I have colon cancer and have been through 97 rounds of chemo in 8 years.I am currently on Lonsurf pills and Avastin.Lately I've been experiencing some shortness of breath upon standing,yet I can walk 2 or 3 blocks without any severe shortness of breath.It's only when i stand up.My oncologist listened to my lungs last week and said they sounded fine,although I do have some cancer on my lungs.