Table 3.

Estimated Joint Effect^* of Premenopausal Hysterectomy or Hormone Therapy and Endometriosis on the Odds of Ovarian Cancer

	Endometriosis								Endometriosis within Strata of effect modifier		RERIa	RERIm
	No				Yes
	N Cases	N Controls	OR†	95% CI	N Cases	N Controls	OR†	95% CI	OR†	95% CI
Premenopausal Hysterectomy
All participants
No	2267	3842	1.00		184	170	1.97	1.57–2.48	1.99	1.58–2.50	−0.55 (−1.22–0.12) p=0.10	0.69 (0.46–1.02) p=0.07
Yes	582	738	1.17	1.02–1.33	93	95	1.59	1.16–2.16	1.32	0.94–1.84
Black participants
No	649	1312	1.00		52	56	2.28	1.48–3.51	2.32	1.51–3.59	−0.36 (−1.84–1.11) p=0.62	0.81 (0.39–1.65) p=0.56
Yes	211	365	1.09	0.88–1.36	29	36	2.01	1.15–3.53	1.91	1.05–3.48
White participants
No	1618	2530	1.00		132	114	1.83	1.39–2.39	1.85	1.41–2.43	−0.65 (−1.68–0.09) p=0.09	0.63 (0.39–1.01) p=0.06
Yes	371	373	1.24	1.05–1.47	64	59	1.42	0.98–2.07	1.09	0.73–1.64
Hormone Therapy
All participants
No	1773	3115	1.00		161	156	1.96	1.54–2.50	2.01	1.57–2.58	−0.46 (−1.12–0.19) p=0.17	0.74 (0.51–1.07) p=0.11
Yes	1094	1465	1.13	1.00–1.26	116	109	1.63	1.22–2.18	1.40	1.04–1.87
Black participants
No	693	1316	1.00		56	67	2.03	1.35–3.05	1.99	1.32–3.01	0.34 (−1.45–2.13) p=0.71	1.10 (0.51, 2.41) p=0.80
Yes	176	362	1.11	0.87–1.41	23	25	2.48	1.28–4.78	2.39	1.18–4.83
White participants
No	1080	1799	1.00		105	89	1.89	1.39–2.57	1.97	1.44–2.70	−0.57 (−1.30–0.15) p=0.12	0.68 (0.44–1.06) p=0.09
Yes	918	1103	1.11	0.97–1.27	93	84	1.43	1.03–1.98	1.24	0.90–1.72

^*Measure of relative excess of interaction on the additive and multiplicative scales.

^†Odd ratios were adjusted for site, age at diagnosis, education, parity, OC duration, BMI, smoking status, tubal ligation, family history of cancer, menopausal status, hormone therapy duration or premenopausal hysterectomy, and age at menarche.