February 4th Is World Cancer Day

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February 4 is the annual observance of World Cancer Day. This year's theme is reducing stigma and dispelling myths about cancer. In the lead-up to the day, the World Health Organization's International Agency for Research on Cancer released a new report emphasizing that treatment alone will not win the global battle against cancer without also focusing on prevention. Recent reports from the U.S. show that cancer death rates continue to decline and fewer years of life are being lost to cancer, but cancer mortality has not fallen as fast of that of other diseases.

The World Cancer Day Declaration includes 9 targets:

For 2014, World Cancer Day organizers focused on 4 common cancer-related myths:

Find out more on the World Cancer Day website.

WHO IARC Report

IARC's World Cancer Report 2014 shows that cancer is now the leading global cause of death, with an estimated 8 million deaths worldwide in 2012. Furthermore, the number of cancer deaths is expected to increase substantially in coming years as mortality due to other causes is reduced, reaching 13 million within the next 2 decades. Global cancer incidence was estimated at 14 million cases in 2012, and it is predicted to rise by about 70%, reaching 25 million per year.

The most common types of cancer in 2012 were lung cancer (1.8 million cases, or 13% of the total), breast cancer (1.7 million, or 12%), and colon cancer (1.4 million, or 10%). The most common causes of cancer death were lung cancer (1.6 million, or 19), liver cancer (0.8 million, or 9%), and stomach cancer (0.7 million, or 9%).

"The rise of cancer worldwide is a major obstacle to human development and well-being," said IARC director Christopher Wild. "These new figures and projections send a strong signal that immediate action is needed to confront this human disaster, which touches every community worldwide, without exception."

Though often considered to be characteristic of wealthier countries, cancer mortality among people in poorer countries is rising faster than previously expected. More than 60% of cases occur in Africa, Asia, and Central and South America, and these regions account for about 70% of cancer deaths, according to the report.

Compared with more developed areas, a larger proportion of cancers in developing countries are due to infections including human papillomavirus (which causes cervical and anal cancers) and hepatitis B and C (which cause liver cancer). Also, smoking is on the rise in some developing countries even as it declines in wealthier ones.

The IARC report recommends development of national cancer control plans, awareness efforts to alter modifiable risk factors, cancer screening programs, and wider implementation of HPV vaccination programs.

U.S. Reports

The latest annual cancer statistics report from the American Cancer Society showed steady declines in cancer-related mortality over past 2 decades, adding up to a 20% decrease in the risk of dying from cancer -- or approximately 1,340,400 cancer deaths avoided -- during that period.

According to "Cancer Statistics 2014," published in the January-February 2014 edition of CA: A Cancer Journal for Clinicians, there are expected to be 1,665,540 new cancer cases and 585,720 cancer deaths in the U.S. in 2014.

Prostate cancer is the most common cancer (accounting for about 25%) among U.S. men, while breast cancer (accounting for 29%) is most common among women. Lung and colon cancer are in second and third place for both men and women. Together, these 4 types cause almost half of all U.S. cancer deaths.

Cancer death rates from 1991 to 2010 fell by 16% among white women, 20% among black women, 24% among white men, and 33% among black men. Yet while middle-aged African-American men have seen the most improvement, they continue to have the highest cancer incidence and death rates. Asian-Americans have the lowest cancer rate overall, despite their higher risk for liver cancer due to hepatitis B.

During the most recent 5 years with available data (2006-2010), cancer incidence declined slightly (by 0.6% per year) among men and was stable among women. Cancer death rates decreased by 1.8% and 1.4% per year, respectively, during the same period. The decline follows increases during most of the 20th century, largely driven by rising lung cancer deaths due to smoking, first among men and later among women.

While incidence rates for most cancers have declined, liver and bile duct cancers have increased by 3%-4% per year, in part attributable to progression of hepatitis B and C among people infected years ago. Melanoma skin cancer incidence and mortality also rose during the period covered by the report.

The report authors concluded that further progress in reducing cancer incidence and death "can be accelerated by applying existing cancer control knowledge across all segments of the population, with an emphasis on those groups in the lowest socioeconomic bracket and other disadvantaged populations."

Another recent report on the cancer burden in the U.S. showed that fewer years of life are being lost to cancer after taking into account the faster decline in mortality due to other causes such as cardiovascular disease.

As described in the January 13 advance edition of the Journal of Clinical Oncology, Samir Soneji from Dartmouth-Hitchcock Medical Center and colleagues looked at data on breast, colon, lung, and prostate cancer mortality from the Surveillance, Epidemiology, and End Results registries, as well mortality due to other causes from national death certificates.

Since cancer incidence and mortality rises as people live longer thanks to falling cardiovascular and other-cause mortality, the study authors calculated the burden of cancer mortality as the average person-years of life lost due to cancer.

They found that falling cancer mortality rates reduced the burden of death from leading cancers, but at the same time the increase in cancer incidence as a result of larger declines in other-cause mortality partially offset this progress. Between 1970 and 2008, for example, deaths due to heart disease, stroke, and accidents declined by 62%, 73%, and 38%, respectively, while cancer mortality fell by only 12%.

"By using a measure that accounts for increased cancer incidence as a result of improvements in [cardiovascular disease] mortality, we find that prior assessments have underestimated the impact of cancer interventions," they concluded.

"We have made steady progress against the burden of many cancers for decades," Soneji said in a Dartmouth press release. "As fewer and fewer people die from heart disease, stroke, and accidents, more and more people are alive long enough to be at risk of developing and dying from cancer."

2/4/14

Reference

R Siegel, J Ma, Z Zou, and A Jemal. Cancer statistics, 2014. CA: A Cancer Journal for Clinicians. 64(1):9-19. January-February 2014.

S Soneji, H Beltran-Sanchez, and HC Sox. Assessing Progress in Reducing the Burden of Cancer Mortality, 1985-2005. Journal of Clinical Oncology. January 13, 2014 (Epub ahead of print).

Other Sources

World Cancer Day. http://www.worldcancerday.org.

World Health Organization, International Agency for Research on Cancer. Global battle against cancer won’t be won with treatment alone Effective prevention measures urgently needed to prevent cancer crisis. Press release. February 3, 2014.

Union for International Cancer Control. Crisis of cancer impact worldwide exposed. Press release. February 4, 2014.

American Cancer Society. Cancer Statistics 2014: Deaths Continue to Drop. Press release. January 7, 2014.

Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center. New Analysis Shows Fewer Years of Life Lost to Cancer. Press release. January 14, 2014.