Cimetidine Use and Risk of Prostate and Breast Cancer

DOI: Published March 2000

Article Figures & Data

Table 1

Risk of breast cancer among female users of H₂ blockers in GHC relative to the general population of western Washington State, 1977–1996

	Observed	Expected	SIR	95% CI
All users	507	518.2	1.0	0.9–1.1
Time since cohort entry (mo)
0–11	68	76.8	0.9	0.7–1.1
12–59	223	234.8	1.0	0.8–1.1
60–119	154	149.8	1.0	0.9–1.2
120+	62	56.8	1.1	0.8–1.4
By type(s) of H₂ blocker used
Cimetidine only	267	281.8	0.9	0.8–1.1
Time since cohort entry (mo)
0–11	30	42.0	0.7	0.5–1.0
12–59	118	122.5	1.0	0.8–1.2
60–119	83	84.3	1.0	0.8–1.2
120+	36	33.0	1.1	0.8–1.5
Cimetidine and other	165	166.3	1.0	0.8–1.2
Time since cohort entry (mo)
0–11	20	18.2	1.1	0.7–1.7
12–59	62	70.2	0.9	0.7–1.1
60–119	58	54.8	1.1	0.8–1.4
120+	25	23.2	1.1	0.7–1.6
Other only	75	70.0	1.1	0.8–1.3
Time since cohort entry (mo)
0–11	18	16.6	1.1	0.6–1.7
12–59	43	42.2	1.0	0.7–1.4
60–119	13	10.7	1.2	0.6–2.1
120+	1	0.6	1.7	0.0–9.4

Table 2

Risk of prostate cancer among male users of H₂ blockers in GHC relative to the general population of western Washington State, 1977–1996

	Observed	Expected	SIR	95% CI
All users	403	535.3	0.8	0.7–0.8
Time since cohort entry (mo)
0–11	47	73.0	0.6	0.5–0.9
12–59	176	230.1	0.8	0.7–0.9
60–119	130	167.3	0.8	0.6–0.9
120+	50	64.9	0.8	0.6–1.0
By type(s) of H₂ blocker used
Cimetidine only	191	271.7	0.7	0.6–0.8
Time since cohort entry (mo)
0–11	18	33.8	0.5	0.3–0.8
12–59	92	109.4	0.8	0.7–1.0
60–119	54	91.0	0.6	0.4–0.8
120+	27	37.5	0.7	0.5–1.0
Cimetidine and other	151	180.2	0.8	0.7–1.0
Time since cohort entry (mo)
0–11	13	17.6	0.7	0.4–1.3
12–59	50	71.8	0.7	0.5–0.9
60–119	65	64.0	1.0	0.8–1.3
120+	23	26.7	0.9	0.5–1.3
Other only	61	83.4	0.7	0.6–0.9
Time since cohort entry (mo)
0–11	16	21.6	0.7	0.4–1.2
12–59	34	48.9	0.7	0.5–1.0
60–119	11	12.3	0.9	0.4–1.6
120+	0	0.7	0	0.0–5.6^a

Table 3

Relation of cimetidine use to risk of breast cancer among female users of H₂ blockers in GHC, 1984–1996

	Controls (N = 4740)			Cases (N = 474)		RR (95% CI)
		N	%	N	%	RR (95% CI)
Ever used cimetidine
No	793	16.7	82	17.3	1.0
Yes	3947	83.3	392	82.7	1.0 (0.7–1.2)
No. of prescriptions
Never used	793	16.7	82	17.3	1.0
1	763	16.1	75	15.8	0.9 (0.7–1.3)
2–3	874	18.4	92	19.4	1.0 (0.7–1.4)
4–10	1146	24.2	110	23.2	0.9 (0.7–1.3)
11–20	590	12.4	53	11.2	0.9 (0.6–1.2)
21+	574	12.1	62	13.1	1.0 (0.7–1.5)
Time since first eligible prescription
Never used	793	16.7	82	17.3	1.0
<2 yr	953	20.1	88	18.6	0.9 (0.6–1.2)
2 to <5 yr	1134	23.9	109	23.0	0.9 (0.7–1.2
5 to <8 yr	906	19.1	91	19.2	1.0 (0.7–1.3)
8+ yr	954	20.1	104	21.9	1.1 (0.8–1.4)
Time since last prescription
Never used	793	16.7	82	17.3	1.0
≤1 yr	1804	38.1	182	38.4	1.0 (0.7–1.3)
>1 yr to <2 yr	494	10.4	47	9.9	0.9 (0.6–1.3)
2 to <5 yr	941	19.8	82	17.3	0.8 (0.6–1.2)
5+ yr	708	14.9	81	17.1	1.1 (0.8–1.5)

Table 4

Relation of cimetidine use to risk of prostate cancer among male users of H₂ blockers in GHC, 1984–1996

	Controls (N = 3920)			Cases (N = 392)		RR (95% CI)
		N	%	N	%	RR (95% CI)
Ever used cimetidine
No	708	18.1	68	17.4	1.0
Yes	3212	81.9	324	82.6	1.0 (0.8–1.4)
No. of prescriptions
Never used	708	18.1	68	17.4	1.0
1	558	14.2	55	14.0	1.0 (0.7–1.5)
2–3	673	17.2	54	13.8	0.8 (0.6–1.2)
4–10	899	22.9	96	24.5	1.1 (0.8–1.5)
11–20	542	13.8	48	12.2	0.9 (0.6–1.4)
21+	540	13.8	71	18.1	1.4 (1.0–1.9)
Time since first eligible prescription
Never used	708	18.1	68	17.4	1.0
<2 yr	681	17.4	54	13.8	0.8 (0.5–1.2)
2 to <5 yr	948	24.2	103	26.3	1.1 (0.8–1.6)
5 to <8 yr	790	20.2	81	20.7	1.1 (0.8–1.5)
8+ yr	793	20.2	86	21.9	1.1 (0.8–1.6)
Time since last prescription
Never used	708	18.1	68	17.4	1.0
≤1 yr	1461	37.3	154	39.3	1.1 (0.8–1.5)
>1 yr to <2 yr	407	10.4	36	9.2	0.9 (0.6–1.4)
2 to <5 yr	747	19.1	69	17.6	1.0 (0.7–1.4)
5+ yr	597	15.2	65	16.6	1.1 (0.8–1.6)