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

• Published in: Journal of the American College of Surgeons Vol. 206; no. 1; pp. 66 - 75
• Main Authors: Ulcickas Yood, Marianne, DSc, MPH, Owusu, Cynthia, MD, MSc, Buist, Diana S.M., PhD, MPH, Geiger, Ann M., PhD, MPH, Field, Terry S., DSc, Thwin, Soe Soe, PhD, MS, Lash, Timothy L., DSc, MPH, Prout, Marianne N., MD, MPH, Wei, Feifei, PhD, Quinn, Virginia P., PhD, MPH, Frost, Floyd J., PhD, Silliman, Rebecca A., MD, PhD
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 2008; Elsevier Science
• Subjects: Aged; Aged, 80 and over; Antineoplastic Agents, Hormonal - therapeutic use; Biological and medical sciences; Breast Neoplasms - mortality; Breast Neoplasms - pathology; Breast Neoplasms - therapy; Epidemiology; Female; Follow-Up Studies; General aspects; Humans; Mastectomy - methods; Medical sciences; Neoplasm Staging; Proportional Hazards Models; Public health. Hygiene; Public health. Hygiene-occupational medicine; Radiotherapy, Adjuvant - methods; Retrospective Studies; Surgery; Survival Rate - trends; Tamoxifen - therapeutic use; Treatment Outcome; United States - epidemiology; United States; estrogen receptor positive; PR; RT; BCS; breast-conserving surgery; AJCC; radiation therapy; HR; hazards ratio; progesterone receptor positive; American Joint Commission on Cancer; ER; Human; Therapy; Mortality; Patient; Breast cancer; Standard; Malignant tumor; Epidemiology; Standards; Medicine; Mammary gland diseases; Treatment; Surgery; Mammary gland; Elderly; Age; Cancer
• DOI: 10.1016/j.jamcollsurg.2007.07.015
• ISSN: 1072-7515

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.