T E Rohan, L. Martinez, C. Theetranont, Anne Tjønneland, Victor Siskind, Elio Riboli, Diana Bull, Elisabete Weiderpass, C. La Vecchia, John T. Casagrande, O. Meirik, Anthony B. Miller, Linda Werner Hartman, Chris Bain, Domenico Palli, P. C. Nasca, Kristin E. Anderson, P. H. M. Peeters, Håkan Olsson, Michael E. Carney, Jenny Chang-Claude, N. S. Weiss, Harvey A. Risch, Penelope M. Webb, M. Vessey, Clicerio Gonzalez, Aaron R. Folsom, Galit Hirsh-Yechezkel, Klea Katsouyanni, K. Callaghan, Patricia Hartge, Adèle C. Green, Suporn Koetsawang, F. Clavel-Chapelon, P.A. van den Brandt, Alpa V. Patel, T. Byers, James V. Lacey, A. Dabancens, Andy H. Lee, A. Goodill, O. Salas, P. Hannaford, Valerie Beral, G Reeves, Galina Lurie, Amanda Black, Mary Anne Rossing, Lynne R. Wilkens, Louise A. Brinton, Timothy J. Key, Mark A. Morgan, Anna H. Wu, D. Rachawat, Catherine Schairer, R. Ness, L. Dal Maso, Marc T. Goodman, M. Zhang, N. Lee, Patricia F. Coogan, Flora Lubin, K Gaitskell, Xiao-Ou Shu, Howard W. Ory, B. Crossley, Alicja Wolk, Julie R. Palmer, L A Brinton, Lynn Rosenberg, Roberta B. Ness, Eva Negri, Leo J. Schouten, R. Paffenbarger, Dimitrios Trichopoulos, K. Moser, J. E. Wheeler, A. Berrington de Gonzalez, Cecilia Magnusson, Colin W. Binns, S. Silpisornkosol, D. Yeates, Sidsel Graff-Iversen, Kay Cr, Timothy M.M. Farley, S. Chutivongse, Jo L. Freudenheim, Randi Selmer, Kim Robien, Richard Peto, Merethe Kumle, B. Boosiri, P. Jimakorn, Eugenia E. Calle, R. Molina, Susan E. Hankinson, Antonia Trichopoulou, Jonas Manjer, Jeane Ann Grisso, Linda Titus-Ernstoff, L. Mcgowan, Tieng Pardthaisong, Robert N. Hoover, Eiliv Lund, Rory Collins, R. K. Ross, Anastasia Tzonou, J. Kelsey, David M. Purdie, Phyllis A. Wingo, Berit Jul Mosgaard, M. C. Pike, C Hermon, Alice S. Whittemore, Pramuan Virutamasen, David B. Thomas, Angela Chetrit, R. Talamini, N. Martin, N. Chantarakul, Polly A. Marchbanks, Herbert B. Peterson, R. Doll, Naomi E. Allen, Tomas Riman, Jane Green, Silvia Franceschi, Shelley S. Tworoger, Rudolf Kaaks, Wei Zheng, D. M. Freedman, Siegal Sadetzki, S. Holck, Susan E. McCann, Ann W. Hsing, Susan M. Gapstur, C. Wongsrichanalai, Daniel W. Cramer, Epidemiologie, RS: CAPHRI School for Public Health and Primary Care, and RS: GROW - School for Oncology and Reproduction
A reanalysis of published and unpublished data from epidemiological studies examines the association between height, body mass index, and the risk of developing ovarian cancer., Background Only about half the studies that have collected information on the relevance of women's height and body mass index to their risk of developing ovarian cancer have published their results, and findings are inconsistent. Here, we bring together the worldwide evidence, published and unpublished, and describe these relationships. Methods and Findings Individual data on 25,157 women with ovarian cancer and 81,311 women without ovarian cancer from 47 epidemiological studies were collected, checked, and analysed centrally. Adjusted relative risks of ovarian cancer were calculated, by height and by body mass index. Ovarian cancer risk increased significantly with height and with body mass index, except in studies using hospital controls. For other study designs, the relative risk of ovarian cancer per 5 cm increase in height was 1.07 (95% confidence interval [CI], 1.05–1.09; p, Editors' Summary Background Cancer of the ovaries, usually referred to as ovarian cancer, is the fifth leading cause of cancer death in women, and, unfortunately, symptoms (such as abdominal pain and swelling) usually occur late in the disease process; fewer than one-third of ovarian cancers are detected before they have spread outside of the ovaries. There is no definitive evidence that screening reduces mortality from ovarian cancer, and given the poor prognosis of advanced ovarian cancer, there has been much research over recent years to increase understanding of this serious condition. There are recognized risk factors that increase the chance of developing ovarian cancer, such as increasing age, having fewer children, not having used oral contraceptives, and use of menopausal hormone therapy. Age and oral contraceptive use have by far the biggest impact on ovarian cancer risk. Why Was This Study Done? To date, there is no definitive information about the relevance of women's height, weight, and body mass index to their subsequent risk of developing ovarian cancer. There have been roughly 50 epidemiological studies of ovarian cancer, but only about half of these studies have published results on the association between body size and ovarian cancer risk, and so far, these findings have been inconsistent. Therefore, the researchers—an international collaboration of researchers studying ovarian cancer—re-analyzed the available epidemiological evidence to investigate the relationship between ovarian cancer risk and adult height, weight, and body mass index, and to examine the consistency of the findings across study designs. What Did the Researchers Do and Find? After an extensive literature search, the researchers identified 47 eligible studies that collected individual data on women's reproductive history, use of hormonal therapies, height, weight, and/or body mass index, and in which the principal investigators of each study accepted the invitation from the researchers to be involved in the re-analysis. The researchers combined data from the different studies. To ensure that women in one study were only directly compared with controls (similar women without ovarian cancer) in the same study, all analyses were routinely stratified by study, center within study, age, parity, use of oral contraceptives, use of hormonal therapy for menopause, and menopausal status or hysterectomy. The 47 studies were conducted in 14 countries and comprised a total of 25,157 women with ovarian cancer (mostly from Europe and North America) and 81,311 women without ovarian cancer. The researchers found a significant increase in relative risk (1.07) of ovarian cancer per 5 cm increase in height. Furthermore, this risk did not vary depending on other studied factors—age, year of birth, education, age at menarche, parity, menopausal status, smoking, alcohol consumption, having had a hysterectomy, having first degree relatives with ovarian or breast cancer, use of oral contraceptives, or use of menopausal hormone therapy. However, the researchers found that for body mass index, the risks depended on whether women had ever taken menopausal hormone therapy: the relative risk for ovarian cancer per 5 kg/m2 increase in body mass index was 1.10 in women who had never taken menopausal hormone therapy but was only 0.95 in women who had previously taken menopausal hormone therapy. What Do These Findings Mean? These findings suggest that increasing height can be considered as a risk factor for ovarian cancer and that in women who have never taken menopausal hormone therapy, increased body mass index can be considered an additional risk factor. These findings have public health implications, especially in high-income countries, because the average height of women has increased by about 1 cm per decade and average body mass index has increased by about 1 kg/m2 per decade. The findings suggest an associated increase in ovarian cancer incidence of 3% per decade if all other factors relevant for ovarian cancer remain constant. Additional Information Please access these web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001200. The following organizations give more information on ovarian cancer which may be of use to patients: MedicineNet, the US National Cancer Institute, Ovarian Cancer National Alliance, Macmillan Cancer Support