Intrinsic Breast Cancer Subtypes and Benefit of Paclitaxel in CALGB 9344 and Dose Dense Therapy in CALGB 9741

OBJECTIVES:

Primary

• To determine whether subtype-specific treatment effects correlate with disease-free survival (DFS), as determined by a significant interaction between PAM50-based intrinsic subtypes, and (a) paclitaxel benefit in CLB-9344 and (b) dose density in CALGB-9741.
• To determine whether subtype-specific treatment effects correlate with DFS for the HER2-negative subsets in CALGB-9344 and CALGB-9741, as determined by analysis of tissue microarray (TMA) and slides.
• To determine the relationship between PAM50-defined risk of relapse (ROR) score and DFS in CALGB-9344 and CALGB-9741.
• To evaluate the relationship between PAM50-defined ROR score and DFS in the HER2-negative subsets in CALGB-9344 and CALGB-9741, as determined by analysis of TMA and slides.
• To examine the relationship between PAM50-defined proliferation score and DFS in CALGB-9344 and CALGB-9741 in multivariate Cox-proportional hazards models including the following covariates: (a) number of positive lymph nodes, square root transformation; (b) menopausal status (pre versus peri/post); CALGB-9344 only; c) dose of doxorubicin hydrochloride (60/75/90 mg/m^2); and CALGB-9741 only; and (d) sequence of treatment.

Secondary

• To evaluate overall survival (OS) in a Cox-proportional hazards-regression model for testing the interaction between ROR with (a) paclitaxel benefit in CALGB-9344 and (b) dose density in CALGB-9741.
• To test for a significant interaction between ROR and paclitaxel benefit at 5-year and 10-year DFS.
• To test whether 5-year and 10-year DFS rates can be associated to a significant interaction between the proliferation score with (a) paclitaxel benefit in CALGB-9344 and (b) dose density in CALGB-9741.