Treatment with Avastan

I have lung cancer and have been treated with Proton Radiation and chemo therapy.  Now a new cancer has been found in my lymph node.  In addition to the same chemo treatment, it has been recommended that I add avastan to the treatment.  I have heard of several scary side effects.  How common are the side effects.  Have any of you every had this for lung cancer?Thanks,Libby...