California Cancer Research Program
Completed Projects
The following Principal
Investigators have completed their research as funded by CRP. Where applicable,
publications resulting from CRP funding are also included.
CYCLE I FINAL LAY
ABSTRACTS
Investigator-Initiated
Awards
Barbara A. Cohn, Ph.D.:
Prostate Cancer: Prospective Serum Markers in Blacks and Whites
Malcolm C. Pike, Ph.D.: Candidate Gene Association Studies of Ovarian Cancer
Anna H. Wu, Ph.D.: A
Multiethnic Study of Ovarian Cancer in Los Angeles County
Beate Ritz, Ph.D.: Extended
Follow-Up of the Rocketdyne Worker Cohort
Robert J. Melton, M.D., M.P.H.: IMPACTO II: The Monterey County Hispanic Behavioral
Risk Factor Survey Study
Prostate Cancer: Prospective Serum
Markers in Blacks and Whites
Public
Health Institute
$747,419.00
/ 36 months
Prostate
Cancer
Investigator-Initiated
Award
One goal in the prevention
and early treatment of prostate cancer is to find characteristics that identify
individuals who will eventually get cancer, particularly factors that are easy
to measure such as agents found in the blood. These blood factors may include: prostate specific antigen
(PSA), levels of hormones and growth factors, and DNA markers which show
alterations in genes that affect the way hormones are used. Blood markers can be used to identify
"high risk" individuals who require intensive scrutiny for signs of
early cancers that can be more effectively treated. It may also be possible to design new prevention and
treatment strategies to block factors that might promote cancer.
The best way to identify
these factors is to take blood samples from a group of men who are cancer-free
and follow those men to determine who gets prostate cancer. Recently, growth factors that predict
prostate cancer were identified in a study composed mainly of white men. These new risk factors are the growth
factor, IGF-I, and the sex hormones, testosterone and estrogen. It is important to see whether these
same results are true for African-Americans who are known to have higher rates
of prostate cancer.
Our study made progress in
accomplishing this goal by using existing data from the Child Health and
Development Studies (CHDS) population.
More than 15,000 Northern California families entered the CHDS between
1959 and 1967 and have been followed for cancer incidence for over 30
years. Blood samples were drawn
when men entered the study and were used to measure growth factors, hormones,
and PSA in young men (average age of 32 years) and genetic factors that might
increase risk. The young age of subjects in this study and the inclusion of
African-American men is unique.
Our genetic studies were not
conclusive, but we made important progress on develeoping new ways to measure
genetic factors in stored blood samples. This is important because ours is one
of the only studies that can look at how charceristics of young men work with
genetic factors to cause prostate cancer.
Further studies in our cohort could help uncover ways to reduce prostate
cancer risk at a young age.
Our findings on PSA levels,
if confirmed in other studies, could lead to a change in screening for early
prostate cancer. At this time,
most physicians begin PSA screening for prostate cancer in middle-aged men. Our
study is the first to show that levels of PSA in the blood of younger men may
provide information about future risk.
PSA levels in young men were correlated with risk of prostate cancer
more than 30 years later for both African-American and white men. This result is very important because
it might lead to finding prostate cancer earlier when it can be treated more
successfully.
Unlike our findings for PSA,
our findings on hormones and growth factors in the serum of young men suggest
that these may not be consistent predictors of prostate cancer in African
Americans and whites. Blood levels of the growth factor, IGF-1, were not
different for young African American and white men and were not related to
prostate cancer. Although blood
levels of testosterone and estrogen were higher for African Americans, the
ratio of these hormones (tesosterone to estrogen) did not differ by race.
Paradoxically, hormone levels did not predict prostate cancer in white or
African American men, but the ratio (higher testosterone to estrogen) did
predict prostate cancer but in white men only. In contrast, high body mass predicted prostate cancer only
in African American men, who were heavier than white men in our study. These perplexing findings about race
differences suggest that further research should examine how body mass might
modify the impact of sex hormones on prostate cancer risk.
IMPACTO II: The Monterey County Hispanic
Behavioral Risk Factor Survey Study
Robert J. Melton, M.D., M.P.H.
John P. Snider, M.P.H., M.P.A.
Monterey
County Health Department
Marilyn
A. Winkleby, Ph.D.
Stanford
University
$777,219.00
/ 36 months
Cervical
Cancer, Colorectal Cancer
Community
Initiated Research Collaboration Award – Full
The goal of this three-year
project was to implement a population-based epidemiological Hispanic Behavioral
Risk Factor Survey (HBRFS) focused
in Monterey County with a focus on the Salinas Valley. This was accomplished by: (1)
Completing an epidemiological cross-sectional survey (the Monterey County
Hispanic Behavioral Risk Factor Survey) with approximately 1,000 Latino men and
women in Monterey County to learn more about cancer-related risk factors and
screening factors, and how these varied across population sub-groups; and (2)
disseminating findings of the survey to the Latino population in Monterey
County utilizing a community development model to offer tailored programs to
Latino men and women. These
programs encouraged the adoption of healthy lifestyle behaviors and promoted
early detection and screening of prevalent cancers.
The survey implementation
included a random digit dial, cross-sectional survey of over 800 Latino men and
women, 18-65 years of age. To
insure the lowest income residents were included, a sample of 150 residents of
agricultural labor camps was also surveyed. The HBRFS survey used a similar design and methodology as a
survey that was completed 10 years ago with 1,000 Latino men and women in
Monterey County (IMPACTO I). The
survey repeated questions from IMPACTO I and focused on four cancer-related
risk factors: high dietary fat
intake, excess body weight, high alcohol intake, and low leisure-time physical
activity. The survey also assessed
health care access and screening practices related to the diagnosis and
treatment of prevalent cancers. In
addition, the survey incorporated new questions (e.g. workplace physical
activity, alcohol intake by type of alcohol, impact of discrimination on
health). Significant findings/accomplishments
were made in the following areas:
1. Released the key findings of the IMPACTO II Survey and
developed an 8-page report titled ÒSnapshots of
Latino Health.Ó
2. Completed data analysis
3. Implemented community interventions based on the
key survey findings.
4.
Developed five fact sheets, in English and Spanish, to highlight the key
survey findings. The topics
are: Active for life, Binge Drinking, You can Have
a Healthy Weight, Healthy Eating is Right at Your Doorstep, and Colorectal Cancer.
5.
Three articles, using the IMPACTO II survey results, were submitted for
publication to the following:
Ethnicity and Disease, Preventive Medicine and the Hispanic Journal of
Behavioral Sciences.
6.
Conducted community presentations to the Monterey County Board of
Supervisors, Migrant Education Program, Community Action Agency and Latino
Network Luncheon to present the survey findings.
7.
Submitted a grant proposal to the Centers for Disease Control and
Prevention utilizing the results of the IMPACTO II survey and the community support gained throughout
the project.
Significant Survey Findings:
á
Cancer control programs
for Latinos need a particular focus on weight, nutrition, and physical
activity. Alcohol, and colorectal screening.
á
The strongest correlated
to obesity in this Latino population relate to exposure to the American
culture, which may have contributed to the sudden and serious increases on
obesity in Latino women and men.
1.
Winkleby
MA, Snider J, Davis B, Garcia-Jenings M, Ahn D. David K. Ahn. Cancer-Related
Health Behaviors and Screening Practices among Latinos: Findings from a
Community and Agricultural Labor Camp Survey.Ethnicity and Disease, 2003:13;376-386.
2.
Urizar G, Winkleby, MA. AIDS Knowledge among
Latinos (in press, Hispanic Journal of Behavioral Sciences).
Candidate Gene Association Studies of
Ovarian Cancer
University
of Southern California
$836,857.00
/ 36 months
Ovarian
Cancer
Investigator-Initiated
Award
No
final report submitted.
Extended Follow-Up of the Rocketdyne
Worker Cohort
University
of California, Los Angeles
$324,508.00
/ 36 months
Prostate
Cancer, Bladder Cancer, General Cancer
New
Investigator Award
No
final report submitted.
A Multiethnic Study of Ovarian Cancer in
Los Angeles County
University
of Southern California
$1,095,523.00
/ 36 months
Ovarian
Cancer
Investigator-Initiated
Award
This population-based
case-control study of epithelial ovarian cancer (EOC) in Los Angeles County
aims to investigate the relationship between risk of EOC
and: (1) regular use of over-the-counter and prescribed analgesics, and (2)
regular use of psychotropic agents.
Our primary objectives are to examine the overall association between
risk of EOC and any use of analgesics and psychotropic medications after
adjustment for potential confounders.
Dose, duration, and latency of use as well as formulations of
medications will be evaluated. We
will also determine the inter-relationships between risk of EOC and use of
analgesics and psychotropic medications and the underlying reasons for which
these medications are prescribed.
Patients diagnosed with
EOC are identified from the Los
Angeles County Cancer Surveillance Program, the population-based tumor registry
for this study area.
Eligible cases include women of all race/ethnicity, diagnosed with
histologically confirmed primary EOC, at ages 79 or younger, and Los Angeles
County residents at the time of diagnosis. To date, we have completed interviews with 702 case patients
diagnosed with EOC and 543 controls.
Preliminary analyses have been completed on 669 EOC patients and 451
controls.
Preliminary results show that
risk of ovarian cancer is significantly reduced in association with number of
pregnancies (p trend<0.0001) and livebirths (p trend=0.03). Additionally, use of oral contraceptives
was significantly inversely associated with risk (p trend=0.001). Risk of ovarian cancer was
significantly increased among women with a family history of ovarian cancer
(p=0.03) and among those who used talc regularly (p=0.03). Combined use of psychotropic
medications (including antidepressants, anti-anxiety mood stabilizers,
hypnotics/sedatives, and other psychotropic medications) was not associated
with risk of ovarian cancer.
However, when we examined risk patterns separately by specific class of
psychotropic medication, there was a suggestion of increased risk associated
with use of anti-anxiety agents, particularly among long-term users (>2
years of use) (P trend =0.07).
Risk of ovarian cancer was not reduced in association with use of
aspirin, acetaminophen and other NSAIDs.
In contrast, our preliminary analysis suggested increased risk
associated with increasing duration of use of acetaminophen (P trend =0.07) and
other NSAIDS (P trend=0.01).
Analysis on the complete data set (we expect completed interviews on 705
cases and 640 controls) will be conducted in early 2005 to follow-up on these
preliminary results on the role of non-hormonal medications in this study
population.
California Cancer Research Program
(916) 449-5550
E-mail crp@dhs.ca.gov