Table 1 Distribution of age at diagnosis in relation to patient characteristics, tumor characteristics, and surgical treatment

Time of diagnosis

1961-1970

31

34

29

26

23

20

1971-1980

27

34

39

36

35

32

1981-1991

42

33

32

38

42

48

Menopausal status

Premenopausal

97

90

21

0

0

0

Postmenopausal

3

10

79

100

100

100

Body Mass Index

<20

16

11

6

4

5

6

20 - <25

48

43

37

28

26

17

25 - <30

9

16

20

26

26

17

≥30

2

4

8

11

10

5

Missing

25

26

29

31

33

55

Parity (number of children)

Nullipara

23

20

21

25

28

28

1

26

25

27

25

22

16

2

32

32

31

25

19

12

3

14

15

12

12

13

7

≥4

3

3

5

7

9

10

Unknown

2

5

4

6

9

27

Size of primary tumor (millimeters)

<5

2

2

4

2

2

1

5 - ≤10

9

12

16

15

10

7

10 - ≤20

30

29

30

34

33

25

20 - ≤50

31

25

23

26

31

33

>50

2

3

3

3

4

6

Missing

26

29

24

20

20

28

Histological type

Tubular

4

8

8

6

8

4

Tubulo-ductal

9

13

14

18

17

15

Comedo

49

31

28

26

25

23

Lobular

4

10

8

9

9

8

Invasive, variable, unknown

14

12

12

11

11

22

Invasive, type not assessed

20

26

30

30

30

28

Tumor location

Upper inner quadrant

19

15

18

18

18

16

Lower inner quadrant

7

8

7

7

7

6

Upper outer quadrant

42

43

43

42

41

38

Lower outer quadrant

12

13

11

13

12

11

Central

10

14

14

14

15

18

Missing

10

7

7

6

7

11

Axillary lymph node status

Negative

51

50

49

55

46

22

Positive

46

44

42

36

34

22

Unknown

3

6

9

9

20

56

Distant metastasis at diagnosis

No

99

97

95

94

91

90

Yes

1

3

5

6

9

10

Type of surgery

Mastectomy

85

87

84

81

84

64

Partial mastectomy/local excision

15

13

14

16

9

14

Inoperable

0

0

0

3

7

22

Axillary dissection

Yes

98

94

92

91

81

44

No

2

6

6

6

12

33

Inoperable

0

0

2

3

7

22