Body mass index and survival after breast cancer diagnosis in Japanese women

BMC Cancer

Table 1 Characteristics of the study cohort

		BMI				Total
		< 21.2	≥ 21.2 to< 23.3	≥ 23.3 to< 25.8	≥ 25.8
Age (years) mean ± S.D.		53.7 ± 13.4	55.2 ± 11.2	58.9 ± 12.0	60.0 ± 11.9	57.0 ± 12.4
Person-years		963.0	1052.4	1020.1	997.3	4032.8
Patients (n)		163	166	161	163	653
All-cause death (n)		42	27	29	38	136
Breast cancer-specific death (n)		34	21	26	27	108
Smoking (%)
	Never	72.4	78.9	85.7	82.2	79.8
	Current or Past	25.2	17.5	12.4	14.1	17.3
	Missing	2.5	3.6	1.9	3.7	2.9
Stage (%)
	In situ or Locarized	39.9	43.4	34.2	39.3	39.2
	Lymph node Metastasis	30.7	34.9	41.6	35.6	35.7
	Local Invasion	10.4	6.6	9.9	8.0	8.7
	Distant Metastasis	1.8	2.4	5.0	3.1	3.1
	Missing	17.2	12.7	9.3	14.1	13.3
Hormone receptor (%)
	ER + or PgR+	58.9	57.8	65.2	69.3	62.8
	ER-/PgR-	28.2	30.1	25.5	22.7	26.6
	Missing	12.9	12.0	9.3	8.0	10.6
Radiation therapy (%)
	No	77.3	78.3	86.3	83.4	81.3
	Yes	22.7	21.7	13.7	16.6	18.7
Chemotherapy (%)
	No	74.8	76.5	75.2	78.5	76.3
	Yes	25.2	23.5	24.8	21.5	23.7
Endocrine therapy (%)
	No	75.5	75.9	79.5	71.2	75.5
	Yes	24.5	24.1	20.5	28.8	24.5
	No	95.1	92.8	90.7	86.5	91.3
	Yes	4.9	7.2	9.3	13.5	8.7
Menopausal status (%) ^a
	Premenopausal	54.6	44.0	39.1	31.9	42.4
	Postmenopausal	41.1	51.8	57.8	66.3	54.2
	Missing		4.2	3.1	1.8	3.4
Physical activity (%)
	Almost no	51.5	53.0	45.3	46.6	49.2
	More than one hour per week	43.6	39.8	46.0	50.3	44.9
	Missing	4.9	7.2	8.7	3.1	6.0
Comorbidities (%) ^b
	No	86.5	80.1	71.4	67.5	76.4
	Yes	13.5	19.9	28.6	32.5	23.6

^a Menopause was defined as the cessation of menstrual periods due to natural or other reasons including surgery.
^b Includes hypertension/ischemic heart disease/stroke/diabetes mellitus.
During a median follow-up period of 5.85 years, 136 all-cause and 108 breast cancer-specific deaths were observed.

ISSN: 1471-2407