Cancer treatments alter genetic mutations in healthy tissues

Research published in Nature Genetics by experts from the Wellcome Sanger Institute, University of Cambridge, and University College London reveals that cancer treatments like chemotherapy and chemoradiotherapy can alter the genetic makeup of healthy tissues.

By analyzing healthy esophageal tissue from 70 patients treated for esophageal cancer, scientists found that these therapies disrupt the natural evolutionary competition between cells. In patients receiving chemoradiotherapy, there was a significant increase in healthy cells carrying mutations in the TP53 tumor suppressor gene and the PPM1D stress-response gene. Rather than creating new mutations, the treatments appear to provide an evolutionary advantage to existing mutant cells, allowing them to outcompete neighboring cells.

Additionally, patients receiving combined chemotherapy showed an increase in healthy cells carrying mutations associated with resistance to the drug 5-fluorouracil. This suggests that treatment can select for specific mutant cells that are more resilient to the medication, potentially reshaping the genetic landscape of healthy tissue within weeks.