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Research Studies

California Teachers Study

California Teachers Study website: http://www.calteachersstudy.org

The California Teachers Study (CTS) is a long-term, follow-up (prospective cohort) study of 133,479 female teachers and school administrators. In 1995 and 1996, participants completed an extensive questionnaire that focused on lifestyle, medical history, and women's health. Each year, cohort members receive a newsletter, and every other year, they provide the CTS researchers with updated or new information about their health and lifestyle. Cancer diagnoses are confirmed through the statewide California Cancer Registry (www.ccrcal.org).

The CTS is a collaborative study conducted by the Northern California Cancer Center (NCCC), City of Hope (COH), University of Southern California (USC), the University of California at Irvine (UCI), and the California Cancer Registry (CCR).

September 2009 Press Release on the California Teachers Study and some of its findings

Emergent Hypotheses Regarding the Causes of Breast and Other Cancers
The main focus of the CTS is the evaluation of a wide range of emergent hypotheses related to the development of breast and other cancers. NCCC researchers are investigating the influence of obesity, diet, alcohol, early life exposures, and environmental exposures, such as tobacco smoke, pesticides, and air pollution. The researchers at other institutions are looking at factors such as physical activity, hormone therapy, medication use, and heredity.

Early on, we evaluated cancer risk in our cohort. Teachers developed breast, endometrial, ovarian and thyroid cancer, melanoma, lymphoma, and leukemia more often than comparable women in California. Teachers, however, developed less cervical and lung cancer. These observations have helped us focus our efforts on trying to understand the causes and prevention of cancer in women.

Regional Differences in Breast Cancer Incidence Rates
We have combined data from the cohort with ecological, environmental databases to evaluate the factors that might be responsible for the urban-rural (and other geographic) differences in breast cancer incidence rates. We found that as reported in other areas, breast cancer rates among cohort participants are higher in urban areas (the San Francisco Bay Area and the Southern Coastal region) than in other (largely rural) areas of the state. Socioeconomic and personal risk factors (e.g., alcohol consumption, use of hormone replacement therapy, delayed childbearing, etc.) do not account for more than a small portion of these geographic differences.

Diet, Alcohol and Breast Cancer
Drinking two or more alcoholic beverages a day increases a woman's risk of breast cancer only if she is using hormone therapy. One drink per day - which helps reduce the risk of heart disease - does NOT increase breast cancer risk even. Current drinking is more important than past drinking. The combination of alcohol consumption (of 2+ drinks per day) and use of hormone replacement therapy was associated with the greatest breast cancer risk.

Other than drinking alcohol, there are no overall associations between dietary intake and breast cancer risk.

NCCC investigators evaluated the relationship between alcohol and breast cancer risk. We found that current research is expanding on these findings by looking at the influence of normal genetic variation in metabolism on the relationship between alcohol and breast cancer risk; the relationship between alcohol and mortality; and whether diet affects specific types of breast cancer such as ER+/PR+ or ER-/PR-. We are also investigating whether compounds found in particular plant foods (e.g., the isothiocyanates found in cruciferous vegetables such as broccoli and cauliflower) may reduce the risk of developing breast cancer in some women.

Cadmium and Breast Cancer
Cadmium is a carcinogenic metal that exhibits estrogen-like activity. The major sources of non-occupational exposure to cadmium include cigarette smoke, diet (leafy vegetables and seafood), and inhalation of contaminated ambient air. We will then investigate thethe effects of total, dietary, and environmental exposure to cadmium on breast cancer risk. In order to evaluate the contribution of dietary and environmental sources to the total body burden, we are using data and urine specimens collected from the SNAP substudy (see below).

Special Nutrition Assessment Project (SNAP)
The Special Nutrition Assessment Project (SNAP) collected detailed dietary and environmental exposure information on a sample of 320 cohort members. This information was used to (1) better understand and sharpen our measures of dietary intake for the entire cohort, and (2) evaluate differences in environmental exposures for residents of urban areas as compared to residents of rural areas (as a group, residents of rural areas experience lower breast cancer rates).

Dietary Patterns and Cancer Risk
One of our interests is how overall dietary patterns may impact cancer risk. We have identified five major dietary patterns among cohort members: "plant-based," "high-protein/high-fat," "high-carbohydrate," "ethnic," and "salad-and-wine" and are currently evaluating how these patterns influence the risk of breast and endometrial and cancers. For ovarian cancer, we found little relationship between these dietary patterns and the development of that cancer.

Second Hand Smoke and Breast Cancer
We have evaluated the role of lifetime exposure to second hand smoke (i.e., "passive smoking") on the development of breast cancer. We found that while current smoking increases the risk of breast cancer, current exposure to household second hand smoke does not. We are currently evaluating the role of lifetime second hand smoke and exposure in the work place ans social settings on breast cancer risk.

Read press release: "Northern California Cancer Center findings on breast cancer and secondhand smoke released internationally by the American Association for Cancer Research"

Built Environment and Breast Cancer
The built environment refers to man-made attributes of a person's surroundings, such as the existence and condition of sidewalks, availability of resources (health care, food, playgrounds, public transportation) and the number of destinations in walking distance. We are currently examining whether characteristics of the built environment affect the risk of developing breast cancer.

Hygiene Hypothesis and Cancer Risk
The hygiene hypothesis holds that exposure to microbes in early life prevents asthma and allergy in early life, perhaps by priming the immune system. In our most recent questionnaire, we asked CTS participants about some of their early life exposure to barns, stables, pets, and children in order to understand if these are associated with later risk of cancer. We have interesting preliminary results consistent with a protective role of living near barns and stables for both breast cancer and melanoma. We have submitted a grant to follow-up these results in a dedicated study of CTS participants.

Nutrition, Estrogens and Endometrial Cancer in Teachers (NEET)
This special study is investigating how normal genetic variation in the metabolism of female hormones impacts the relationship between endometrial cancer and its two major risk factors -- obesity and use of estrogen hormone therapy. In addition, we are evaluating whether phytoestrogens and isothiocyanates may reduce the risk of endometrial cancer and the role that normal genetic variation plays in this process. We are also investigating the effects of foods that impact insulin-levels.

Body Size and Cancer Risk
We are in the process of using data on height, weight, and waist and hip circumferences to evaluate how various aspects of body size (including overall and abdominal obesity and weight gain during different periods of life) impact the development of breast, endometrial, ovarian, and thyroid cancers, and whether factors, such as the use of hormone therapy, modify these relationships.

Obesity and Asthma
There has been recent interest in the association between obesity and asthma, particularly in women. We have evaluated the relationship between indicators of body size and asthma prevalence and severity. We found that the more obese a woman was, the greater her likelihood of experiencing asthma. Additionally, women who had a large waist (35 inches or more) were also more likely to have asthma. Because of the many CTS participants, this study offered the opportunity to look at these relationships in greater detail than has been possible in previous studies.

BBC news coverage of findings on obesity and asthma

Air Pollution and Cardiopulmonary Mortality
Working with colleagues at the California Department of Public Health and the California Environmental Protection Agency, we are utilizing our Geographic Information System and specialized air monitoring data generated by the California Air Resources Board to assess the contribution of air pollutants on cardiopulmonary mortality. Because of the geographic diversity of CTS members in California and the extensive air monitoring information available, findings from this study can have an important impact on regulatory standards in the state.

Collaborators
NCCC: Pamela L. Horn-Ross, Ph.D., Peggy Reynolds, Ph.D., Dee W. West, Ph.D., Christina A. Clarke, Ph.D., Ellen T. Chang, Ph.D.
COH: Leslie Bernstein, Ph.D, Katherine D. Henderson, Ph.D.
USC: Dennis Deapen, Dr.P.H., Giske Ursin, M.D., Daniel O. Stram, Ph.D.
UCI: Hoda Anton-Culver, Ph.D., Al Ziogas, Ph.D., Susan L. Neuhausen, Ph.D., Joan Largent, Ph.D.
CCR: Rosemary Cress, Ph.D.

Funding
National Cancer Institute (R01 CA77398, R01 CA91019, U01 CA81789, R03 CA125819, R03 CA113024, R03 CA128009 and R03 CA135687), California Breast Cancer Research Program (4JB-0116 and 6JB-0111), California Breast Cancer Research Fund (97-10500), California Tobacco Related Diseases Research Program (7TR-0142, 13RT-0018 and 18XT-0108), US Army Medical Research, Breast Cancer Research Program (BC074049) and The Carl Gellert and Celia Berta Gellert Foundation.

Publications
Bernstein L, Allen M, Anton-Culver H, Deapen D, Horn-Ross PL, Peel D, Pinder R, Reynolds P, Sullivan-Halley J, West D, Wright W, Ziogas A, Ross RK. High breast cancer incidence rates among California teachers: results from the California Teachers Study. Cancer Causes Control 2002; 13:625-635.

Horn-Ross PL, Hoggatt KJ, West DW, Krone MR, Stewart SL, Anton H, Bernstein CL, Deapen D, Peel D, Pinder R, Reynolds P, Ross RK, Wright W, Ziogas A. Recent diet and breast cancer risk: the California Teachers Study. Cancer Causes and Control 2002; 13:407-415.

Hoggatt KJ, Bernstein L, Reynolds P, Anton-Culver H, Deapen D, Peel D, Pinder R, Ross RK, West DW, Wright W, Ziogas A, Horn-Ross PL. Correlates of vitamin supplement use in the California Teachers Study cohort. Cancer Causes Control 2002; 13:735-740.

Marshall SF, Deapen D, Allen M, Anton-Culver H, Bernstein L, Horn-Ross PL, Peel D, Pinder R, Reynolds P, Ross RK, West D, Ziogas A. Validating California Teachers Study self-reports of recent hospitalization: comparison with California hospital discharge data. Am J Epidemiol 2003; 158:1012-1020.

Parikh-Patel A, Allen MA, Wright WE. The California Teachers Study Steering Committee. Validation of self-reported cancers in the California Teachers Study. Am J Epidemiol 2003; 157:539-545.

Reynolds P, Goldberg DE, Hurley S, and the California Teachers Study Investigators. Prevalence and patterns of ETS exposures among California teachers. Am J Hlth Promotion 2004; 18:358-365.

Reynolds R, Hurley S, Goldberg DE, Anton-Culver H, Bernstein L, Deapen D, Horn-Ross PL, Peel D, Pinder R, Ross RK, West D, Wright WE, Ziogas A. Active smoking, household passive smoking, and breast cancer: evidence from the California Teachers Study. J Natl Cancer Inst 2004; 96(1):29-37.

Horn-Ross PL, Canchola AJ, West DW, Stewart SL, Bernstein L, Deapen D, Pinder R, Ross RK, Anton-Culver H, Peel D, Ziogas A, Reynolds P, Wright W. Patterns of alcohol consumption and breast cancer risk in the California Teachers Study Cohort. Cancer Epidemiol Biomarker Prev 2004; 13:405-411.

Reynolds P, Hurley SE, Goldberg DE, Yerabati S, Gunier RB, Hertz A, Anton-Culver H, Bernstein L, Deapen D, Horn-Ross PL, Peel D, Pinder R, Ross RK, West D, Wright WE, Ziogas A. Residential proximity to agricultural pesticide use and incidence of breast cancer in the California Teachers Study cohort. Environ Res 2004; 96:206-218.

Reynolds P, Hurley S, Goldberg DE, Anton-Culver H, Bernstein L, Deapen D, Horn-Ross PL, Peel D, Pinder, Ross RK, West DW, Wright WE, Ziogas A. Regional variations in breast cancer incidence in the California Teachers Study cohort. Epidemiology 2004; 15:746-754.

Reynolds P, Hurley S, Hoggatt KJ, Anton-Culver H, Bernstein L, Deapen D, Peel D, Pinder R, Ross RK, West D, Wright W, Ziogas A, Horn-Ross PL. Correlates of active and passive smoking in the California Teachers Study cohort. J Women's Health 2004; 13:778-790.

Hurley SE, Reynolds P, Goldberg DE, Hertz A, Anton-Culver H, Bernstein L, Deapen D, Peel D, Pinder R, Ross RK, West D, Wright WE, Ziogas A, Horn-Ross PL. Residential mobility in the California Teachers Study: implications for geographic differences in disease rates. Social Sci Med 2005; 60:1547-1555.

Marshall SF, Bernstein L, Anton-Culver H, Deapen D, Horn-Ross PL, Peel D, Pinder R, Purdie D, Reynolds P, Stram D, West D, Wright WE, Ziogas A, Ross RK. Non-steroidal anti-inflammatory drug use and breast cancer risk by stage and hormone-receptor status. J Natl Cancer Inst 2005; 97:805-812.

Horn-Ross PL, Barnes S, Lee VS, Collins CN, Reynolds P, Lee MM, Stewart SL, Canchola AJ, Wilson L, Jones K. Reliability and validity of an assessment of usual phytoestrogen consumption. Cancer Causes Control 2006; 17:85-93.

Reynolds P, Hurley S, Goldberg G, and the California Teachers Study Steering Committee. “Accumulating evidence on passive and active smoking and breast cancer risk” (letter). Int J Cancer 2006; 119:239.

Smith-Warner SA, Spiegelman D, Ritz J, Albanes D, Beeson WL, Bernstein L, Berrino F, van den Brandt PA, Buring JE, Cho E, Colditz GA, Folsom AR, Freudenheim JL, Giovannucci E, Goldbohm RA, Graham S, Harnack L, Horn-Ross PL, Krogh V, Leitzmann MF, McCullough ML, Miller AB, Rodriguez C, Rohan TE, Schatzkin A, Shore R, Virtanen M, Willett WC, Wolk A, Zeleniuch-Jacquotte A, Zhang SM, Hunter DJ. Methods for pooling of results of epidemiologic studies: the pooling project of prospective studies of diet and cancer. Am J Epidemiol 2006; 163:1054-1063.

Gunier RB, Reynolds P, Hurley SE, Yerabati S, Hertz A, Strickland P, Horn-Ross, PL. Estimating exposure to polycyclic aromatic hydrocarbons: a comparison of survey, biological monitoring, and Geographic Information System-based methods. Cancer Epidemiol Biomarker Prev 2006; 15:1376-1381.

Chang ET, Lee VS, Canchola AJ, Clarke CA, Purdie DM, Anton-Culver H, Bernstein L, Cress R, Deapen D, Peel D, Pinder R, Reynolds P, Ross RK, Stram DO, West DW, Wright W, Ziogas A, Horn-Ross PL. Dietary intake and risk of ovarian cancer in the California Teachers Study cohort. Am J Epidemiol 2007; 165:802-813.

Chang ET, Canchola AJ, Lee VS, Clarke CA, Purdie DM, Reynolds P, Anton-Culver H, Bernstein L, Deapen D, Mohrenweiser H, Peel D, Pinder R, Stram DO, Ross RK, West DW, Wright W, Ziogas A, Horn-Ross PL. Wine and other alcohol consumption and risk of ovarian cancer in the California Teachers Study cohort. Cancer Causes Control 2007; 18:91-103.

Dallal CM, Sullivan-Halley J, Ross RK, Wang Y, Deapen D, Horn-Ross PL, Reynolds P, Stram DO, Pinder R, Clarke CA, Anton-Culver H, Ziogas A, Peel D, West DW, Wright W, Bernstein L. Long-term recreational physical activity and risk of invasive and in situ breast cancer: the California Teachers Study. Arch Internal Med 2007; 167:408-415.

Mai PL, Sullivan-Halley J, Ursin G, Stram DO, Deapen D, Villaluna D, Horn-Ross PL, Clark CA, Reynolds P, Ross RK, West DW, Anton-Culver A, Ziogas A, Bernstein L. Physical activity and colon cancer risk among users and non-users of hormone therapy: the California Teachers Study. Cancer Epidemiol Biomarker Prev 2007; 16:517-525.

Lee JE, Hunter DJ, Spiegelman D, Adami H-O, Albanes D, Bernstein L, van den Brandt PA, Buring JE, Cho E, Folsom AR, Freudenheim JL, Giovannucci E, Graham S, Horn-Ross PL, Leitzmann MF, McCullough ML, Miller AB, Parker AS, Rodriguez C, Rohan TE, Schatzkin A, Schouten LJ, Virtanen M, Willett WC, Wolk A, Zhang SM, Smith-Warner SA. Alcohol intake and renal cell cancer in a pooled analysis of 12 prospective studies. J Nat'l Cancer Inst 2007; 99:801-810.

Lee JE, Hunter DJ, Spiegelman D, Adami H-O, Bernstein L, van den Brandt PA, Buring JE, Cho E, Folsom AR, Freudenheim JL, Giles GG, Giovannucci E, Horn-Ross PL, Leitzmann M, Marshall JR, Männistö S, McCullough ML, Miller AB, Parker AS, Pietinen P, Rodriguez C, Rohan TE, Schatzkin A, Schouten LJ, Willet WC, Wolk A, Zhang SM, Smith-Warner SA. Intakes of coffee, tea, milk, soda, and juice and renal cell cancer in a pooled analysis of 13 prospective studies. Int J Cancer, 2007: 121: 2246-2253.

Wakelee HA, Chang ET, Gomez SL, Keegan TH, Feskanich D, Clarke CA, Holmberg L, Yong LC, Kolonel LN, Gould MK, West DW. Lung cancer incidence in never-smokers. J Clin Oncology 2007; 25:472-478.

Chang ET, Lee VS, Canchola AJ, Clarke CA, Purdie DM, Reynolds P, Anton-Culver H, Bernstein L, Deapen D, Peel D, Pinder R, Ross RK, Stram DO, West DW, Wright W, Ziogas A, Horn-Ross PL. Diet and risk of ovarian cancer in the California Teachers Study cohort. Am J Epidemiol 2007; 165:802-813.

Setiawan VW, Ursin G, Horn-Ross PL, van den Berg D, Le Marchand L, Henderson BC, Bernstein L, Haiman CA. Germline variation at 8q24 and endometrial cancer risk. Cancer Epidemiol Biomarker Prev 2007; 16:2166-2168.

Templeman C, Marshall SF, Ursin G, Horn-Ross PL, Clarke CA, Allen, M, Deapen D, Ziogas A, Reynolds P, Cress R, Anton-Culver H, West DW, Ross RK, Bernstein L. Adenomyosis and endometriosis in the California Teachers Study: reproductive and lifestyle correlates. Fertil Steril, 2008; 90: 415-424.

Henderson K, Halley-Sullivan J, Reynolds P, Horn-Ross PL, Clarke CA, Chang ET, Neuhausen S, Ursin G, Bernstein L. Incomplete pregnancy is not associated with breast cancer risk: the California Teachers Study. Contraception 2008; 77:391-396.

Chang ET, Lee VS, Canchola AJ, Dalvi TB, Clarke CA, Reynolds P, Purdie DM, Stram DO, West DW, Bernstein L, Horn-Ross PL. Dietary patterns and risk of ovarian cancer in the California Teachers Study cohort. Nutr Cancer 2008; 60:285-291.

Horn-Ross PL, Lee VS, Collins CN, Stewart SL, Canchola AJ, Lee MM, Reynolds P, Clarke CA, Bernstein L, Stram DO. Dietary assessment in the California Teachers Study: reproducibility and validity. Cancer Causes Control 2008; 19:595-603.

Lee JE, Spiegelman D, Hunter DJ, Albanes D, Bernstein L, van den Brandt PA, Buring JE, Cho E, English D, Freudenheim JL, Giles GG, Graham S, Horn-Ross PL, Håkansson N, Jacobs EJ, Leitzmann M, Mäbbustö S, McCullough ML, Miller AB, Parker AS, Rohan TE, Schatzkin A, Schouten LJ, Sweeney C, Willet WC, Wolk A, Zhang SM, Smith-Warner SA. Fat, protein, and meat consumption and risk of renal cell cancer in a pooled analysis of 13 prospective studies. J Nat’l Cancer Inst 2008; 100:1695-1706.

Setiawan VW, Doherty JA, Shu X-O, Akbari M, Chen C, DeVivo I, DeMichele A, Goodman MT, Haiman CA, Hankinson SE, Henderson BE, Horn-Ross PL, Le Marchand L, Levine DA, Liang X, Lurie G, McGrath M, Narod SA, Rebbeck TR, Ursin G, Weiss NS, Xiang Y-B, Zheng W, Olson SH. Two estrogen-related variants in CYP19A1 and endometrial cancer risk: pooled analysis in the Epidemiology of Endometrial Cancer Consortium (E2C2). Cancer Epidemiol Biomark Prev 2009; 18:242-247.

Lu Y, Sullivan-Halley J, Cozen W, Henderson K, Ma H, Chang ET, Clarke CA, Neuhausen S, Reynolds P, Bernstein L. Family history of hematopoietic malignancies and non-Hodgkin’s lymphoma risk in the California Teachers Study. Br J Cancer 2009; 100:524-526.

Genkinger JM, Spiegelman D, Anderson KE, Bergkvist L, Bernstein L, van den Brandt PA, English DR, Freudenheim JL, Fuchs CS, Giles GG, Giovannucci E, Hankinson SE, Horn-Ross PL, Leitzman M, Marshall JR, Mannisto S, McCullough ML, Miller AB, Reding DJ, Robein K, Rohan TE, Schatzkin A, Stevens VL, Verhage BAJ, Wolk A, Ziegler R, Smith-Warner SA. Alcohol intake and pancreatic cancer risk: a pooled analysis of fourteen cohort studies. Cancer Epidemiol Biomarkers Prev 2009; 18:765-776.Templeman C, Marshall SF, Clarke CA, Henderson KD, Largent J, Neuhausen S, Reynolds P, Ursin G, Bernstein L. Risk factors for surgically-removed fibroids in a large cohort of teachers. Fertil Steril, in press.

Lee JE, Männistö S, Spiegelman D, Hunter DJ, Bernstein L, van den Brandt PA, Buring JE, Cho E, English DR, Flood A, Freudenheim JL, Giles GG, Giovannucci E, Horn-Ross PL, Håkansson N, Jacobs EJ, Leitzmann MF, Marshall JR, McCullough ML, Miller AB, Rohan TE, Ross JA, Schatzkin A, Schouten LJ, Virtamo J, Wolk A, Zhang SM, Smith-Warner SA. Intakes of fruit, vegetables, and carotenoids and renal cell cancer risk: a pooled analysis of 13 prospective studies. Cancer Epidemiol Biomark Prev, in press.

Lu Y, Prescott J, Sullivan-Halley J, Henderson KD, Ma H, Chang ET, Clarke CA, Horn-Ross PL, Ursin G, Bernstein L. Body size, recreational physical activity and B-cell non-Hodgkin lymphoma risk among women in the California Teachers Study. Am J Epidemiol, in press.

Voh Behren J, Lipsett M, Horn-Ross PL, Delfino RJ, Gilliland F, McConnell R, Bernstein L, Clarke CA, Reynolds P. Obestiy, waist size, and risk of current asthma in the California Teachers Study cohort. Thorax, in press.

Zell JA, Ziogas A, Bernstein L, Clarke CA, Deapen D, Largent J, Neuhausen S, Stram DO, Ursin G, Anton-Culver H. Non-steroidal anti-inflammatory drugs: effects on mortality after colorectal cancer diagnosis. Cancer, in press.

Razavi P, Pike MC, Horn-Ross PL, Templeman C, Bernstein L, Ursin G. Long-term postmenopausal hormone therapy and endometrial cancer. Cancer Epidemiol Biomarker Prev, in press.

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