Does Surgery Cause Cancer to Spread

This is a really scary idea that seems to hang around. Generally it is thought to be in the old wives' tale category, along with things like anti-antiperspirant causes breast cancer. However, a recent study from MIT raised alarms. It suggested that, in mice, surgery might cause a reaction that enabled breast cancer cells to spread. This report hit the news, and caused a fair amount of confusion and even panic. First grounding comment: This was a basic research study, using mice, and no one is suggesting that the same mechanism exists in people. Second important reminder: surgery has long been the central and usually first treatment for breast (and many other) cancers. Getting the primary tumor out of the body makes it much more likely that systemic treatments, chemotherapy or hormonal therapy or immunotherapy, and radiation can clean out any remaining cancer cells. Before surgery was routinely used in cancer care, everyone with cancer died. Period.

I am sharing a thoughtful response from Dr. Larry Norton of Memorial Sloan Kettering in New York. Here is the start and a link and another reminder to take all cancer headlines with a big grain of salt.

Reality Check: Study Examines Metastasis after Breast Cancer Surgery

By Julie Grisham

Summary
New research conducted in mice shows that surgery for breast cancer may cause a response that makes it easier for the disease to spread. We spoke with an MSK expert to learn more.

Earlier this week, scientists from the Massachusetts Institute of Technology published a study looking at some of the ways in which breast cancer spreads, or metastasizes, in mice. They reported data showing that surgery may trigger an immune response that makes it easier for cancer to spread throughout the body. Additionally, the study pointed to anti-inflammatory drugs like aspirin and ibuprofen as a possible way to decrease cancer’s ability to spread.

The news media reported on the research, which is still in early stages. These headlines may be scary or confusing for people facing a recent diagnosis, as well as for those who have already had surgery.

We spoke with Larry Norton, Memorial Sloan Kettering’s Senior Vice President and Medical Director of the Evelyn H. Lauder Breast Center, about what people should know about the study and why it shouldn’t affect decisions about treatment.

Can you tell us how this study was conducted?
This was a study done in the lab using a mouse model. The mice had been injected with cancer cells and then underwent simulated surgeries. Those mice later developed tumors. However, when the mice were given an anti-inflammatory drug at the time of the surgical procedure, the tumors were smaller.

I want to emphasize that this is an excellent lab experiment, and it fits in with much of the lab research we’re doing here at MSK. But it’s far from ready to influence clinical care.