Risk of sex-specific cancers in opposite-sex and same-sex twins in Denmark and Sweden

Linda Juel Ahrenfeldt, Axel Skytthe, Sören Möller, Kamila Czene, Hans-Olov Adami, Lorelei A Mucci, Jaakko Kaprio, Inge Petersen, Kaare Christensen, Rune Lindahl-Jacobsen

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

BACKGROUND: Increasing evidence shows that some cancers originate in utero. It is hypothesized that elevated exposure to some steroid hormones might increase cancer risk, and that hormone transfer between twin fetuses could result in different prenatal exposure to testosterone.

METHODS: This large-scale prospective twin study compared opposite-sex (OS) and same-sex (SS) twins to test the impact of intrauterine exposures on cancer risk. Based on the Danish and Swedish twin and cancer registries, we calculated incidence rate ratios for OS and SS twins while standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were calculated for OS/SS twins compared with the general population.

RESULTS: A total of 18,001 cancers were identified during 1943-2009. No significant differences were observed between OS and SS twins, neither for the sex-specific cancers nor for cancer at all sites. All-cause cancer was slightly reduced for OS and SS twins compared with the general population, significant for OS males (SIR = 0.95; 95% CI 0.92-0.98) and for SS males and females (SIR = 0.97; 95% CI 0.94-0.99).

CONCLUSIONS: Our data suggest that having a male co-twin - which may entail higher exposure to prenatal testosterone - does not increase the risk of sex-specific cancers in OS females. Furthermore, the study supports that twinning per se is not a risk factor of cancer.

IMPACT: Findings are reassuring as they fail to provide evidence for the hypothesis that endocrine or other difference in the in utero milieu affects the risk of sex-specific cancers.

Original languageEnglish
JournalCancer Epidemiology, Biomarkers & Prevention
Volume24
Issue number10
Pages (from-to)1622-8
ISSN1055-9965
DOIs
Publication statusPublished - Oct 2015

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Denmark
Neoplasms
Incidence
Confidence Intervals
Hormones
Twin Studies
Sex Ratio
Population
Registries
Fetus

Cite this

@article{b9d1a14a47cc47f48880b50273d7ea78,
title = "Risk of sex-specific cancers in opposite-sex and same-sex twins in Denmark and Sweden",
abstract = "BACKGROUND: Increasing evidence shows that some cancers originate in utero. It is hypothesized that elevated exposure to some steroid hormones might increase cancer risk, and that hormone transfer between twin fetuses could result in different prenatal exposure to testosterone.METHODS: This large-scale prospective twin study compared opposite-sex (OS) and same-sex (SS) twins to test the impact of intrauterine exposures on cancer risk. Based on the Danish and Swedish twin and cancer registries, we calculated incidence rate ratios for OS and SS twins while standardized incidence ratios (SIRs) with 95{\%} confidence intervals (CIs) were calculated for OS/SS twins compared with the general population.RESULTS: A total of 18,001 cancers were identified during 1943-2009. No significant differences were observed between OS and SS twins, neither for the sex-specific cancers nor for cancer at all sites. All-cause cancer was slightly reduced for OS and SS twins compared with the general population, significant for OS males (SIR = 0.95; 95{\%} CI 0.92-0.98) and for SS males and females (SIR = 0.97; 95{\%} CI 0.94-0.99).CONCLUSIONS: Our data suggest that having a male co-twin - which may entail higher exposure to prenatal testosterone - does not increase the risk of sex-specific cancers in OS females. Furthermore, the study supports that twinning per se is not a risk factor of cancer.IMPACT: Findings are reassuring as they fail to provide evidence for the hypothesis that endocrine or other difference in the in utero milieu affects the risk of sex-specific cancers.",
keywords = "Cancer, in utero exposure, testosterone, hormones, twins",
author = "Ahrenfeldt, {Linda Juel} and Axel Skytthe and S{\"o}ren M{\"o}ller and Kamila Czene and Hans-Olov Adami and Mucci, {Lorelei A} and Jaakko Kaprio and Inge Petersen and Kaare Christensen and Rune Lindahl-Jacobsen",
note = "Copyright {\circledC} 2015, American Association for Cancer Research.",
year = "2015",
month = "10",
doi = "10.1158/1055-9965.EPI-15-0317",
language = "English",
volume = "24",
pages = "1622--8",
journal = "Cancer Epidemiology, Biomarkers & Prevention",
issn = "1055-9965",
publisher = "American Association for Cancer Research (A A C R)",
number = "10",

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Risk of sex-specific cancers in opposite-sex and same-sex twins in Denmark and Sweden. / Ahrenfeldt, Linda Juel; Skytthe, Axel; Möller, Sören; Czene, Kamila; Adami, Hans-Olov; Mucci, Lorelei A; Kaprio, Jaakko; Petersen, Inge; Christensen, Kaare; Lindahl-Jacobsen, Rune.

In: Cancer Epidemiology, Biomarkers & Prevention, Vol. 24, No. 10, 10.2015, p. 1622-8.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Risk of sex-specific cancers in opposite-sex and same-sex twins in Denmark and Sweden

AU - Ahrenfeldt, Linda Juel

AU - Skytthe, Axel

AU - Möller, Sören

AU - Czene, Kamila

AU - Adami, Hans-Olov

AU - Mucci, Lorelei A

AU - Kaprio, Jaakko

AU - Petersen, Inge

AU - Christensen, Kaare

AU - Lindahl-Jacobsen, Rune

N1 - Copyright © 2015, American Association for Cancer Research.

PY - 2015/10

Y1 - 2015/10

N2 - BACKGROUND: Increasing evidence shows that some cancers originate in utero. It is hypothesized that elevated exposure to some steroid hormones might increase cancer risk, and that hormone transfer between twin fetuses could result in different prenatal exposure to testosterone.METHODS: This large-scale prospective twin study compared opposite-sex (OS) and same-sex (SS) twins to test the impact of intrauterine exposures on cancer risk. Based on the Danish and Swedish twin and cancer registries, we calculated incidence rate ratios for OS and SS twins while standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were calculated for OS/SS twins compared with the general population.RESULTS: A total of 18,001 cancers were identified during 1943-2009. No significant differences were observed between OS and SS twins, neither for the sex-specific cancers nor for cancer at all sites. All-cause cancer was slightly reduced for OS and SS twins compared with the general population, significant for OS males (SIR = 0.95; 95% CI 0.92-0.98) and for SS males and females (SIR = 0.97; 95% CI 0.94-0.99).CONCLUSIONS: Our data suggest that having a male co-twin - which may entail higher exposure to prenatal testosterone - does not increase the risk of sex-specific cancers in OS females. Furthermore, the study supports that twinning per se is not a risk factor of cancer.IMPACT: Findings are reassuring as they fail to provide evidence for the hypothesis that endocrine or other difference in the in utero milieu affects the risk of sex-specific cancers.

AB - BACKGROUND: Increasing evidence shows that some cancers originate in utero. It is hypothesized that elevated exposure to some steroid hormones might increase cancer risk, and that hormone transfer between twin fetuses could result in different prenatal exposure to testosterone.METHODS: This large-scale prospective twin study compared opposite-sex (OS) and same-sex (SS) twins to test the impact of intrauterine exposures on cancer risk. Based on the Danish and Swedish twin and cancer registries, we calculated incidence rate ratios for OS and SS twins while standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were calculated for OS/SS twins compared with the general population.RESULTS: A total of 18,001 cancers were identified during 1943-2009. No significant differences were observed between OS and SS twins, neither for the sex-specific cancers nor for cancer at all sites. All-cause cancer was slightly reduced for OS and SS twins compared with the general population, significant for OS males (SIR = 0.95; 95% CI 0.92-0.98) and for SS males and females (SIR = 0.97; 95% CI 0.94-0.99).CONCLUSIONS: Our data suggest that having a male co-twin - which may entail higher exposure to prenatal testosterone - does not increase the risk of sex-specific cancers in OS females. Furthermore, the study supports that twinning per se is not a risk factor of cancer.IMPACT: Findings are reassuring as they fail to provide evidence for the hypothesis that endocrine or other difference in the in utero milieu affects the risk of sex-specific cancers.

KW - Cancer

KW - in utero exposure

KW - testosterone

KW - hormones

KW - twins

U2 - 10.1158/1055-9965.EPI-15-0317

DO - 10.1158/1055-9965.EPI-15-0317

M3 - Journal article

VL - 24

SP - 1622

EP - 1628

JO - Cancer Epidemiology, Biomarkers & Prevention

JF - Cancer Epidemiology, Biomarkers & Prevention

SN - 1055-9965

IS - 10

ER -