They say 'God is in the details'. Many often repeated statistics or facts about breast cancer are misleading or untrue. A few extra details can completely re-frame the statistic's significance. Or a word or two that gets changed when the fact is repeated makes it false. Here's some commonly heard factoids about breast cancer risks and what's behind them.
1. OFTEN HEARD BUT FALSE: Breast cancer is not the most common
cancer among women, lung cancer is.
Breast cancer is the most common cancer among women, accounting
for about 30% of cancer in women. Lung cancer is the leading cause
of cancer-related death in women. So women get more breast
cancer, but also many survive. Women get lung cancer less frequently
than breast, but lung is more deadly.
2. MISLEADING: One out of eight women will get breast cancer.
For women who reach the age of eighty (80) years old, one out of eight
(about 13%) of those women will have/had breast cancer by then. Breast
cancer rates start to go up in the 20's and the majority of cases are after
the age of 50. If a woman is 50 years old today and cancer-free,
her chances of being diagnosed in the next 10 years (by age 60) is only
about 2%. In the next 20 years, by the time she is age 70, she has
a chance of about 5-6% chance.
3. MISLEADING Breast cancer rates have risen dramatically
over the century.
The number of women and the percentage rise in breast cancer have been
dramatic. There is 161% rise in breast cancer cases (from 69,000
in 1940 to 181,000 in 1980) and deaths (50% increase). But, this
is mostly due to a good things -- women living longer and getting mammograms.
There are many more women surviving into the older age groups where most
of the breast cancer occurs. Adjusting for age, there is only a 1%
rise per year between 1940-1980 and 4% per year from 1980 to 1987.
4. OFTEN HEARD BUT FALSE: A woman should have children early in
life to prevent breast cancer and live longer.
Having a first baby after the age of 30 or not having children is associated
with higher risks of post-menopausal breast cancer. But every pregnancy
raises the risk of getting breast cancer for a few years afterwards.
Only later on is there the protective effect. Also, pregnancy has
its own risks. Only a small percentage of women with pregnancies
early in life will die directly or indirectly from it, but the impact is
so much greater. When it happens to a 25 year old, over a half
a century of expected life is lost.
5. OFTEN HEARD BUT FALSE: With all the new treatments, a woman
has a much better chance of survival than in past years .
Sad, but true, the death rates have not changed much over the years.
Some age groups, races, types of cancer have better survival rates than
in the past. But overall, about 25% of those diagnosed will die now,
the same as 20 years ago.
6. LACKS DETAIL OR UNPROVEN :; A woman should
avoid x-rays, computers, and pesticides to prevent breast cancer.
X-ray exposure has its greatest impact on breast cancer rates when done before the age of 20. After the age of 50, it has almost no effect.
In any case, it is directly related to the amount of exposure and it needs to be a lot. An x-ray for a turned ankle won't matter much.
The studies associating electronic equipment (which produce electro-magnetic waves) with breast cancer
have been mixed. The studies on organochlorines (PCBs
found in flame retardants and DDT with pesticides) have found weak or no
associion with breast cancer.