Annals of Surgical Oncology

, Volume 14, Issue 2, pp 695–703

Type and Duration of Exogenous Hormone Use Affects Breast Cancer Histology

  • Anjali S. Kumar
  • Elizabeth Cureton
  • Veronica Shim
  • Theadora Sakata
  • Dan H. Moore
  • Christopher C. Benz
  • Laura J. Esserman
  • E. Shelley Hwang
Article

DOI: 10.1245/s10434-006-9129-2

Cite this article as:
Kumar, A.S., Cureton, E., Shim, V. et al. Ann Surg Oncol (2007) 14: 695. doi:10.1245/s10434-006-9129-2

Abstract

Background

It is unclear whether hormone replacement therapy (HRT), in addition to increasing risk for breast cancer, affects the type of breast cancer diagnosed. We conducted this investigation to assess whether the type of hormone used (none, estrogen, progesterone, or combined) and duration of use influences subsequent breast cancer histology.

Methods

We performed a retrospective cohort analysis among women listed as incident cases of breast malignancy in the Kaiser Permanente Northern California Cancer Registry during 2003 (n = 2830). Type and duration of hormone used (none, estrogen, progesterone, or combined) before breast cancer diagnosis was obtained from electronic pharmacy records. The association between type and duration of hormone use with characteristics of subsequent breast cancers was examined.

Results

Among women aged >50 years (n = 1701), any use of estrogen, progesterone, or combination therapy was not associated with an increased risk of estrogen receptor (ER)-positive disease. However, >6 months’ use of combined HRT increased the odds of ER-positive tumors (odds ratio, 1.65; 95% confidence interval, 1.07–2.5; P = .02). Estrogen HRT patients were more likely than nonusers to present with low-grade (P = .05), and early-stage tumors (P = .03). This trend was not seen in combined HRT users.

Conclusions

Short-duration HRT did not increase the likelihood of ER-positive breast cancer. However, prolonged duration of combined HRT, but not estrogen or progesterone alone, resulted in a marked increase in ER-positive disease. Our findings suggest that the effect of combined HRT on breast cancer incidence or progression is not immediate and that long-term use is more likely to affect breast cancer histology.

Keywords

Breast cancerHormone replacement therapyEstrogen receptor

Copyright information

© Society of Surgical Oncology 2006

Authors and Affiliations

  • Anjali S. Kumar
    • 1
    • 2
    • 3
  • Elizabeth Cureton
    • 1
    • 2
  • Veronica Shim
    • 1
  • Theadora Sakata
    • 3
  • Dan H. Moore
    • 4
  • Christopher C. Benz
    • 5
    • 6
  • Laura J. Esserman
    • 3
  • E. Shelley Hwang
    • 3
  1. 1.Department of SurgeryKaiser Permanente Oakland Medical CenterOaklandUSA
  2. 2.Department of SurgeryUniversity of California San Francisco—East BayOaklandUSA
  3. 3.Department of SurgeryUniversity of California San Francisco, Comprehensive Cancer CenterSan FranciscoUSA
  4. 4.Department of Epidemiology and BiostatisticsUniversity of California San FranciscoSan FranciscoUSA
  5. 5.Department of Medicine, Division of Hematology and OncologyUniversity of California San FranciscoSan FranciscoUSA
  6. 6.Buck Institute for Age ResearchNovatoUSA