(HealthDay News) — Death rates from cancer continue to decline in the United States, but the presence of comorbidity can be an important influence on overall survival, according to a report published online Dec. 16 in Cancer.
Brenda K. Edwards, PhD, from the National Cancer Institute in Bethesda, Md., and colleagues used data from the US Centers for Disease Control and Prevention, the National Cancer Institute and the North American Association of Central Cancer Registries to analyze cancer incidence and death rates from 1975 to 2010. Medicare data were also analyzed to determine the prevalence of comorbidity among cancer patients diagnosed from 1992 to 2005.
From 2001 to 2010, the researchers noted an annual 0.4% per person decrease in overall delay-adjusted and age-adjusted cancer incidence rates, according to the report, which continues a trend from 1998. Although rates remained stable among women, rates declined by 0.8% per year among children and 0.6% per year among men.
Delay-adjusted and age-adjusted incidence rates among men during this time period decreased for six of the 17 most common cancer sites, including prostate, lung, colon and rectum, stomach, brain and other nervous system, and larynx. However, rates increased for eight cancer sites, including melanoma, non-Hodgkin lymphoma, kidney and pelvis, leukemia, pancreas, liver and intrahepatic bile duct, myeloma and thyroid. The largest decrease was seen in colorectal cancer while the largest increase was seen in thyroid cancer.
Among women, trends were comparable for the 18 most common sites. The researchers identified decreases six sites, including colon and rectum, ovary, urinary bladder, cervix uteri, oral cavity and pharynx, and stomach. They also found increases at eight sites, including corpus and uterus otherwise not specified, thyroid, melanoma, kidney, pancreas, leukemia, myeloma and liver. The largest decrease was seen among cervical cancers, and, similar to men, the largest increase was seen among thyroid cancers. Rates for all other sites, including breast cancer, remained stable.
From 2001 to 2010, results indicated a continued decline in mortality for all cancers combined, for most major sites and for all racial and ethnic groups. Combined rates for both sexes decreased by 1.5% per year, although the decrease was larger for men than women (1.8% vs. 1.4%).
Also during this time period, the researchers observed decreases in mortality for lung, prostate, colon and rectum, leukemia, non-Hodgkin lymphoma, kidney, stomach, myeloma, oral and larynx cancers among men and decreases in lung, breast, colon and rectum, ovary, leukemia, non-Hodgkin lymphoma, brain, myeloma, kidney, stomach, cervix, bladder, esophagus, oral and gallbladder cancers among women. In contrast, mortality rates for pancreas and liver cancers increased among both men and women; for melanoma and cancer of soft tissue in men; and for cancer of the uterus in women.
Long-term trends in cancer mortality, however, have been inconsistent, according to the researchers.
The researchers also analyzed the prevalence of comorbidity among older patients with cancer and Medicare beneficiaries. They found that the prevalence of comorbidity was highest among lung cancer patients (52.9%), similar for breast and prostate cancer patients (around 30%) and intermediate for colorectal cancer patients (40.7%). The most common comorbidities included diabetes, COPD, congestive heart failure and cerebrovascular disease.
Age and comorbidity level were important influences on overall survival but varied depending on whether the cancer was local and regional or distant.
“Cancer death rates in the United States continue to decline,” Edwards and colleagues conclude. “Estimates of survival that include the probability of dying of cancer and other causes stratified by comorbidity level, age, and stage can provide important information to facilitate treatment decisions.”
In a statement, Clifford A. Hudis, MD, FACP, president of the American Society of Clinical Oncology, said the association is encouraged by the report’s results.
“The continuing decrease in overall cancer death rates is a clear indicator that our societal investments are paying off, in particular for those patients with cancers that have been traditionally most challenging to treat, such as lung cancer,” Hudis said in the statement., noting that the successful translation from research to clinical practice has played a major role in reducing cancer mortality.
“Even better than treatment is prevention when possible,” Hudis said. “Building on this year’s report related to patients in the US, even more work is needed to accelerate the pace of progress worldwide.”