May 27, 2009 — Cancer incidence and mortality rates in the United States are declining, according to the latest statistics from the American Cancer Society (ACS). The steady decline of cancer-related mortality over the past 15 years means that about 650,000 deaths have been prevented or delayed.
Nevertheless, cancer remains a leading cause of death, coming second after cardiovascular disease in 2006. The numbers are still huge — a total of 1,479,350 new cancer cases and 562,340 cancer-related deaths are projected in 2009.
The annual cancer-statistics report from the ACS was published online May 27 in CA: A Cancer Journal for Clinicians.
"A drop of 1% or 2% per year in the cancer mortality rate may sound small, but as this report shows, that adds up to 650,000 cancer deaths avoided over 15 years," said John R. Seffrin, PhD, chief executive officer of the ACS, in a statement. "And because the rate continues to drop, it means that in recent years about 100,000 people each year who would have died if cancer death rates had not declined are living to celebrate another birthday. That is undeniable evidence of the lifesaving progress that we, as a country, must dedicate ourselves to continuing."
Declines Seen in Both Mortality and Incidence
Since 1975, there have been notable improvements in relative 5-year survival rates for many types of cancers and for all cancers combined. These increased rates reflect a combination of earlier diagnoses and advances in treatment. But the report points out that little progress has been made in improving outcomes for several different types of malignancies, including those of the lung and pancreas. In addition, cancer incidence and mortality can vary by sex, race/ethnicity, education, and geographic area.
Between 1990 and 2005, the overall cancer death rate decreased by 19.2% in men and by 11.4% in women. In men, the decline in morality rates was largely due to decreasing rates of lung (37%), prostate (24%), and colorectal (17%) cancers, which accounted for almost 80% of the total decrease. In women, the decreased mortality rate was largely driven by declining rates in breast (37%) and colorectal (24%) cancers, which accounted for 60% of the total decrease.
Cancer incidence rates decreased by 1.8% per year in men from 2001 to 2005, and by 0.6% per year in women from 1998 to 2005. These rates were due largely to decreases in the 3 major cancer sites in men (lung, prostate, and colorectum) and the 2 major sites in women (breast and colorectum).
Trends in Incidence and Outcomes
In 2009, cancers of the prostate, lung and bronchus, and colon and rectum will account for about 50% of all newly diagnosed cancers in men, with prostate cancer alone accounting for 25% (192,280) of incident cases. Based on data from 1996 and 2004, an estimated 91% of new cases of prostate cancer are expected to be diagnosed at local or regional stages; the good news is that 5-year relative survival for these cases approaches 100%.
Among women in 2009, the 3 most commonly diagnosed types of cancer will be cancers of the breast, lung and bronchus, and colon and rectum, accounting for 51% of estimated cancer cases. Breast cancer alone is expected to account for 27% (192,370) of all new cancer cases.
Cancers of the lung and bronchus, prostate, and colorectum in men, and cancers of the lung and bronchus, breast, and colorectum in women continue to be the most common fatal cancers, the report points out, and these 4 malignancies account for nearly half of all cancer-related mortality among people of both sexes.
However, mortality rates are declining for these 4 cancer sites, except for lung cancer in women, in which rates stabilized from 2003 to 2005. The incidence trends for these major cancers have also declined, except for lung cancer in women, in which rates are still increasing, but are doing so more slowly than in previous years.
Influence of Race/Ethnicity
Both incidence and mortality continue to vary considerably among racial and ethnic groups. Compared with white men, black men have an 18% higher incidence rate and a 36% higher death rate for all cancer sites combined. Conversely, black women have an incidence rate that is 6% lower than the rate for white women, but their mortality rate is 17% higher.
Cancer incidence and death rates are generally lower in other racial and ethnic groups than they are in whites and blacks, although both incidence and death rates tend to be higher for cancers of the uterine cervix, stomach, and liver than in whites.
Once the diagnosis of cancer is made, black Americans have worse outcomes than whites. The 5-year relative survival rate is lower in every stratum of disease stage and for nearly every cancer site. Disparities in outcomes are multifactorial, and include factors such as unequal access to quality healthcare and/or differences in comorbidities.
Increase in Cancer Deaths in 2006
Cancer accounted for about 23% of all deaths in the United States in 2006, but there were 568 more cancer deaths reported that year than in 2005. This is believed to be due to the growth and aging of the population, because "the decrease in the age-standardized death rates did not offset the influence of the aging and growth of the population on the total number of cancer deaths," the report notes.
However, when the mortality causes are ranked by age groups (in 20-year intervals), cancer is 1 of the 5 leading causes of death in all age groups and in both sexes. It is the leading cause of death for women between 40 and 79 years and for men between 60 and 79 years, and surpasses heart disease as the leading cause of death for men and women younger than 85 years.
Lifetime Probability of Developing Cancer
The authors of the report emphasize that these estimates are "based on the average experience of the general population and may overestimate or underestimate individual risk because of differences in exposure and/or genetic susceptibility." But based on population data, the lifetime probability of being diagnosed with an invasive cancer is 44% for men and 37% for women. Because of the earlier median age of diagnosis for breast cancer, compared with other major malignancies, women appear to have a slightly higher probability of being diagnosed with cancer before the age of 60 years.
"Although progress has been made in reducing incidence and mortality rates and improving survival, cancer still accounts for more deaths than heart disease in persons younger than 85 years of age," write the authors. "Further progress can be accelerated by applying existing cancer-control knowledge across all segments of the population and by supporting new discoveries in cancer prevention, early detection, and treatment."
The researchers have disclosed no relevant financial relationships.
CA Cancer J Clin. Published online before print May 27, 2009.
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