These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: Reproductive factors and the risk of breast cancer in old age: a Norwegian cohort study. Author: Horn J, Åsvold BO, Opdahl S, Tretli S, Vatten LJ. Journal: Breast Cancer Res Treat; 2013 May; 139(1):237-43. PubMed ID: 23605085. Abstract: Reproductive factors, including early age at menarche, late age at first birth, low parity, and late age at menopause, are associated with increased risk of breast cancer, but it is not clear to which degree the associations persist into old age. Altogether 58,426 Norwegian women born between 1886 and 1928 were followed up for breast cancer incidence from 1961 to 2008. Associations of reproductive factors with breast cancer risk were analyzed separately for the age intervals 55-69 and 70 years and older, using Cox regression. The associations were of similar strength in the two age strata. At 70 years and later, hazard ratios (HR) for the following comparisons were found: late (≥17 years) versus early (<13 years) age at menarche [HR 0.79, 95 % confidence interval (CI): 0.62, 1.01, P for trend <0.001]; late (≥35 years) versus early (<20 years) age at first birth (HR 1.54, 95 % CI: 1.13, 2.11, P for trend <0.001); high (≥5) versus low (1) parity (HR 0.68, 95 % CI: 0.54, 0.86, P for trend = 0.001) and late (50-54 years) versus early (<45 years) age at menopause (HR 1.44, 95 % CI: 1.10, 1.90, P for trend = 0.002). These findings suggest that reproductive events may have life-long effects on breast cancer risk.[Abstract] [Full Text] [Related] [New Search]