New biomarkers for Metastatic Colorectal Cancer treatment

Metastatic Colorectal Cancer, the third deadliest cancer in the Unites States, is typically treated with two chemotherapy drugs, 5-Fluorouracil in combination with either Oxaliplatin or Irinotecan.
"Several large trials compared oxaliplatin and irinotecan head-to-head and concluded that the response rate is about equal. How an oncologist bases his or her treatment decision can be based on experience, comfort level prescribing and the patient's health," said senior author Paul FantaThe researchers found that 33 of their 41 patients had low ERCC1 levels. These same patients also had significantly longer average survival times (36 months) compared to patients with high ERCC1 levels (10 months). Similarly, 29 patients had low TS levels and significantly longer average survival times (36 months) than patients with high TS levels (15 months).
Twenty-two of the 41 patients had low levels of both ERCC1 and TS. Twenty of that group responded to Oxaliplatin, suggesting that this should be the first treatment choice for patients with low ERCC1 and TS. Patients responded to Irinotecan at the same rate whether they had low or high levels of these genes. This finding suggests that physicians might want to select irinotecan as the first-choice chemotherapy for patients with high ERCC1 or TS levels. ERCC1 and TS profiling could help physicians better manage patients with metastatic colorectal cancer, individualizing and optimizing therapy for subsequent interventions such as surgical removal of metastatic tumors
"Given this proof-of-principle, it's our hope that molecular biomarkers will be included in future. prospective clinical trials in metastatic colorectal cancer."