Breast Cancer-Specific Mortality Pattern and Its Changing Feature According to Estrogen Receptor Status in Two Time Periods.
OBJECTIVE
To determine whether and how the patterns of breast cancer-specific mortality (BCSM) changed along with time periods.


METHODS
We used the Surveillance, Epidemiology and End Results registry to identify 228209 female patients diagnosed with invasive breast cancer between 1990 and 2000 (cohort 1 [C1], 112981) and between 2001 and 2005 (cohort 2 [C2], 115228). BCSM was compared in two cohorts using Cox proportional hazard regression models. We analysed the relative hazard ratios (HRs) and absolute BCSM rates by flexible parametric survival modelling.


RESULTS
The patterns of BCSM were similar between the two cohorts, with the peak of mortality presenting in the first 2-3 years after diagnosis, and mortality rate significantly decreased in C2 in all cases. In C2, the annual BCSM rate of all cases was 9.64 (per 1000 persons per year) in year 10 with a peak rate of 23.34 in year 2. In ER-negative and high-risk patients, marked survival improvements were achieved mostly in the first 5 years, while in ER-positive and low-risk patients, survival improvements were less but constant up to 10 years.


CONCLUSIONS
There has been a significant improvement of BCSM with substantially decreased mortality within 5 years. The current pattern of BCSM and its changing feature differs according to ER status. Our findings have some clinical implications both for treatment decisions and adjuvant treatment trial design.
Department of Breast Surgery, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, People's Republic of China.|Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China.
Junjie
J
Li
Department of Breast Surgery, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, People's Republic of China.|Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China.
Yirong
Y
Liu
Department of Breast Surgery, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, People's Republic of China.|Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China.
Yizhou
Y
Jiang
Department of Breast Surgery, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, People's Republic of China.|Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China.
Zhimin
Z
Shao
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000453:epidemiology* / Q000401:mortality; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D016016:Proportional Hazards Models; D011960:Receptors, Estrogen / Q000032:analysis*; D018426:SEER Program; D016019:Survival Analysis; D055815:Young Adult
D011960:Receptors, Estrogen