Birth weight as a predictor of breast cancer: a case–control study in Norway

Abstract

The hypothesis that birth weight is positively associated with adult risk of breast cancer implies that factors related to intrauterine growth may be important for the development of this malignancy. Using stored birth records from the two main hospitals in Trondheim and Bergen, Norway, we collected information on birth weight, birth length and placenta weight among 373 women who developed breast cancer. From the same archives, we selected as controls 1150 women of identical age as the cases without a history of breast cancer. Information on age at first birth and parity were collected from the Central Person Registry in Norway. Based on conditional logistic regression analysis, breast cancer risk was positively associated with birth weight and with birth length (P for trend=0.02). Birth weights in the highest quartile (3730 g or more) were associated with 40% higher risk (odds ratio, 1.4, 95% confidence interval, 1.1 -1.9) of breast cancer compared to birth weights in the lowest quartile (less than 3090 g). For birth length, the odds ratio for women who were 51.5 cm or more (highest quartile) was 1.3 (95% confidence interval, 1.0 -1.8) compared to being less than 50 cm (lowest quartile) at birth. Adjustment for age at first birth and parity did not change these estimates. Placenta weight was not associated with breast cancer risk. This study provides strong evidence that intrauterine factors may influence future risk of breast cancer. A common feature of such factors would be their ability to stimulate foetal growth and, simultaneously, to influence intrauterine development of the mammary gland.

Birth weight and risk of cancer

“…Similar to several previous reports, we found a linear association between breast cancer and birth weight. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] We also found an inverse association between birth weight and testicular cancer, which thereby strengthens the previous findings. [40][41][42][43][44][45][46] To our knowledge, only 2 smaller studies published to date have previously addressed the association between the overall risk of cancer and birth weight.…”

An alternative, non-intrauterine hypothesis, based on maternal mitochondrial oocyte inheritance, to explain inconsistent findings of birth weight on (breast) cancer risk

“…With great interest, I read the different results found for birth weight and birth length on adult breast cancer risk reported by Vatten (2002) and Sanderson (2002). Both articles referred to a hypothesis on early through postconception life events and breast cancer risk (Trichopoulos, 1990).…”

“…This is evident by the lack of correlation between placenta weight and breast cancer risk reported by Vatten (2002). The placenta as a predominantly foetal organ (Susser, 1982) depends for its growth on paternal genes active in the blastocyst, especially the IGF-2 gene, which becomes expressed only around nidation (Ferguson, 2001).…”

Associations of adult measures of childhood growth with breast cancer: findings from the British Women's Heart and Health Study

“…The association may be explained by factors that jointly influence stature and breast cancer risk. These include hormones such as insulin-likegrowth factor I (IGF-I) (Hankinson et al, 1998;Kaaks et al, 2002), energy intake in childhood (McCay et al, 1939;Hart and Turturro, 1997;Frankel et al, 1998), and also intrauterine growth, reflected by birth weight, which has been found to be positively associated with breast cancer risk (Michels et al, 1996;Stavola et al, 2000;Vatten et al, 2002). Since the two components of adult height -leg length and trunk length -are poorly correlated with each other and appear to be influenced by different early life factors (Gunnell, 2002;Wadsworth et al, 2002), examining their separate associations with breast cancer may provide additional insights into the mechanisms responsible for the association between height and breast cancer.…”