Chemotherapy is a common, well-known course of cancer treatment. About 650,000 cancer patients receive chemotherapy each year. While doctors and patients hope for miraculous results through treatment, chemotherapy also has deadly side effects. In fact, researchers are now saying that chemotherapy can trigger even more aggressive tumors in the body.
A research team at the Albert Einstein College of Medicine of Yeshiva University studied the unintended consequences of chemotherapy. While chemo does help to kill cancer cells, researchers found it can also cause cancer cells to disperse, causing more harmful tumors to develop in the lungs and in other parts of the body.
Dr. George Karagiannis led the study, which focused on breast cancer patients. He explained, “Many are given chemotherapy before surgery, but the new research suggests that, although it shrinks tumours in the short term, it could 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 tumours to grow back stronger. It also increases the number of ‘doorways’ on blood vessels which allow cancer to spread throughout the body.”
The study shows that in some cases, chemotherapy actually increases the likelihood that cancer will spread throughout a patient’s body. This happens when the cancer cells react to the chemo by dispersing throughout the body in order to search for new hosts.
Karagiannis and his team saw an increase in cancer cells circulating throughout the body and lungs when mice were exposed to chemotherapy. This offers an explanation as to why many patients see their cancer spread into other parts of their bodies after they begin chemo or radiation treatment.
Dr. Karagiannis explained that this particular study was isolated to breast cancer patients, but the negative effects of chemotherapy may exist in other forms of cancer as well. “In this study we only investigated chemotherapy-induced cancer cell dissemination in breast cancer. We are currently working on other types of cancer to see if similar effects are elicited,” he said.