Factors that Increase the Risk of Breast Cancer
|
Approximate Relative Risk
|
Primary Reference(s)
|
Being female
|
Very high
|
Ries et al., 2008 [5]
|
Getting older
|
Very high
|
Ries et al., 2008 [5]
|
Lobular carcinoma in situ (LCIS)
|
7 - 10
|
Morrow & Schnitt, 2000 [26]
|
Confirmed inherited genetic mutations (BRCA1 or BRCA2)
|
5 - 14
|
Struewing et al., 1997 [10]
Antoniou et al., 2003 [12]
Risch et al., 2006 [54]
|
Family history of breast cancer: Two immediate family members affected with breast cancer
|
3 - 4
|
Colditz et al., 1993 [135]
Pharoah et al., 1997 [28]
CGHFBC, 2001 [29]
|
Family history of breast cancer: Mother affected before age 60
|
2 - 3
|
Colditz et al., 1993 [135]
|
Family history of breast cancer: Mother affected after age 60
|
1.4
|
Colditz et al., 1993 [135]
|
High breast density
|
3 - 6
|
Barlow et al., 2006 [136]
|
Personal history of breast cancer (including DCIS)
|
2 — 6
|
Chen et al., 1999 [137]
|
Benign breast conditions (proliferative): Atypical hyperplasia
|
4
|
Tamimi et al., 2005 [47]
Hartmann et al., 2005 [48]
Degnim et al., 2007 [138]
|
Benign breast conditions (proliferative): Usual hyperplasia
|
1.5 - 1.9
|
Tamimi et al., 2005 [47]
Hartmann et al., 2005 [48]
|
Radiation exposure or frequent X-rays during youth
|
2 — 4
|
Hankcock et al., 1993 [36]
Swerdlow et al., 2000 [37]
Travis et al., 2003 [38]
|
High levels of estrogen in the blood after menopause
|
2
|
EHBCCG, 2002 [139]
|
High bone density
|
1.5 - 3.5
|
Zhang et al., 1997 [58]
Zmuda et al., 2001 [59]
|
Menopause at age 55 or older
|
2
|
Trichopoulos, 1972 [140]
|
Not having children (compared to women who give birth at age 35 or younger)
|
1.3
|
Ewertz et al., 1990, [56]
|
First child after age 35
|
1.1-1.4
|
Ewertz et al., 1990 [56]
Rosner et al., 1994 [55]
|
Overweight/weight gain
|
1.2 - 1.5
|
Van den Brandt et al., 2000 [65]
Eliassen et al., 2006 [141]
|
High socioeconomic status
|
1.2 - 1.8
|
Yost et al., 2001 [72]
Braaten et al., 2005 [74]
|
Lack of exercise
|
1.2
|
Rockhill et al., 1999 [85]
McTiernan et al., 2003 [86]
Tehard et al., 2006 [87]
|
Drinking alcohol (2 - 4 drinks/day)
|
1.4
|
Smith-Warner et al., 1998 [142]
EHBCCG, 2002 [82]
|
Postmenopausal hormone use-estrogen plus progestin (current or recent use for 5 or more years)
|
1.3 - 2.0
|
WHI, 2002 [96]
Beral et al., 2003 [97]
Collins et al., 2005 [99]
|
Current or recent use of birth control pills
|
1.1 - 1.3
|
CGHFBC, 1996 [124]
|
First period before age 12
|
1.2 - 1.3
|
Kelsey et al., 1996 [122]
Ma et al., 2006 [123]
|
Being tall
|
1.2
|
Van den Brandt et al., 2000 [65]
|
Not breastfeeding
|
1.1 - 1.2
|
CGHFBC, 2002 [133]
Bernier et al., 2002 [132]
|
Ashkenazi Jewish heritage
|
1.1
|
Egan et al., 1996 [78]
|
