Which of the following is the most impoant prognostic factor in breast cancer?

Components of tumor staging include major prognostic factors such as tumor size, invasion of the tumor, nodal involvement, distant metastases, inflammation and local features. Hence, stage of the tumor at the time of diagnosis is a better predictor of prognosis. Ref: Bailey and Love's Sho Practice of Surgery, 24th Edition, Page 839; Pathologic Basis of Disease By Robbins, 6th Edition, Page 1114.