Compared with chemotherapy alone, adjuvant (post-surgery) treatment of Stage III colon cancer with chemotherapy plus Avastin® (bevacizumab) does not reduce the risk of cancer recurrence or improve overall survival. These results were presented at the 2011 Gastrointestinal Cancers Symposium.
Targeted therapies are anticancer drugs that interfere with specific pathways involved in cancer cell growth or survival. Some targeted therapies block growth signals from reaching cancer cells; others reduce the blood supply to cancer cells; and still others stimulate the immune system to recognize and attack the cancer cell. Depending on the specific “target,” targeted therapies may slow cancer cell growth or increase cancer cell death.
Avastin is a targeted therapy that blocks a protein known as VEGF. VEGF plays a key role in the development of new blood vessels. By blocking VEGF, Avastin deprives the cancer of nutrients and oxygen and inhibits its growth. Avastin’s effects on blood vessels may also improve the delivery of chemotherapy to the tumor.
Multiple studies have shown that the addition of Avastin to standard chemotherapy improves outcomes among patients with metastatic colon cancer. Given these results, researchers also initiated studies to evaluate Avastin in patients with earlier-stage colon cancer.
The current results are from a Phase III trial known as AVANT. The study enrolled patients with high-risk Stage II or Stage III colon cancer. After surgical removal of the cancer, patients were assigned to receive chemotherapy alone or chemotherapy plus Avastin followed by six months of Avastin alone.
Among patients with Stage III cancer (the focus of the primary analysis), the addition of Avastin did not reduce the risk of cancer recurrence and did not improve overall survival.
These results suggest that the benefit of Avastin that has been observed among patients with metastatic colon cancer does not apply to patients with earlier-stage colon cancer.
Reference: De Gramont A, Van Cutsem E, Tabernero J et al. AVANT: results from a randomized, three-arm multinational phase III study to investigate bevacizumab with either XELOX or FOLFOX4 versus FOLFOX4 alone as adjuvant treatment for colon cancer. Presented at the 2011 Gastrointestinal Cancers Symposium. Abstract 362.