Oral contraceptive use and breast cancer risk: A cohort study of BRCA1 and BRCA2 mutation carriers

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Oral contraceptive use and breast cancer risk: A cohort study of BRCA1 and BRCA2 mutation carriers. / Schrijver, L; H., Olsson; Antoniou, A; Milne, R; Phillips, K; Andrieu, N; Easton, D; Goldgar, D; Engel, C; Kast, K; Blom, M-J; Mooij, T; Hopper, J; Van Leeuwen, F; Terry, M; Rookus, M.

In: Cancer Research, Vol. 77, No. 13 Suppl 1, Abstract 4276, 2017.

Research output: Contribution to journalPublished meeting abstract

Harvard

Schrijver, L, H., O, Antoniou, A, Milne, R, Phillips, K, Andrieu, N, Easton, D, Goldgar, D, Engel, C, Kast, K, Blom, M-J, Mooij, T, Hopper, J, Van Leeuwen, F, Terry, M & Rookus, M 2017, 'Oral contraceptive use and breast cancer risk: A cohort study of BRCA1 and BRCA2 mutation carriers', Cancer Research, vol. 77, no. 13 Suppl 1, Abstract 4276. https://doi.org/10.1158/1538-7445.AM2017-4276

APA

Schrijver, L., H., O., Antoniou, A., Milne, R., Phillips, K., Andrieu, N., ... Rookus, M. (2017). Oral contraceptive use and breast cancer risk: A cohort study of BRCA1 and BRCA2 mutation carriers. Cancer Research, 77(13 Suppl 1), [Abstract 4276]. https://doi.org/10.1158/1538-7445.AM2017-4276

CBE

Schrijver L, H. O, Antoniou A, Milne R, Phillips K, Andrieu N, Easton D, Goldgar D, Engel C, Kast K, Blom M-J, Mooij T, Hopper J, Van Leeuwen F, Terry M, Rookus M. 2017. Oral contraceptive use and breast cancer risk: A cohort study of BRCA1 and BRCA2 mutation carriers. Cancer Research. 77(13 Suppl 1). https://doi.org/10.1158/1538-7445.AM2017-4276

MLA

Vancouver

Author

Schrijver, L ; H., Olsson ; Antoniou, A ; Milne, R ; Phillips, K ; Andrieu, N ; Easton, D ; Goldgar, D ; Engel, C ; Kast, K ; Blom, M-J ; Mooij, T ; Hopper, J ; Van Leeuwen, F ; Terry, M ; Rookus, M. / Oral contraceptive use and breast cancer risk: A cohort study of BRCA1 and BRCA2 mutation carriers. In: Cancer Research. 2017 ; Vol. 77, No. 13 Suppl 1.

RIS

TY - JOUR

T1 - Oral contraceptive use and breast cancer risk: A cohort study of BRCA1 and BRCA2 mutation carriers

AU - Schrijver, L

AU - H., Olsson

AU - Antoniou, A

AU - Milne, R

AU - Phillips, K

AU - Andrieu, N

AU - Easton, D

AU - Goldgar, D

AU - Engel, C

AU - Kast, K

AU - Blom, M-J

AU - Mooij, T

AU - Hopper, J

AU - Van Leeuwen, F

AU - Terry, M

AU - Rookus, M

PY - 2017

Y1 - 2017

N2 - Background: BRCA1 and BRCA2 mutation carriers are at high risk of breast and ovarian cancer. Oral contraceptive preparations (OCPs) may reduce ovarian cancer risk, but its effect on breast cancer risk remains unclear. Methods: Combined data from three cohorts of 5705 BRCA1 and 3521 BRCA2 mutation carriers (IBCCS, BCFR and kConFab) were analyzed using age-dependent Cox regression models stratified for study and birth cohort. We conducted the first prospective analyses on this topic. Our additional main retrospective analyses were leftcensored 5 years preceding date of baseline questionnaire to control for survival bias. The full-cohort retrospective analyses, without left-censoring, was performed to compare results with the literature. Prospective analyses were considered most valid, while retrospective analyses were most powerful. Results: For BRCA1 mutation carriers we found no association between ever OCP use and risk of breast cancer in the prospective analyses (HR=1.08, 95% CI 0.75-1.56), but 23% and 27% increased risks for ever OCP use in the left-censored and full retrospective analyses, respectively. Retrospectively, an increasing trend for longer duration of use, especially before first full-term pregnancy (FFTP) was found (left-censored analyses: 10 years HR 1.41 (95%CI 1.10-1.813), p-trend=0.001 for duration of use before FFTP). For BRCA2 mutation carriers we found a positive association between ever OCP use and risk of breast cancer prospectively (HR=1.75, 95% CI 1.03-2.97), but retrospectively findings were inconsistent (HR=1.06, 95% CI 0.85-1.33 and HR=1.52, 95% CI 1.28-1.81 for the left-censored and full analyses, respectively). Conclusion: For BRCA1 mutation carriers the discrepancy between results of prospective and retrospective analyses may be explained by time since last OCP use before FFTP. Thus, a temporal increased risk of breast cancer following longer duration of OCP use before FFTP cannot be ruled out. The discordant findings between prospective and retrospective analyses for BRCA2 carriers could not be explained. Because of the lack of scientific clarity it is too early to give an unequivocal advice on OCP use with respect to breast cancer risk to BRCA1 and BRCA2 mutation carriers.

AB - Background: BRCA1 and BRCA2 mutation carriers are at high risk of breast and ovarian cancer. Oral contraceptive preparations (OCPs) may reduce ovarian cancer risk, but its effect on breast cancer risk remains unclear. Methods: Combined data from three cohorts of 5705 BRCA1 and 3521 BRCA2 mutation carriers (IBCCS, BCFR and kConFab) were analyzed using age-dependent Cox regression models stratified for study and birth cohort. We conducted the first prospective analyses on this topic. Our additional main retrospective analyses were leftcensored 5 years preceding date of baseline questionnaire to control for survival bias. The full-cohort retrospective analyses, without left-censoring, was performed to compare results with the literature. Prospective analyses were considered most valid, while retrospective analyses were most powerful. Results: For BRCA1 mutation carriers we found no association between ever OCP use and risk of breast cancer in the prospective analyses (HR=1.08, 95% CI 0.75-1.56), but 23% and 27% increased risks for ever OCP use in the left-censored and full retrospective analyses, respectively. Retrospectively, an increasing trend for longer duration of use, especially before first full-term pregnancy (FFTP) was found (left-censored analyses: 10 years HR 1.41 (95%CI 1.10-1.813), p-trend=0.001 for duration of use before FFTP). For BRCA2 mutation carriers we found a positive association between ever OCP use and risk of breast cancer prospectively (HR=1.75, 95% CI 1.03-2.97), but retrospectively findings were inconsistent (HR=1.06, 95% CI 0.85-1.33 and HR=1.52, 95% CI 1.28-1.81 for the left-censored and full analyses, respectively). Conclusion: For BRCA1 mutation carriers the discrepancy between results of prospective and retrospective analyses may be explained by time since last OCP use before FFTP. Thus, a temporal increased risk of breast cancer following longer duration of OCP use before FFTP cannot be ruled out. The discordant findings between prospective and retrospective analyses for BRCA2 carriers could not be explained. Because of the lack of scientific clarity it is too early to give an unequivocal advice on OCP use with respect to breast cancer risk to BRCA1 and BRCA2 mutation carriers.

KW - BRCA1 protein

KW - BRCA2 protein

KW - endogenous compound

KW - oral contraceptive agent

KW - adverse drug reaction

KW - age

KW - breast cancer

KW - cancer risk

KW - cancer survival

KW - case report

KW - cohort analysis

KW - female

KW - gene mutation

KW - genetic susceptibility

KW - human

KW - oral contraceptive use

KW - pregnancy

KW - proportional hazards model

KW - prospective study

KW - questionnaire

KW - retrospective study

KW - side effect

U2 - 10.1158/1538-7445.AM2017-4276

DO - 10.1158/1538-7445.AM2017-4276

M3 - Published meeting abstract

VL - 77

JO - Cancer research. Supplement

JF - Cancer research. Supplement

SN - 1538-7445

IS - 13 Suppl 1

M1 - Abstract 4276

ER -