A new study has suggested that chemotherapy could allow cancer to spread, and trigger more aggressive tumors. Researchers in the U.S. studied the impact of drugs on patients with breast cancer and found, “medication increases the chance of cancer cells migrating to other parts of the body, where they are almost always lethal.” 1 The study was published in the journal Science Translational Medicine.


Every year, around 55,000 women are diagnosed with breast cancer in Britain and 11,000 die from the illness. Many of these women are given chemotherapy before surgery but this new study suggests that while it might shrink tumors initially, it could also trigger the spread of cancer cells around the body.

“It is thought the toxic medication switches on a repair mechanism in the body which ultimately allows tumors to grow back stronger. It also increases the number of ‘doorways’ on blood vessels which allow cancer to spread throughout the body.

Dr George Karagiannis, of the Albert Einstein College of Medicine of Yeshiva University, New York, found the number of doorways was increased in 20 patients receiving two common chemotherapy drugs.

He also discovered that in mice with breast cancer chemotherapy increased the number of cancer cells circulating the body and in the lungs.” 2

Dr. Karagiannis thinks one solution might be to monitor women during chemotherapy to check if cancer is starting to circulate and doorways are emerging. If that happens, doctors can discontinue chemo until after surgery.


Sources and References

  1. Telegraph, July 6, 2017.
  2. Telegraph, July 6, 2017.