Chemotherapy Plus Lapatinib or Trastuzumab or Both in Her2+ Primary Breast Cancer. A Randomized Phase IIb Study With Biomarker Evaluation.

Percentage of Participants With Pathological Complete Response (pCR) in the Breast and in the Lymph Nodes

时间窗: At Baseline and surgery (within 5 weeks after the last chemotherapy administration) (assessed up to Study Week 29)

Pathological Complete Response (pCR) is defined by the complete absence of infiltrating tumor cells in the breast and in the lymph nodes. The pathological response in the breast was evaluated according to the criteria of Miller and Payne as follows: Grade 1, no change or some alteration to individual malignant cells, but no reduction in overall cellularity; Grade 2, a minor loss in tumor cells (up to 30%); Grade 3, between an estimated 30% and 90% reduction in tumor cells; Grade 4, marked disappearance of tumor cells, with only a small cluster or a dispersed cell remaining (more than 90% loss); Grade 5, no identifiable malignant cells. Ductal carcinoma in situ (DCIS) may be present. Grades were interpreted as follows: Grade 1-2=no response; Grade 3-4=partial response; Grade 5=complete response. pCR was defined by comparing specimens obtained at Baseline (biopsy) to those obtained upon surgery.