According to two research from UCL and Yale, chemotherapy becomes less effective when healthy cells encourage cancer cells to grow more slowly. In the two trials, which were supported by Cancer Research UK and published in Cell, researchers employed mini-tumors and the most recent single-cell analysis technologies to begin to understand the mystery of why healthy cells in a patient`s colon cancer tumour may contribute to bad outcomes.

Bowel cancer kills over 900,000 people a year and is the second highest cause of cancer mortality worldwide. In the UK, it accounts for 10% of all cancer deaths. In the first study, UCL researchers used the latest single-cell analysis technologies to measure how 1,107 mini-tumours derived from mice responded to changes in both their genes and their environment. Analysis revealed that bowel cancer cells can exist in two major states, fast-growing or slow-growing, and that healthy cells can push bowel cancer cells towards the slow-growing state. Because chemotherapies target fast-growing cells, these slow-growing cancer cells are more likely to be resistant to treatment.