. 2008 Apr 30;10(2):R38. doi: 10.1186/bcr2089

Table 6.

Association between nonsteroidal anti-inflammatory drug (NSAID) use and breast cancer according to stage among screened women, National Institutes of Health–AARP Study

	In situ breast cancer					Invasive breast cancer

NSAID use	Number of cancers	Person-years	Relative risk^a	95% confidence interval	P value for trend	Number of cancers	Person-years	Relative risk^a	95% confidence interval	P value for trend
Aspirin use^b
Never	241	192,125	1.00 (referent)		0.02	916	194,396	1.00 (referent)		0.15
<1/week	180	179,747	0.77	0.63 to 0.93		847	181,986	0.98	0.89 to 1.07
1–6/week	97	90,680	0.82	0.65 to 1.05		402	91,715	0.90	0.80 to 1.01
1+/day	96	99,793	0.75	0.59 to 0.95		476	101,064	0.95	0.85 to 1.06
Non-aspirin NSAID use^b
Never	218	209,044	1.00 (referent)		0.50	982	211,655	1.00 (referent)		0.62
<1/week	222	185,624	1.16	0.95 to 1.40		852	187,741	0.98	0.89 to 1.07
1–6/week	97	90,035	1.03	0.81 to 1.31		428	91,161	1.03	0.92 to 1.16
1+/day	76	77,462	0.89	0.69 to 1.16		384	78,439	1.02	0.91 to 1.15

This analysis was restricted to women who reported ≥2 mammograms in the past 3 years. ^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.