For generations, chemotherapy has been regarded as one of medicine's most powerful weapons against cancer.
But in 2017, scientists published research that revealed a disturbing news. chemotherapy helps some cancer cells escape the primary tumour.
The study, published in the prestigious journal Science Translational Medicine by researchers from Albert Einstein College of Medicine, found that chemotherapy given before surgery caused unexpected changes inside breast tumours. Rather than simply killing cancer cells, the treatment appeared to increase the formation of microscopic structures known as Tumour Microenvironment of Metastasis (TMEM) doorways. These act like tiny escape hatches, allowing invasive cancer cells to enter the bloodstream, the first step in the spread of cancer throughout the body.
In mouse models, commonly used chemotherapy drugs, including paclitaxel (Taxol), doxorubicin, and cyclophosphamide, increased the number of these TMEM doorways. Researchers also observed more circulating tumour cells and a greater number of microscopic lung metastases following treatment.
The team then examined tumour samples from 20 women with breast cancer who received chemotherapy before surgery. Most had an increase in TMEM doorways following treatment, and five women experienced more than a fivefold increase which is a huge concern. While the study did not prove these women developed more metastatic disease, the findings raised important questions about how chemotherapy alters the tumour environment.
The research did not conclude that chemotherapy causes cancer to spread in patients. Instead, it uncovered a previously unrecognised biological effect that scientists believe deserves further investigation. Researchers also identified an experimental drug called rebastinib, which blocked this effect in mice, raising hopes that future treatments may neutralise this unwanted response while preserving chemotherapy's cancer killing benefits. But these finding are sadly to late for many.
The study in 2017 study reminds us that cancer biology is extraordinarily complex, and even our most effective treatments may have unintended effects that science is only now beginning to except and understand.
As researchers continue to unravel these hidden mechanisms, one thing is becoming increasingly clear. The future of cancer treatment may depend not only on destroying tumours, but also on preventing cancer cells from escaping in the first place.
Written by Maryjayne Aria Author of Immune Health, Terrain and Gcmaf
