Combined chemotherapy of hydroxycampothecin with oxaliplatin as an adjuvant treatment for human colorectal cancer.

Colorectal cancer (CRC) is a major cause of morbidity and mortality for cancer worldwide, but many patients with CRC are resistant to chemotherapy. We therefore investigated the therapeutic mechanism and clinical effect of combined chemotherapy of hydroxycampothecin (HCPT) with oxaliplatin (L-OHP) on CRC. HCPT represents a potential antitumor agent of Chinese herb. Mice carrying the xenografted human LS174T CRC cells were injected into peritoneal cavities with different drugs: HCPT + L-OHP (OH), HCPT, L-OHP, or saline. Treatment of mice with OH caused the decrease in the volume of tumor and the expression of p53, but increased the apoptotic rate and Fas-L expression, compared to those of animals treated with HCPT or L-OHP, or control animals. Thus, the combination of HCPT with L-OHP could more effectively induce the apoptosis of CRC cells. Furthermore, 56 patients with CRC were treated with HCPT and L-OHP (28 cases, OH group) or L-OHP plus leucovorin plus 5-fluorouracil (28 cases, OFL group), then reviewed the response rate, survival rate and toxicity. The one-year survival rate was 35.07% in OH group and 24.21% in OFL group. However, the occurrence of anemia (51.8%) or diarrhea (60.7%) was higher in OH group than that of 19.6% or 46.4% in OFL group. The clinical results suggest that HCPT plus L-OHP combined chemotherapy could increase the survival time of patients. Taken together, the present study indicates that the combined chemotherapy of HCPT with L-OHP could become a new adjuvant treatment for CRC.