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Sub-category:
Other: Detection / Diagnosis
Category:
Detection / Diagnosis
Meeting:
2008 Breast Cancer Symposium
Session Type and Session Title:
General Poster Session E
Abstract No:
77
Author(s):
S. S. Shinde, M. R. Forman, H. M. Kuerer, K. K. Hunt, L. Pusztai, W. F. Symmans
Abstract:
Background: Short duration of breastfeeding or no breastfeeding at all could arrest the maturation of progenitor cells that populated the breast parenchyma during pregnancy (and have a propensity for long-term survival), such that future oncogenic events in those cells might result in an undifferentiated breast cancer phenotype. We investigated whether parity and average duration of breastfeeding as months per child (m/c) were independently associated with triple-negative breast cancer phenotype (TNBC). Methods: We conducted a cross-sectional study of the 2,511 females with invasive breast cancer who received surgical treatment at the M. D. Anderson Cancer Center between 2001 and 2006. Information about reproductive and demographic risk factors and breast cancer phenotype was abstracted from medical records. Results: The frequency of TNBC was 18.9% (468/2,473): 17.4% in whites (73% of the population), 17.1% in Hispanics (12%), 35.4% in African Americans (10%), and 11.0% in Asians (5%). Using multivariate logistic regression adjusted for age at menarche and history of breast or ovarian cancer in first-degree relative, TNBC was associated with parity (odds ratio [OR] 2.76, CI 1.86-4.08 for >3 live births; OR 1.89, CI 1.30-2.74 if <2 live births, vs. nulliparous), shorter breastfeeding duration (OR 0.55, CI 0.41-0.74 if >3 m/c; OR 0.58, CI 0.42-0.82 if <2 m/c, vs. none), African American (AA) ethnicity (OR 2.10, 95% CI 1.52-2.92), and younger age at diagnosis (OR 3.02, CI 2.03-4.47 if <40, vs. over 60). In AA or Asian parous women, breastfeeding duration and parity were not independent risk factors. In Hispanic parous women, TNBC was strongly associated with shorter breastfeeding duration (OR 0.27, CI 0.11-0.67 if >3 m/c; OR 0.34, CI 0.13-0.89 if <2 m/c, vs. none) and higher parity (OR 2.43, CI 1.11-5.33 if >3 live births, vs. 1-2 live births). Conclusions: In women with breast cancer, higher parity and absence or short duration of breastfeeding were independently associated with triple-negative phenotype. This association was particularly strong in Hispanic women. However, it was not observed in AA women (despite their high rate of TNBC), suggesting that other risk factors may predominate.
Abstract Disclosures
Abstracts that were granted an exception in accordance with ASCO's Conflict of Interest Policy
and are designated with a caret symbol (^) here and in the print version.
 Associated Presentation(s):
Other Abstracts in this Sub-Category:
Abstracts by S. S. Shinde:
Presentations by S. S. Shinde:
Educational Book Manuscripts by S. S. Shinde:
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