Benefit from chemotherapy in metastatic breast cancer: A retrospective analysis at the BC Cancer Agency—Vancouver Island Centre.

e12505Background: Chemotherapy (CTX) can palliate symptoms and modestly prolong survival in patients with metastatic breast cancer (MBC). From clinical trials we have an understanding of the toxicity, response rate, and progression free survival associated with earlier lines of CTX. The difficulty for both medical oncologists and patients is in estimating the likelihood of benefit from CTX in later lines of treatment, and how response in prior lines influences that estimation. Methods: We performed a retrospective review of 288 patients with Her2-negative or Her2-unknown MBC treated with at least two lines of CTX to identify predictors of benefit or lack of benefit to further lines of therapy at the BC Cancer Agency (Vancouver Island Centre) from 2000-2010. We assigned the score of “Benefit” to those who had improvement in disease symptoms and/or improvement on imaging, and then examined for predictors of that Benefit. Initial improvement but then progression prior to the completion of 6 cycles of CTX, or...