A Study of Herceptin (Trastuzumab) in Women With Human Epidermal Growth Factor Receptor (HER) 2-Positive Advanced and/or Metastatic Breast Cancer

Participants will receive oral Xeloda, 950 mg/m\^2 twice a day on Days 1 to 14 of each 21-day cycle.

Participants will receive Taxotere, 75 milligrams per meter-squared (mg/m\^2) in the Herceptin + Taxotere + Xeloda arm or 100 mg/m\^2 in the Herceptin + Taxotere arm, via IV infusion on Day 1 of each 21-day cycle. The lower starting dose will be used in the triple-therapy arm.

Participants will receive Herceptin, 6 milligrams per kilogram (mg/kg) via IV infusion, on Day 1 of each 21-day cycle. The first dose will be a loading dose of 8 mg/kg in Cycle 1; the dose of 6 mg/kg will be given from Cycle 2 onward.