- ATLANTA (Reuters Health) - Major changes are taking place in cancer incidence
around the world, with increases in breast, prostate, colorectal and lung
cancer, largely due to lifestyle factors.
- At the same time, cancer of the stomach,
cervix and liver is declining due to better treatment and prevention of
- "Three major transitions are taking
place in global cancer statistics,'' Dr. Michael Thun announced here at
the 2nd World Conference for Cancer Organizations. In Thun's opinion, the
increase in lung cancer associated with the increased usage of tobacco
products worldwide represents the most important transition.
- "That is best illustrated by lung
cancer becoming the leading fatal cancer worldwide in the early 1980s,''
said Thun, vice president for Epidemiology and Surveillance Research with
the American Cancer Society. "Tobacco-related cancers will predominate
in cancer occurrences well into the next century.''
- The good news is declining incidence
rates for three cancers caused in part by infection, including stomach,
cervical, and liver cancer. Stomach cancer can be caused by Helicobacter
pylori bacteria, cervical cancer can result from infection with the sexually
transmitted human papillomavirus, and liver cancer is associated with hepatitis
B infection, said Thun. He attributed the declining rates to more widespread
treatment and preventive screening.
- Developing countries have begun to adopt
a "Western'' lifestyle, and are thus experiencing a rise in the breast,
prostate and colorectal cancers that are associated with such a lifestyle.
However, the increase in tobacco use is of greatest importance, according
- "The tobacco transition dominates
the other two, not just because of cancer but because it impacts health
in so many other ways. It is very important for physicians to continue
to counsel their patients to quit smoking. For cancer, reducing smoking
is the single most important priority worldwide,'' Thun told Reuters Health.
- In the year 2000, there will be an estimated
8 million deaths from cancer, he said. Thun noted that roughly 75% to 80%
of cancers in the US are avoidable.
- "We are not normally predestined
to get cancer. It is mostly brought about by environmental factors,'' he