Format

Send to

Choose Destination
Breast Cancer Res Treat. 2018 Jun;169(3):481-487. doi: 10.1007/s10549-018-4701-6. Epub 2018 Feb 10.

Breast cancer subtype and survival by parity and time since last birth.

Author information

1
Department of Gynecology and Obstetrics, University Hospitals Leuven, KU Leuven - University of Leuven, Herestraat 49, 3000, Louvain, Belgium. hanne.demulder@student.kuleuven.be.
2
Interuniversity Centre for Biostatistics and Statistical Bioinformatics, 3000, Louvain, Belgium.
3
Multidisciplinary Breast Centre UZ Leuven, University Hospitals Leuven, KU Leuven - University of Leuven, 3000, Louvain, Belgium.
4
Department of Oncology, University Hospitals Leuven, KU Leuven - University of Leuven, 3000, Louvain, Belgium.
5
Department of General Medical Oncology, University Hospitals Leuven, KU Leuven - University of Leuven, 3000, Louvain, Belgium.
6
Department of Gynecology and Obstetrics, University Hospitals Leuven, KU Leuven - University of Leuven, Herestraat 49, 3000, Louvain, Belgium.
7
Department of Oncological Surgery, University Hospitals Leuven, KU Leuven - University of Leuven, 3000, Louvain, Belgium.
8
Department of Radiotherapy, University Hospitals Leuven, KU Leuven - University of Leuven, 3000, Louvain, Belgium.
9
Laboratory of Translational Cell & Tissue Research, Department of Imaging and Pathology, University Hospitals Leuven, KU Leuven - University of Leuven, 3000, Louvain, Belgium.
10
Department of Pathology, University Hospitals Leuven, KU Leuven - University of Leuven, 3000, Louvain, Belgium.

Abstract

BACKGROUND:

Pregnancy affects breast cancer risk but how it affects the subtype and prognosis remain controversial. We studied the effect of parity and time since last birth on breast cancer subtype and outcome.

PATIENTS AND METHODS:

We conducted a retrospective multivariate cohort study including all premenopausal women with early breast cancer aged ≤ 50 years (N = 1306) at diagnosis at the University Hospitals Leuven (Jan. 2000-Dec. 2009). Primary study endpoints were the breast cancer subtype, disease-free survival, and distant disease-free survival by parity and time since last birth. Statistical methods used were baseline-category logits models and Cox proportional hazard models. Multivariable models were used to correct for possible confounders.

RESULTS:

Breast cancer subtypes did not differ between nulliparous (N = 266) and parous women (N = 1040) but subtypes differed significantly in parous women by time since last birth (p < 0.001). Tumors within 5 years of last birth were proportionally more likely triple negative and HER-2 like, even when corrected for age at diagnosis. After a mean follow-up period of 10 years, parous women had a better disease-free survival compared to nulliparous women (HR 0.733; CI 0.560-0.961; p = 0.025, HR 0.738; CI 0.559-0.974; p = 0.032 before and after correction for known prognostic factors, respectively). In parous women, a longer time since last birth was correlated with a longer disease-free survival compared to patients with a recent pregnancy (HR 0.976; CI 0.957-0.996; p = 0.018). However, after correction, this association completely disappeared (HR 1.010; CI 0.982-1.040; p = 0.480).

CONCLUSION:

We observed a better disease-free survival for parous than nulliparous women. The influence of recent birth on disease-free survival is probably due to tumor and patient characteristics, as recent birth is associated with more aggressive subtypes.

KEYWORDS:

Breast cancer subtype; Breast cancer survival; Parity; Time since last birth

PMID:
29426984
DOI:
10.1007/s10549-018-4701-6

Supplemental Content

Full text links

Icon for Springer
Loading ...
Support Center