"The overall absolute increase in breast cancers diagnosed among current and recent users of any hormonal contraceptive was 13 (95% CI, 10 to 16) per 100,000 person-years, or approximately *1 extra breast cancer for every **7690** women* using hormonal contraception for 1 year."
Knowing the difference between absolute and relative risk is **imperative** when reading scientific literature.
There is a link between fertility/birth rates and breast cancer incidence, I wonder how much that has a confounding effect?
The wording of this article is kind of sensationalized. It's important to distinguish between *absolute* versus *relative* risk increase when reporting the results. It sounds very sensational to say "the risk of breast cancer increased by 38%" but that doesn't mean it increased by 38 percentage points. For example, let's say that your risk of getting breast cancer as a 25-year-old is 1% per year. (It's likely way lower than that.) Then let's say you take a pill that increases your risk by 38% - now your chance of breast cancer is 1.38%, not 39%.
Think of it this way: the chance of a young woman getting breast cancer is very low. Even if the risk doubled or tripled while on OCPs, the risk would *still* be very low.
Source: Medical student who will still be taking her birth control pills.
Serious question, wasn't this already known?
I'm currently taking pharmacology and our lecture that talked about birth control was only a few weeks ago. I swear my professor said that WHI did a study years ago and it showed an increase in breast cancer.
Does the paper address if the mechanism is via exogenous hormones or via fewer natural hormonal cycles?
If the former, that's yet another point in favor of IUDs, and hormonal IUDs prevent much bleeding while not having much in the way of systemic effects...
The effects seem to slow down with more years on it, making me suspect that the exogenous hormones are the mechanism.