Pretreatment Chromosomal Instability Correlates With Radiation Sensitivity in Squamous Cell Cancers

Continuous chromosome missegregation over successive mitotic divisions, known as chromosomal instability (CIN), is common in cancer. Though it has been associated with treatment resistance and poor prognosis, increasing CIN above a maximally tolerated threshold leads to cell death because of loss of essential chromosomes. Because radiation causes CIN, we hypothesize that pre-existing CIN sensitizes tumor cells to radiation therapy.