OBJECTIVES: Late age at first birth and nulliparity are established risk factors for breast cancer, yet the extent to which fertility problems contribute to these associations remains largely unexplored. Here, we examine self-reported fertility problems as a risk factor for breast cancer in young women. METHODS: We used a population-based case-control study of 2,173 cases and 1,990 controls aged 20 to 54 years in the United States. Structured in-person interviews were used to elicit detailed information on established and potential breast cancer risk factors. Information was collected on pregnancy details, including difficulties becoming pregnant or maintaining a pregnancy. RESULTS: Self-reported difficulty in becoming pregnant or maintaining a pregnancy was reported by 450 cases and 377 controls. Overall, there was little association between these fertility problems and risk of breast cancer (odds ratio [OR] = 1.05). Parity was associated with a decreased risk of breast cancer in women both with (OR = 0.71) and without (OR = 0.79) fertility problems. There was little evidence of an increased risk of breast cancer with later age at first full-term birth among women without fertility problems (ORage 35+ :age <20 = 1.13, 95 percent confidence interval [CI] = 0.7-1.9), but a relatively strong association among women with fertility problems (ORage 35+ :age <20 = 2.96, CI = 1.3-7.0). Among women with a first full-term birth at age 35 or older, fertility problems were associated with a twofold risk of breast cancer. Analyses of duration of unprotected sexual intercourse prior to first pregnancy as an alternative estimate of infertility produced similar results. CONCLUSIONS: Our study suggests that the association between late age at first birth and breast cancer is stronger among women with self-reported fertility problems than among women with no fertility problems.
OBJECTIVES: Late age at first birth and nulliparity are established risk factors for breast cancer, yet the extent to which fertility problems contribute to these associations remains largely unexplored. Here, we examine self-reported fertility problems as a risk factor for breast cancer in young women. METHODS: We used a population-based case-control study of 2,173 cases and 1,990 controls aged 20 to 54 years in the United States. Structured in-person interviews were used to elicit detailed information on established and potential breast cancer risk factors. Information was collected on pregnancy details, including difficulties becoming pregnant or maintaining a pregnancy. RESULTS: Self-reported difficulty in becoming pregnant or maintaining a pregnancy was reported by 450 cases and 377 controls. Overall, there was little association between these fertility problems and risk of breast cancer (odds ratio [OR] = 1.05). Parity was associated with a decreased risk of breast cancer in women both with (OR = 0.71) and without (OR = 0.79) fertility problems. There was little evidence of an increased risk of breast cancer with later age at first full-term birth among women without fertility problems (ORage 35+ :age <20 = 1.13, 95 percent confidence interval [CI] = 0.7-1.9), but a relatively strong association among women with fertility problems (ORage 35+ :age <20 = 2.96, CI = 1.3-7.0). Among women with a first full-term birth at age 35 or older, fertility problems were associated with a twofold risk of breast cancer. Analyses of duration of unprotected sexual intercourse prior to first pregnancy as an alternative estimate of infertility produced similar results. CONCLUSIONS: Our study suggests that the association between late age at first birth and breast cancer is stronger among women with self-reported fertility problems than among women with no fertility problems.
Authors: Myung Kyung Lee; Sohee Park; Eun Sook Lee; Jungsil Ro; Han Sung Kang; Kyung Hwan Shin; Keun Seok Lee; Ki Wook Chung; Seok Won Kim; Young Ho Yun Journal: Support Care Cancer Date: 2010-07-30 Impact factor: 3.603
Authors: F Fioretti; A Tavani; C Bosetti; C La Vecchia; E Negri; F Barbone; R Talamini; S Franceschi Journal: Br J Cancer Date: 1999-04 Impact factor: 7.640
Authors: Meggiorini Maria Letizia; Vestri Anna Rita; De Stefano Maria Grazia; Cipolla Valentina; Bellati Filippo; Maffucci Diana; Nusiner Maria Paola; Aragona Cesare; De Felice Carlo Journal: BMC Womens Health Date: 2016-02-09 Impact factor: 2.809
Authors: I dos Santos Silva; P A Wark; V A McCormack; D Mayer; C Overton; V Little; J Nieto; P Hardiman; M Davies; A B MacLean Journal: Br J Cancer Date: 2009-05-12 Impact factor: 7.640