education and engagement program developed by the Orange County Herald Center (OCHC), a non-profit organization that serves the Chinese American community in Orange County, California. Two key CEWP components are the Community Gatekeeper Education Session (CGES), which is a formal education session led by trained OCHC staff to engage and educate Chinese American community leaders, and the E-Women Tea Time (EWTT), which is an informal peer group education session led by a past CGES participant. All CGES and EWTT events presented information on breast cancer epidemiology, biology, and screening. Questionnaires testing breast cancer knowledge were administered before and after the education session at each event. We pooled data across the CGES and EWTT events separately and used Wilcoxon signed rank test to evaluate change in participants’ overall knowledge. We also examined change in knowledge by question using McNemar’s test. Results: Our analysis included a total of 94 CGES and 149 EWTT female participants. For both CGES and EWTT, we observed significant improvements in overall breast cancer knowledge after the education session (both p&lt;0.0001). Although we did identify one question related to mammography and another question related to personal breast health that did not show significant improvement after the session, knowledge for all other questions significantly improved (all p&lt;0.05). Conclusions: These findings highlight community-based education sessions as effective ways of both informing Chinese American women about breast cancer and engaging them to become advocates of breast health wellness in their community. Future research should evaluate whether these types of sessions can lead to positive individual changes in behavior and screening practice.

Citation Format: Alice W Lee, Cindy Puga, Michelle Tsai, Sherry Huang. Chinese E-Women Project: A community-based approach to improving breast cancer knowledge among Chinese American women [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D021.

Immigration history, lifestyle characteristics, and breast density in the Vietnamese American Women's Health Study: a cross-sectional analysis

PURPOSE

Breast density is an important risk factor for breast cancer and varies substantially across racial-ethnic groups. However, determinants of breast density in Vietnamese immigrants in the United States (US) have not been studied. We investigated whether reproductive factors, immigration history, and other demographic and lifestyle factors were associated with breast density in Vietnamese Americans.

METHODS

We collected information on demographics, immigration history, and other lifestyle factors and mammogram reports from a convenience sample of 380 Vietnamese American women in California aged 40 to 70 years. Breast Imaging Reporting and Data System (BI-RADS) breast density was abstracted from mammogram reports. Multivariable logistic regression was used to investigate the association between lifestyle factors and having dense breasts (BI-RADS 3 or 4).

RESULTS

All participants were born in Viet Nam and 82% had lived in the US for 10 years or longer. Younger age, lower body mass index, nulliparity/lower number of deliveries, and longer US residence (or younger age at migration) were associated with having dense breasts. Compared to women who migrated at age 40 or later, the odds ratios and 95% confidence intervals for having dense breasts among women who migrated between the ages of 30 and 39 and before age 30 were 1.72 (0.96-3.07) and 2.48 (1.43-4.32), respectively.

CONCLUSIONS

Longer US residence and younger age at migration were associated with greater breast density in Vietnamese American women. Identifying modifiable mediating factors to reduce lifestyle changes that adversely impact breast density in this traditionally low-risk population for breast cancer is warranted.

Abstract DP-011: PRE-DIAGNOSIS USE OF MENOPAUSAL HORMONE THERAPY ASSOCIATED WITH BETTER OVARIAN CANCER SURVIVAL

BACKGROUND: Several lifestyle factors have consistently been associated with survival of ovarian cancer, including body mass index, analgesic medications, physical activity, and smoking. Menopausal hormone therapy (HT), which can comprise of estrogen only (ET) or a combination of estrogen and progestin (EPT), has also been studied for its impact on ovarian survival. Randomized trials as well as a recent meta-analysis have shown better survival for women who took HT after their diagnosis in comparison to women who did not (HR=0.67, 95% CI 0.47-0.97). However, the relationship between use of HT prior to ovarian cancer diagnosis and survival is less clear.

METHODS: Approximately 4,700 ovarian cancer patients across nine population-based studies participating in the Ovarian Cancer Association Consortium (OCAC) were included in our analysis. Information on HT use prior to diagnosis and potential confounders was obtained via phone or in-person interviews. To estimate the effect of pre-diagnostic HT use on ovarian cancer survival, hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards regression models with left and right truncation to account for different observation times. Effects by type and duration of HT use as well as disease histotype were also evaluated.

RESULTS: Women who used HT before diagnosis had an 11% decreased risk of death in comparison to those who did not use HT (95% CI 0.82-0.97). Similar effects were observed for both types of HT (HR=0.86, 95% CI 0.75-0.98 for ET and HR=0.89, 95% CI 0.80-0.99 for EPT). In addition, there appeared to be a duration effect with longer HT use conferring better survival (p-trend=0.07 for ET, p-trend=0.003 for EPT). When histotype was considered, the overall decreased risk was driven by serous and mucinous ovarian cancers (HR=0.85, 95% CI 0.77-0.93 and HR=0.54, 95% CI 0.28-1.07, respectively).

CONCLUSIONS: Use of HT after diagnosis also affords a survival advantage based on published observational and clinical trials data. We now report that pre-diagnosis HT use may confer a survival advantage among women with ovarian cancer. Interestingly, use of ET prior to diagnosis is associated with increased risk of ovarian cancer, but better survival among women diagnosed with the disease. These observations taken together demonstrate the complex nature of ovarian cancer.

Citation Format: Alice W. Lee, Siri Peterson, Ashley Wiensch, Malcolm C. Pike, Celeste L. Pearce on behalf of the Ovarian Cancer Association Consortium. PRE-DIAGNOSIS USE OF MENOPAUSAL HORMONE THERAPY ASSOCIATED WITH BETTER OVARIAN CANCER SURVIVAL [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr DP-011.

Insight into hepatitis B prevalence and risk factors among Vietnamese Americans: a cross-sectional analysis of data from a community-based screening program

OBJECTIVES

The aims of our study were to describe current hepatitis B prevalence among Vietnamese Americans and to examine predictors of hepatitis B risk in this specific ethnic community.

DESIGN

Cross-sectional analysis of data from a community-based screening program.

SETTING

This analysis was based on hepatitis screening community events in Southern California.

PARTICIPANTS

2508 Vietnamese Americans in Southern California.

OUTCOME MEASURES

Serological tests for hepatitis B surface antigen, hepatitis B surface antibody, and total hepatitis B core antibody were used to classify participants as one of four hepatitis B infection statuses: currently infected, previously infected, susceptible, or immune due to a previous hepatitis B vaccination.

RESULTS

Across 2508 participants, 9.0% were currently infected with hepatitis B and 17.7% were at risk for hepatitis B. Females and those reporting a previous hepatitis B vaccination were at significant decreased risk of hepatitis B (OR=0.48, 95% CI 0.33 to 0.69 and OR=0.53, 95% CI 0.31 to 0.93, respectively) whereas those born outside of the USA and with a family history of the disease showed substantial increased risk (OR=13.36, 95% CI 1.62 to 110.05 and OR=4.68, 95% CI 2.66 to 8.22, respectively). Among those who reported a previous hepatitis B vaccination, less than half (42.9%) possessed the protective antibodies that result from a hepatitis B vaccination.

CONCLUSIONS

Vietnamese Americans remain disproportionately burdened by hepatitis B. Public health efforts that focus on improving hepatitis B awareness and vaccination knowledge and that are tailored to specific high-risk subgroups, such as immigrants and those with infected family members, could help in addressing the disease's burden in this high-prevalence population.

Clear differences in ovarian cancer incidence and trends by ethnicity among Asian Americans

BACKGROUND

Across major races in the United States (U.S.), ovarian cancer incidence is low among Asian American women. However, this observation aggregates Asian Americans as a single group despite their heterogeneity. Disaggregating the ethnic Asian population will produce more useful information to better understand ovarian cancer incidence among Asian women in the U.S.

METHODS

Data from the Surveillance, Epidemiology, and End Results Program from 1990 to 2014 were used to compare age-adjusted incidence rates (AAIRs, per 100,000 women) for ovarian cancer for the six largest U.S. Asian ethnicities (Asian Indian/Pakistani, Chinese, Filipino, Japanese, Korean, Vietnamese) to non-Hispanic whites (NHWs). The race/ethnicity-specific AAIRs were calculated by time period and histotype. We examined the magnitude and direction of AAIR trends using average annual percent change (AAPC) statistics.

RESULTS

All Asian ethnicities had significantly lower ovarian cancer incidence rates than NHWs. However, among Asian ethnicities, Asian Indians/Pakistanis had the highest rate of ovarian cancer (AAIR = 10.51, 95% CI: 9.65-11.42) while Koreans had the lowest (AAIR = 7.23, 95% CI: 6.62-7.88). Clear cell ovarian cancer had significantly higher incidence rates among Chinese, Filipino, and Japanese women than NHW women (incidence rate ratio (IRR) = 1.49, 95% CI: 1.29-1.72, IRR = 1.30, 95% CI: 1.12-1.51, IRR = 1.64, 95% CI: 1.36-1.97, respectively). Incidence trends also differed by Asian ethnicity with significant decreases only observed for Chinese (AAPC = -1.49, 95% CI: -2.22 to -0.74) and Japanese (AAPC = -1.75, 95% CI: -2.57 to -0.92).

CONCLUSIONS

Examining Asian Americans as a single group results in missed ethnic-specific disparities in ovarian cancer, hence disaggregating this heterogeneous population in future research is warranted.

A comprehensive gene-environment interaction analysis in Ovarian Cancer using genome-wide significant common variants

As a follow-up to genome-wide association analysis of common variants associated with ovarian carcinoma (cancer), our study considers seven well-known ovarian cancer risk factors and their interactions with 28 genome-wide significant common genetic variants. The interaction analyses were based on data from 9971 ovarian cancer cases and 15,566 controls from 17 case-control studies. Likelihood ratio and Wald tests for multiplicative interaction and for relative excess risk due to additive interaction were used. The top multiplicative interaction was noted between oral contraceptive pill (OCP) use (ever vs. never) and rs13255292 (p value = 3.48 × 10-4 ). Among women with the TT genotype for this variant, the odds ratio for OCP use was 0.53 (95% CI = 0.46-0.60) compared to 0.71 (95%CI = 0.66-0.77) for women with the CC genotype. When stratified by duration of OCP use, women with 1-5 years of OCP use exhibited differential protective benefit across genotypes. However, no interaction on either the multiplicative or additive scale was found to be statistically significant after multiple testing correction. The results suggest that OCP use may offer increased benefit for women who are carriers of the T allele in rs13255292. On the other hand, for women carrying the C allele in this variant, longer (5+ years) use of OCP may reduce the impact of carrying the risk allele of this SNP. Replication of this finding is needed. The study presents a comprehensive analytic framework for conducting gene-environment analysis in ovarian cancer.

rs495139 in the TYMS-ENOSF1 Region and Risk of Ovarian Carcinoma of Mucinous Histology

Thymidylate synthase (TYMS) is a crucial enzyme for DNA synthesis. TYMS expression is regulated by its antisense mRNA, ENOSF1. Disrupted regulation may promote uncontrolled DNA synthesis and tumor growth. We sought to replicate our previously reported association between rs495139 in the TYMS-ENOSF1 3' gene region and increased risk of mucinous ovarian carcinoma (MOC) in an independent sample. Genotypes from 24,351 controls to 15,000 women with invasive OC, including 665 MOC, were available. We estimated per-allele odds ratios (OR) and 95% confidence intervals (CI) using unconditional logistic regression, and meta-analysis when combining these data with our previous report. The association between rs495139 and MOC was not significant in the independent sample (OR = 1.09; 95% CI = 0.97⁻1.22; p = 0.15; N = 665 cases). Meta-analysis suggested a weak association (OR = 1.13; 95% CI = 1.03⁻1.24; p = 0.01; N = 1019 cases). No significant association with risk of other OC histologic types was observed (p = 0.05 for tumor heterogeneity). In expression quantitative trait locus (eQTL) analysis, the rs495139 allele was positively associated with ENOSF1 mRNA expression in normal tissues of the gastrointestinal system, particularly esophageal mucosa (r = 0.51, p = 1.7 × 10-28), and nonsignificantly in five MOC tumors. The association results, along with inconclusive tumor eQTL findings, suggest that a true effect of rs495139 might be small.

Variants in genes encoding small GTPases and association with epithelial ovarian cancer susceptibility

Epithelial ovarian cancer (EOC) is the fifth leading cause of cancer mortality in American women. Normal ovarian physiology is intricately connected to small GTP binding proteins of the Ras superfamily (Ras, Rho, Rab, Arf, and Ran) which govern processes such as signal transduction, cell proliferation, cell motility, and vesicle transport. We hypothesized that common germline variation in genes encoding small GTPases is associated with EOC risk. We investigated 322 variants in 88 small GTPase genes in germline DNA of 18,736 EOC patients and 26,138 controls of European ancestry using a custom genotype array and logistic regression fitting log-additive models. Functional annotation was used to identify biofeatures and expression quantitative trait loci that intersect with risk variants. One variant, ARHGEF10L (Rho guanine nucleotide exchange factor 10 like) rs2256787, was associated with increased endometrioid EOC risk (OR = 1.33, p = 4.46 x 10-6). Other variants of interest included another in ARHGEF10L, rs10788679, which was associated with invasive serous EOC risk (OR = 1.07, p = 0.00026) and two variants in AKAP6 (A-kinase anchoring protein 6) which were associated with risk of invasive EOC (rs1955513, OR = 0.90, p = 0.00033; rs927062, OR = 0.94, p = 0.00059). Functional annotation revealed that the two ARHGEF10L variants were located in super-enhancer regions and that AKAP6 rs927062 was associated with expression of GTPase gene ARHGAP5 (Rho GTPase activating protein 5). Inherited variants in ARHGEF10L and AKAP6, with potential transcriptional regulatory function and association with EOC risk, warrant investigation in independent EOC study populations.

Robust Tests for Additive Gene-Environment Interaction in Case-Control Studies Using Gene-Environment Independence

There have been recent proposals advocating the use of additive gene-environment interaction instead of the widely used multiplicative scale, as a more relevant public health measure. Using gene-environment independence enhances statistical power for testing multiplicative interaction in case-control studies. However, under departure from this assumption, substantial bias in the estimates and inflated type I error in the corresponding tests can occur. In this paper, we extend the empirical Bayes (EB) approach previously developed for multiplicative interaction, which trades off between bias and efficiency in a data-adaptive way, to the additive scale. An EB estimator of the relative excess risk due to interaction is derived, and the corresponding Wald test is proposed with a general regression setting under a retrospective likelihood framework. We study the impact of gene-environment association on the resultant test with case-control data. Our simulation studies suggest that the EB approach uses the gene-environment independence assumption in a data-adaptive way and provides a gain in power compared with the standard logistic regression analysis and better control of type I error when compared with the analysis assuming gene-environment independence. We illustrate the methods with data from the Ovarian Cancer Association Consortium.

Timing of births and oral contraceptive use influences ovarian cancer risk

Increasing parity and duration of combined oral contraceptive (COC) use provide substantial protection against ovarian carcinoma (cancer). There are limited data on the impact of the age of the births or age of COC use on reducing ovarian cancer risk. Here, we examined the effects of age at first and last births and age at use of COCs using data from studies conducted in Los Angeles County, California, USA (1,632 cases, 2,340 controls). After adjusting for the number of births, every 5 years that a first birth was delayed reduced the risk of ovarian cancer by 13% (95% CI 5-21%; p = 0.003); a first birth after age 35 was associated with a 47% lower risk than a first birth before age 25. COC use before age 35 was associated with greater protection per year of use than COC use at older ages. Considering previously published results as well as the results presented here, increasing parity and a later age at births are both important protective factors against ovarian cancer and the protection extends over 30 or more years from last birth. Current models of the etiology of ovarian cancer do not encompass an effect of late age at births. Our result of an attenuation of the protective effect with COC use after around age 35 needs further investigation as it has not been seen in all studies.

Cigarette smoking is associated with adverse survival among women with ovarian cancer: Results from a pooled analysis of 19 studies

Cigarette smoking is associated with an increased risk of developing mucinous ovarian tumors but whether it is associated with ovarian cancer survival overall or for the different histotypes is unestablished. Furthermore, it is unknown whether the association between cigarette smoking and survival differs according to strata of ovarian cancer stage at diagnosis. In a large pooled analysis, we evaluated the association between various measures of cigarette smoking and survival among women with epithelial ovarian cancer. We obtained data from 19 case-control studies in the Ovarian Cancer Association Consortium (OCAC), including 9,114 women diagnosed with ovarian cancer. Cox regression models were used to estimate adjusted study-specific hazard ratios (HRs), which were combined into pooled hazard ratios (pHR) with corresponding 95% confidence intervals (CIs) under random effects models. Overall, 5,149 (57%) women died during a median follow-up period of 7.0 years. Among women diagnosed with ovarian cancer, both current (pHR = 1.17, 95% CI: 1.08-1.28) and former smokers (pHR = 1.10, 95% CI: 1.02-1.18) had worse survival compared with never smoking women. In histotype-stratified analyses, associations were observed for mucinous (current smoking: pHR = 1.91, 95% CI: 1.01-3.65) and serous histotypes (current smoking: pHR = 1.11, 95% CI: 1.00-1.23; former smoking: pHR = 1.12, 95% CI: 1.04-1.20). Further, our results suggested that current smoking has a greater impact on survival among women with localized than disseminated disease. The identification of cigarette smoking as a modifiable factor associated with survival has potential clinical importance as a focus area to improve ovarian cancer prognosis.

A splicing variant of TERT identified by GWAS interacts with menopausal estrogen therapy in risk of ovarian cancer

Menopausal estrogen-alone therapy (ET) is a well-established risk factor for serous and endometrioid ovarian cancer. Genetics also plays a role in ovarian cancer, which is partly attributable to 18 confirmed ovarian cancer susceptibility loci identified by genome-wide association studies. The interplay among these loci, ET use and ovarian cancer risk has yet to be evaluated. We analyzed data from 1,414 serous cases, 337 endometrioid cases and 4,051 controls across 10 case-control studies participating in the Ovarian Cancer Association Consortium (OCAC). Conditional logistic regression was used to determine the association between the confirmed susceptibility variants and risk of serous and endometrioid ovarian cancer among ET users and non-users separately and to test for statistical interaction. A splicing variant in TERT, rs10069690, showed a statistically significant interaction with ET use for risk of serous ovarian cancer (pint  = 0.013). ET users carrying the T allele had a 51% increased risk of disease (OR = 1.51, 95% CI 1.19-1.91), which was stronger for long-term ET users of 10+ years (OR = 1.85, 95% CI 1.28-2.66, pint  = 0.034). Non-users showed essentially no association (OR = 1.08, 95% CI 0.96-1.21). Two additional genomic regions harboring rs7207826 (C allele) and rs56318008 (T allele) also had significant interactions with ET use for the endometrioid histotype (pint  = 0.021 and pint  = 0.037, respectively). Hence, three confirmed susceptibility variants were identified whose associations with ovarian cancer risk are modified by ET exposure; follow-up is warranted given that these interactions are not adjusted for multiple comparisons. These findings, if validated, may elucidate the mechanism of action of these loci.

Assessment of variation in immunosuppressive pathway genes reveals TGFBR2 to be associated with risk of clear cell ovarian cancer

BACKGROUND

Regulatory T (Treg) cells, a subset of CD4+ T lymphocytes, are mediators of immunosuppression in cancer, and, thus, variants in genes encoding Treg cell immune molecules could be associated with ovarian cancer.

METHODS

In a population of 15,596 epithelial ovarian cancer (EOC) cases and 23,236 controls, we measured genetic associations of 1,351 SNPs in Treg cell pathway genes with odds of ovarian cancer and tested pathway and gene-level associations, overall and by histotype, for the 25 genes, using the admixture likelihood (AML) method. The most significant single SNP associations were tested for correlation with expression levels in 44 ovarian cancer patients.

RESULTS

The most significant global associations for all genes in the pathway were seen in endometrioid ( p = 0.082) and clear cell ( p = 0.083), with the most significant gene level association seen with TGFBR2 ( p = 0.001) and clear cell EOC. Gene associations with histotypes at p < 0.05 included: IL12 ( p = 0.005 and p = 0.008, serous and high-grade serous, respectively), IL8RA ( p = 0.035, endometrioid and mucinous), LGALS1 ( p = 0.03, mucinous), STAT5B ( p = 0.022, clear cell), TGFBR1 ( p = 0.021 endometrioid) and TGFBR2 ( p = 0.017 and p = 0.025, endometrioid and mucinous, respectively).

CONCLUSIONS

Common inherited gene variation in Treg cell pathways shows some evidence of germline genetic contribution to odds of EOC that varies by histologic subtype and may be associated with mRNA expression of immune-complex receptor in EOC patients.

Abstract 797: A splicing variant of TERT identified by GWAS interacts with menopausal estrogen therapy in risk of ovarian cancer

Menopausal estrogen-alone therapy (ET) is a well-established risk factor for serous and endometrioid ovarian carcinoma. Genetics also plays an important role in ovarian carcinoma etiology, which is partly attributable to 18 confirmed susceptibility loci identified by genome-wide association studies (GWASs). Each of these common variants is associated with a modest relative risk estimate, but it is possible that interactions between non-genetic and genetic risk factors exist, thereby putting some women at higher risk. This interplay among the 18 loci, ET use, and ovarian carcinoma risk has yet to be evaluated.

In our analysis, we used individual questionnaire data from 1,414 serous cases, 337 endometrioid cases, and 4,051 controls across 10 case-control studies participating in the Ovarian Cancer Association Consortium (OCAC). The genotype data was based on information from three GWASs, their replication efforts, and two large-scale arrays. Conditional logistic regression was used to determine the association between the 18 confirmed variants and risk of serous and endometrioid ovarian carcinoma among ET users and non-users separately. A likelihood ratio test was used to test for statistical interaction (i.e., departure from a multiplicative model).

After controlling for well-established ovarian carcinoma risk factors as well as genetic ancestry, a splicing variant in TERT, rs10069690, showed a significant interaction with ET use for risk of serous ovarian carcinoma (pint = 0.014). ET users carrying the T allele had a 50% increased risk of disease (OR = 1.50, 95% CI 1.16-1.93); the impact of this allele was even stronger for long-term ET users of 10+ years (OR = 2.13, 95% CI 1.39-2.37, pint = 0.036). Non-ET users showed essentially no association with the disease (OR = 1.09, 95% CI 0.97-1.22). In addition, two SNPS, rs7207826 (C allele) and rs56318008 (T allele), in other genomic regions had significant interactions with ET use for the endometrioid histotype (pint = 0.030 and pint = 0.042, respectively).

Overall, we have shown evidence of statistical interactions between postmenopausal ET use and three confirmed ovarian cancer susceptibility alleles with risk of serous and endometrioid ovarian cancer. We observed four statistically significant interactions, which is twice as many as would be expected by chance at the p≤0.05 level, although none survived correction for multiple comparisons. This is the first study, to our knowledge, to suggest potential gene-environment interactions in ovarian carcinoma in the context of hormone therapy use with confirmed susceptibility alleles. It is also intriguing that the identified interactions include confirmed variants that are located in or adjacent to genes in which estrogen is biologically involved. These findings, if replicated, may be critical for future risk prediction modeling.

Citation Format: Alice W. Lee, Ashley Bomkamp, Elisa V. Bandera, Allan Jensen, Susan J. Ramus, Marc T. Goodman, Mary Anne Rossing, Francesmary Modugno, Kirsten B. Moysich, Jenny Chang-Claude, Anja Rudolph, Aleksandra Gentry-Maharaj, Kathryn L. Terry, Simon A. Gayther, Daniel W. Cramer, Jennfier A. Doherty, Joellen M. Schildkraut, Susanne K. Kjaer, Roberta B. Ness, Usha Menon, Andrew Berchuck, Bhramar Mukherjee, Lynda Roman, Paul D. Pharoah, Georgia Chenevix-Trench, Anna H. Wu, Malcolm C. Pike, Celeste L. Pearce. A splicing variant of TERT identified by GWAS interacts with menopausal estrogen therapy in risk of ovarian cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 797.

The association between socioeconomic status and tumour stage at diagnosis of ovarian cancer: A pooled analysis of 18 case-control studies

PURPOSE

Socioeconomic status (SES) is a known predictor of survival for several cancers and it has been suggested that SES differences affecting tumour stage at diagnosis may be the most important explanatory factor for this. However, only a limited number of studies have investigated SES differences in tumour stage at diagnosis of ovarian cancer. In a pooled analysis, we investigated whether SES as represented by level of education is predictive for advanced tumour stage at diagnosis of ovarian cancer, overall and by histotype. The effect of cigarette smoking and body mass index (BMI) on the association was also evaluated.

METHODS

From 18 case-control studies, we obtained information on 10,601 women diagnosed with epithelial ovarian cancer. Study specific odds ratios (ORs) with corresponding 95% confidence intervals (CI) were obtained from logistic regression models and combined into a pooled odds ratio (pOR) using a random effects model.

RESULTS

Overall, women who completed ≤high school had an increased risk of advanced tumour stage at diagnosis compared with women who completed >high school (pOR 1.15; 95% CI 1.03-1.28). The risk estimates for the different histotypes of ovarian cancer resembled that observed for ovarian cancers combined but did not reach statistical significance. Our results were unchanged when we included BMI and cigarette smoking.

CONCLUSION

Lower level of education was associated with an increased risk of advanced tumour stage at diagnosis of ovarian cancer. The observed socioeconomic difference in stage at diagnosis of ovarian cancer calls for further studies on how to reduce this diagnostic delay.

Evidence of a genetic link between endometriosis and ovarian cancer

OBJECTIVE

To evaluate whether endometriosis-associated genetic variation affects risk of ovarian cancer.

DESIGN

Pooled genetic analysis.

SETTING

University hospital.

PATIENT(S)

Genetic data from 46,176 participants (15,361 ovarian cancer cases and 30,815 controls) from 41 ovarian cancer studies.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Endometriosis-associated genetic variation and ovarian cancer.

RESULT(S)

There was significant evidence of an association between endometriosis-related genetic variation and ovarian cancer risk, especially for the high-grade serous and clear cell histotypes. Overall we observed 15 significant burden statistics, which was three times more than expected.

CONCLUSION(S)

By focusing on candidate regions from a phenotype associated with ovarian cancer, we have shown a clear genetic link between endometriosis and ovarian cancer that warrants further follow-up. The functional significance of the identified regions and SNPs is presently uncertain, though future fine mapping and histotype-specific functional analyses may shed light on the etiologies of both gynecologic conditions.

Epithelial-Mesenchymal Transition (EMT) Gene Variants and Epithelial Ovarian Cancer (EOC) Risk

Epithelial-mesenchymal transition (EMT) is a process whereby epithelial cells assume mesenchymal characteristics to facilitate cancer metastasis. However, EMT also contributes to the initiation and development of primary tumors. Prior studies that explored the hypothesis that EMT gene variants contribute to epithelial ovarian carcinoma (EOC) risk have been based on small sample sizes and none have sought replication in an independent population. We screened 15,816 single-nucleotide polymorphisms (SNPs) in 296 genes in a discovery phase using data from a genome-wide association study of EOC among women of European ancestry (1,947 cases and 2,009 controls) and identified 793 variants in 278 EMT-related genes that were nominally (P < 0.05) associated with invasive EOC. These SNPs were then genotyped in a larger study of 14,525 invasive-cancer patients and 23,447 controls. A P-value <0.05 and a false discovery rate (FDR) <0.2 were considered statistically significant. In the larger dataset, GPC6/GPC5 rs17702471 was associated with the endometrioid subtype among Caucasians (odds ratio (OR) = 1.16, 95% CI = 1.07-1.25, P = 0.0003, FDR = 0.19), whereas F8 rs7053448 (OR = 1.69, 95% CI = 1.27-2.24, P = 0.0003, FDR = 0.12), F8 rs7058826 (OR = 1.69, 95% CI = 1.27-2.24, P = 0.0003, FDR = 0.12), and CAPN13 rs1983383 (OR = 0.79, 95% CI = 0.69-0.90, P = 0.0005, FDR = 0.12) were associated with combined invasive EOC among Asians. In silico functional analyses revealed that GPC6/GPC5 rs17702471 coincided with DNA regulatory elements. These results suggest that EMT gene variants do not appear to play a significant role in the susceptibility to EOC.

Common variants at the CHEK2 gene locus and risk of epithelial ovarian cancer

Genome-wide association studies have identified 20 genomic regions associated with risk of epithelial ovarian cancer (EOC), but many additional risk variants may exist. Here, we evaluated associations between common genetic variants [single nucleotide polymorphisms (SNPs) and indels] in DNA repair genes and EOC risk. We genotyped 2896 common variants at 143 gene loci in DNA samples from 15 397 patients with invasive EOC and controls. We found evidence of associations with EOC risk for variants at FANCA, EXO1, E2F4, E2F2, CREB5 and CHEK2 genes (P ≤ 0.001). The strongest risk association was for CHEK2 SNP rs17507066 with serous EOC (P = 4.74 x 10(-7)). Additional genotyping and imputation of genotypes from the 1000 genomes project identified a slightly more significant association for CHEK2 SNP rs6005807 (r (2) with rs17507066 = 0.84, odds ratio (OR) 1.17, 95% CI 1.11-1.24, P = 1.1×10(-7)). We identified 293 variants in the region with likelihood ratios of less than 1:100 for representing the causal variant. Functional annotation identified 25 candidate SNPs that alter transcription factor binding sites within regulatory elements active in EOC precursor tissues. In The Cancer Genome Atlas dataset, CHEK2 gene expression was significantly higher in primary EOCs compared to normal fallopian tube tissues (P = 3.72×10(-8)). We also identified an association between genotypes of the candidate causal SNP rs12166475 (r (2) = 0.99 with rs6005807) and CHEK2 expression (P = 2.70×10(-8)). These data suggest that common variants at 22q12.1 are associated with risk of serous EOC and CHEK2 as a plausible target susceptibility gene.

Network-Based Integration of GWAS and Gene Expression Identifies a HOX-Centric Network Associated with Serous Ovarian Cancer Risk

BACKGROUND

Genome-wide association studies (GWAS) have so far reported 12 loci associated with serous epithelial ovarian cancer (EOC) risk. We hypothesized that some of these loci function through nearby transcription factor (TF) genes and that putative target genes of these TFs as identified by coexpression may also be enriched for additional EOC risk associations.

METHODS

We selected TF genes within 1 Mb of the top signal at the 12 genome-wide significant risk loci. Mutual information, a form of correlation, was used to build networks of genes strongly coexpressed with each selected TF gene in the unified microarray dataset of 489 serous EOC tumors from The Cancer Genome Atlas. Genes represented in this dataset were subsequently ranked using a gene-level test based on results for germline SNPs from a serous EOC GWAS meta-analysis (2,196 cases/4,396 controls).

RESULTS

Gene set enrichment analysis identified six networks centered on TF genes (HOXB2, HOXB5, HOXB6, HOXB7 at 17q21.32 and HOXD1, HOXD3 at 2q31) that were significantly enriched for genes from the risk-associated end of the ranked list (P < 0.05 and FDR < 0.05). These results were replicated (P < 0.05) using an independent association study (7,035 cases/21,693 controls). Genes underlying enrichment in the six networks were pooled into a combined network.

CONCLUSION

We identified a HOX-centric network associated with serous EOC risk containing several genes with known or emerging roles in serous EOC development.

IMPACT

Network analysis integrating large, context-specific datasets has the potential to offer mechanistic insights into cancer susceptibility and prioritize genes for experimental characterization.

Cis-eQTL analysis and functional validation of candidate susceptibility genes for high-grade serous ovarian cancer

Genome-wide association studies have reported 11 regions conferring risk of high-grade serous epithelial ovarian cancer (HGSOC). Expression quantitative trait locus (eQTL) analyses can identify candidate susceptibility genes at risk loci. Here we evaluate cis-eQTL associations at 47 regions associated with HGSOC risk (P≤10(-5)). For three cis-eQTL associations (P<1.4 × 10(-3), FDR<0.05) at 1p36 (CDC42), 1p34 (CDCA8) and 2q31 (HOXD9), we evaluate the functional role of each candidate by perturbing expression of each gene in HGSOC precursor cells. Overexpression of HOXD9 increases anchorage-independent growth, shortens population-doubling time and reduces contact inhibition. Chromosome conformation capture identifies an interaction between rs2857532 and the HOXD9 promoter, suggesting this SNP is a leading causal variant. Transcriptomic profiling after HOXD9 overexpression reveals enrichment of HGSOC risk variants within HOXD9 target genes (P=6 × 10(-10) for risk variants (P<10(-4)) within 10 kb of a HOXD9 target gene in ovarian cells), suggesting a broader role for this network in genetic susceptibility to HGSOC.

Common Genetic Variation in Circadian Rhythm Genes and Risk of Epithelial Ovarian Cancer (EOC)

Disruption in circadian gene expression, whether due to genetic variation or environmental factors (e.g., light at night, shiftwork), is associated with increased incidence of breast, prostate, gastrointestinal and hematologic cancers and gliomas. Circadian genes are highly expressed in the ovaries where they regulate ovulation; circadian disruption is associated with several ovarian cancer risk factors (e.g., endometriosis). However, no studies have examined variation in germline circadian genes as predictors of ovarian cancer risk and invasiveness. The goal of the current study was to examine single nucleotide polymorphisms (SNPs) in circadian genes BMAL1, CRY2, CSNK1E, NPAS2, PER3, REV1 and TIMELESS and downstream transcription factors KLF10 and SENP3 as predictors of risk of epithelial ovarian cancer (EOC) and histopathologic subtypes. The study included a test set of 3,761 EOC cases and 2,722 controls and a validation set of 44,308 samples including 18,174 (10,316 serous) cases and 26,134 controls from 43 studies participating in the Ovarian Cancer Association Consortium (OCAC). Analysis of genotype data from 36 genotyped SNPs and 4600 imputed SNPs indicated that the most significant association was rs117104877 in BMAL1 (OR = 0.79, 95% CI = 0.68-0.90, p = 5.59 × 10^-4]. Functional analysis revealed a significant down regulation of BMAL1 expression following cMYC overexpression and increasing transformation in ovarian surface epithelial (OSE) cells as well as alternative splicing of BMAL1 exons in ovarian and granulosa cells. These results suggest that variation in circadian genes, and specifically BMAL1, may be associated with risk of ovarian cancer, likely through disruption of hormonal pathways.

Common Genetic Variation In Cellular Transport Genes and Epithelial Ovarian Cancer (EOC) Risk

BACKGROUND

Defective cellular transport processes can lead to aberrant accumulation of trace elements, iron, small molecules and hormones in the cell, which in turn may promote the formation of reactive oxygen species, promoting DNA damage and aberrant expression of key regulatory cancer genes. As DNA damage and uncontrolled proliferation are hallmarks of cancer, including epithelial ovarian cancer (EOC), we hypothesized that inherited variation in the cellular transport genes contributes to EOC risk.

METHODS

In total, DNA samples were obtained from 14,525 case subjects with invasive EOC and from 23,447 controls from 43 sites in the Ovarian Cancer Association Consortium (OCAC). Two hundred seventy nine SNPs, representing 131 genes, were genotyped using an Illumina Infinium iSelect BeadChip as part of the Collaborative Oncological Gene-environment Study (COGS). SNP analyses were conducted using unconditional logistic regression under a log-additive model, and the FDR q<0.2 was applied to adjust for multiple comparisons.

RESULTS

The most significant evidence of an association for all invasive cancers combined and for the serous subtype was observed for SNP rs17216603 in the iron transporter gene HEPH (invasive: OR = 0.85, P = 0.00026; serous: OR = 0.81, P = 0.00020); this SNP was also associated with the borderline/low malignant potential (LMP) tumors (P = 0.021). Other genes significantly associated with EOC histological subtypes (p<0.05) included the UGT1A (endometrioid), SLC25A45 (mucinous), SLC39A11 (low malignant potential), and SERPINA7 (clear cell carcinoma). In addition, 1785 SNPs in six genes (HEPH, MGST1, SERPINA, SLC25A45, SLC39A11 and UGT1A) were imputed from the 1000 Genomes Project and examined for association with INV EOC in white-European subjects. The most significant imputed SNP was rs117729793 in SLC39A11 (per allele, OR = 2.55, 95% CI = 1.5-4.35, p = 5.66x10-4).

CONCLUSION

These results, generated on a large cohort of women, revealed associations between inherited cellular transport gene variants and risk of EOC histologic subtypes.