Premium
Effect of treatment and mammography detection on breast cancer survival over time: 1990‐2007
Author(s) -
Kaplan Henry G.,
Malmgren Judith A.,
Atwood Mary K.,
Calip Gregory S.
Publication year - 2015
Publication title -
cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.052
H-Index - 304
eISSN - 1097-0142
pISSN - 0008-543X
DOI - 10.1002/cncr.29371
Subject(s) - medicine , mammography , breast cancer , oncology , cancer detection , cancer , gynecology
BACKGROUND The extent to which improvements over time in breast cancer survival are related to earlier detection by mammography or to more effective treatments is not known. METHODS At a comprehensive cancer care center, the authors conducted a retrospective cohort study of women ages 50 to 69 years who were diagnosed with invasive breast cancer (stages I through III) and were followed over 3 periods (1990‐1994, 1995‐1999, and 2000‐2007). Data were abstracted from patient charts and included detection method, diagnosis, treatment, and follow‐up for vital status in the institutional breast cancer registry (n = 2998). The method of detection was categorized as patient or physician detected or mammography detected. Cox proportional hazards models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for 5‐year disease‐specific survival in relation to detection method and treatment factors, and differences in survival were analyzed using the Kaplan‐Meier method. RESULTS Fifty‐eight percent of breast cancers were mammography detected, and 42% were patient or physician detected; 56% of tumors were stage I, 31% were stage II, and 13% were stage III. The average length of follow‐up was 10.71 years. The combined 5‐year disease‐specific survival rate was 89% from 1990 to 1994, 94% from 1995 to 1999, and 96% from 2000 to 2007 ( P < .001). In an adjusted model, mammography detection (HR, 0.43; 95% CI, 0.27‐0.70), hormone therapy (HR, 0.47; 95% CI, 0.30‐0.75), and taxane‐containing chemotherapy (HR, 0.61; 95% CI, 0.37‐0.99) were significantly associated with a decreased risk of disease‐specific mortality. CONCLUSIONS Better breast cancer survival over time was related to mammography detection, hormone therapy, and taxane‐containing chemotherapy. Treatment improvements alone are not sufficient to explain the observed survival improvements over time. Cancer 2015;121:2553–2561 . © 2015 American Cancer Society .