What are you talking about? Two studies, looking at the SAME thing(so the story says) concluded percentages that differed by 100%. How can two valid studies, looking at the same "linkage" vary by that much? Makes no sense.
A study in 1981 found that women who had an abortion before having a full-term pregnancy had a 140% increased risk of breast cancer, while another major study in 1994 found a 40% increased risk for the same category of women.
It is simply saying that
two different studies,
looking at two different groups of women,
both of which consisted of women who had an abortion before having a FFTP
both showed an increased risk of breast cancer.
What is so hard to comprehend?
Its like saying that two studies, one done in 1950, and one done in 1990, of men who drink beer and eat steaks every night, both displayed an increased risk of heart disease, one 40% and one 140%.
The essential finding is the absolute increase in risk, NOT the percentage increase in risk.