You will be assigned to a combination dose level of bevacizumab and cetuximab based on when you joined this study. Up to 4 combination dose levels of bevacizumab and cetuximab will be tested. Up to 6 participants will be enrolled at each dose level. The first group of participants will receive the lowest dose level. Each new group will receive a higher dose than the group before it, if no intolerable side effects were seen.