Risk Factors Associated with Breast Cancer among Women in Addis Ababa, Ethiopia: Unmatched Case–Control Study

Figures & data

Table 1 Sociodemographic Characteristics of Women among Cases and Controls at TASH and SPHMMC Addis Ababa, Ethiopia, 2020

Variables	Controls (n=232)	Cases (n=116)	Total (n=348)
	Count (%)	Count (%)	Count (%)
Place of residence
Urban	223 (96.1)	98 (84.5)	321 (92.2)
Rural	9 (3.9)	18 (15.5)	27 (7.8)
Region
Addis Ababa	162 (69.8)	98 (84.5)	260 (76.1)
Oromia	45(19.4)	10 (8.6)	55 (14.9)
Amhara	20 (8.6)	5 (4.3)	25 (7.2)
Others	5 (2.2)	3 (2.6)	8 (1.7)
Educational status
No formal education	39 (16.8)	27 (23.3)	66 (19.0)
Primary	76 (32.8)	33 (28.4)	109 (31.3)
Secondary	33 (14.2)	19 (16.4)	52 (14.9)
College and above	84 (36.2)	37 (31.9)	121 (34.8)
Marital status
Married	135 (58.2)	84 (72.4)	219 (62.9)
Widowed	28 (12.1)	8 (6.9)	36 (10.3)
Divorced	11 (4.7)	10 (8.6)	21 (6.0)
Single	58 (25.0)	14 (12.1)	72 (20.7)
Occupation
House wife	106 (45.7)	55 (47.4)	161 (46.3)
Employed	91 (39.2)	50 (43.1)	141 (40.5)
Merchant	12 (5.2)	3 (2.6)	15 (4.2)
Farmer	23 (9.9)	8 (6.9)	31 (9.0)
Family monthly income
≤ 1000	62 (26.7)	37 (31.9)	99 (28.4)
1001–1999	36 (15.5)	20 (17.2)	56 (16.1)
≥ 2000 ETB	134 (57.8)	59 (50.9)	193 (55.5)

Table 2 Behavioral and Biological Related Characteristics of Women among Cases and Controls at TASH and SPHMMC Addis Ababa, Ethiopia, 2020

Variables	Controls (n=232)	Cases (n=116)	Total (n=348)
	Count (%)	Count (%)	Count (%)
BMI
Underweight	15 (6.5)	10 (8.6)	25 (7.2)
Normal weight	159 (68.5)	69 (59.5)	228 (65.5)
Overweight and/or Obesity	58 (25.0)	37 (31.9)	95 (27.3)
Physical activity
Yes	34 (14.7)	18 (15.5)	52 (14.9)
No	198 (85.3)	98 (84.5)	296 (85.1)
Intensity of activity
Light	17 (50.0)	10 (55.6)	27 (51.9)
Moderate	14 (41.2)	6 (33.3)	20 (38.5)
Heavy	3 (8.8)	5 (11.1)	8 (9.6)
Vegetable or fruit intake per week
≤ 7	132 (56.9)	79 (68.1)	211 (60.6)
> 7	100 (43.1)	37 (31.9)	137 (39.4)
Exposure to smoked meat
Yes	70 (30.2)	58 (50.0)	128 (36.8)
No	162 (69.8)	58 (50.0)	220 (63.2)
Packed food consumption
Yes	46 (19.8)	39 (33.6)	85 (24.4)
No	186 (80.2)	77 (66.4)	263 (75.6)
History of trauma to the breast
Yes	51 (22.0)	32 (27.6)	83 (23.9)
No	181 (78.0)	84 (72.4)	265 (76.1)
Ever had a mammogram
Yes	5 (2.2)	7 (6.0)	12 (3.4)
No	227 (97.8)	109 (94.0)	336 (96.6)
Breast self-examination
Yes	94 (40.5)	46 (39.7)	140 (40.2)
No	138 (59.5)	70 (60.3)	208 (59.8)

Table 3 Reproductive Health-Related Characteristics of Women among Cases and Controls at TASH and SPHMMC Addis Ababa, Ethiopia, 2020

Variables	Controls (n=232)	Cases (n=116)	Total (n=348)
	Count (%)	Count (%)	Count (%)
Menstrual period regularity
Yes	208 (89.7)	93 (80.2)	301 (86.5)
No	24 (10.3)	23 (19.8)	47 (13.5)
Menopausal status
Premenopausal	148 (63.8%)	60 (51.7)	208 (59.8)
Menopausal	84 (36.2)	56 (48.3)	140 (40.2)
Age at menopause
≤ 45 years	58 (69.0)	37 (66.1)	95 (67.9)
46–54 years	24 (28.6)	19 (33.9)	43 (30.7)
≥ 55 years	2 (2.4)	0 (0.0)	2 (1.4)
Duration of contraceptive use
≤ 4 years	50 (54.9)	25 (52.1)	75 (54.0)
> 4 years	41 (45.1)	23 (47.9)	64 (46.0)
Age at first live birth
≤ 20 years	67 (46.2)	33 (39.3)	100 (43.7)
21–29 years	58 (40.0)	38 (45.2)	96 (41.9)
≥ 30 years	20 (13.8)	13 (15.5)	33 (14.4)
History of abortion
Yes	51 (22.0)	38 (32.8)	89 (25.6)
No	181 (78.0)	78 (67.2)	259 (74.4)
Breastfeeding
Yes	180 (77.6)	94 (81.0)	274 (78.7)
No	52 (22.4)	22 (19.0)	74 (21.3)

Figure 1 Distribution of women with age at menarche among cases and controls at TASH and SPHMMC Addis Ababa, Ethiopia, 2020.

Table 4 Bivariable and Multivariable Logistic Regression Analysis of Factors Associated with Breast Cancer Risk at TASH and SPHMMC Addis Ababa, Ethiopia, 2020

Variables		Breast Cancer		COR (95% CI)	AOR (95% CI)	P-value
	Categories	Control (n=232)	Cases (n=116)
Place of residence	Urban	223	98	1.00	1.00
	Rural	9	18	4.55 (1.97, 10.49)	3.64 (1.38, 9.57)*	0.009
Smoked meat exposure	Yes	70	58	2.31 (1.46, 3.66)	2.41 (1.36, 4.27)*	0.003
	No	162	58	1.00	1.00
Use of packed food or drinks	Yes	46	39	2.05 (1.24, 3.39)	2.80 (1.52, 5.15)*	0.001
	No	186	77	1.00	1.00
Vegetable consumptions per week	Less than 7	132	79	1.62 (1.01, 2.59)	1.36 (0.75, 2.45)	0.315
	7 and more	100	37	1.00	1.00
Age at menarche in years	≤ 12	27	40	3.50 (1.74, 7.03)	4.10 (1.84, 9.15)*	0.001
	13–15	153	54	0.83 (0.46, 1.50)	1.06 (0.56, 2.02)	0.861
	≥ 16	52	22	1.00	1.00
Menstrual regularity	Yes	208	93	1.00	1.00
	No	24	23	2.14 (1.15, 3.99)	1.38 (0.67, 2.85)	0.384
BMI	Underweight	15	10	1.54 (0.66, 3.59)	1.44 (0.53, 3.91)*	0.474
	Overweight and obesity	58	37	1.47 (0.89, 2.42)	2.38 (1.31, 4.31)	0.004
	Normal weight	159	69	1.00	1.00
Number of children	One or less	138	81	1.57 (0.98, 2.54)	1.86 (1.01, 3.41)*	0.046
	Two and more	94	35	1.00	1.00
Educational status	No formal education	39	27	1.57 (0.84, 2.94)	1.69 (0.75, 3.84)	0.209
	Primary and secondary education	109	52	1.08 (0.65, 1.80)	1.11 (0.60, 2.03)	0.733
	College and above	84	37	1.00	1.00
History of abortion	Yes	51	38	1.73 (1.05, 2.84)	1.50 (0.84, 2.70)	0.168
	No	181	78	1.00	1.00
Family history of Cancer	Yes	29	23	1.73 (0.95, 3.15)	2.11 (1.04, 4.26)*	0.038
	No	203	93	1.00	1.00

Note: *Statistically significant at P ≤ 0.05.

Abbreviations: COR, crude odds ratio; AOR, adjusted odds ratio.