Effect of celecoxib and aspirin on the growth of MCF-7aro xenograft. Mice were inoculated with MCF-7aro cells at 2 sites per mouse after ovariectomy. They were injected subcutaneously with androstenedione every day starting on the next day after inoculation. Tumor volumes (A) were estimated once a week from Day 7 after inoculation. Day labeled as (*) was the time when AD Group significantly deviated from Control Group sacrifice. (**) was the day when tumor volumes of AD+Celecoxib and AD+Aspirin started deviated from that of AD. The tumor weight was measured at the day of sacrifice (B). Groups labeled as AD, AD+celecoxib, and AD+aspirin are the mice treated with androstenedione, androstenedione and celecoxib, and androstenedione and aspirin, respectively. Values are means ± SEM, n=6 to 8 (2 inoculation sites combined as one data point). The data was analyzed by One-way ANOVA, followed by Tukey’s Multiple Comparison test when P<0.05. Means labeled with different letters are significantly different (order: b>a).