Breast Cancer Export

@article{citeulike:3563836, abstract = {There has been slow but steady progress over the last two decades in our understanding of the aetiology of breast cancer. The large variation in international rates, particularly that between the low rates in Japan and the high rates in the UK and USA, and the sharp changes in rates with migration, have provided the stimulus to much valuable work. Hormones appear to hold the key to the understanding of the human disease, just as they do in certain animal species. At present it appears that the factors most likely involved in the explanation of the major differences in rates between different population groups are: age at menarche and frequency of ovulation; post-menopausal weight; and oestrogen levels and the percentage of E2 bound to sex hormone binding globulin (SHBG). During this century the age at menarche has progressively decreased both in the UK and USA and in many other areas of the world. In a series of extensive cross-sectional studies, Tanner and others demonstrated that age at menarche is directly related to childhood growth patterns: attainment of a critical body weight to height ratio appears necessary for menarche to occur. The increase in breast cancer that accompanies a decline in average age at menarche may be inevitable: but the average age at menarche can be increased through a reduction in childhood obesity and an increase in strenuous physical activity; and the frequency of ovulation (after menarche) decreased by an increase in strenuous physical activity. The increase in breast cancer that accompanies increased postmenopausal weight adds another good reason for avoiding obesity. The basis of the increased risk associated with increased weight is in all likelihood mediated by the increased oestrogen levels and the decreased SHBG levels caused by increased weight. The recent findings of Moore et al. that a very high percentage of E2 is bound to SHBG in Japanese women is potentially the key to explaining much of the differences between Japanese and US breast cancer rates that cannot be explained by the major risk factors of menarche and post-menopausal weight. The basis of this difference in binding of E2 is not understood: 'weight alone probably does not explain [the] findings... Whether the difference relates to genetic differences in the structure of albumin or to factors such as dietary intake of lipids or other substances remains to be determined'. Much further work is needed to discover a fuller range of factors that influence both age at menarche and freqeuncy of ovulation - international studies, not only comparing the UK or USA to Japan but to other parts of Asia and Africa, should be fruitful. Further international studies of the nature of E2 bindig in different populations are particularly needed. The relation of binding to diet is likely to be a most interesting and rewarding field of study.}, author = {Pike, M. C. and Ross, R. K.}, citeulike-article-id = {3563836}, citeulike-linkout-0 = {http://bmb.oxfordjournals.org/cgi/content/abstract/40/4/351}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/6532514}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=6532514}, day = {1}, journal = {Br Med Bull}, keywords = {breast, cancer, estrogen, hormone, review}, month = {January}, number = {4}, pages = {351--354}, posted-at = {2008-11-18 06:02:41}, priority = {2}, title = {Breast Cancer}, url = {http://bmb.oxfordjournals.org/cgi/content/abstract/40/4/351}, volume = {40}, year = {1984} }

TY - JOUR ID - citeulike:3563836 L3 - citeulike-article-id:3563836 N2 - There has been slow but steady progress over the last two decades in our understanding of the aetiology of breast cancer. The large variation in international rates, particularly that between the low rates in Japan and the high rates in the UK and USA, and the sharp changes in rates with migration, have provided the stimulus to much valuable work. Hormones appear to hold the key to the understanding of the human disease, just as they do in certain animal species. At present it appears that the factors most likely involved in the explanation of the major differences in rates between different population groups are: age at menarche and frequency of ovulation; post-menopausal weight; and oestrogen levels and the percentage of E2 bound to sex hormone binding globulin (SHBG). During this century the age at menarche has progressively decreased both in the UK and USA and in many other areas of the world. In a series of extensive cross-sectional studies, Tanner and others demonstrated that age at menarche is directly related to childhood growth patterns: attainment of a critical body weight to height ratio appears necessary for menarche to occur. The increase in breast cancer that accompanies a decline in average age at menarche may be inevitable: but the average age at menarche can be increased through a reduction in childhood obesity and an increase in strenuous physical activity; and the frequency of ovulation (after menarche) decreased by an increase in strenuous physical activity. The increase in breast cancer that accompanies increased postmenopausal weight adds another good reason for avoiding obesity. The basis of the increased risk associated with increased weight is in all likelihood mediated by the increased oestrogen levels and the decreased SHBG levels caused by increased weight. The recent findings of Moore et al. that a very high percentage of E2 is bound to SHBG in Japanese women is potentially the key to explaining much of the differences between Japanese and US breast cancer rates that cannot be explained by the major risk factors of menarche and post-menopausal weight. The basis of this difference in binding of E2 is not understood: 'weight alone probably does not explain [the] findings... Whether the difference relates to genetic differences in the structure of albumin or to factors such as dietary intake of lipids or other substances remains to be determined'. Much further work is needed to discover a fuller range of factors that influence both age at menarche and freqeuncy of ovulation - international studies, not only comparing the UK or USA to Japan but to other parts of Asia and Africa, should be fruitful. Further international studies of the nature of E2 bindig in different populations are particularly needed. The relation of binding to diet is likely to be a most interesting and rewarding field of study. IS - 4 JF - Br Med Bull EP - 354 TI - Breast Cancer VL - 40 SP - 351 KW - breast KW - cancer KW - estrogen KW - hormone KW - review AU - Pike, MC AU - Ross, RK PY - 1984/01/01/ UR - http://bmb.oxfordjournals.org/cgi/content/abstract/40/4/351 ER -