Is birth history the key to highly educated women's higher breast cancer mortality? A follow‐up study of 500,000 women aged 35–54

• Published in: International journal of cancer 2005-12, Vol.117 (6), p.1002-1006
• Main Authors: Strand, Bjørn Heine, Tverdal, Aage, Claussen, Bjørgulf, Zahl, Per‐Henrik
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; breast cancer; Breast Neoplasms - epidemiology; Breast Neoplasms - mortality; education; Educational Status; Female; Follow-Up Studies; Gynecology. Andrology. Obstetrics; Humans; Mammary gland diseases; Maternal Age; Medical sciences; Middle Aged; mortality; Norway - epidemiology; Parity; Pregnancy; Proportional Hazards Models; prospective study; Risk Factors; Tumors
• ISSN: 0020-7136; 1097-0215
• DOI: 10.1002/ijc.21239

A positive relationship has been found between high levels of education and breast cancer mortality. The aim of our study is to determine if the educational gradient in breast cancer mortality persists after adjustment for reproductive history. Register data including the total adult population in Norway were used. A total of 512,353 Norwegian women 35–54 years of age at the Norwegian Census in 1990 were followed with respect to breast cancer deaths until December 31, 2001. The analysis included 2,052 breast cancer deaths in 5.6 million person years. Educational differences in breast cancer mortality were analysed using Cox regression. The age adjusted relative risk of dying from breast cancer for women with >12 years of education compared to women with