Effect of undertreatment on the disparity in age-related breast cancer-specific survival among older women.
OBJECTIVE
Assess the relationship between age and breast cancer-specific survival among older women and determine whether the observed age-related disparities in survival is explained by differences in breast cancer treatments received.


METHODS
Women > or =65 years old at diagnosis with stage I-IIIA breast cancer diagnosed between 1997 and 1998 were recruited from four regions of the United States and followed prospectively for 5 years after diagnosis. Data was obtained from tumor registries, medical records, and telephone interviews. The primary endpoint was breast cancer-specific survival. Our independent variables were age operationalized as < or =75 years vs. >75 years, and receipt of recommended guideline therapy, adapted from the National Institutes of Health guideline consensus conference.


RESULTS
Of 689 women, 36% were >75 years. Women >75 years were less likely to have received the following; axillary lymph node dissection (84% vs. 93%, P = 0.0003), radiotherapy (40% vs. 54%, P = 0.0003), definitive primary therapy (71% vs. 84%, P < 0.0001), chemotherapy (9% vs. 28%, P < 0.0001), and guideline therapy (31% vs. 54%, P < 0.0001). The 5-year breast cancer-specific survival was 95% (95% confidence interval [CI], 90%, 97%) for those < or =75 years who received guideline therapy, 94% (95% CI, 90%, 97%) for those < or =75 years who did not receive guideline therapy, 96% (95% CI, 88%, 99%) for those >75 years who received guideline therapy and 83% (95% CI, 74%, 89%) for those >75 years who did not receive guideline therapy, (P = 0.002) by the log-rank test.


CONCLUSIONS
Receipt of guideline therapy may reduce the age-related disparity in breast cancer survival among older women.
Owusu
Cynthia
C
Hematology and Medical Oncology Section, Department of Medicine, Boston University School of Medicine, Evans Biomedical Research Center, Boston, MA 02118-2393, USA. cynthia.owusu@bmc.org
Lash
Timothy L
TL
Silliman
Rebecca A
RA
D017677:Age Distribution; D000368:Aged; D001943:Breast Neoplasms / Q000401:mortality* / Q000628:therapy; D005260:Female; D006801:Humans; D008408:Mastectomy / Q000706:statistics & numerical data*; D009367:Neoplasm Staging; D011446:Prospective Studies; D018714:Radiotherapy, Adjuvant / Q000706:statistics & numerical data; D015996:Survival Rate; D014481:United States / Q000453:epidemiology