Scientists discover why cancer drugs don’t work for everyone

Scientists have identified a previously unrecognized mechanism that may explain why cancer treatments produce uneven responses across patients. The research revealed that certain anticancer drugs can become sequestered inside lysosomes within tumor cells, effectively creating slow-release reservoirs that lead to highly uneven drug distribution across the tumor. As a result, some cancer cells receive lethal drug concentrations while others are barely exposed, potentially allowing resistant clones to survive and drive relapse. This finding could inform the development of more effective dosing strategies and combination therapies designed to ensure more uniform drug delivery. The discovery opens a new avenue for personalizing cancer treatment by accounting for intracellular drug trapping.