Transcript 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
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