Can peritoneal carcinomatosis of colorectal origin be treated with oral everolimus alone or in combination with capecitabine? Preliminary results

Background: We wanted to evaluate the effectiveness of oral everolimus alone and in combination with capecitabine treatment on colorectal cancer-induced peritoneal carcinomatosis animal model. Methods: Caco-2 colon adenocarcinoma cells were injected intraperitoneally to BALB/cOlaHsd-Foxn1nu mice to establish peritoneal carcinomatosis. Mice were divided into four groups (everolimus, everolimus plus capecitabine, capecitabine, control group) with 2 mice in each group. Treatment was initiated 5 days after inoculation of Caco-2 cells. 7.5 mg/kg everolimus was administered orally every 2 days. 2.1 mmol/kg capecitabine was administered orally every 5 days a week. 22 days after inoculation of Caco-2 cells, mice were sacrificed. Results: The mean weight of the tumor was 25 ± 7.07 mg in the control group (n=2); 0.7 ± 0.7 mg in the everolimus group (n=2); 0.28 ± 0.36 mg in the capecitabine group; 0.48 ± 0.07 mg in the everolimus plus capecitabine group. Conclusion: Tumor samples excised from BALB/cOlaHsd-Foxn1nu mice revealed that everolimus alone, and in combination with capecitabine suppressed tumor growth. However, a comparison of tumor weights revealed no statistically significant difference within the four groups (p=0.227). To reach statistically significant data, the sample size should be increased.