Kleiner-Hancock et al. BMC Cancer 2010, 10:394 http://www.biomedcentral.com/1471-2407/10/394 Page 5 of 10 rapidly at day 15 to day 25 after inoculation in the con- 3 trol diet groups, reaching a maximum of 650-875 mm . ACA had a marginally significant effect on tumor volume between days 18-22 (Figures 3A, B) and [Addi- tional file 1: Supplemental Tables S1, S2]. Dietary ATRA (5 ppm) modestly suppressed tumor volume but not sig- nificantly [Additional file 1: Supplemental Tables S1, S2]. Comparing both parametric and non-parametric analyses, the combination of 5 ppm ATRA and ACA in the diet significantly inhibited tumor volume starting at 11 days and continuing throughout the study, ranging from 56-76% inhibition [Additional file 1: Supplemental Tables S1, S2]. 10 ppm ATRA modestly inhibited tumor volume from 45-58% starting at day 11 up to day 22, but its effects were marginally significant - significant for a few days [Additional file 1: Supplemental Tables S1, S2]. The combination of 10 ppm ATRA and ACA significantly suppressed tumor volume by 50-67% start- ing at day 11 to day 25, again comparing both parametric and non-parametric analyses [Additional file 1: Supplemental Tables S1, S2]. In the 30 ppm ATRA experiment, ACA did not exhibit any significant effects on its own, although there was a 51% inhibition of tumor volume at day 23 that was not statistically signifi- cant. A lower number of subjects (5 mice instead of 7- 8) in this experiment likely contributed to this lack of statistical significance, compared to the 5 and 10 ppm ATRA studies. However, 30 ppm ATRA strongly sup- pressed tumor volume by 70-93% from day 9 to day 23, and the combination of ATRA 30 with ACA signifi- cantly suppressed tumor volume from 89-98% (Figure 3C) and [Additional file 1: Supplemental Tables S1, S2]. Body weight analyses demonstrated a significant change in the ATRA 5 and 30 groups, for most time-points [Additional file 1: Supplemental Table S3]. However, dose-response analyses suggested that the effect was independent of ACA [Additional file 1: Supplemental Table S5]. Dose-response analyses of ATRA 5, 10, and Figure 3 Effects of combinations of ACA/AUR ± ATRA on SRB12-p9 SCC tumor growth in SCID/bg mice. Groups of mice were fed diets containing the following combinations [A] ACA 500 ppm ± ATRA 5 ppm (n = 7-8); [B] ACA 500 ppm ± ATRA 10 ppm (n = 7-8); [C] ACA 500 ppm ± ATRA 30 ppm (n = 5); and [D] AUR 1000 ppm ± ATRA 10 ppm (n = 5). Figures represent means ± S.E. Note that the first two experiments (panels A & B) were conducted simultaneously, so the control and ACA groups are the same, but the two different doses of ATRA ± ACA were split into separate graphs for clarity.