Nonsteroidal anti-inflammatory drugs and breast cancer risk in the National Institutes of Health–AARP Diet and Health Study

Table 3 Association between nonsteroidal anti-inflammatory drug (NSAID) use and breast cancer among 126,124 women, National Institutes of Health–AARP Study

	Number of cancers	Person-years	Relative risk^a	95% confidence interval	P value for trend
NSAID use
Never	667	124,265	1.00 (referent)		n/a
Aspirin only	1,085	203,145	0.97	0.88 to 1.07
Non-aspirin NSAID only	874	157,017	1.01	0.92 to 1.12
Both	1,781	334,792	0.95	0.87 to 1.04
Aspirin use^b
Never	1,556	284,342	1.00 (referent)		0.08
<1/week	1,405	265,676	0.95	0.89 to 1.03
1–6/week	716	133,331	0.95	0.87 to 1.04
1+/day	774	145,317	0.93	0.85 to 1.01
Non-aspirin NSAID use^b
Never	1,764	329,944	1.00 (referent)		0.58
<1/week	1,415	262,000	1.00	0.93 to 1.07
1–6/week	693	126,373	1.02	0.93 to 1.11
1+/day	585	109,098	0.96	0.87 to 1.05

^aAdjusted for age (continuous), race, age at first birth, hormone therapy use, number of breast biopsies, alcohol intake, history of hypertension, and family history of breast cancer in first-degree relative.
^bThese models also include terms for frequency of use of opposite NSAID type.

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