Mortality Impact of Less-Than-Standard Therapy in Older Breast Cancer Patients

J Am Coll Surg. 2008 Jan;206(1):66-75. doi: 10.1016/j.jamcollsurg.2007.07.015. Epub 2007 Oct 3.

Abstract

Background: The purpose of this study was to compare the rates of all-cause and breast cancer-specific mortality after breast-conserving surgery (BCS) only, BCS plus radiation therapy (RT), mastectomy, and the receipt of adjuvant tamoxifen in a large population-based cohort of older women with early-stage disease.

Study design: This cohort study was conducted within six US integrated health-care delivery systems. Automated administrative databases, medical records, and tumor registries were used to identify women aged 65 years or older who received BCS or mastectomy to treat stage I or II breast cancer diagnosed from January 1, 1990, through December 31, 1994. We compared cause-specific 10-year mortality rates across treatment categories by fitting Cox proportional hazards models adjusted for demographics and tumor characteristics.

Results: We identified 1,837 women having operations for stage I or II breast cancer. Compared with women receiving mastectomy, those receiving BCS without RT were twice as likely to die of breast cancer (adjusted hazards ratio [HR]=2.19, 95% confidence interval [CI], 1.51 to 3.18). Breast cancer mortality rates were similar between women receiving BCS plus RT and women receiving mastectomy (adjusted HR=1.08, 95% CI, 0.79 to 1.48). In the subset of 886 chemotherapy-naive women treated with tamoxifen, those treated with tamoxifen for less than 1 year had a substantially higher breast cancer mortality rate than those exposed 5 years or more (adjusted HR=6.26, 95% CI, 3.10 to 12.64).

Conclusions: Our findings indicate that older women receiving BCS alone have higher rates of breast cancer death than those receiving BCS + RT or mastectomy and that the survival benefit from tamoxifen increases with increasing duration of treatment.

Publication types

  • Comparative Study
  • Multicenter Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Aged, 80 and over
  • Antineoplastic Agents, Hormonal / therapeutic use*
  • Breast Neoplasms / mortality*
  • Breast Neoplasms / pathology
  • Breast Neoplasms / therapy*
  • Female
  • Follow-Up Studies
  • Humans
  • Mastectomy / methods*
  • Neoplasm Staging
  • Proportional Hazards Models
  • Radiotherapy, Adjuvant / methods
  • Retrospective Studies
  • Survival Rate / trends
  • Tamoxifen / therapeutic use
  • Treatment Outcome
  • United States / epidemiology

Substances

  • Antineoplastic Agents, Hormonal
  • Tamoxifen