Competing causes of death from a randomized trial of extended adjuvant endocrine therapy for breast cancer.

Abstract

BACKGROUND:

Older women with early-stage breast cancer experience higher rates of non-breast cancer-related death. We examined factors associated with cause-specific death in a large cohort of breast cancer patients treated with extended adjuvant endocrine therapy.

METHODS:

In the MA.17 trial, conducted by the National Cancer Institute of Canada Clinical Trials Group, 5170 breast cancer patients (median age = 62 years; range = 32-94 years) who were disease free after approximately 5 years of adjuvant tamoxifen treatment were randomly assigned to treatment with letrozole (2583 women) or placebo (2587 women). The median follow-up was 3.9 years (range 0-7 years). We investigated the association of 11 baseline factors with the competing risks of death from breast cancer, other malignancies, and other causes. All statistical tests were two-sided likelihood ratio criterion tests.

RESULTS:

During follow-up, 256 deaths were reported (102 from breast cancer, 50 from other malignancies, 100 from other causes, and four from an unknown cause). Non-breast cancer deaths accounted for 60% of the 252 known deaths (72% for those > or = 70 years and 48% for those < 70 years). Two baseline factors were differentially associated with type of death: cardiovascular disease was associated with a statistically significant increased risk of death from other causes (P.002), and osteoporosis was associated with a statistically significant increased risk of death from other malignancies (P.05). An increased risk of breast cancer-specific death was associated with lymph node involvement (P < .001). Increased risk of death from all three causes was associated with older age (P < .001).

CONCLUSIONS:

Non-breast cancer-related deaths were more common than breast cancer-specific deaths in this cohort of 5-year breast cancer survivors, especially among older women.

• Authors: Judith-Anne W Chapman, Daniel Meng, Lois Shepherd, Wendy Parulekar, James N Ingle, Hyman B Muss, Michael Palmer, Changhong Yu, Paul E Goss
• Journal: Journal of the National Cancer Institute (J Natl Cancer Inst) Vol. 100 Issue 4 Pg. 252-60 (Feb 20 2008) ISSN: 1460-2105 [Electronic] United States
• PMID: 18270335 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents, Hormonal
• Nitriles
• Receptors, Estrogen
• Receptors, Progesterone
• Triazoles
• Letrozole

Topics

• Age Factors
• Aged
• Antineoplastic Agents, Hormonal (therapeutic use)
• Breast Neoplasms (chemistry, drug therapy, mortality)
• Canada (epidemiology)
• Cardiovascular Diseases (mortality)
• Cause of Death
• Chemotherapy, Adjuvant
• Disease-Free Survival
• Double-Blind Method
• Female
• Follow-Up Studies
• Humans
• Letrozole
• Middle Aged
• Neoplasms, Hormone-Dependent (drug therapy, mortality)
• Nitriles (therapeutic use)
• Osteoporosis, Postmenopausal (mortality)
• Prospective Studies
• Receptors, Estrogen (analysis)
• Receptors, Progesterone (analysis)
• Research Design
• Risk Factors
• Triazoles (therapeutic use)