Can other cancers develop during chemo?

A fellow caregiver asked...

I have breast cancer. Cancer in the lymph nodes too. I have completed eight sessions of chemo. Once completed I had another CT Scan and bone scan. Now they see an irregularity on my right lung that wasn't there in March when I had my initial CT. My oncologist says to see a lung doctor. Could cancer develop or move during chemo? What could this irregularity be?

Expert Answer

Andrew Putnam, M.D. is a Palliative Care physician at Smilow Cancer Center at Yale New Haven Hospital and Yale University.

Sadly new cancer can develop during chemo if the chemo is not as effective as we wish. There are several things the irregularity in your lung could be, but it is possible that the breast cancer has spread to a new place. The irregularity could also be a different cancer or something that is not cancer at all. It is important to see the lung doctor because she or he may try to biopsy a small piece to learn what the irregularity is.