March 17, 2015
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Did you know?

  • We envision a world free from cancer.

    Our research scientists and their teams collaborate with colleagues around the world to conduct cutting-edge research using large data-sets to:
    • understand the causes of cancer
    • find ways to prevent it or detect it early
    • improve outcomes for cancer survivors 
  • Our mission began more than 40 years ago.

    Established in 1974 as the Northern California Cancer Program, the organization later became known as the Northern California Cancer Center. The name was changed again in 2010 when it became the Cancer Prevention Institute of California (CPIC), which reflects the organization's broader scope and demonstrates its large scale impact of preventing cancer before it starts.
  • We are an independent research institute and a valued partner to many.

    Through its collaborative approach, CPIC also serves as an asset to the nation’s leading cancer fighting organizations, including the National Cancer Institute, and to scientists worldwide, educators, patients, and clinicians, and is affiliated with the Stanford Cancer Institute.
  • We work hard to understand who gets cancer and why.

    Our scientists are frequent contributors to major scientific journals, and often present their findings at important cancer-related conferences. CPIC research has been covered by numerous local, national and international media outlets, such as The New York Times and The Washington Post.
  • Every case of cancer counts…and is counted.

    CPIC operates the Greater Bay Area Cancer Registry as part of the National Cancer Institute's Surveillance, Epidemiology and End Results program and the California Cancer Registry. As required by law, the registry gathers data from hospitals and doctors on all cancers diagnosed and treated in nine Bay Area counties. This information is used to produce cancer statistics and as a platform for research to understand cancer occurrences and survival. Our registry regularly earns Gold Standard Certification by the North American Association of Central Cancer Registries.
  • Our educational efforts reach people of all ethnicities and backgrounds.

    Our Community Education team provides important information to cancer survivors, health professionals and others through conferences and publications on many cancer-related topics including employment, patient advocacy, care giving, specific cancers, and treatments.

  • Breast cancer rates decline when hormone therapy is stopped.

    CPIC was first to report on the alarmingly high and increasing rates of breast cancer in the Bay Area and Marin County in the 1990s. In subsequent studies, CPIC found that when women stopped taking hormone replacement therapy, breast cancer rates declined immediately and dramatically. This showed that hormone therapy was a major contributor to the high rates previously reported and identified one clear path to breast cancer prevention.
  • Our work to associate tanning beds and melanoma prompted legislation.

    CPIC described increased occurrence of melanoma in young women in California, particularly in high socioeconomic areas, implicating use of tanning beds as one cause. This finding led to passage of the first statewide legislation to ban minors from using tanning beds, which should ultimately reduce occurrences of deadly melanoma in young persons.
  • Physical activity lowers your risk of Breast Cancer

    CPIC found that risk of breast cancer was lower for women engaging in more physical activity, such as walking and biking, doing household chores and yard work, and being active on the job. This shows a simple and practical way women can help prevent breast cancer from occurring.
  • Second-hand smoke increases the risk of lung and breast cancer.

    CPIC studies have shown that women exposed to second-hand tobacco smoke have a higher risk of lung cancer even if they don't smoke, and that exposure to household smoke increases their risk of breast cancer over and above the risk they incur from smoking themselves. These findings have been important in leading to anti-smoking legislation.
  • Vitamin D may reduce the risk of prostate cancer.

    CPIC assessed whether sun exposure, which is the main source of vitamin D, is related to prostate cancer risk. Using the difference in skin color measured on the forehead and upper underarm as an indicator of sun exposure, the study found that prostate cancer risk was reduced by 50% in men with a high sun exposure index, with an even higher reduction in risk noted in men with certain alterations in the vitamin D receptor gene.
  • Survival outcomes differ among Asian women of different ethnic backgrounds.

    CPIC was the first to show that breast cancer survival is not uniform across women of different Asian ethnicities, irrespective of how advanced the cancer was when diagnosed. In California, Korean, South Asian and Vietnamese women had the poorest survival after breast cancer, pointing to the need in these communities for better screening and/or breast cancer treatment.
  • Melanoma is on the rise throughout California.

    CPIC demonstrated that the rates of both early and more advanced melanomas were rising in all populations in California. This disturbing finding signals a true and alarming epidemic of this deadly cancer, and it has been cited over 245 times in the medical literature since 2009 because it identifies a major public health problem.
  • Survival disparities occur across many cancer types.

    CPIC showed that survival after follicular lymphoma, a common form of this cancer, is lower in poorer communities than in more affluent communities. This demonstrates population disparities in cancer treatment and shows a need in poorer communities for more access to skilled lymphoma care, including access to new successful drug treatments.
  • Our nail salon studies have widespread positive impact.

    CPIC found that California nail salons had higher than expected levels of carcinogens and other banned substances in the air, identifying the need for better standards and the importance of clarifying whether such exposures lead to cancer and other undesirable health outcomes.
  • Tailored approaches to healthcare are needed to address cultural differences.

    CPIC used two approaches to learn how best to help Vietnamese communities in California receive lifesaving colorectal cancer screening: one approach involved lay health workers directly educating the community on the importance of screening, and the other involved advertising about colorectal cancer screening. CPIC found that the use of lay health workers worked best to improve the screening rate, proving that organized community involvement improves colorectal screening practices among Vietnamese-Americans in California.
  • Lung cancer afflicts nonsmoking women more than men.

    CPIC was the first to show definitively that among nonsmokers, women were more likely than men to have lung cancer. Until this paper, there were no hard data about the incidence of lung cancer in nonsmokers. This study has been cited extensively as motivation for other research to understand the reasons why.
  • Genetic screening is especially important for African American and Hispanic women.

    CPIC was the first to study the level of BRCA1 mutations (genetic changes responsible for increased risk of breast cancer) in nonwhite women. This work found that young African American and Hispanic women with breast cancer had a particularly high prevalence of BRCA1 mutations, and signaled the importance to these communities and their doctors of screening for this mutation when indicated.

Press Releases

Hazardous Air Pollutants May Increase Risk of Certain Breast Cancers

Incidence rates tend to be highest in urban areas 

FREMONT, CA (March 17, 2015) -  Scientists know that geographic location is one of the strongest predictors of breast cancer incidence and that rates tend to be highest in urban areas. Interestingly, less than half of these cases can be attributed to traditional risk factors, such as diet and lifestyle differences associated with urban living.  Could the environment be to blame?

CPIC Senior Scientist Peggy Reynolds and her colleagues are particularly interested in the role urban environmental exposures, like air pollution, might play in the development of breast cancer. Animal studies have shown a link between breast tumors and certain chemicals, known as mammary gland carcinogens, which are present in the air at varying levels. The team at CPIC took a close look at these levels, examining the differences in breast cancer incidence for women living in neighborhoods with higher concentrations of pollutants thought to be associated with breast cancer, and women living in neighborhoods with lower levels of these chemicals. 

The study, “Hazardous air pollutants and breast cancer risk in California teachers: a cohort study,” was published January 30, 2015 in the journal Environmental Health and included more than 112,000 women living throughout California. 

Since 1996, the Environmental Protection Agency (EPA) has provided estimates of the levels of up to 180 hazardous air pollutants in neighborhoods throughout the United States. From this list, the researchers selected 24 chemicals that had been identified in prior animal studies as mammary gland carcinogens. The research team examined the relationship between breast cancer incidence and levels of these 24 chemicals present in the air in neighborhoods where study participants lived. 

While a direct connection between the 24 hazardous air pollutants and breast cancer in general was not found, the team did find significant associations between certain of these chemicals and specific breast cancer subtypes.  For example, levels of carbon tetrachloride are higher in urban areas and appeared to be associated with ER+/PR+* breast cancers. Vinyl chloride and its byproduct ethylidene chloride, present in consumer products as well as in the air, also showed an association with ER+/PR+ breast cancer, particularly among post-menopausal women who were current or former users of hormone replacement therapy.  And, finally, findings suggest a link between neighborhood levels of the chemical benzene and the rarer ER-/PR- breast cancer subtype. Vehicle emissions are the primary source of benzene exposure; thus, this contaminant is closely associated with urban environments.

This CPIC study is the first to examine the relationship between exposure to these kinds of harmful air pollutants at the neighborhood level and risk of breast cancer incidence, evaluating the chemicals as individual compounds. Other studies have looked only at summary levels. CPIC’s findings suggest that women living in neighborhoods where higher levels of dangerous chemicals are present in the ambient air may be at greater risk of developing both common and rare types of breast cancer.

The strengths of this study include the large and well-followed group of women in the California Teachers Study (CTS), who have provided extensive personal health and behavior information since 1995. The careful assessments of air pollutants by the EPA over time allowed the team to conduct detailed analyses, as well. Further study is warranted to evaluate the chemicals noted to be of greatest concern, the researchers suggest.  

*ER+/PR+ = estrogen-receptor positive / progesterone-receptor positive breast cancers accounted for 77% of all breast cancers in this study population. 

About the Cancer Prevention Institute of California
The Cancer Prevention Institute of California (CPIC) is the nation’s premier organization dedicated to preventing cancer and to reducing its burden where it cannot yet be prevented. CPIC tracks patterns of cancer throughout the entire population and identifies those at risk for developing cancer. Its research scientists are leaders in investigating the causes of cancer in large populations to advance the development of prevention-focused interventions. CPIC’s innovative cancer prevention research and education programs, together with the work of the Stanford Cancer Institute, deliver a comprehensive arsenal for defeating cancer. For more information, visit

Media Contact: Jana Cuiper, 510-608-5160 |