TY - JOUR
T1 - Postmastectomy radiation and mortality in women with T1-2 node-positive breast cancer
AU - Smith, Benjamin D.
AU - Smith, Grace L.
AU - Haffty, Bruce G.
PY - 2005
Y1 - 2005
N2 - Purpose: To determine the relationship between postmastectomy radiotherapy (PMRT) and mortality in a population-based cohort of women with T1-2 node-positive breast cancer. Patients and Methods: Using data from the Surveillance, Epidemiology, and End Results program, we identified 18,038 women with T1-2 node-positive invasive breast cancer who were treated with mastectomy between 1988 and 1995. The relationship between PMRT and mortality was determined using proportional hazards multivariate modeling and propensity score matched case-control analysis. Results: Median follow-up was 8.1 years. Only 2,648 women (15%) received PMRT. After adjusting for covariates, PMRT use was not associated with mortality (hazard ratio [HR] = 0.96; 95% CI, 0.90 to 1.03). However, the interaction term for PMRT use and number of involved regional lymph nodes was significant (P = .002), suggesting that, above a certain threshold of involved nodes, a mortality benefit from PMRT may exist. Adjusted analysis stratified by number of involved nodes revealed that patients with seven or more involved nodes treated with PMRT experienced a significant reduction in all-cause (HR = 0.84; 95% CI, 0.76 to 0.93) and cause-specific mortality (HR = 0.86; 95% CI, 0.77 to 0.96). Propensity score matched case-control analysis confirmed that PMRT was associated with reduced mortality only in the subset of patients with seven or more involved nodes (HR = 0.81; 95% CI, 0.73 to 0.91 for all-cause mortality; and HR = 0.82; 95% CI, 0.72 to 0.93 for cause-specific mortality). Conclusion: For women with T1-2 breast cancer, PMRT is associated with a 15% to 20% relative reduction in mortality for patients with seven or more involved regional lymph nodes.
AB - Purpose: To determine the relationship between postmastectomy radiotherapy (PMRT) and mortality in a population-based cohort of women with T1-2 node-positive breast cancer. Patients and Methods: Using data from the Surveillance, Epidemiology, and End Results program, we identified 18,038 women with T1-2 node-positive invasive breast cancer who were treated with mastectomy between 1988 and 1995. The relationship between PMRT and mortality was determined using proportional hazards multivariate modeling and propensity score matched case-control analysis. Results: Median follow-up was 8.1 years. Only 2,648 women (15%) received PMRT. After adjusting for covariates, PMRT use was not associated with mortality (hazard ratio [HR] = 0.96; 95% CI, 0.90 to 1.03). However, the interaction term for PMRT use and number of involved regional lymph nodes was significant (P = .002), suggesting that, above a certain threshold of involved nodes, a mortality benefit from PMRT may exist. Adjusted analysis stratified by number of involved nodes revealed that patients with seven or more involved nodes treated with PMRT experienced a significant reduction in all-cause (HR = 0.84; 95% CI, 0.76 to 0.93) and cause-specific mortality (HR = 0.86; 95% CI, 0.77 to 0.96). Propensity score matched case-control analysis confirmed that PMRT was associated with reduced mortality only in the subset of patients with seven or more involved nodes (HR = 0.81; 95% CI, 0.73 to 0.91 for all-cause mortality; and HR = 0.82; 95% CI, 0.72 to 0.93 for cause-specific mortality). Conclusion: For women with T1-2 breast cancer, PMRT is associated with a 15% to 20% relative reduction in mortality for patients with seven or more involved regional lymph nodes.
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U2 - 10.1200/JCO.2005.05.100
DO - 10.1200/JCO.2005.05.100
M3 - Article
C2 - 15735117
AN - SCOPUS:14944344706
SN - 0732-183X
VL - 23
SP - 1409
EP - 1419
JO - Journal of Clinical Oncology
JF - Journal of Clinical Oncology
IS - 7
ER -