The increase was not seen in women under 60 taking estrogen alone, however.
Moreover, the longer the women took estrogen, the lower their risk.
Millions of women take estrogen in one form or another.
Women who took estrogen alone had a 20 percent increase.
It is usually used by women who cannot take estrogen.
Since many women cannot or will not take estrogen, other effective products have been developed.
Many women today don't want to take estrogen for very good reasons.
For those taking only estrogen, the increased risk was 30 percent.
Women taking estrogen wondered if they had done the right thing.
But could there be even better reasons to take estrogen?