All About Black Health
Selected Quote: "We
are highly committed to reducing the disparities that exist among
African Americans, but we realize we cannot do it alone,"said
Kevin Fenton, M.D., Ph.D., Director of the CDC's National Center for
HIV, STD, and TB Prevention at a meeting of more than 100
African-American leaders held in Atlanta on March 7-8 2007 in Atlanta.
Prostate cancer presents a
serious problem for all Americans men. However, it is widely recognized that
prostate cancer is a particular serious problem for black men: mortality
from this disease is higher in black Americans than in all other races.
This is due to a higher incidence, more advanced stage at diagnosis, and
lower rate of survival. This article will examine each of these factors,
and present clinically useful reference ranges for using PSA to diagnose
prostate cancer in black Americans.
High Incidence
African Americans have the
highest prostate cancer incidence rates in the world. In contrast, the
disease is rare in Africa, the Near East, and South America. According to
the American Cancer Society, some of the increase in rates may be related to
socioeconomic differences reflected in lifestyles behaviors that contribute
to cancer risk. This may include a diet high in saturated fats and tobacco
and/or alcohol use. Whatever the reason, the incidence of prostate cancer
in American Blacks is currently 50% higher than in American whites.
When the National Cancer
Institute analyzed black and white cancer rates by socioeconomic status,
they found that, in general, cancer incidence was higher in low-education
and low-income groups regardless of race. However, the incidence of prostate
cancer remained higher among blacks, even after adjustment for income or
education.
Late stage at
diagnosis
Significantly more blacks
than whites are diagnosed with advanced disease. In fact, blacks are more
likely than white to have all cancers, regardless of site, diagnosed at a
late stage.
Poor Survival
Experience
Prostate cancer mortality
rates are more that 2 times higher for black Americans than white
Americans. Data from the Surveillance, Epidemiologic, and End Results
program of the National Cancer Institute indicates that the relative 5-year
survival rate of black Americans with prostate cancer is less than that of
white American for all stages of disease.
Age and PSA
(Prostatic Specific Antigen)
Because serum PSA
increases with patien age, primarily due to the increase in prostatic volume
with age, the use of age-specific reference ranges may make the test more
sensitive in younger men and more specific in older men. Age-specific
reference ranges might find more organ-confined, "curable" cancer in younger
men, and spare more older men an invasive and costly biopsy. Some
urologists recommend using age-specific reference ranges only for patients
40 to 59 years of age, and the conventional range of 0.0 to 4.0 ng/ml for
men 60 and older. Age-specific reference ranges for white men have been
determined from a study in Olmsted County, Minnesota.
Race and PSA
Subsequent investigations
with a Japanese population revealed significantly lower PSA levels than seen
in white men. This indicated the importance of considering the patient's
race when using PSA to diagnose prostate cancer. A study of military
personnel at Walter Reed Army Medical Center became the first to apply, to
black men, PSA reference ranges determined from a black population. These
values were significantly different from those in white men, but also
correlated directly with age.
PSA in Practice
The American Cancer
Society currently recommends that every man over 40 have a digital rectal
exam as part of his annual physical. In addition, the American Urological
Association recommends that annual PSA blood tests also be initiated at age
40 for black Americans or those with a family history of prostate cancer.
The high incidence and
mortality of prostate cancer in black men justify aggressive detection using
race-specific ranges derived from a black population. This should allow the
practicing clinician to detect more clinically significant cancers at an
early, potentially curable stage.
The article was
originally written by Joseph E. Oesterling, M.D., Professor and
Urologist-In-Chief Director, The Michigan Prostate Institute, The University
of Michigan, Ann Arbor, Michigan (An educational service of MERCK & CO.,
Inc.)
