Cancer Etiology

City of Hope’s Division of Cancer Etiology works tirelessly to better understand the various causes of cancer. Armed with this powerful knowledge, scientists can more efficiently develop solutions to reduce the risk of cancer, especially in people who possess the greatest likelihood of developing the disease.
Our Researchers
Leslie Bernstein, Ph.D., Director of the Division of Cancer Etiology
Among the most accomplished researchers working in cancer epidemiology today, Bernstein was instrumental in identifying physical activity as a means by which to reduce the risk of breast cancer. She is deeply involved in scientific exploration of the links between hormone exposures, physical activity, obesity, and cancer. She also examines how breast cancer impacts the lives of women following their treatment.
Clague DeHart examines the genetic and molecular epidemiology of women’s cancers. Her foci are the biological mechanisms that underlie associations between modifiable risk factors, cancer risk reduction, and survival.
Lacey’s work has been key in demonstrating that women using menopausal progestins and estrogens are more likely to develop uterine and ovarian cancer. In addition to leading the expansion of the California Teachers Study, Lacey continues to investigate the ways in which hormones affect the risks of developing uterine cancer, ovarian cancer, breast cancer, and other diseases among women.
Huiyan Ma, Ph.D., Associate Research Professor
The lead manager of the databases that constitute the California Teachers Study, Ma studies the epidemiology of women’s cancers. Her primary foci include understanding the roles of alternative and complementary medicines among breast cancer survivors and identifying the risk factors for different subtypes of breast cancer.
Susan L. Neuhausen, Ph.D., Morris and Horowitz Families Professor in Cancer Etiology and Outcomes Research
Neuhausen researches identification of environmental and genetic stressors that predispose people to disease. Her work focuses primarily on ovarian and breast cancers and on celiac disease. Neuhausen works to understand why some individuals are more prone to develop certain illnesses. Her research emboldens the design and implementation of programs created to keep such at-risk people healthy.
Wang has focused on epidemiological research in cervical cancer and in non-Hodgkin lymphoma and seeks to better understand the molecular and genetic contributions to cancer causation. Wang investigates the role of immunity and inflammation in cancers among women and is currently expanding the scope of her research to other chronic diseases that disproportionately affect women.
Research Highlights
California Teachers Study
In 1995 and 1996, 133,479 female teachers and public school professionals in California participated in a large prospective cohort study. Since then, through mailed questionnaires and biological samples, those women have offered information about their respective lifestyles, health, and backgrounds. This huge cache of data has allowed researchers to determine a set of differentiators between women who have developed cancer from those who have not.
Some of the most recent findings from the California Teacher Study include:
  • Obesity is related to an increased risk of pancreatic cancer
  • Small-particulate air pollution is related to the risk death from cardiovascular disease
  • Smoking and secondhand smoke may increase the risk of non-Hodgkin lymphoma
  • Delayed onset of puberty may be related to an increased risk of thyroid cancer in younger women
  • A decrease in invasive breast cancer is explained, in large part, by the decline in use of hormone therapy to treat menopausal symptoms
Now, in an expansion of the California Teacher Study, researchers are collecting blood and saliva samples from more than 20,000 cohort members with no history of any cancer. This large group of biospecimens—combined with data on diet, lifestyle and other factors—will help researchers identify new biomarkers for early detection, predict responses to treatments, and identify genetic and environmental interactions. The new information could lead to better treatments and, perhaps, the prevention of cancer.