WASHINGTONOverall incidence and mortality rates for cancer
continue to decline in the United States. However, a new report finds
considerable disparities among racial and ethnic groups, and it warns
that a resurgence of smoking among teen-agers forewarns of a likely
reversal of the downward trend, especially for lung cancer.
In the increases in tobacco use among teens, we can also see
the seeds of future increases in cancer, said James S. Mark,
MD, of the Centers for Disease Control and Prevention (CDC), who
spoke at a press conference releasing the statistics.
The incidence rate for all cancers combined declined an average of
0.9% per year from 1990 to 1996, and the death rate dropped an
average of 0.6% annually. The trend continues to reverse the upward
climb in overall incidence and mortality documented from 1973 to
The scourge of cancer has been so pervasive that even the
relatively small decline each yeara fraction of a
percentmeans that now 53,000 fewer Americans get cancer each
year than would have had the rates from 1990 not changed and that
about 18,000 fewer die, Dr. Marks said.
The report was prepared by the American Cancer Society (ACS),
National Cancer Institute (NCI), and CDC. Incidence data came from
NCIs Surveillance, Epidemiology, and End Results (SEER)
program. Mortality data came from the National Center for Health
Statistics national database of death certificates. For the
first time, the report included a breakdown of cancers among
Hispanics, Asians and Pacific Islanders, and American Indians and
Alaskan Natives in addition to whites and blacks.
A Combination of Reasons
The precise reason for the overall decline remains unknown, although
screening, treatment, and prevention all receive some credit.
Its undoubtedly a combination of screening and treatments
primarily, but were trying to figure out exactly how much to
attribute to each point, said Barbara K. Rimer, DrPH, director
of NCIs Division of Cancer Control and Population Sciences.
Among the five most common-occurring cancersbreast, prostate,
lung, colorectal, and non-Hodgkins lymphomaonly
non-Hodgkins lymphoma showed an upward trend, with an average
annual increase of 0.6% in incidence and 1.8% in deaths rates.
Although breast cancer incidence remained flat during the period,
deaths declined at an annual rate of 1.8%. Incidence also dropped 2%
for prostate cancer, 1.4% for lung cancer, and 2.1% for colorectal
cancer. Mortality dropped 1.6% for prostate cancer, 0.4% for lung
cancer, and 1.7% for colorectal cancer.
The overall decline in cancer incidence and mortality was
significantly influenced by decreases in the four leading
malignancies. Breast, prostate, lung, and colon are responsible
for over half of all cancers, said National Center for Health
Statistics director Edward J. Sondik, PhD.
The average annual increase in the incidence of non-Hodgkins
lymphoma during 1990-1996 (0.6%) was significantly lower than from
1973-1979 (3%) and during the 1980s (3.7%). The average annual
increase in the death rate for the disease (1.8%) was lower than
during the 1980s (2.4%), but this slowing was accounted for entirely
by a decline in the annual average rate for men (1.5%).
The melanoma incidence rate rose substantially from 1990 to 1996,
rising an average of 2.7% per year. However, the mortality rate for
melanoma remained constant. The average yearly drop of 0.3% in
pancreatic cancer mortality resulted from a decline in mortality
among men (0.8% a year), which offset an average annual increase
among women (0.1%).
Considerable variations among different populations appeared in the
mortality and incidence figures. Breast, prostate, lung, and
colorectal cancer were ranked in the top four most common-occurring
cancers for all the populations. For the remainder of the top
10 sites, there were notable differences, Dr. Sondik said.
Some sites tended to be unique to a specific population. For example,
melanoma was among the top 10 only in the white population; cancer of
the pancreas only in blacks; liver cancer only in Asians/Pacific
Islanders and American Indians/Alaskan Natives; and bladder cancer
only in whites and Hispanics.
With one exception, the same four sites were also the top four causes
of cancer death, the report said. For Asian and Pacific Islanders,
breast cancer was replaced in the top four by liver cancer.
While incidence rates for blacks are about 10% higher than
whites for all sites combined, mortality was more than 30%
higher, Dr. Sondik said. African-Americans have the
highest rate of new cancer cases for all the major cancers, except
breast cancer, and death rates are highest among blacks for all these
cancers as well.
The report features a special section on tobacco and lung cancer,
which caused 28% of cancer deaths in 1998. During the first 7 years
of the 1990s, lung cancer incidence and mortality rates decreased in
men and increased in women, although the rate of increase has slowed
in recent years. Indeed, the report found a decrease for the first
time in lung cancer incidence and death rates among women under 60.
We must be mindful that these favorable trends are influenced
most by the reduction in adult tobacco use in the past 2½
decades, said John R. Seffrin, PhD, the ACS chief executive
officerthus the concern about teenage smoking, which increased
among whites, blacks, and Hispanics from 1991 to 1997.