Does surgery make cancer spread faster because of oxygen exposure?

A fellow caregiver asked...

Does surgery make cancer spread faster because of oxygen exposure? Is it true that if someone has untreatedĀ cancer and needs surgery that the cancer spreads faster onceĀ  the air hits that area?

Expert Answer

Ernest Rosenbaum, MD, is an oncologist affiliated with Stanford University and with the Comprehensive Cancer Center at the University of California, San Francisco, where he has developed protocols for supportive care and clinical practices.

No, it's not true that exposing a tumor to the air can make cancer spread faster. I hear this fear all the time from patients, it's one of the most common cancer myths. People seem to think that when you "open up" the body during surgery it somehow "stirs things up," and can cause tumor cels to spread but that's not the case at all.

When cancer metastasizes to other parts of the body, it does so because cancer cells get into the blood stream and travel to another part of the body where they lodge and begin to grow. (Although only a very small percentage of free cancer cells do actually take hold and cause a new tumor.) Exposure to air during surgery does not have any effect on this process. All surgery does is excise an area of cancerous cells from a particular part of the body so that only healthy cells remain.