senescence

Chemotherapy pushes cells into senescence: they stop dividing but stay alive and keep releasing inflammatory signals. The usual marker, p16INK4a in blood T cells, rises sharply during treatment and is still raised a year later. In one study the rise matched about fifteen years of ordinary ageing, in another the gap in survivors was larger still.

Senolytics are drugs meant to kill the worn-out cells that chemotherapy leaves behind. The idea is good and the animal work is striking. The human evidence is four small trials in other diseases, none in cancer survivors, and the one properly randomised trial missed its main target. Nobody should be buying these.