African Americans and Hispanics Remain at Lower Risk of Ovarian Cancer Than Non-Hispanic Whites after Considering Nongenetic Risk Factors and Oophorectomy Rates

DOI: 10.1158/1055-9965.EPI-15-0023 Published July 2015

Article Figures & Data

Table 1.

Tumor characteristics of invasive ovarian cancer in non-Hispanic whites, Hispanics, and African Americans: Los Angeles County Ovarian Cancer Study

↵^aP value comparing non-Hispanic whites with each of the other two groups separately.
↵^bP value based on cases of serous, mucinous, endometrioid, and clear-cell histology only.
↵^cP value excluding cases with no known histology or stage of cancer at diagnosis.

Table 2.

Prevalence of risk factors in non-Hispanic white, Hispanic, and African-American control women (top) and ovarian cancer cases (bottom)

Factors	Non-Hispanic whites	Hispanics	African Americans	P1^b	P2^c	P3^d
Controls^a
Nulliparous (%)	23.7%	13.7%	16.8%	<0.001	0.076	0.45
Mean # births among parous (SD)	2.5 (1.3)	3.0 (1.7)	2.7 (1.5)	<0.001	0.03	0.15
Oral contraceptive use (no/<1 year; %)	41.5%	54.7%	47.6%	<0.001	0.19	0.17
Mean # months of OC use among users (SD)	95.9 (74.9)	81.0 (67.0)	93.1 (74.2)	0.014	0.75	0.21
No tubal ligation (%)	85.9%	73.7%	69.2%	<0.001	<0.001	0.36
Endometriosis (%)	7.5%	3.4%	5.6%	0.006	0.50	0.38
Family history of ovarian cancer (%)	2.5%	3.4%	2.8%	0.37	0.98	0.93
Talc use ≥1 year (%)	30.4%	28.9%	44.1%	0.61	0.0001	0.002
Mean # years of talc use among users (SD)	23.9 (17.4)	21.3 (16.7)	22.9 (17.0)	0.15	0.67	0.55
Cases^e
Nulliparous (%)	27.8%	17.9%	16.4%	<0.001	0.007	0.82
Mean # births among parous (SD)	2.5 (1.2)	3.1 (1.7)	2.8 (1.6)	<0.001	0.003	0.24
Oral contraceptive use (no/< 1 year; %)	57.4%	69.8%	50.0%	<0.001	0.13	<0.001
Mean # months of OC use among users (SD)	73.4 (61.1)	59.8 (53.1)	75.7 (66.7)	0.044	0.75	0.10
No tubal ligation (%)	90.6%	83.8%	80.5%	<0.001	<0.001	0.49
Endometriosis (%)	11.1%	5.5%	9.4%	0.005	0.66	0.21
Family history of ovarian cancer (%)	5.1%	4.9%	7.0%	0.96	0.48	0.50
Talc use ≥1 year (%)	41.2%	38.6%	47.7%	0.45	0.19	0.10
Mean # years of talc use among users (SD)	27.5 (18.4)	21.6 (16.9)	26.6 (18.2)	0.001	0.71	0.069

↵^aControls included: 1,868 non-Hispanic whites, 380 Hispanics, and 143 African Americans.
↵^bP_1df for differences between non-Hispanic whites and Hispanic controls (top)/P_1df for differences between non-Hispanic whites and Hispanic cases (bottom).
↵^cP_1df for differences between non-Hispanic whites and African American controls (top)/P_1df for differences between non-Hispanic whites and African American cases (bottom).
↵^dP_1df for differences between Hispanic and African American controls (top)/P_1df for differences between Hispanic and African American cases (bottom).
^eCases included: 1,265 non-Hispanic whites, 308 Hispanics, and 128 African Americans.

Table 3.

Mutually adjusted ORs^a for invasive ovarian cancer in Los Angeles County non-Hispanic whites, Hispanics, and African Americans

	Non-Hispanic whites (1,265/1,868)		Hispanics (308/380)		African Americans (128/143)		All (1701/2391)
	ca/co	OR (95% CI)	ca/co	OR (95% CI)	ca/co	OR (95% CI)	ca/co	OR (95% CI)
Live-births
Yes	913/1,426	1.00	253/328	1.00	107/119	1.00	1,273/1,873	1.00
No	352/442	1.43 (1.19–1.73)	55/52	2.22 (1.28–3.84)	21/24	1.42 (0.54–3.75)	428/518	1.47 (1.24–1.75)
Per birth		0.70 (0.58–0.84)		0.45 (0.26–0.78)		0.70 (0.27–1.86)		0.68 (0.57–0.81)
Oral contraceptive (OC)
Yes	539/1,092	1.00	93/172	1.00	64/75	1.00	696/1,339	1.00
None/<1 year	726/776	1.55 (1.31–1.84)	215/208	1.29 (0.87–1.92)	64/68	1.30 (0.64–2.63)	1,005/1,052	1.47 (1.26–1.70)
Per 5 years OC		0.64 (0.54–0.76)		0.77 (0.52–1.15)		0.77 (0.38–1.55)		0.68 (0.59–0.79)
Tubal ligation
Yes	119/263	1.00	50/100	1.00	25/44	1.00	194/407	1.00
No	1,146/1,605	1.41 (1.10–1.81)	258/280	1.71 (1.07–2.74)	103/99	1.65 (0.73–3.74)	1,507/1,984	1.52 (1.23–1.87)
Endometriosis
No	1,125/1,728	1.00	291/367	1.00	116/135	1.00	1,532/2,230	1.00
Yes	140/140	1.51 (1.15–1.98)	17/13	2.21 (0.89–5.48)	12/8	1.74 (0.45–6.74)	169/161	1.56 (1.21–2.00)
First-degree family history of ovarian cancer
No	1,200/1,822	1.00	293/367	1.00	119/139	1.00	1,612/2,328	1.00
Yes	65/46	2.12 (1.40–3.21)	15/13	2.38 (0.94–6.01)	9/4	7.84 (1.66–37.0)	89/63	2.26 (1.58–3.25)
Genital talc use
None/<1 year	744/1,300	1.00	189/270	1.00	67/80	1.00	1,000/1,650	1.00
Yes	521/568	1.41 (1.21–1.67)	119/110	1.77 (1.20–2.62)	61/63	1.56 (0.80–3.04)	701/741	1.46 (1.27–1.69)
Per 5 years talc		1.14 (1.08–1.21)		1.18 (1.02–1.36)		1.15 (0.90–1.47)		1.14 (1.09–1.20)

↵^aRace/ethnic specific multivariate logistic regression analyses were jointly stratified for age group (<30, 5-year age groups to age 79), interviewer and study, and adjusted for menopausal status, age at menarche, hormone therapy use, BMI, income, education, and each of the six factors shown. In analyses on “all subjects,” we also jointly stratified by race/ethnicity.

Table 4.

Ovarian cancer PAR%s and 95% CI in Los Angeles County non-Hispanic whites, Hispanics, and African Americans^a

	Using race-adjusted ORs^a
	Non-Hispanic whites	Hispanics	African Americans
	PAR%^b	PAR%^b	PAR%^b
No live birth	8.9%	5.7%	5.3%
	5.3%–11.9%	3.4%–7.6%	3.1%–7.0%
No/<1 year oral contraceptives	18.3%	22.2%	15.9%
	12.0%–23.7%	14.5%–28.8%	10.4%–20.7%
No tubal ligation	31.0%	28.7%	27.5%
	17.2%–42.3%	15.9%–39.1%	15.2%–37.5%
Yes endometriosis	4.0%	2.0%	3.4%
	2.0%–5.5%	1.0%–2.8%	1.7%–4.7%
Yes family history ovarian cancer	2.9%	2.7%	3.9%
	1.9%–3.6%	1.8%–3.4%	2.6%–4.9%
Yes/≥1 year talc use	13.0%	12.2%	15.1%
	8.7%–16.8%	8.1%–15.8%	10.0%–19.5%
Three factors (no tubal ligation	50.8%	51.2%	47.9%
no/<1 year oral contraceptives, yes/≥1 year talc use)	39.7%–59.5%	40.8%–59.3%	37.8%–55.8%
All 6 factors	57.9%	56.1%	53.8%
	48.7%–65.3%	46.8%–63.3%	45.0%–60.7%

↵^aUsing the all race/ethnicity adjusted ORs from Table 3.
↵^bThe PARs were mutually adjusted for the variables shown in this table as well as for age group (<30, 5-year age groups to age 79), interviewer and study, menopausal status, age at menarche, hormone therapy use, BMI, income, and education.