Δευτέρα 24 Οκτωβρίου 2016

MANY CANCERS LINKED TO ALCOHOL AND SMOKING

Eleven of the 15 cancers responsible for premature death and loss of healthy life years in US residents are closely linked to smoking and alcohol, a new study shows.
Estimates of the burden of cancer in 2011, assessed by race and ethnicity for 24 cancers, reveal a loss of 9.8 million years of healthy life because of cancer, say Joannie Lortet-Tieulent, of the American Cancer Society in Atlanta, Georgia, and colleagues.
Premature death was responsible for about 90% of all healthy years of life lost because of cancer, and 10% were due to cancer-related health problems that led to a decrease in quality of life.
The report was published online October 18 in the Journal of Preventive Medicine.
The loss of healthy years of life is measured as disability-adjusted life years (DALYs). One DALY is the equivalent to loss of 1 year of healthy life and is a combined measure of mortality, incidence, survival, and quality of life.
The report shows that men and women shared the cancer burden equally, with each group losing 4.9 DALYs of healthy life years. However, the cancer burden was 20% to 30% higher in African Americans than in all races/ethnicities combined.
Populations with the next highest DALYs, in descending order, were non-Hispanic whites, Hispanics, and non-Hispanic Asians.
"In all races/ethnicities, the cancer burden was largely driven by years of life lost, highlighting the need to prevent death at middle age through broad implementation of structural and behavioral measures of primary prevention, early detection, and treatment," the researchers note.
To accomplish this, access to care must be improved, existing public health policies must be strengthened, and new ones must be implemented, lead author Lortet-Tieulent told Medscape Medical News.
"Avoiding smoking and avoiding drinking alcohol is a good way to decrease the risk of losing healthy life years to cancer. Almost a quarter of all healthy years lost to cancer are due to lung cancer," she pointed out.
The researchers used population-based cancer registry data of nationwide cancer incidence, survival, mortality, and treatment collected in 2013. They also used reports from the literature as well as vital statistics to determine the cancer burden.
In 2011, lung cancer accounted for 24% of the cancer burden (2.4 million DALYs). Breast cancer was responsible for 10% of the cancer burden, followed by colorectal cancer at 9%, pancreatic cancer at 6%, prostate cancer at 5%, and leukemia at 4%.
Brain cancer, non-Hodgkin's lymphoma, and ovarian cancer each accounted for 3% of the cancer burden, the study showed.
Almost 50% of all years of healthy life lost or DALYs were the result of lung, breast, colorectal and pancreatic cancers — "the four most-burdensome cancers," the researchers note.
The study showed that age-standardized DALY rate (ASR) ratios of non-Hispanic black men were 1.3 times higher than in non-Hispanic white men for all cancers and 1.2 times higher in non-Hispanic black women compared to non-Hispanic white women. Prostate cancers in black men and breast and corpus uteri cancer in black women contributed predominantly to these differences.
The ASR ratios were also higher in African American men and women for 15 cancers.
Hispanics and non-Hispanic Asians had lower ASRs for all cancers and common cancers but higher ASRs for infection-related cancers of the stomach, liver, and cervix.
Non-Hispanic whites had the highest ASRs for ovarian cancer, melanoma, cancers of the brain and nervous system, and bladder cancer in men.
Analysis showed that age-specific DALY rates increased as age increased, starting at 50 years.
Health disparities usually arise from a complex combination of socioeconomic, behavioral, and biological factors as well as structural barriers, such as lack of access to care for primary prevention, early detection, and timely treatment, the researchers note.
For example, in black women, the incidence of breast cancer was lower than in white women, but the breast cancer mortality rates were higher. This reflects a pattern of diagnosis at a later stage of disease, the researchers say.
A "substantial portion" of DALYs due to cancer could be avoided with primary prevention, screening, and early detection, the authors emphasize. Breast cancer and colorectal cancer can be prevented through screening, and cervical cancer can be prevented through screening and vaccination, they note.
The researchers estimate that screening of individuals at high risk for lung cancer could potentially avert approximately 12,000 death per years — or save more than 80,000 years of lost life, assuming that 72 years is the median age at death.
They point out that although the number of years lost to disability accounts for only 10% of the DALYs for all cancers combined, this still represents a significant disease burden in several cancers. The study showed that 76% of the years lost to disability came from cured patients.
What's more, the number of years lost to disability is expected to increase as survival for many cancers improves. "This highlights the need to prevent or manage treatment side effects such as incontinence, impotence and dyspareunia, and to improve quality of life among the ever-growing number of cancer survivors," the authors note.
Funding for this study was provided by the American Cancer Society. The study authors have disclosed no relevant financial relationships.

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