Table 1. Characteristics at baseline of 3405 women with invasive breast cancer in the Swedish Mammography Cohort by quartiles of vitamin C intakea.
| |
Quartile of vitamin C intake (mg d−1) |
|||
|---|---|---|---|---|
| <42.9 | 42.9–65.5 | 65.6–92.4 | ⩾92.5 | |
| Median vitamin C intake (mg d−1) |
32.0 |
53.7 |
78.1 |
113.6 |
| Breast cancer deaths (n) |
128 |
103 |
97 |
88 |
| Non-breast cancer deaths (n) |
192 |
145 |
153 |
149 |
| Age at enrolment (years) |
54.1 |
52.5 |
52.6 |
52.3 |
| Age at diagnosis (years) |
66.5 |
65.4 |
65.4 |
65.4 |
| Post-secondary education (%) |
11.3% |
15.1% |
14.7% |
13.9% |
| Married (%) |
67.6% |
73.8% |
72.9% |
69.5% |
| Body mass index (kg m−2) |
25.2 |
24.9 |
24.9 |
24.7 |
| Height (cm) |
164.6 |
164.4 |
164.8 |
164.9 |
| Age at menarche (years) |
13.3 |
13.1 |
13.2 |
13.1 |
| Nulliparous (%) |
13.7% |
13.9% |
11.4% |
12.1% |
| Age at first birth among parous women (years) |
24.3 |
24.7 |
24.6 |
24.7 |
| Number of children |
2.3 |
2.3 |
2.3 |
2.3 |
| Family history of breast cancer (%) |
10.5% |
11.7% |
10.8% |
11.4% |
| Ever use of oral contraceptives (%) |
51.7% |
56.2% |
56.8% |
58.4% |
| Ever use of postmenopausal hormones (%) |
41.6% |
48.0% |
47.8% |
48.6% |
| Postmenopausal at diagnosis (%) |
92.6% |
90.9% |
90.8% |
91.4% |
| Fruit intake (servings per d) |
0.7 |
1.2 |
1.7 |
2.4 |
| Alcohol intake (g d−1) |
2.4 |
2.7 |
3.1 |
3.0 |
| Total energy intake (kcal d−1) |
1591 |
1586 |
1624 |
1533 |
|
Disease stage (%)b | ||||
| Stage I | 53.9% | 53.4% | 52.3% | 54.6% |
| Stage II | 39.8% | 41.1% | 41.9% | 40.7% |
| Stage III/IV |
6.3% |
5.5% |
5.9% |
4.8% |
|
Treatment (%)c | ||||
| Radiation | 49.4% | 56.0% | 50.5% | 52.4% |
| Chemotherapy | 13.7% | 15.2% | 14.2% | 13.2% |
| Hormonal |
32.7% |
33.6% |
28.8% |
34.2% |
| Oestrogen receptor-positive (%) |
80.0% |
83.1% |
81.8% |
82.4% |
| Progesterone receptor-positive (%) |
68.7% |
64.4% |
68.5% |
67.1% |
| Oestrogen receptor-/progesterone receptor-positive (%) | 62.3% | 60.2% | 63.3% | 63.6% |
a
Data represent mean unless otherwise indicated.
b
Percents may not equal 100 due to missing values.
c
>100% because some breast cancer patients receive more than one treatment.