TY - JOUR
T1 - Relative effectiveness of letrozole compared with tamoxifen for patients with lobular carcinoma in the BIG 1-98 Trial
AU - Filho, Otto Metzger
AU - Giobbie-Hurder, Anita
AU - Mallon, Elizabeth
AU - Gusterson, Barry
AU - Viale, Giuseppe
AU - Winer, Eric P.
AU - Thürlimann, Beat
AU - Gelber, Richard D.
AU - Colleoni, Marco
AU - Ejlertsen, Bent
AU - Debled, Marc
AU - Price, Karen N.
AU - Regan, Meredith M.
AU - Coates, Alan S.
AU - Goldhirsch, Aron
PY - 2015/9/1
Y1 - 2015/9/1
N2 - Purpose To evaluate the relative effectiveness of letrozole compared with tamoxifen for patients with nvasive ductal or lobular carcinoma Patients and Methods Patients diagnosed with early-stage invasive ductal carcinoma (IDC) or classic invasive lobular carcinoma (ILC) who were randomly assigned onto the Breast International Group (BIG) 1-98 tria and who had centrally reviewed pathology data were included (N = 2,923). HER2-negative IDC and LC were additionally classified as hormone receptor-positive with high (luminal B [LB] -like) or low (luminal A [LA] -like) proliferative activity by Ki-67 labeling index. Survival analyses were performed with weighted Cox models that used inverse probability of censoring weighted modeling Results The median follow-up time was 8.1 years. In multivariable models for disease-free survival (DFS), significant interactions between treatment and histology (ILC or IDC; P = .006) and treatment and subgroup (LB like or LA like; P = .01) were observed. In the ILC subset, there was a 66% reduction in the hazard of a DFS event with letrozole for LB (hazard ratio [HR], 0.34; 95% CI, 0.21 to 0.55) and a 50% reduction for LA subtypes (HR, 0.50; 95% CI, 0.32 to 0.78). In the IDC subset, there was a significant 35% reduction in the hazard of a DFS event with letrozole forthe LB subtype (HR, 0.65; 95% CI, 0.53 to 0.79), but no difference between treatments was noted for IDC and the LA subtype (HR, 0.95; 95% CI, 0.76 to 1.20) Conclusion The magnitude of benefit of adjuvant letrozole is greater for patients diagnosed with lobular carcinoma versus ductal carcinoma.
AB - Purpose To evaluate the relative effectiveness of letrozole compared with tamoxifen for patients with nvasive ductal or lobular carcinoma Patients and Methods Patients diagnosed with early-stage invasive ductal carcinoma (IDC) or classic invasive lobular carcinoma (ILC) who were randomly assigned onto the Breast International Group (BIG) 1-98 tria and who had centrally reviewed pathology data were included (N = 2,923). HER2-negative IDC and LC were additionally classified as hormone receptor-positive with high (luminal B [LB] -like) or low (luminal A [LA] -like) proliferative activity by Ki-67 labeling index. Survival analyses were performed with weighted Cox models that used inverse probability of censoring weighted modeling Results The median follow-up time was 8.1 years. In multivariable models for disease-free survival (DFS), significant interactions between treatment and histology (ILC or IDC; P = .006) and treatment and subgroup (LB like or LA like; P = .01) were observed. In the ILC subset, there was a 66% reduction in the hazard of a DFS event with letrozole for LB (hazard ratio [HR], 0.34; 95% CI, 0.21 to 0.55) and a 50% reduction for LA subtypes (HR, 0.50; 95% CI, 0.32 to 0.78). In the IDC subset, there was a significant 35% reduction in the hazard of a DFS event with letrozole forthe LB subtype (HR, 0.65; 95% CI, 0.53 to 0.79), but no difference between treatments was noted for IDC and the LA subtype (HR, 0.95; 95% CI, 0.76 to 1.20) Conclusion The magnitude of benefit of adjuvant letrozole is greater for patients diagnosed with lobular carcinoma versus ductal carcinoma.
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U2 - 10.1200/JCO.2015.60.8133
DO - 10.1200/JCO.2015.60.8133
M3 - Article
AN - SCOPUS:84941332235
VL - 33
SP - 2772
EP - 2778
JO - Journal of Clinical Oncology
JF - Journal of Clinical Oncology
SN - 0732-183X
IS - 25
ER -