Fax: (713) 745-3740
Higher parity and shorter breastfeeding duration
Association with triple-negative phenotype of breast cancer
Article first published online: 21 JUL 2010
Copyright © 2010 American Cancer Society
Volume 116, Issue 21, pages 4933–4943, 1 November 2010
How to Cite
Shinde, S. S., Forman, M. R., Kuerer, H. M., Yan, K., Peintinger, F., Hunt, K. K., Hortobagyi, G. N., Pusztai, L. and Symmans, W. F. (2010), Higher parity and shorter breastfeeding duration. Cancer, 116: 4933–4943. doi: 10.1002/cncr.25443
- Issue published online: 21 JUL 2010
- Article first published online: 21 JUL 2010
- Manuscript Accepted: 15 APR 2010
- Manuscript Revised: 31 MAR 2010
- Manuscript Received: 6 JAN 2010
- breast cancer;
The combination of increased parity and shorter breastfeeding duration might increase the odds of the least differentiated triple-negative breast cancer (BC) phenotype, theoretically because an expanded progenitor cell population from each pregnancy would incompletely differentiate postpartum.
Subjects consisted of a consecutive case series of 2473 women treated for invasive breast cancer between 2001 and 2006. Breast cancer phenotype (triple-negative BC, vs non–triple-negative BC) was compared with reproductive and demographic information. Odds ratios (OR) with 95% confidence intervals (CIs) for the association of breastfeeding duration (months per child) and parity with triple-negative BC were calculated after adjusting for ethnicity, age at menarche, family history, and age at diagnosis.
Compared with non–triple-negative BC, triple-negative BC was associated with shorter duration of breastfeeding per child (OR, 0.93; 95% CI, 0.90-0.97) and with higher parity (OR, 1.12; 95% CI, 1.06-1.20). By using multivariate logistic regression, triple-negative BC was independently associated with higher parity (OR, 2.76 [95% CI, 1.86-4.08] if ≥3 live births; OR, 1.89 [95% CI, 1.30-2.74] if ≤2 live births vs nulliparae), breastfeeding duration (OR, 0.55 [95% CI, 0.41-0.74] if >2 mo/child and OR, 0.58 [95% CI, 0.42-0.82] if ≤2 mo/child vs none), African American ethnicity (OR, 2.10; 95% CI, 1.52-2.92), and younger age at diagnosis (OR, 3.02 [95% CI, 2.03-4.47] if ≤40 years vs >60 years).
Among women with invasive breast cancer, higher parity and the absence or short duration of breastfeeding were independently associated with triple-negative BC. Any duration of breastfeeding was found to be associated with lower probability of triple-negative BC, and the odds of this phenotype decreased with increasing duration of breastfeeding. Cancer 2010. © 2010 American Cancer Society.