Cancer Concerns

1. Cancer Concerns Monica Brown, PhD Cancer Epidemiologist the California Cancer Registry Cancer Epidemiology (EPI-272) January 21, 2011 UCD, Dept of Public Health

2. What Drives the Public’s Concern of the Clustering of Cancers in Communities and Workplaces? • There is considerable public concern that environmental exposures cause an excess in cancers in some communities. • The public believes environmental pollutants/toxins increase risk of cancer - although, there’s no evidence that there is increased risk to the general population in amounts that are typically present in the air, soil or drinking water. • Cancer clusters may be suspected when people notice that several family members, friends, neighbors or co-workers have been diagnosed with cancer, when the distribution of cancers may be “normal” given the age, sex, race/ethnic and lifestyle of that group.

3. … continued • Other phenomena that may drive suspicion of environmental cancer clusters are... • Media reports sensationalized cancer clusters • Distrust of government, manufacturing and business • Fear that we’ve created an environment filled with hazards that is causes us and our families harm • The perceived inability to control cancer risk and environmental hazards • Ever changing and varied Public Health (PH) messages

4. What We know • Cancers are common! • Cancer incidence varies by age, sex, race/ethnicity & risk factors • Cancers are complex diseases - PH has oversimplified cancer • Use of the singular – “cancer” instead of “cancers” • Lumping all non-clinical risk factors as “environmental” • Communities members are often similar - age, SES, race/ethnicity & lifestyles – these factors contribute more to cancer incidence than shared environment • Knowledge of cancer causes, its distribution and prevention varies greatly in the general public – • PH has done a poor job educating the public about cancer; therefore the public has many misconceptions about cancer & cancer clusters

5. Common Misconceptions about Cancer

6. Causes of Cancer Family History/Genetics 13% • Family History/Genetics • Family History 5% • Prenatal Factors/Growth 5% • Reproductive Factors 3% Lifestyle 68% Environment/ Occupation 19% • Environmental/Occupation • Occupation 5% • Viruses/other biologics 5% • SES 3% • Pollution 2% • Radiation 2% • Other 2% • Lifestyle • Tobacco Use 30% • Diet 10% • Physical Inactivity 5% • Alcohol Use 3% • Other 20% Source: Harvard Report on Cancer Prevention, 1996

7. Age-Specific Incidence Rate (ASIR) for most prevalent cancers

8. Common Misconceptions about Cancer Clusters

9. Examples of Documented Cancer Clusters

10. The California Cancer Registry • The California Cancer Registry (CCR) is administered by the California Department of Public Health (CDPH). • The CCR is a true population-based registry. • Cancer reporting is mandated for hospitals and physicians. • Data collected by the registry are used: • To monitor incidence and mortality. • For research into the causes, cures and prevention of cancer; • To produce reports including the state and regional annual reports and the American Cancer Society’s Cancer Facts and Figures; and • The evaluation of community cancer concerns.

11. When a Californian has a Cancer Concern: the Role of the CCR • The CCR and it’s regional cancer registries respond to numerous requests for evaluation of community and workplace cancer concerns. • The registry’s role is to statistically assess whether the number of cases of targeted cancers observed in a community or workplace are significantly greater than what would be expected. • If there is a statistically significant excess of cases, report to the Environmental Health Investigations Branch (EHIB) of CDPH who will investigate.

12. The Role of the CCR, continued • The CCR does not: • Conduct epidemiologic “outbreak”, clinical or laboratory investigations. • On-site surveys of residents or employees to assess risk. • Direct others in exposure assessments. • Coordinate the efforts of other state and county agencies in their investigations.

13. We define a Cancer Cluster as… An aggregation of cancer cases that has been determined to be unusual when compared to the cancers that would be expected if the group of location in question had the same cancer rates as the underlying population. The cluster must differ substantially from the expected pattern in number, type, or the age of cases.

14. The CDC defines a Cluster as … An unusual aggregation, real or perceived, of health events that are grouped together in time or space and that are reported to a health agency* * Guidelines for Investigating Clusters of Health Events, 1990, Centers for Disease Control and Prevention

15. Procedures • Obtain Information from Informant • Provide Cancer Education and Information • Assess Cancer Concern - Determine if Further Analysis is Needed • Explain Procedures, Limitations of Methods and Provide a Timeline • Consult and Notify Relevant Officials • Perform Assessment • Communicate the Results of Assessment

16. Caller’s name & address; affiliation (community member) • Number of specific cases observed • Cancer type(s) observed • Age, sex, race/ethnicity of cases • Geographic area or group • Time period of concern • Method of observation – how did the caller learn of the cases Step One: Obtain Information

17. Education • The frequency of specified cancers in their community or County • Risk factors for specified cancers • If knowledgably, discuss agent and/or exposure • Information • American Cancer Society (ACS) • Centers for Disease Control and Prevention (CDC) • The National Institutes of Health (NIH) • Agency for Toxic Substances and Disease Registry (ATSDR) Step Two: Provide Cancer Education & Information Note: Do not assume that everyone has access to or can use the internet

18. Step Three: Determine if Further Analysis is Needed Indications for Statistical Evaluation Other Considerations • Are cancers unusual in number, type or age of patients? • Has a potential carcinogenic agent been identified? • If a specific exposure is suspected – test 1st – call County Environmental Health, Environmental Protection Agency (EPA) or if workplace, Occupational Safety and Health Agency (OSHA) • Is there a plausible exposure pathway? • Is the request coming from a another State agency or from a County Health Department? • Is informant representing a community or workplace action group? • Are children involved? • Is this perceived cancer cluster “political” or is it already being followed by the press?

19. Step Three: Determine if Further Analysis is Needed Increased Cancer Frequency Occurrence in Unique Population Unusual Cancers or or CCR Documented Cases Biologic Plausibility Carcinogenic Agent + + Further Action Warranted

20. Procedure • We use registry data to confirm case information & determine clinical characteristics of cancers • We use census data for denominators (population at risk) • Perform calculations, write report to county & state. • In the event of a statistically significant excess of cancers, we refer case to EHIB for investigation • Limitations • CCR will not contain most recently diagnosed cases • Only a substantial increase in risk is likely to be detected • We lack information on length of residence and risk factors that may contribute to developing cancer • Timeline • 1-3 months Step Four: Explain Procedure, Limitations & Provide Timeline

21. Workplace Cancer Concerns: Barriers to Evaluations • Obtaining appropriate information on ill & well (population at risk) employees from employers is difficult to impossible. • If necessary, must obtain permission from employees to access their medical records. • Assessing biologic plausibility: Is the suspected agent at work associated with increased risk of reported cancers? • Does workplace exposure have an impact? direct vs. indirect; length of exposure (workday/year(s)); mode of exposure (eat/drink, inhale etc.) • What other risk factors could increase risk of developing reported cancers – smoking, drinking & diet – that cannot be assessed? • Separating endemic cancers from those reported: what cancers would be “normal” for this employee group. • Are there behaviors that are common in this employee group?

22. Management hierarchy of CDPH • County Health Officer • Workplace management Step Five: Consult and Notify Relevant Officials of Report

23. Define geographic area by census tract • Review observed cases • Generate expected number of cancers • 5-year type-, age-, sex- and race-specific rates for the state or region • U.S. Census Bureau year 2000 population data for the census tract(s) • Compare cases observed and expected, calculate 99% confidence interval • Determine whether a statistically significant excess is found Step Six: Perform Assessment

24. Write letter or report describing concern and results of assessment to the … • Informant • County Health Officer • CSRB management hierarchy • If results show a statistically significant excess in cases, include … • EHIB • CDPH public affairs office Step Seven: Communicate Results

25. Challenges in Communicating Results • Science • Scientific evidence is inconclusive, contradictory and ever-changing • Current scientific evidence is not absolute. Therefore, we cannot give definitive answers. • Scientific method - descriptions of methodological limitations and results can sound evasive. • Complicated scientific Concepts: • Random events • 1% of all census tracts would have higher or lower cancer rates simply by chance • No one has ever called me and said “… there’s too few cancers in my neighborhood”. • public seemingly can only grasp concept if discussing the lottery.

26. … continued • Epi & Stat Concepts • Often case and/or population numbers are too small for appropriate statistical analysis, and we are unable to conduct analysis. • sometimes viewed as demeaning the current number of cases. • sometimes viewed as evasive or manipulative. • For environmentally based cancer concerns, we examine only related cancers not “all cancers” due to etiologic differences in cancers – often public thinks all cancers are germane. • Causality - if cluster confirmed statistically, doesn’t mean cancer is due to a single causal pathway. • Epidemiologists & Statisticians (us) • Objectiveness viewed as lack of empathy. • Expertise viewed as “Ivory Tower’ism” • We are not good at saying we don’t know

27. The Seven Cardinal Rules of Risk Communication Rules • Accept and involve the public as a partner. • Plan carefully and evaluate your efforts. • Listen to the public's specific concerns. • Be honest, frank, and open. • Work with other credible sources. • Meet the needs of the media. • Speak clearly and with compassion. • Your primary goal is to produce an informed public, not to defuse public concerns. • Different goals, audiences, and media require different actions. • People often care more about trust, credibility, competence, fairness, and empathy than statistics and details. • Trust and credibility are difficult to obtain; once lost, they are almost impossible to regain. • Conflicts and disagreements among organizations make communication with the public more difficult. • The media are usually more interested in politics than risk, simplicity than complexity, danger than safety. • Always acknowledge the tragedy of an illness or death. People can understand risk information, but they may still not agree with you; some people will not be satisfied. From: The Seven Cardinal Rules of Risk Communications, Covello and Allen 1988

28. In Conclusion • Cancer clusters DO occur in communities, but are difficult to investigate and nearly impossible to prove. • Our tools to investigate are crude and we often lack pertinent information or time to see the natural history of events. • Cancer never 1st disease manifestation in true cluster • From exposure to diagnosis can be 20 – 50 years, depending on carcinogen • Most prevalent cancers are not strictly caused by environmental exposures – i.e., lung or prostate cancer • Ignorance: what we think is harmless today, tomorrow we may learn is dangerous. • We must take responsibility and precautions to safeguard our health.

29. For More Information on Cancer Clusters • ACS: http://www.cancer.org/Cancer/CancerCauses/OtherCarcinogens/GeneralInformationaboutCarcinogens/cancer-clusters • NIH: http://www.cancer.gov/cancertopics/factsheet/Risk/clusters • CDC: http://www.cdc.gov/nceh/clusters/ • ATSDR: http://www.atsdr.cdc.gov/csem/cluster/docs/clusters.pdf Harvard School of Public Health, Disease Risk Profile: http://www.diseaseriskindex.harvard.edu/update/hccpquiz.pl?lang=english&func=home&page=cancer_index

30. Thank You!