Transcript Epidemiology of Prostate Cancer

Elizabeth Radke, MPH
Faina Linkov, PhD
University of Pittsburgh Cancer Institute
Background
 Most commonly diagnosed cancer in American men
 Incidence rate=168.9 per 100,000 men
 Third most common cause of cancer death in the U.S.
 Mortality rate = 33.9 per 100,000 men
 Incidence rates soared in the early to mid 1990s when
widespread screening for PSA was instituted
Prostate cancer 2008 (estimate)
 New cases: 186,32
 Deaths: 28,660
Survival
 Five year survival rates for local and regional stages are
essentially 100%
 For distant metastases, five year survival is only 34%
Demographics
 Median age at prostate cancer diagnosis is 71 in whites and
69 in blacks
 Has dropped slightly since introduction of PSA screening
 African-Americans have the highest incidence and
mortality rates
 Incidence and mortality in Asian/Pacific Islanders,
American Indians, and Hispanics are substantially lower
than whites
 Incidence and mortality are positively correlated with the
gross national product
Prostate Cancer Incidence Rates,
by State, 2004
International Patterns
 Lowest rates are observed in the Far East and on the
Indian subcontinent
 2.9 per 100,000 men in China
 Highest rates occur in Western Europe, Australia, and
North America
 107.8 and 185.4 per 100,000 white and black men in the
United States
 Migration studies show that men of Asian heritage
living in the U.S. are at lower risk than white
Americans but greater risk than men of similar
ancestries living in Asia
Diet – Fruits and Vegetables
 Some studies have shown decreased risk of prostate
cancer with increased intake of vegetables, but these
findings are inconsistent
 Tomatoes
 Overall data indicate that the intake of tomatoes
(associated with higher circulating concentrations of
lycopene) is associated with lower risk of prostate cancer
 Brassica or Cruciferous vegetables (Broccoli, etc.)
 Small number of studies suggest inverse association
between eating brassica vegetables and prostate cancer
Diet – Protein
 Soy
 Possible decrease in prostate risk with increased soy
intake
 Red meat and processed meat
 Consumption of red or processed meat has been
associated with a higher risk of total or advanced
prostate cancer in some cohort studies
 Fish
 Some studies have shown protective effect of eating fish
regularly, mostly attributed to omega-3 fatty acids
Diet – Other
 Association between fat consumption and prostate
cancer has been observed in some studies
 Countries with greater per capita milk consumption
have higher prostate cancer mortality rates
 No significant association between smoking and
alcohol use has been observed
Other Factors
 Aspirin and Non-Steroidal Anti-Inflammatory Agents
 Weak inverse association between regular antiinflammatory use and prostates cancer
 Vasectomy
 Some studies have shown increased risk following
vasectomy
 Occupational and Environmental Exposures
 Pesticide use
 High electromagnetic field exposure
 STD Infection
Family History
 Relative risk for having either a father or brother with
prostate cancer ranges from 2-3
 Risk is higher with increasing number of first-degree
relatives with disease
 Higher concordance for prostate cancer diagnosis
between monozygotic than dizygotic twins
 Segregation analyses support an autosomal dominant
mode of inheritance
 Gene(s) is not yet identified
Genetic Factors
 Sex Steroid Hormones and Hormone Metabolizing
Enzymes
 Polymorphisms in Vitamin D Receptor Gene
 Growth Factors
 Infection and Response to Infection (Inflammation)
 Sexually transmitted infections
 Prostatitis
 Biotransformation Enzymes
Screening and Early Detection
 In 2001, 75 % of American men aged 50 years or older
reported that they had every had a PSA test, 54% had
recently had one
 Efficacy of screening to detect prostate cancer at an
earlier stage than digital rectal exam has been shown
 Sensitivity of PSA test is roughly 67.5-80%, Specificity
is 60-70%
 Many false positives
 With PSA concentration over 4 ng/mL, most men will
receive work-up including prostate biopsy
Diagnosing Prostate Cancer
DETECTING PROSTATE CANCER

PSA

Kallikrein Tumor Markers

Digital Rectal Exam

Biopsy
STAGING PROSATE CANCER

The TNM staging system

Histologic Grading: The Gleason Score

Post-Surgical Evaluation

Imaging Bone Metastases
PSA and Prostate Cancer Incidence
and Mortality
250
(U.S. 1975-2000)
PSA Screening
225
200
14
175
13
150
12
125
100
Mortality
Incidence
15
11
75
2000
1995
1990
1985
1980
10
1975
50
Source: Surveillance, Epidemiology, and End Results Program, 1975-2000, Division of Cancer Control
and Population Sciences, National Cancer Institute, 2003.
What is PSA?
 Prostate-Specific Antigen
 An antigen is something an antibody binds to.
 Member of the Kallikrein protease family.
 Vast majority of PSA in our body is produced by
secretory prostate epithelial cells.
 Also made in very low amounts in the breast, thyroid, and
placenta, among others.
Future Directions
 Etiology
 Role of factors such as obesity
 Genetic factors
 Role of different nutrients
 Role of chronic intraprostatic inflammation
 Excess risk in African-Americans
 Early detection (improve specificity)
References
 Cancer Epidemiology, 3rd ed. 2006. Oxford University
Press
 Centers for Disease Control
 American Cancer Society
 Lecture by Donald Vander Griend, PhD, University of
Chicago Urology Research Laboratory