Pregnancy outcomes and risk of endometrial cancer: A pooled analysis of individual participant data in the Epidemiology of Endometrial Cancer Consortium

Susan J. Jordan; Renhua Na; Elisabete Weiderpass; Hans Olov Adami; Kristin E. Anderson; Piet A. van den Brandt; Louise A. Brinton; Chu Chen; Linda S. Cook; Jennifer A. Doherty; Mengmeng Du; Christine M. Friedenreich; Gretchen L. Gierach; Marc T. Goodman; Vittorio Krogh; Fabio Levi; Lingeng Lu; Anthony B. Miller; Susan E. McCann; Kirsten B. Moysich; Eva Negri; Sara H. Olson; Stacey Petruzella; Julie R. Palmer; Fabio Parazzini; Malcolm C. Pike; Anna E. Prizment; Timothy R. Rebbeck; Peggy Reynolds; Fulvio Ricceri; Harvey A. Risch; Thomas E. Rohan; Carlotta Sacerdote; Leo J. Schouten; Diego Serraino; Veronica W. Setiawan; Xiao Ou Shu; Todd R. Sponholtz; Amanda B. Spurdle; Rachael Z. Stolzenberg-Solomon; Britton Trabert; Nicolas Wentzensen; Lynne R. Wilkens; Lauren A. Wise; Herbert Yu; Carlo La Vecchia; Immaculata De Vivo; Wanghong Xu; Anne Zeleniuch-Jacquotte; Penelope M. Webb

doi:10.1002/ijc.33360

Pregnancy outcomes and risk of endometrial cancer: A pooled analysis of individual participant data in the Epidemiology of Endometrial Cancer Consortium

Susan J. Jordan, Renhua Na, Elisabete Weiderpass, Hans Olov Adami, Kristin E. Anderson, Piet A. van den Brandt, Louise A. Brinton, Chu Chen, Linda S. Cook, Jennifer A. Doherty, Mengmeng Du, Christine M. Friedenreich, Gretchen L. Gierach, Marc T. Goodman, Vittorio Krogh, Fabio Levi, Lingeng Lu, Anthony B. Miller, Susan E. McCann, Kirsten B. MoysichEva Negri, Sara H. Olson, Stacey Petruzella, Julie R. Palmer, Fabio Parazzini, Malcolm C. Pike, Anna E. Prizment, Timothy R. Rebbeck, Peggy Reynolds, Fulvio Ricceri, Harvey A. Risch, Thomas E. Rohan, Carlotta Sacerdote, Leo J. Schouten, Diego Serraino, Veronica W. Setiawan, Xiao Ou Shu, Todd R. Sponholtz, Amanda B. Spurdle, Rachael Z. Stolzenberg-Solomon, Britton Trabert, Nicolas Wentzensen, Lynne R. Wilkens, Lauren A. Wise, Herbert Yu, Carlo La Vecchia, Immaculata De Vivo, Wanghong Xu, Anne Zeleniuch-Jacquotte, Penelope M. Webb

Research output: Contribution to journal › Article › peer-review

21 Scopus citations

Abstract

A full-term pregnancy is associated with reduced endometrial cancer risk; however, whether the effect of additional pregnancies is independent of age at last pregnancy is unknown. The associations between other pregnancy-related factors and endometrial cancer risk are less clear. We pooled individual participant data from 11 cohort and 19 case-control studies participating in the Epidemiology of Endometrial Cancer Consortium (E2C2) including 16 986 women with endometrial cancer and 39 538 control women. We used one- and two-stage meta-analytic approaches to estimate pooled odds ratios (ORs) for the association between exposures and endometrial cancer risk. Ever having a full-term pregnancy was associated with a 41% reduction in risk of endometrial cancer compared to never having a full-term pregnancy (OR = 0.59, 95% confidence interval [CI] 0.56-0.63). The risk reduction appeared the greatest for the first full-term pregnancy (OR = 0.78, 95% CI 0.72-0.84), with a further ~15% reduction per pregnancy up to eight pregnancies (OR = 0.20, 95% CI 0.14-0.28) that was independent of age at last full-term pregnancy. Incomplete pregnancy was also associated with decreased endometrial cancer risk (7%-9% reduction per pregnancy). Twin births appeared to have the same effect as singleton pregnancies. Our pooled analysis shows that, while the magnitude of the risk reduction is greater for a full-term pregnancy than an incomplete pregnancy, each additional pregnancy is associated with further reduction in endometrial cancer risk, independent of age at last full-term pregnancy. These results suggest that the very high progesterone level in the last trimester of pregnancy is not the sole explanation for the protective effect of pregnancy.

Original language	English (US)
Pages (from-to)	2068-2078
Number of pages	11
Journal	International Journal of Cancer
Volume	148
Issue number	9
Early online date	Oct 26 2020
DOIs	https://doi.org/10.1002/ijc.33360
State	Published - 2020

Bibliographical note

Funding Information:
: This investigation was supported in part by USPHS Grants P01‐CA‐33619, R01‐CA‐58598, R01‐CA‐55700, and P20‐CA‐57113 and by contracts N01‐CN‐05223 and N01‐CN‐55424 from the National Cancer Institute, NIH, Department of Health and Human Services. HAWAII

Funding Information:
L. S. Cook held a Canada Research Chair, received AHFMR career award funding and received support from NCI P30CA118100. M. Du and M. C. Pike were supported by the Memorial Sloan Kettering NCI Support Grant P30 CA008748. C. M. Friedenreich received career awards from the Canadian Institutes of Health Research and the Alberta Heritage Foundation for Medical Research (AHFMR) during the conduct of this study. C. La Vecchia was supported by the Italian Foundation for Research in Cancer. A. B. Miller was supported in part by a National Health Scientist Award from Health and Welfare Canada. R. Na was supported by NHMRC Program Grant GNT 1073898. A. B. Spurdle was supported by a fellowship from the NHMRC (ID 1061778).

Funding Information:
Alberta Heritage Foundation for Medical Research; Associazione Italiana per la Ricerca sul Cancro; California Department of Public Health; Canadian Breast Cancer Research Alliance; Canadian Cancer Society; Canadian Institutes of Health Research; Cancer Council Tasmania, Grant/Award Numbers: 403031, 457636; Centers for Disease Control and Prevention's National Program of Cancer Registries; Health and Welfare Canada; Intramural Research Program of the National Cancer Institute/National Institutes of Health, Department of Health and Human Services, United States; Italian League Against Cancer; KWF Kankerbestrijding; le Ministère de la Santé et des Services Soçiaux du Québec; Nova Scotia Department of Health; Manitoba Health Services Commission; Medical Research Council Canada; Memorial Sloan Kettering NCI Support Grant, Grant/Award Number: P30 CA008748; National Cancer Institute, Grant/Award Numbers: 2R01 CA082838, P01 CA87969, CA11535, N01‐CN‐05223, N01‐CN‐55424, P01‐CA77596, P30CA016056, P30CA118100, R01 CA081212, U01 CA182934, P30 CA016087, R01 CA083918, R01 CA092585, R01 CA39742, R01 CA48774, P30 CA14089, R01 CA058420, U01 CA164974, R03 CA169888, R01 CA098346, R01 CA77398, R35 CA39779, R01 CA47749, R01 CA75977, N01 HD 2 31, U01 CA164973, RO3 CA135632; National Cancer Institute of Canada; National Health and Medical Research Council, Grant/Award Numbers: APP339435, APP1073898, APP1061341, APP1061779, ID 1061778, GNT 1073898; National Institutes of Health, Grant/Award Number: R01 CA74877; Ontario Ministry of Health; Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Grant/Award Number: 32.9495.88; Krebsforschung Schweiz Stiftung, Grant/Award Number: OCS 1633‐02‐2005; U.S. Public Health Service, Grant/Award Numbers: P01‐CA‐33619, R01‐CA‐58598, R01‐CA‐55700, P20‐CA‐57113; Vetenskapsrådet, Grant/Award Number: 521‐2011‐2955 Funding information

Funding Information:
: Swiss National Science Foundation grant 32.9495.88 and the Krebsforschung Schweiz Stiftung grant OCS 1633‐02‐2005. VAUD

Funding Information:
: National Institutes of Health (R01CA77398) and the CBCRP fund; the collection of cancer incidence data was supported by the California Department of Public Health as part of the state wide cancer reporting program mandated by California Health and Safety Code Section 103885, the NCI's Surveillance, Epidemiology, and End Results Program awarded to the Cancer Prevention Institute of California, the Public Health Institute, University of Southern California, and the Centers for Disease Control and Prevention's National Program of Cancer Registries. CTS

Funding Information:
: This study was supported by funding from the Canadian Breast Cancer Research Alliance, the Canadian Cancer Society, Health and Welfare Canada, the National Cancer Institute of Canada, the Alberta Heritage Foundation for Medical Research, Manitoba Health Services Commission, Medical Research Council of Canada, le Ministre de la Santé et des Services Soçiaux du Québec, the Nova Scotia Department of Health, and the Ontario Ministry of Health. CNBSS è

Keywords

endometrial cancer
induced abortion
miscarriage
parity
sex of offspring

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1002/ijc.33360

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Jordan, S. J., Na, R., Weiderpass, E., Adami, H. O., Anderson, K. E., van den Brandt, P. A., Brinton, L. A., Chen, C., Cook, L. S., Doherty, J. A., Du, M., Friedenreich, C. M., Gierach, G. L., Goodman, M. T., Krogh, V., Levi, F., Lu, L., Miller, A. B., McCann, S. E., ... Webb, P. M. (2020). Pregnancy outcomes and risk of endometrial cancer: A pooled analysis of individual participant data in the Epidemiology of Endometrial Cancer Consortium. International Journal of Cancer, 148(9), 2068-2078. https://doi.org/10.1002/ijc.33360

Jordan, SJ, Na, R, Weiderpass, E, Adami, HO, Anderson, KE, van den Brandt, PA, Brinton, LA, Chen, C, Cook, LS, Doherty, JA, Du, M, Friedenreich, CM, Gierach, GL, Goodman, MT, Krogh, V, Levi, F, Lu, L, Miller, AB, McCann, SE, Moysich, KB, Negri, E, Olson, SH, Petruzella, S, Palmer, JR, Parazzini, F, Pike, MC, Prizment, AE, Rebbeck, TR, Reynolds, P, Ricceri, F, Risch, HA, Rohan, TE, Sacerdote, C, Schouten, LJ, Serraino, D, Setiawan, VW, Shu, XO, Sponholtz, TR, Spurdle, AB, Stolzenberg-Solomon, RZ, Trabert, B, Wentzensen, N, Wilkens, LR, Wise, LA, Yu, H, La Vecchia, C, De Vivo, I, Xu, W, Zeleniuch-Jacquotte, A & Webb, PM 2020, 'Pregnancy outcomes and risk of endometrial cancer: A pooled analysis of individual participant data in the Epidemiology of Endometrial Cancer Consortium', International Journal of Cancer, vol. 148, no. 9, pp. 2068-2078. https://doi.org/10.1002/ijc.33360

@article{c92a79788ba9453eb485bf2c8d7b3a22,

title = "Pregnancy outcomes and risk of endometrial cancer: A pooled analysis of individual participant data in the Epidemiology of Endometrial Cancer Consortium",

abstract = "A full-term pregnancy is associated with reduced endometrial cancer risk; however, whether the effect of additional pregnancies is independent of age at last pregnancy is unknown. The associations between other pregnancy-related factors and endometrial cancer risk are less clear. We pooled individual participant data from 11 cohort and 19 case-control studies participating in the Epidemiology of Endometrial Cancer Consortium (E2C2) including 16 986 women with endometrial cancer and 39 538 control women. We used one- and two-stage meta-analytic approaches to estimate pooled odds ratios (ORs) for the association between exposures and endometrial cancer risk. Ever having a full-term pregnancy was associated with a 41% reduction in risk of endometrial cancer compared to never having a full-term pregnancy (OR = 0.59, 95% confidence interval [CI] 0.56-0.63). The risk reduction appeared the greatest for the first full-term pregnancy (OR = 0.78, 95% CI 0.72-0.84), with a further ~15% reduction per pregnancy up to eight pregnancies (OR = 0.20, 95% CI 0.14-0.28) that was independent of age at last full-term pregnancy. Incomplete pregnancy was also associated with decreased endometrial cancer risk (7%-9% reduction per pregnancy). Twin births appeared to have the same effect as singleton pregnancies. Our pooled analysis shows that, while the magnitude of the risk reduction is greater for a full-term pregnancy than an incomplete pregnancy, each additional pregnancy is associated with further reduction in endometrial cancer risk, independent of age at last full-term pregnancy. These results suggest that the very high progesterone level in the last trimester of pregnancy is not the sole explanation for the protective effect of pregnancy.",

keywords = "endometrial cancer, induced abortion, miscarriage, parity, sex of offspring",

author = "Jordan, {Susan J.} and Renhua Na and Elisabete Weiderpass and Adami, {Hans Olov} and Anderson, {Kristin E.} and {van den Brandt}, {Piet A.} and Brinton, {Louise A.} and Chu Chen and Cook, {Linda S.} and Doherty, {Jennifer A.} and Mengmeng Du and Friedenreich, {Christine M.} and Gierach, {Gretchen L.} and Goodman, {Marc T.} and Vittorio Krogh and Fabio Levi and Lingeng Lu and Miller, {Anthony B.} and McCann, {Susan E.} and Moysich, {Kirsten B.} and Eva Negri and Olson, {Sara H.} and Stacey Petruzella and Palmer, {Julie R.} and Fabio Parazzini and Pike, {Malcolm C.} and Prizment, {Anna E.} and Rebbeck, {Timothy R.} and Peggy Reynolds and Fulvio Ricceri and Risch, {Harvey A.} and Rohan, {Thomas E.} and Carlotta Sacerdote and Schouten, {Leo J.} and Diego Serraino and Setiawan, {Veronica W.} and Shu, {Xiao Ou} and Sponholtz, {Todd R.} and Spurdle, {Amanda B.} and Stolzenberg-Solomon, {Rachael Z.} and Britton Trabert and Nicolas Wentzensen and Wilkens, {Lynne R.} and Wise, {Lauren A.} and Herbert Yu and {La Vecchia}, Carlo and {De Vivo}, Immaculata and Wanghong Xu and Anne Zeleniuch-Jacquotte and Webb, {Penelope M.}",

note = "Funding Information: : This investigation was supported in part by USPHS Grants P01‐CA‐33619, R01‐CA‐58598, R01‐CA‐55700, and P20‐CA‐57113 and by contracts N01‐CN‐05223 and N01‐CN‐55424 from the National Cancer Institute, NIH, Department of Health and Human Services. HAWAII Funding Information: L. S. Cook held a Canada Research Chair, received AHFMR career award funding and received support from NCI P30CA118100. M. Du and M. C. Pike were supported by the Memorial Sloan Kettering NCI Support Grant P30 CA008748. C. M. Friedenreich received career awards from the Canadian Institutes of Health Research and the Alberta Heritage Foundation for Medical Research (AHFMR) during the conduct of this study. C. La Vecchia was supported by the Italian Foundation for Research in Cancer. A. B. Miller was supported in part by a National Health Scientist Award from Health and Welfare Canada. R. Na was supported by NHMRC Program Grant GNT 1073898. A. B. Spurdle was supported by a fellowship from the NHMRC (ID 1061778). Funding Information: Alberta Heritage Foundation for Medical Research; Associazione Italiana per la Ricerca sul Cancro; California Department of Public Health; Canadian Breast Cancer Research Alliance; Canadian Cancer Society; Canadian Institutes of Health Research; Cancer Council Tasmania, Grant/Award Numbers: 403031, 457636; Centers for Disease Control and Prevention's National Program of Cancer Registries; Health and Welfare Canada; Intramural Research Program of the National Cancer Institute/National Institutes of Health, Department of Health and Human Services, United States; Italian League Against Cancer; KWF Kankerbestrijding; le Minist{\`e}re de la Sant{\'e} et des Services So{\c c}iaux du Qu{\'e}bec; Nova Scotia Department of Health; Manitoba Health Services Commission; Medical Research Council Canada; Memorial Sloan Kettering NCI Support Grant, Grant/Award Number: P30 CA008748; National Cancer Institute, Grant/Award Numbers: 2R01 CA082838, P01 CA87969, CA11535, N01‐CN‐05223, N01‐CN‐55424, P01‐CA77596, P30CA016056, P30CA118100, R01 CA081212, U01 CA182934, P30 CA016087, R01 CA083918, R01 CA092585, R01 CA39742, R01 CA48774, P30 CA14089, R01 CA058420, U01 CA164974, R03 CA169888, R01 CA098346, R01 CA77398, R35 CA39779, R01 CA47749, R01 CA75977, N01 HD 2 31, U01 CA164973, RO3 CA135632; National Cancer Institute of Canada; National Health and Medical Research Council, Grant/Award Numbers: APP339435, APP1073898, APP1061341, APP1061779, ID 1061778, GNT 1073898; National Institutes of Health, Grant/Award Number: R01 CA74877; Ontario Ministry of Health; Schweizerischer Nationalfonds zur F{\"o}rderung der Wissenschaftlichen Forschung, Grant/Award Number: 32.9495.88; Krebsforschung Schweiz Stiftung, Grant/Award Number: OCS 1633‐02‐2005; U.S. Public Health Service, Grant/Award Numbers: P01‐CA‐33619, R01‐CA‐58598, R01‐CA‐55700, P20‐CA‐57113; Vetenskapsr{\aa}det, Grant/Award Number: 521‐2011‐2955 Funding information Funding Information: : Swiss National Science Foundation grant 32.9495.88 and the Krebsforschung Schweiz Stiftung grant OCS 1633‐02‐2005. VAUD Funding Information: : National Institutes of Health (R01CA77398) and the CBCRP fund; the collection of cancer incidence data was supported by the California Department of Public Health as part of the state wide cancer reporting program mandated by California Health and Safety Code Section 103885, the NCI's Surveillance, Epidemiology, and End Results Program awarded to the Cancer Prevention Institute of California, the Public Health Institute, University of Southern California, and the Centers for Disease Control and Prevention's National Program of Cancer Registries. CTS Funding Information: : This study was supported by funding from the Canadian Breast Cancer Research Alliance, the Canadian Cancer Society, Health and Welfare Canada, the National Cancer Institute of Canada, the Alberta Heritage Foundation for Medical Research, Manitoba Health Services Commission, Medical Research Council of Canada, le Ministre de la Sant{\'e} et des Services So{\c c}iaux du Qu{\'e}bec, the Nova Scotia Department of Health, and the Ontario Ministry of Health. CNBSS {\`e} ",

year = "2020",

doi = "10.1002/ijc.33360",

language = "English (US)",

volume = "148",

pages = "2068--2078",

journal = "International Journal of Cancer",

issn = "0020-7136",

publisher = "John Wiley and Sons Inc.",

number = "9",

}

TY - JOUR

T1 - Pregnancy outcomes and risk of endometrial cancer

T2 - A pooled analysis of individual participant data in the Epidemiology of Endometrial Cancer Consortium

AU - Jordan, Susan J.

AU - Na, Renhua

AU - Weiderpass, Elisabete

AU - Adami, Hans Olov

AU - Anderson, Kristin E.

AU - van den Brandt, Piet A.

AU - Brinton, Louise A.

AU - Chen, Chu

AU - Cook, Linda S.

AU - Doherty, Jennifer A.

AU - Du, Mengmeng

AU - Friedenreich, Christine M.

AU - Gierach, Gretchen L.

AU - Goodman, Marc T.

AU - Krogh, Vittorio

AU - Levi, Fabio

AU - Lu, Lingeng

AU - Miller, Anthony B.

AU - McCann, Susan E.

AU - Moysich, Kirsten B.

AU - Negri, Eva

AU - Olson, Sara H.

AU - Petruzella, Stacey

AU - Palmer, Julie R.

AU - Parazzini, Fabio

AU - Pike, Malcolm C.

AU - Prizment, Anna E.

AU - Rebbeck, Timothy R.

AU - Reynolds, Peggy

AU - Ricceri, Fulvio

AU - Risch, Harvey A.

AU - Rohan, Thomas E.

AU - Sacerdote, Carlotta

AU - Schouten, Leo J.

AU - Serraino, Diego

AU - Setiawan, Veronica W.

AU - Shu, Xiao Ou

AU - Sponholtz, Todd R.

AU - Spurdle, Amanda B.

AU - Stolzenberg-Solomon, Rachael Z.

AU - Trabert, Britton

AU - Wentzensen, Nicolas

AU - Wilkens, Lynne R.

AU - Wise, Lauren A.

AU - Yu, Herbert

AU - La Vecchia, Carlo

AU - De Vivo, Immaculata

AU - Xu, Wanghong

AU - Zeleniuch-Jacquotte, Anne

AU - Webb, Penelope M.

N1 - Funding Information: : This investigation was supported in part by USPHS Grants P01‐CA‐33619, R01‐CA‐58598, R01‐CA‐55700, and P20‐CA‐57113 and by contracts N01‐CN‐05223 and N01‐CN‐55424 from the National Cancer Institute, NIH, Department of Health and Human Services. HAWAII Funding Information: L. S. Cook held a Canada Research Chair, received AHFMR career award funding and received support from NCI P30CA118100. M. Du and M. C. Pike were supported by the Memorial Sloan Kettering NCI Support Grant P30 CA008748. C. M. Friedenreich received career awards from the Canadian Institutes of Health Research and the Alberta Heritage Foundation for Medical Research (AHFMR) during the conduct of this study. C. La Vecchia was supported by the Italian Foundation for Research in Cancer. A. B. Miller was supported in part by a National Health Scientist Award from Health and Welfare Canada. R. Na was supported by NHMRC Program Grant GNT 1073898. A. B. Spurdle was supported by a fellowship from the NHMRC (ID 1061778). Funding Information: Alberta Heritage Foundation for Medical Research; Associazione Italiana per la Ricerca sul Cancro; California Department of Public Health; Canadian Breast Cancer Research Alliance; Canadian Cancer Society; Canadian Institutes of Health Research; Cancer Council Tasmania, Grant/Award Numbers: 403031, 457636; Centers for Disease Control and Prevention's National Program of Cancer Registries; Health and Welfare Canada; Intramural Research Program of the National Cancer Institute/National Institutes of Health, Department of Health and Human Services, United States; Italian League Against Cancer; KWF Kankerbestrijding; le Ministère de la Santé et des Services Soçiaux du Québec; Nova Scotia Department of Health; Manitoba Health Services Commission; Medical Research Council Canada; Memorial Sloan Kettering NCI Support Grant, Grant/Award Number: P30 CA008748; National Cancer Institute, Grant/Award Numbers: 2R01 CA082838, P01 CA87969, CA11535, N01‐CN‐05223, N01‐CN‐55424, P01‐CA77596, P30CA016056, P30CA118100, R01 CA081212, U01 CA182934, P30 CA016087, R01 CA083918, R01 CA092585, R01 CA39742, R01 CA48774, P30 CA14089, R01 CA058420, U01 CA164974, R03 CA169888, R01 CA098346, R01 CA77398, R35 CA39779, R01 CA47749, R01 CA75977, N01 HD 2 31, U01 CA164973, RO3 CA135632; National Cancer Institute of Canada; National Health and Medical Research Council, Grant/Award Numbers: APP339435, APP1073898, APP1061341, APP1061779, ID 1061778, GNT 1073898; National Institutes of Health, Grant/Award Number: R01 CA74877; Ontario Ministry of Health; Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Grant/Award Number: 32.9495.88; Krebsforschung Schweiz Stiftung, Grant/Award Number: OCS 1633‐02‐2005; U.S. Public Health Service, Grant/Award Numbers: P01‐CA‐33619, R01‐CA‐58598, R01‐CA‐55700, P20‐CA‐57113; Vetenskapsrådet, Grant/Award Number: 521‐2011‐2955 Funding information Funding Information: : Swiss National Science Foundation grant 32.9495.88 and the Krebsforschung Schweiz Stiftung grant OCS 1633‐02‐2005. VAUD Funding Information: : National Institutes of Health (R01CA77398) and the CBCRP fund; the collection of cancer incidence data was supported by the California Department of Public Health as part of the state wide cancer reporting program mandated by California Health and Safety Code Section 103885, the NCI's Surveillance, Epidemiology, and End Results Program awarded to the Cancer Prevention Institute of California, the Public Health Institute, University of Southern California, and the Centers for Disease Control and Prevention's National Program of Cancer Registries. CTS Funding Information: : This study was supported by funding from the Canadian Breast Cancer Research Alliance, the Canadian Cancer Society, Health and Welfare Canada, the National Cancer Institute of Canada, the Alberta Heritage Foundation for Medical Research, Manitoba Health Services Commission, Medical Research Council of Canada, le Ministre de la Santé et des Services Soçiaux du Québec, the Nova Scotia Department of Health, and the Ontario Ministry of Health. CNBSS è

PY - 2020

Y1 - 2020

N2 - A full-term pregnancy is associated with reduced endometrial cancer risk; however, whether the effect of additional pregnancies is independent of age at last pregnancy is unknown. The associations between other pregnancy-related factors and endometrial cancer risk are less clear. We pooled individual participant data from 11 cohort and 19 case-control studies participating in the Epidemiology of Endometrial Cancer Consortium (E2C2) including 16 986 women with endometrial cancer and 39 538 control women. We used one- and two-stage meta-analytic approaches to estimate pooled odds ratios (ORs) for the association between exposures and endometrial cancer risk. Ever having a full-term pregnancy was associated with a 41% reduction in risk of endometrial cancer compared to never having a full-term pregnancy (OR = 0.59, 95% confidence interval [CI] 0.56-0.63). The risk reduction appeared the greatest for the first full-term pregnancy (OR = 0.78, 95% CI 0.72-0.84), with a further ~15% reduction per pregnancy up to eight pregnancies (OR = 0.20, 95% CI 0.14-0.28) that was independent of age at last full-term pregnancy. Incomplete pregnancy was also associated with decreased endometrial cancer risk (7%-9% reduction per pregnancy). Twin births appeared to have the same effect as singleton pregnancies. Our pooled analysis shows that, while the magnitude of the risk reduction is greater for a full-term pregnancy than an incomplete pregnancy, each additional pregnancy is associated with further reduction in endometrial cancer risk, independent of age at last full-term pregnancy. These results suggest that the very high progesterone level in the last trimester of pregnancy is not the sole explanation for the protective effect of pregnancy.

AB - A full-term pregnancy is associated with reduced endometrial cancer risk; however, whether the effect of additional pregnancies is independent of age at last pregnancy is unknown. The associations between other pregnancy-related factors and endometrial cancer risk are less clear. We pooled individual participant data from 11 cohort and 19 case-control studies participating in the Epidemiology of Endometrial Cancer Consortium (E2C2) including 16 986 women with endometrial cancer and 39 538 control women. We used one- and two-stage meta-analytic approaches to estimate pooled odds ratios (ORs) for the association between exposures and endometrial cancer risk. Ever having a full-term pregnancy was associated with a 41% reduction in risk of endometrial cancer compared to never having a full-term pregnancy (OR = 0.59, 95% confidence interval [CI] 0.56-0.63). The risk reduction appeared the greatest for the first full-term pregnancy (OR = 0.78, 95% CI 0.72-0.84), with a further ~15% reduction per pregnancy up to eight pregnancies (OR = 0.20, 95% CI 0.14-0.28) that was independent of age at last full-term pregnancy. Incomplete pregnancy was also associated with decreased endometrial cancer risk (7%-9% reduction per pregnancy). Twin births appeared to have the same effect as singleton pregnancies. Our pooled analysis shows that, while the magnitude of the risk reduction is greater for a full-term pregnancy than an incomplete pregnancy, each additional pregnancy is associated with further reduction in endometrial cancer risk, independent of age at last full-term pregnancy. These results suggest that the very high progesterone level in the last trimester of pregnancy is not the sole explanation for the protective effect of pregnancy.

KW - endometrial cancer

KW - induced abortion

KW - miscarriage

KW - parity

KW - sex of offspring

UR - http://www.scopus.com/inward/record.url?scp=85096684730&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85096684730&partnerID=8YFLogxK

U2 - 10.1002/ijc.33360

DO - 10.1002/ijc.33360

M3 - Article

C2 - 33105052

AN - SCOPUS:85096684730

SN - 0020-7136

VL - 148

SP - 2068

EP - 2078

JO - International Journal of Cancer

JF - International Journal of Cancer

IS - 9

ER -

Pregnancy outcomes and risk of endometrial cancer: A pooled analysis of individual participant data in the Epidemiology of Endometrial Cancer Consortium

Abstract

Bibliographical note

Keywords

UN SDGs

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